Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-30 (of 162 Records) |
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Ongoing transmission of trachoma in low prevalence districts in Mozambique: results from four cross-sectional enhanced impact surveys, 2022
Sitoe HM , Oswald WE , Zita F , Fall M , Momade T , Adams MW , Flueckiger RM , McPherson S , Eyob S , Doan T , Lietman TM , Arnold BF , Wickens K , Gwyn S , Martin DL , Kasubi M , Boyd S , Bakhtiari A , Jimenez C , Solomon AW , Harding-Esch EM , Mwingira UJ , Ngondi JM . Sci Rep 2024 14 (1) 22842 Mozambique is making progress towards elimination of trachoma as a public health problem, but in some districts trachomatous inflammation-follicular (TF) prevalence remains above the 5% elimination threshold despite years of various interventions, including antibiotic mass drug administration. To characterize transmission in four districts, we incorporated testing of ocular infection and serology into routine trachoma impact surveys (TIS) in August 2022. We examined residents aged ≥ 1 year for trachoma and collected information on household water, sanitation, and hygiene. Among children aged 1-9 years, we tested conjunctival swabs for Chlamydia trachomatis nucleic acid and dried blood spots for C. trachomatis antibodies. We modeled age-dependent seroprevalence to estimate seroconversion rate (SCR). We examined 4841 children aged 1-9 years. TF prevalence ranged between 1.1 and 6.0% with three districts below the 5% threshold. PCR-confirmed infection prevalence ranged between 1.1 and 4.8%, and Pgp3 seroprevalence ranged between 8.8 and 24.3%. Pgp3 SCR was 1.9 per 100 children per year in the district with the lowest TF prevalence. Two other districts with TF < 5% had SCR of 5.0 and 4.7. The district with TF ≥ 5% had a SCR of 6.0. This enhanced TIS furthered understanding of transmission in these districts and provides information on additional indicators for monitoring trachoma programs. |
Differences in COVID-19 outpatient antiviral treatment among adults aged ≥65 years by age group - national patient-centered clinical research network, United States, April 2022-September 2023
Quinlan CM , Shah MM , DeSantis CE , Bertumen JB , Draper C , Ahmad FS , Arnold J , Mayer KH , Carton TW , Cowell LG , Smith S , Saydah S , Jones JM , Patel P , Hagen MB , Block J , Koumans EH . MMWR Morb Mortal Wkly Rep 2024 73 (39) 876-882 Adults aged ≥65 years experience the highest risk for COVID-19-related hospitalization and death, with risk increasing with increasing age; outpatient antiviral treatment reduces the risk for these severe outcomes. Despite the proven benefit of COVID-19 antiviral treatment, information on differences in use among older adults with COVID-19 by age group is limited. Nonhospitalized patients aged ≥65 years with COVID-19 during April 2022-September 2023 were identified from the National Patient-Centered Clinical Research Network. Differences in use of antiviral treatment among patients aged 65-74, 75-89, and ≥90 years were assessed. Multivariable logistic regression was used to estimate the association between age and nonreceipt of antiviral treatment. Among 393,390 persons aged ≥65 years, 45.9% received outpatient COVID-19 antivirals, including 48.4%, 43.5%, and 35.2% among those aged 65-75, 76-89, and ≥90 years, respectively. Patients aged 75-89 and ≥90 years had 1.17 (95% CI = 1.15-1.19) and 1.54 (95% CI = 1.49-1.61) times the adjusted odds of being untreated, respectively, compared with those aged 65-74 years. Among 12,543 patients with severe outcomes, 2,648 (21.1%) had received an outpatient COVID-19 antiviral medication, compared with 177,874 (46.7%) of 380,847 patients without severe outcomes. Antiviral use is underutilized among adults ≥65 years; the oldest adults are least likely to receive treatment. To prevent COVID-19-associated morbidity and mortality, increased use of COVID-19 antiviral medications among older adults is needed. |
Estimating community-wide indirect effects of influenza vaccination: triangulation using mathematical models and bias analysis
Arinaminpathy N , Reed C , Biggerstaff M , Nguyen AT , Athni TS , Arnold BF , Hubbard A , Reingold A , Benjamin-Chung J . Am J Epidemiol 2024 Understanding whether influenza vaccine promotion strategies produce community-wide indirect effects is important for establishing vaccine coverage targets and optimizing vaccine delivery. Empirical epidemiologic studies and mathematical models have been used to estimate indirect effects of vaccines but rarely for the same estimand in the same dataset. Using these approaches together could be a powerful tool for triangulation in infectious disease epidemiology because each approach is subject to distinct sources of bias. We triangulated evidence about indirect effects from a school-located influenza vaccination program using two approaches: a difference-in-difference (DID) analysis, and an age-structured, deterministic, compartmental model. The estimated indirect effect was substantially lower in the mathematical model than in the DID analysis (2.1% (95% Bayesian credible intervals 0.4 - 4.4%) vs. 22.3% (95% CI 7.6% - 37.1%)). To explore reasons for differing estimates, we used sensitivity analyses and probabilistic bias analyses. When we constrained model parameters such that projections matched the DID analysis, results only aligned with the DID analysis with substantially lower pre-existing immunity among school-age children and older adults. Conversely, DID estimates corrected for potential bias only aligned with mathematical model estimates under differential outcome misclassification. We discuss how triangulation using empirical and mathematical modelling approaches could strengthen future studies. |
Peripheral immune responses to filoviruses in a reservoir versus spillover hosts reveal transcriptional correlates of disease
Guito JC , Arnold CE , Schuh AJ , Amman BR , Sealy TK , Spengler JR , Harmon JR , Coleman-McCray JD , Sanchez-Lockhart M , Palacios GF , Towner JS , Prescott JB . Front Immunol 2023 14 1306501 Several filoviruses, including Marburg virus (MARV), cause severe disease in humans and nonhuman primates (NHPs). However, the Egyptian rousette bat (ERB, Rousettus aegyptiacus), the only known MARV reservoir, shows no overt illness upon natural or experimental infection, which, like other bat hosts of zoonoses, is due to well-adapted, likely species-specific immune features. Despite advances in understanding reservoir immune responses to filoviruses, ERB peripheral blood responses to MARV and how they compare to those of diseased filovirus-infected spillover hosts remain ill-defined. We thus conducted a longitudinal analysis of ERB blood gene responses during acute MARV infection. These data were then contrasted with a compilation of published primate blood response studies to elucidate gene correlates of filovirus protection versus disease. Our work expands on previous findings in MARV-infected ERBs by supporting both host resistance and disease tolerance mechanisms, offers insight into the peripheral immunocellular repertoire during infection, and provides the most direct known cross-examination between reservoir and spillover hosts of the most prevalently-regulated response genes, pathways and activities associated with differences in filovirus pathogenesis and pathogenicity. |
Seroreversion to chlamydia trachomatis Pgp3 antigen among children in a hyperendemic region of Amhara, Ethiopia
Tedijanto C , Aragie S , Gwyn S , Wittberg DM , Zeru T , Tadesse Z , Chernet A , Thompson IJB , Nash SD , Lietman TM , Martin DL , Keenan JD , Arnold BF . J Infect Dis 2023 Monitoring trachoma transmission with antibody data requires characterization of decay in IgG to Chlamydia trachomatis antigens. In a three-year longitudinal cohort in a high transmission setting, we estimated a median IgG half-life of 3 years and a seroreversion rate of 2.5 (95% CI: 1.6, 3.5) per 100 person-years. |
Association of radiology findings with etiology of community acquired pneumonia among children
Arnold SR , Jain S , Dansie D , Kan H , Williams DJ , Ampofo K , Anderson EJ , Grijalva CG , Bramley AM , Pavia AT , Edwards KM , Nolan VG , McCullers JA , Kaufman RA . J Pediatr 2023 261 113333 OBJECTIVE: To evaluate the association between consolidation on chest radiograph and typical bacterial etiology of childhood community acquired pneumonia (CAP) in the Etiology of Pneumonia in the Community study. STUDY DESIGN: Hospitalized children <18 years of age with CAP enrolled in the Etiology of Pneumonia in the Community study at 3 children's hospitals between January 2010 and June 2012 were included. Testing of blood and respiratory specimens used multiple modalities to identify typical and atypical bacterial, or viral infection. Study radiologists classified chest radiographs (consolidation, other infiltrates [interstitial and/or alveolar], pleural effusion) using modified World Health Organization pneumonia criteria. Infiltrate patterns were compared according to etiology of CAP. RESULTS: Among 2212 children, there were 1302 (59%) with consolidation with or without other infiltrates, 910 (41%) with other infiltrates, and 296 (13%) with pleural effusion. In 1795 children, at least 1 pathogen was detected. Among these patients, consolidation (74%) was the most frequently observed pattern (74% in typical bacterial CAP, 58% in atypical bacterial CAP, and 54% in viral CAP). Positive and negative predictive values of consolidation for typical bacterial CAP were 12% (95% CI 10%-15%) and 96% (95% CI 95%-97%) respectively. In a multivariable model, typical bacterial CAP was associated with pleural effusion (OR 7.3, 95% CI 4.7-11.2) and white blood cell ≥15 000/mL (OR 3.2, 95% CI 2.2-4.9), and absence of wheeze (OR 0.5, 95% CI 0.3-0.8) or viral detection (OR 0.2, 95% CI 0.1-0.4). CONCLUSIONS: Consolidation predicted typical bacterial CAP poorly, but its absence made typical bacterial CAP unlikely. Pleural effusion was the best predictor of typical bacterial infection, but too uncommon to aid etiology prediction. |
The Oregon Child Absenteeism Due to Respiratory Disease Study (ORCHARDS): Rationale, Objectives, and Design (preprint)
Temte JL , Barlow S , Goss M , Temte E , Schemmel A , Maerz B , Bell C , Comp L , Arnold M , Breunig K , Clifford S , Reisdorf E , Shult P , Wedig M , Haupt T , Conway J , Gangnon R , Fowlkes A , Uzicanin A . medRxiv 2021 2021.02.01.21250878 Background Influenza viruses pose significant disease burdens through annual seasonal outbreaks and unpredictable pandemics. Existing influenza surveillance programs have relied heavily on reporting of medically attended influenza (MAI). Continuously monitoring cause-specific school absenteeism may identify local acceleration of seasonal influenza activity. The Oregon Child Absenteeism Due to Respiratory Disease Study (ORCHARDS; Oregon, WI) implements daily school-based monitoring of influenza-like illness–specific student absenteeism (a-ILI) in pre-kindergarten through grade 12 schools and assesses this approach for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities.Methods Starting in September 2014, ORCHARDS combined automated reporting of daily absenteeism within 6 schools and home visits to school children with acute respiratory infections (ARI). Demographic, epidemiological, and symptom data are collected along with respiratory specimens. Specimens are tested for influenza and other respiratory viruses. Household members can opt into a supplementary household transmission study. Community comparisons are possible using a pre-existing, long-standing, and highly effective influenza surveillance program, based on MAI at 5 primary care clinics in the same geographical area.Results Over the first 5 years, a-ILI occurred on 6,634 (0.20%) of 3,260,461 student school days. Viral pathogens were detected in 64.5% of the 1,728 children with ARI who received a home visit. Influenza was the most commonly detected virus, noted in 23.3% of ill students. Influenza (p<0.001) and adenovirus (P=0.004) were significantly associated with a-ILI.Conclusion ORCHARDS uses a community-based design to detect influenza trends over multiple seasons and to evaluate the utility of absenteeism for early detection of accelerated influenza and other respiratory pathogen transmission in schools and surrounding communities. Initial findings suggest the study design is succeeding in collecting appropriate data to achieve study objectives.Competing Interest StatementDr. Jonathan Temte has received financial and material support from Quidel Corporation. Dr. John Tamerius and Quidel Corporation have generously supplied RIDT analyzers and tests.Funding StatementDr. John Tamerius and Quidel Corporation have generously supplied RIDT analyzers and tests. This study has been supported by CDC through the cooperative agreement # 5U01CK000542-02-00. The findings and conclusions in this study are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:All components of this proposed study were reviewed and approved by the Human Subjects Committees of the Education Research IRB - Social and Behavioral Sciences IRB (initial approval on September 4, 2013) and the University of Wisconsin Health Sciences-IRB (initial approval on December 5, 2013, with additional approvals as the protocol expanded and modified). The study is in full compliance with the Health Insurance Portability and Accountability Act of 1996 (HIPAA), FERPA, and all other federally mandated human subjects regulations. The US Office of Management and Budget has approved all forms used in this study.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a s atement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThe datasets generated and/or analyzed during the current study are not publicly available because the study is ongoing, but may be available from the corresponding author on reasonable request.4k4-year-old pre-kindergartena-Iabsenteeism due to illnessa-ILIabsenteeism due to influenza-like illnessa-TOTall-cause absenteeismARIacute respiratory infectionCDCCenters for Disease Control and PreventionCoVcoefficient of variationFERPAFamily Educational Rights and Privacy ActFluinfluenzaFDAFood and Drug AdministrationHIPPAHealth Insurance Portability and Accountability ActILIinfluenza-like illnessITinformation technologyIRBinstitutional review boardMAImedically attended influenzaNPnasopharyngealORCHARDSOregon Child Absenteeism Due to Respiratory Disease StudyOSDOregon School DistrictOPoropharyngealPCRpolymerase chain reactionRIDTrapid influenza diagnostic testRedCapResearch Electronic Data CaptureRPPrespiratory pathogen panelR/Erhinovirus/enterovirusRPhuman RNAse PSISschool information systemW-IISPWisconsin Influenza Incidence Surveillance ProjectWIRWisconsin Immunization RegistryWSLHWisconsin State Laboratory of HygieneVTMviral transport medium |
Predicting future ocular Chlamydia trachomatis infection prevalence using serological, clinical, molecular, and geospatial data (preprint)
Tedijanto C , Aragie S , Tadesse Z , Haile M , Zeru T , Nash SD , Wittberg DM , Gwyn S , Martin DL , Sturrock HJW , Lietman TM , Keenan JD , Arnold BF . medRxiv 2021 2021.07.19.21260623 Trachoma is an infectious disease characterized by repeated exposures to Chlamydia trachomatis (Ct) that may ultimately lead to blindness. Certain areas, particularly in Africa, pose persistent challenges to elimination of trachoma as a public health problem. Efficiently identifying communities with high infection burden could help target more intensive control efforts. We hypothesized that IgG seroprevalence in combination with geospatial layers, machine learning, and model-based geostatistics would be able to accurately predict future community-level ocular Ct infections detected by PCR. We used measurements from 40 communities in the hyperendemic Amhara region of Ethiopia. Median Ct infection prevalence among children 0-5 years old increased from 6% at enrollment to 29% by month 36. At baseline, correlation between seroprevalence and Ct infection was stronger among children 0-5 years old (ρ = 0.77) than children 6-9 years old (ρ = 0.48), and stronger than the correlation between clinical trachoma and Ct infection (0-5y ρ = 0.56; 6-9y ρ = 0.40). Seroprevalence was the strongest concurrent predictor of infection prevalence at month 36 among children 0-5 years old (cross-validated R2 = 0.75, 95% CI: 0.58-0.85), though predictive performance declined substantially with increasing temporal lag between predictor and outcome measurements. Geospatial variables, a spatial Gaussian process, and stacked ensemble machine learning did not meaningfully improve predictions. Serological markers among children 0-5 years old may be an objective, programmatic tool for identifying communities with high levels of active ocular Ct infections, but accurate, future prediction in the context of changing transmission remains an open challenge.SIGNIFICANCE STATEMENT Trachoma is targeted for elimination as a public health problem by 2030. District-level estimates of clinical disease among children 1-9 years old are currently used to guide control programs and assess elimination. However, clinical trachoma is a subjective indicator. Serological markers present an objective, scalable alternative that could be measured in integrated platforms. In a hyperendemic region, community-level seroprevalence aligned more closely with concurrent infection prevalence than clinical trachoma. The correlation between seroprevalence and infection prevalence was stronger among 0–5-year-olds compared to 6–9-year-olds and was consistent over a three-year period of increasing transmission. Serosurveillance among children 0-5 years old may be a promising monitoring strategy to identify communities with the highest burdens of ocular chlamydial infection.Competing Interest StatementThe authors have declared no competing interest.Clinical TrialNCT02754583Funding StatementWe would like to thank the WUHA study participants and field team without whom this research would not be possible. This work was supported by the National Institute of Allergy and Infectious Diseases (R03 AI147128 to BFA) and the National Eye Institute (U10 EY023939 to JDK). This work was also made possible in part by an Unrestricted Grant from Research to Prevent Blindness. We would also like to thank Abbott for its donation of the m2000 RealTime molecular diagnostics system and consumables.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:Approval for the study was obtained from the University of California, San Francisco Institutional Review Board (14-14004).All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesDe-identified data and code to replicate this work is available on Github. https://github.com/ctedijanto/swift-spatial-prediction |
Effect of biannual azithromycin distribution on antibody responses to malaria, bacterial, and protozoan pathogens among children: A cluster-randomized, placebo-controlled trial in Niger (preprint)
Arzika AM , Maliki R , Goodhew EB , Rogier E , Priest JW , Lebas E , O'Brien KS , Le V , Oldenburg CE , Doan T , Porco TC , Keenan JD , Lietman TM , Martin DL , Arnold BF . medRxiv 2021 2021.04.23.21255957 Background The Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) trial in Niger, Malawi, and Tanzania found that biannual mass distribution of azithromycin to children younger than 5 years led to a 13.5% reduction in all-cause mortality. Additional endpoints in the trial have attempted to elucidate the mechanisms for mortality reduction. In this pre-specified secondary analysis, we assessed the effect of azithromycin compared with placebo on IgG- based measures of infectious disease exposure with a multiplex bead assay that included antigens to malaria parasites (Plasmodium falciparum, P. vivax, P. malariae, P. ovale), bacterial pathogens (Campylobacter spp., enterotoxigenic Escherichia coli, Vibrio cholerae, Salmonella enterica, Streptococcus pyogenes) and protozoans (Cryptosporidium parvum, Giardia duodenales).Methods and Findings Thirty communities in rural Niger were randomized 1:1 to biannual distributions of azithromycin or placebo among children ages 1-59 months. The analysis included 5,642 blood specimens collected from 3,814 children ages 1-59 months, measured at 6, 12, 24, and 36 months of follow-up in a repeated cross-sectional design. Campylobacter spp. seroprevalence averaged over all study visits was lower in azithromycin communities compared to placebo (91% vs 94%, difference = –3%, 95% CI: –5%, –1%; P=0.03), which corresponded to a 29% lower seroconversion rate (1.30 versus 1.84 seroconversions per year, hazard ratio = 0.71, 95% CI: 0.56, 0.89; P=0.004). Antibody-based measures of infection with P. falciparum and group A streptococcus were consistently lower in azithromycin communities, but were not statistically different from placebo, and there were no other differences across pathogens. Strengths of the study included masking of participants, investigators, and analysts, high treatment coverage, large sample size, and objective outcomes. Principal limitations included the timing of blood collection with respect to treatment (approximately 6 months later, which could have missed transient effects in the weeks immediately following treatment), and the durability of IgG response following clearance of infection. Both limitations would lead the trial to under-estimate effects on antibody-based measures of infection.Conclusions The reduction in Campylobacter spp. despite these limitations suggests an effect on carriage, findings which align with an independent metagenomic analysis of rectal swabs collected in the same villages and with previously reported reductions in dysentery-associated mortality. Given significant sequelae of Campylobacter infection among preschool aged children, our results support at least one possible mechanism through which biannual mass distribution of azithromycin likely reduced mortality in this study population.Competing Interest StatementThis work was supported by the Bill & Melinda Gates Foundation (award no. OPP1032340 to TML) and was supported in part by an unrestricted grant from Research to Prevent Blindness and by the National Institute of Allergy and Infectious Diseases (award no. K01-AI119180 to BFA). The Gates Foundation approved the study design, but had no role in data collection, data analysis, data interpretation, or writing of the report. The authors declare no competing interests. The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services. Clinical TrialNCT02048007Funding StatementThis work was supported by the Bill & Melinda Gates Foundation (award no. OPP1032340 to TML) and was supported in part by an unrestricted grant from Research to Prevent Blindness and by the National Institute of Allergy and Infectious Diseases (award no. K01-AI119180 to BFA). The Gates Foundation approved the study design, but had no role in data collection, data nalysis, data interpretation, or writing of the report.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The trial protocol was reviewed and approved by the Committee on Human Research at the University of California, San Francisco, and the Niger Ministry of Health's Ethical Committee. Parents or guardians of enrolled children provided oral consent before each azithromycin or placebo treatment and at each specimen collection visit. Parents or guardians were instructed to report any adverse event within 7 days of treatment by contacting their village representative, who then reported events to the site coordinator and UCSF. An independent Data and Safety Monitoring Committee provided additional oversight. CDC researchers had access to de-identified samples for analysis (no personally identifying information).All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData and computational notebooks used to conduct the analyses are available through the Open Science Framework (https://osf.io/954bt) and Dryad (xx DOI forthcoming xx). Analyses used R statistical software, version 4.0.2. https://osf.io/954bt |
Seroprevalence of antibodies against Chlamydia trachomatis and enteropathogens and distance to the nearest water source among young children in the Amhara Region of Ethiopia (preprint)
Aiemjoy K , Aragie S , Wittberg DM , Tadesse Z , Callahan EK , Gwyn S , Martin D , Keenan JD , Arnold BF . medRxiv 2020 2020.04.16.20060996 Background The transmission of trachoma, caused by repeat infections with Chlamydia trachomatis, and many enteropathogens are linked to water quantity. We hypothesized that children living further from a water source would have higher exposure to C. trachomatis and enteric pathogens as determined by antibody responses.Methods We used a multiplex bead assay to measure IgG antibody responses to C. trachomatis, Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica, Campylobacter jejuni, enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae in eluted dried blood spots collected from 2267 children ages 1–9 years in 40 communities in rural Ethiopia in 2016. Linear distance from the child’s house to the nearest water source was calculated. We derived seroprevalence cutoffs using external negative control populations, if available, or by fitting finite mixture models. We used targeted maximum likelihood estimation to estimate differences in seroprevalence according to distance to the nearest water source.Results Seroprevalence among 1–9-year-olds was 43% for C. trachomatis, 28% for S. enterica, 70% for E. histolytica, 54% for G. intestinalis, 96% for C. jejuni, 76% for ETEC and 94% for C. parvum. Seroprevalence increased with age for all pathogens. Median distance to the nearest water source was 473 meters (IQR 268, 719). Children living furthest from a water source had a 12% (95% CI: 2.6, 21.6) higher seroprevalence of S. enterica and a 12.7% (95% CI: 2.9, 22.6) higher seroprevalence of G. intestinalis compared to children living nearest.Conclusion Seroprevalence for C. trachomatis and enteropathogens was high, with marked increases for most enteropathogens in the first two years of life. Children living further from a water source had higher seroprevalence of S. enterica and G. intestinalis indicating that improving access to water in the Ethiopia’s Amhara region may reduce exposure to these enteropathogens in young children.AUTHOR SUMMARY Trachoma, and infection of the eye caused by the bacteria Chlamydia trachomatis, and many diarrhea-causing infections are associated with access to water for washing hands and faces. Measuring these different pathogens in a population is challenging and rarely are multiple infections measured at the same time. Here, we used an integrated approach to simultaneously measure antibody responses to C. trachomatis, Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica, Campylobacter jejuni, enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae among young children residing in rural Ethiopia. We found that the seroprevalence of all pathogens increased with age and that seropositivity to more than one pathogen was common. Children living further from a water source were more likely to be exposed to S. enterica and G. intestinalis. Integrated sero-surveillance is a promising avenue to explore the complexities of multi-pathogen exposure as well as to investigate the relationship water, sanitation and hygiene related exposures disease transmission.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis study was funded by the National Institutes of Health, National Eye Institute (NEI U10 EY016214)Author DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in adva ce).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAssociated data will be available on OSF upon publication |
Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response (preprint)
Arnold BF , Kanyi H , Njenga SM , Rawago FO , Priest JW , Secor WE , Lammie PJ , Won KY , Odiere MR . medRxiv 2020 2020.04.10.20061101 Identifying populations with active transmission and monitoring changes in transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected in stool using microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to schistosomiasis soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. Serological measures of transmission closely aligned with stool-based measures of infection, and serological measures provided better resolution for between-community differences at lower levels of infection. Serology enabled fine- scale measures of heterogeneity in force of infection both geographically and by age. Our results show that serologic surveillance platforms represent an important new opportunity to guide and monitor schistosomiasis control programs.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was supported by the National Institutes of Allergy and Infectious Diseases (K01 AI119180 to BFA) and the Bill & Melinda Gates Foundation (OPP1022543 to PJL). The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services.Author DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData and replication files required to conduct the analyses are available through GitHub and the Open Science Framework: https://osf.io/rnme8. Community location data required to replicate the geostatistical model fits is not publicly available to protect participant confidentiality but is available from the corresponding author upon request, pending appropriate human subjects review and approval. https://osf.io/rnme8 |
Multiplex serologic testing within a cross-sectional lymphatic filariasis sentinel site survey in coastal Kenya reveals community-level differences in IgG antibody responses to parasitic diseases and vaccines (preprint)
Njenga SM , Kanyi HM , Arnold BF , Matendechero SH , Onsongo JK , Won KY , Priest JW . bioRxiv 2019 604181 Accurate, cost-effective measurement of the burden of co-endemic infections would enable public health managers to identify opportunities for implementation of integrated control programs. Dried blood spots (DBS) collected during a cross-sectional lymphatic filariasis sentinel site survey in the Kenyan coastal counties of Lamu, Tana River, Kilifi, Kwale, and Taita-Taveta were used for the integrated detection of serologic IgG antibodies against antigens from several parasitic infections (Wuchereria bancrofti, Schistosoma mansoni, Plasmodium spp, Ascaris lumbricoides, and Strongyloides stercoralis) as well as markers for immunity to vaccine-preventable diseases (measles, diphtheria, and tetanus) on a multiplex bead assay (MBA) platform. High heterogeneity was observed in antibody responses by pathogen and antigen across the sentinel sites. Antibody seroprevalence against Wb123, Bm14, and Bm33 recombinant filarial antigens were generally higher in Ndau Island (p<0.0001), which also had the highest prevalence of filarial antigenemia compared to other communities. Antibody responses to the Plasmodium species antigens CSP and MSP-119 were higher in Kilifi and Kwale counties, with Jaribuni community showing higher overall mean seroprevalence (p<0.0001). Kimorigo community in Taita-Taveta County was the only area where antibody responses against Schistosoma mansoni Sm25 recombinant antigen were detected. Seroprevalence rates to Strongyloides antigen NIE ranged between 3% and 26%, and there was high heterogeneity in immune responses against an Ascaris antigen among the study communities. Differences were observed between communities in terms of seroprevalence to vaccine-preventable diseases. Seroprotection to tetanus was lower in all 3 communities in Kwale County compared to the rest of the communities. This study has demonstrated that the MBA platform holds promise for rapid integrated monitoring of trends of infections of public health importance in endemic areas, and assessing the effectiveness of control and elimination programs.Author Summary Establishment of successful private-public partnerships in the recent past has led to an increase in resources available for control and elimination of malaria and Neglected Tropical Diseases (NTDs). Implementation of control and elimination programs and their subsequent monitoring and evaluation would be greatly facilitated by development of new tools and strategies for rapid identification of areas of transmission so that interventions could be prioritized to regions where they were most needed. Since development of antibody responses in a host depend on exposure to an infectious agent, assessment of such serologic markers provides a sensitive way to measure differences between populations in pathogen exposure. Our study applied a state-of-the-art multiplex bead assay platform to perform integrated measurement of antibody responses to multiple parasitic diseases and immunizing antigens for vaccine-preventable diseases (VPDs) in ten lymphatic filariasis sentinel sites across the Kenyan coastal region. A community-level analysis of age-specific and overall mean seroprevalence fit using a flexible model ensemble provided an improved understanding about the distributions of the various parasitic infections and seroprotection to VPDs. This study provides an important proof of concept for how we could dramatically increase the value of existing surveillance activities using small volumes of blood collected on filter paper and analyzed using a single multiplex laboratory assay and novel data analysis techniques. |
Enteropathogen antibody dynamics and force of infection among children in low-resource settings (preprint)
Arnold BF , Martin DL , Juma J , Mkocha H , Ochieng JB , Cooley GM , Omore R , Goodhew EB , Morris JF , Costantini V , Vinje J , Lammie PJ , Priest JW . bioRxiv 2019 522920 Little is known about enteropathogen seroepidemiology among children in low-resource settings. We measured serological IgG responses to eight enteropathogens (Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica, enterotoxigenic Escherichia coli, Vibrio cholerae, Campylobacter jejuni, norovirus) in cohorts from Haiti, Kenya, and Tanzania. We studied antibody dynamics and force of infection across pathogens and cohorts. Enteropathogens shared common seroepidemiologic features that enabled between-pathogen comparisons of transmission. Overall, exposure was intense: for most pathogens the window of primary infection was <3 years old; for highest transmission pathogens primary infection occurred within the first year. Longitudinal profiles revealed significant IgG boosting and waning above seropositivity cutoffs, underscoring the value of longitudinal designs to estimate force of infection. Seroprevalence and force of infection were rank-preserving across pathogens, illustrating the measures provide similar information about transmission heterogeneity. Our findings suggest multiplex antibody assays are a promising approach to measure population-level enteropathogen transmission in serologic surveillance. |
School-located influenza vaccination and community-wide indirect effects: Reconciling mathematical models to epidemiologic models (preprint)
Arinaminpathy N , Reed C , Biggerstaff M , Nguyen A , Athni TS , Arnold BF , Hubbard A , Colford JM , Reingold A , Benjamin-Chung J . medRxiv 2022 13 Background: Mathematical models and empirical epidemiologic studies (e.g., randomized and observational studies) are complementary tools but may produce conflicting results for a given research question. We used sensitivity analyses and bias analyses to explore such discrepancies in a study of the indirect effects of influenza vaccination. Method(s): We fit an age-structured, deterministic, compartmental model to estimate indirect effects of a school-based influenza vaccination program in California that was evaluated in a previous matched cohort study. To understand discrepancies in their results, we used 1) a model with constrained parameters such that projections matched the cohort study; and 2) probabilistic bias analyses to identify potential biases (e.g., outcome misclassification due to incomplete influenza testing) that, if corrected, would align the empirical results with the mathematical model. Result(s): The indirect effect estimate (% reduction in influenza hospitalization among older adults in intervention vs. control) was 22.3% (95% CI 7.6% - 37.1%) in the cohort study but only 1.6% (95% Bayesian credible intervals 0.4 - 4.4%) in the mathematical model. When constrained, mathematical models aligned with the cohort study when there was substantially lower pre-existing immunity among school-age children and older adults. Conversely, empirical estimates corrected for potential bias aligned with mathematical model estimates only if influenza testing rates were 15-23% lower in the intervention vs. comparison site. Conclusion(s): Sensitivity and bias analysis can shed light on why results of mathematical models and empirical epidemiologic studies differ for the same research question, and in turn, can improve study and model design. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license. |
Seroreversion to Chlamydia trachomatis Pgp3 antigen among young children in a hyperendemic region of Amhara, Ethiopia (preprint)
Tedijanto C , Aragie S , Gwyn S , Wittberg DM , Zeru T , Tadesse Z , Chernet A , Thompson I , Nash SD , Lietman TM , Martin DL , Keenan JD , Arnold BF . medRxiv 2023 07 Monitoring trachoma transmission with antibody data requires characterization of decay in IgG to Chlamydia trachomatis antigens. In a three-year longitudinal cohort in a high transmission setting, we estimated a median IgG half-life of 3 years and a seroreversion rate of 2.5 (95% CI: 1.6, 3.8) per 100 person-years. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Monitoring transmission intensity of trachoma with serology: a multi-country study (preprint)
Tedijanto C , Solomon AW , Martin DL , Nash SD , Keenan JD , Lietman TM , Lammie PJ , Aiemjoy K , Amza A , Aragie S , Arzika AM , Callahan EK , Carolan S , Dawed AA , Goodhew EB , Gwyn S , Hammou J , Kadri B , Kalua K , Maliki R , Nassirou B , Seife F , Tadesse Z , West SK , Wittberg DM , Zeru T , Arnold BF . medRxiv 2023 16 Trachoma, caused by ocular Chlamydia trachomatis infection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitor C. trachomatis transmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 children aged 1-9 years in 14 populations. We demonstrate that age-seroprevalence curves consistently shift along a gradient of transmission intensity: rising steeply in populations with high levels of infection and active trachoma and becoming flat in populations near elimination. Seroprevalence (range: 0-54%) and seroconversion rates (range: 0-15 per 100 person-years) correlate with PCR prevalence (r: 0.88, 95% CI: 0.77, 0.93). A seroprevalence threshold of 13.5% (seroconversion rate 2.75 per 100 person-years) identifies clusters with any infection at high sensitivity (>90%) and moderate specificity (69-75%). Antibody responses in young children provide a robust, generalizable approach to monitor population progress toward and beyond trachoma elimination. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
DNA capture and enrichment: A culture-independent approach for characterizing the genomic diversity of pathogenic leptospira species
Stone NE , McDonough RF , Hamond C , LeCount K , Busch JD , Dirsmith KL , Rivera-Garcia S , Soltero F , Arnold LM , Weiner Z , Galloway RL , Schlater LK , Nally JE , Sahl JW , Wagner DM . Microorganisms 2023 11 (5) Because they are difficult to culture, obtaining genomic information from Leptospira spp. is challenging, hindering the overall understanding of leptospirosis. We designed and validated a culture-independent DNA capture and enrichment system for obtaining Leptospira genomic information from complex human and animal samples. It can be utilized with a variety of complex sample types and diverse species as it was designed using the pan-genome of all known pathogenic Leptospira spp. This system significantly increases the proportion of Leptospira DNA contained within DNA extracts obtained from complex samples, oftentimes reaching >95% even when some estimated starting proportions were <1%. Sequencing enriched extracts results in genomic coverage similar to sequenced isolates, thereby enabling enriched complex extracts to be analyzed together with whole genome sequences from isolates, which facilitates robust species identification and high-resolution genotyping. The system is flexible and can be readily updated when new genomic information becomes available. Implementation of this DNA capture and enrichment system will improve efforts to obtain genomic data from unculturable Leptospira-positive human and animal samples. This, in turn, will lead to a better understanding of the overall genomic diversity and gene content of Leptospira spp. that cause leptospirosis, aiding epidemiology and the development of improved diagnostics and vaccines. |
Monitoring transmission intensity of trachoma with serology
Tedijanto C , Solomon AW , Martin DL , Nash SD , Keenan JD , Lietman TM , Lammie PJ , Aiemjoy K , Amza A , Aragie S , Arzika AM , Callahan EK , Carolan S , Dawed AA , Goodhew EB , Gwyn S , Hammou J , Kadri B , Kalua K , Maliki R , Nassirou B , Seife F , Tadesse Z , West SK , Wittberg DM , Zeru Tadege T , Arnold BF . Nat Commun 2023 14 (1) 3269 Trachoma, caused by ocular Chlamydia trachomatis infection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitor C. trachomatis transmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 children aged 1-9 years in 14 populations. We demonstrate that age-seroprevalence curves consistently shift along a gradient of transmission intensity: rising steeply in populations with high levels of infection and active trachoma and becoming flat in populations near elimination. Seroprevalence (range: 0-54%) and seroconversion rates (range: 0-15 per 100 person-years) correlate with PCR prevalence (r: 0.87, 95% CI: 0.57, 0.97). A seroprevalence threshold of 13.5% (seroconversion rate 2.75 per 100 person-years) identifies clusters with any PCR-identified infection at high sensitivity ( >90%) and moderate specificity (69-75%). Antibody responses in young children provide a robust, generalizable approach to monitor population progress toward and beyond trachoma elimination. |
Greener residential environment is associated with increased bacterial diversity in outdoor ambient air
Styles JN , Egorov AI , Griffin SM , Klein J , Scott JW , Sams EA , Hudgens E , Mugford C , Stewart JR , Lu K , Jaspers I , Keely SP , Brinkman NE , Arnold JW , Wade TJ . Sci Total Environ 2023 880 163266 In urban areas, exposure to greenspace has been found to be beneficial to human health. The biodiversity hypothesis proposed that exposure to diverse ambient microbes in greener areas may be one pathway leading to health benefits such as improved immune system functioning, reduced systemic inflammation, and ultimately reduced morbidity and mortality. Previous studies observed differences in ambient outdoor bacterial diversity between areas of high and low vegetated land cover but didn't focus on residential environments which are important to human health. This research examined the relationship between vegetated land and tree cover near residence and outdoor ambient air bacterial diversity and composition. We used a filter and pump system to collect ambient bacteria samples outside residences in the Raleigh-Durham-Chapel Hill metropolitan area and identified bacteria by 16S rRNA amplicon sequencing. Geospatial quantification of total vegetated land or tree cover was conducted within 500 m of each residence. Shannon's diversity index and weighted UniFrac distances were calculated to measure α (within-sample) and β (between-sample) diversity, respectively. Linear regression for α-diversity and permutational analysis of variance (PERMANOVA) for β-diversity were used to model relationships between vegetated land and tree cover and bacterial diversity. Data analysis included 73 ambient air samples collected near 69 residences. Analysis of β-diversity demonstrated differences in ambient air microbiome composition between areas of high and low vegetated land (p = 0.03) and tree cover (p = 0.07). These relationships remained consistent among quintiles of vegetated land (p = 0.03) and tree cover (p = 0.008) and continuous measures of vegetated land (p = 0.03) and tree cover (p = 0.03). Increased vegetated land and tree cover were also associated with increased ambient microbiome α-diversity (p = 0.06 and p = 0.03, respectively). To our knowledge, this is the first study to demonstrate associations between vegetated land and tree cover and the ambient air microbiome's diversity and composition in the residential ecosystem. |
Changes in spina bifida lesion level after folic acid fortification in the US
Mai CT , Evans J , Alverson CJ , Yue X , Flood T , Arnold K , Nestoridi E , Denson L , Adisa O , Moore CA , Nance A , Zielke K , Rice S , Shan X , Dean JH , Ethen M , Hansen B , Isenburg J , Kirby RS . Obstet Gynecol Surv 2023 78 (4) 189-191 following which a substantial decline in neural tube defects at birth occurred. Studies also have suggested that lesion levels in cases of spina bifida are directly affected by folic acid fortification. Locations of such lesions contribute to outcome and prognosis of the condition. When compared with sacral and lower lumbar lesions, the greatest risks of disability and mortality are associated with cervical, thoracic, and high lumbar lesions. Individuals with thoracic or high lumbar lesions require a wheelchair and orthosis in adulthood for ambulation 70% to 99% of the time. As lesion levels therefore determine function and overall quality of life, assessment of whether folic acid fortification significantly impacts lesion levels is important. This study aimed to examine patterns of lesion levels in spina bifida following mandatory folic acid fortification in the United States. | | A call was issued by the National Birth Defects Prevention Network for State Birth Defects Programs' spina bifida lesion data before and after fortification mandate. To be eligible, programs needed to provide verbatim medical record text descriptions of spina bifida diagnoses. The 6 participating programs were from the states of Arizona, California (covering 8 counties), Oklahoma, South Carolina, Utah, and metropolitan Atlanta (Georgia). Birth years examined included the prefortification years of 1992–1996 and the postfortification period of 1999–2016. Central processing and analysis occurred as each program provided case-level data (deidentified) based on the exclusion/inclusion criteria to the Centers for Disease Control and Prevention. Medical and record text description of the spina bifida diagnosis and codes were the basis of case information, using the International Classification of Diseases, Ninth Edition, Clinical Modification or the Centers for Disease Control and Prevention and Prevention/British Pediatric Association coding system. Types of spina bifida included in the study were spinal rachischisis, myelomeningocele/meningomyelocele, meningocele, and spina bifida not otherwise specified. Cases excluded were cranial lesions, lipomyelomeningocele/lipomeningomyelocele, dysraphism related to split cord malformations, and spina bifida occulta. | | Lesion-level information was provided based on the highest lesion using nonradiographic clinical assessment. Classification of severe upper-level lesions included cervical or thoracic lesion-level cases, whereas lower-level lesions included cases with lumbar or sacral. The study defined open lesion as leaking spinal fluid or membrane covered only, whereas closed lesions were defined as having intact-skin covering and lacking fluid leakage. Spina bifida cases were considered isolated when no other anomalies related to the primary cause of abnormal neural tube closure were present (nor were secondary to the neurologic complications caused by it). Examining associations between fortification period and the outcomes (lesion level and spina bifida) occurred using the generalized estimating approach to logistic (case severity analyses) and log-linear (PR analyses) regression, which accounted for clustering of cases by state. | | From a total of 7,816,062 live births, 2593 cases of spina bifida met the case inclusion criteria. Overall, 573 cases were included in the prefortification period (birth prevalence of 4.07 per 10,000 live births), and 2020 cases were included in the postfortification period (birth prevalence of 3.15 per 10,000 live births). Overall, 80.2% of cases resulted in live births, and most cases of spina bifida involved lower-level lesions (81.3%). Most lesions were lumbar, and the proportions prefortification and postfortification were 61.4% and 72.0%, respectively, with a higher proportion of lumbar lesions seen in the postfortification period. The odds of upper-level to lower-level lesions decreased by 70% after fortification. The spina bifida live birth prevalence decreased significantly and remained consistently low throughout the early, mid, and recent postfortification periods. The study found a 72% decrease overall in prevalence of severe, upper-level lesions following mandatory folic acid fortification in the United States. | | The limitations of the study include the shortcomings of relying on diagnostic codes, the difficulty of coding lesion level using the International Classification of Diseases, Ninth Edition, Clinical Modification coding scheme, the lack of recorded functional outcome for children in medical records (indirect indicators of severity), the lack of preconception and prenatal folic acid data, and the possible variation of case ascertainment within programs contributing studies. A major study strength is its potential to address additional important questions regarding epidemiology and spina bifida. The classification of spinal defects is complex, and this study adds to the limited distribution data that exist for prefortification and postfortification subtypes. | | The study concluded that the overall prevalence of severe upper-level lesions in spina bifida cases experienced a steep reduction following mandatory folic acid fortification institution within the United States, whereas no change in the prevalence of less severe lower-level lesions took place. Additional examinations are warranted to better understand the magnitude and mechanism of spina bifida severity in relation to folic acid intake. |
Use of 3-Dimensional Printers in Educational Settings: The Need for Awareness of the Effects of Printer Temperature and Filament Type on Contaminant Releases
Stefaniak AB , Bowers LN , Cottrell G , Erdem E , Knepp AK , Martin S , Pretty J , Duling MG , Arnold ED , Wilson Z , Krider B , LeBouf RF , Virji MA , Sirinterlikci A . J Chem Health Saf 2021 28 (6) 444-456 Material extrusion-type fused filament fabrication (FFF) 3-D printing is a valuable tool for education. During FFF 3-D printing, thermal degradation of the polymer releases small particles and chemicals, many of which are hazardous to human health. In this study, particle and chemical emissions from 10 different filaments made from virgin (never printed) and recycled polymers were used to print the same object at the polymer manufacturer's recommended nozzle temperature ("normal") and at a temperature higher than recommended ("hot") to simulate the real-world scenarios of a person intentionally or unknowingly printing on a machine with a changed setting. Emissions were evaluated in a college teaching laboratory using standard sampling and analytical methods. From mobility sizer measurements, particle number-based emission rates were 81 times higher; the proportion of ultrafine particles (diameter <100 nm) were 4% higher, and median particle sizes were a factor of 2 smaller for hot-temperature prints compared with normal-temperature prints (all p-values <0.05). There was no difference in emission characteristics between recycled and virgin acrylonitrile butadiene styrene and polylactic acid polymer filaments. Reducing contaminant release from FFF 3-D printers in educational settings can be achieved using the hierarchy of controls: (1) elimination/substitution (e.g., training students on principles of prevention-through-design, limiting the use of higher emitting polymer when possible); (2) engineering controls (e.g., using local exhaust ventilation to directly remove contaminants at the printer or isolating the printer from students); (3) administrative controls such as password protecting printer settings and establishing and enforcing adherence to a standard operating procedure based on a proper risk assessment for the setup and use (e.g., limiting the use of temperatures higher than those specified for the filaments used); and (4) maintenance of printers. |
Influence of puff topographies on e-liquid heating temperature, emission characteristics and modeled lung deposition of Puff Bar™
Ranpara A , Stefaniak AB , Fernandez E , Bowers LN , Arnold ED , LeBouf RF . Aerosol Sci Technol 2023 57 (5) 450-466 Puff Bar™, one of the latest designs of e-cigarettes, heats a mixture of liquid using a battery-powered coil at certain temperatures to emit aerosol. This study presents a mass-based characterization of emissions from seven flavors of Puff Bar™ devices by aerosolizing with three puff topographies [(puff volume: 55 < 65 < 75-mL) within 4-seconds at 30-seconds interval]. We evaluated the effects of puff topographies on heating temperatures; characterized particles using a cascade impactor; and measured volatile carbonyl compounds (VCCs). Modeled dosimetry and calculated mass median aerodynamic diameters (MMADs) were used to estimate regional, total respiratory deposition of the inhaled aerosol and exhaled fractions that could pose secondhand exposure risk. Temperatures of Puff Bar™ e-liquids increased with increasing puff volumes: 55 mL (116.6 °C), 65 mL (128.3 °C), and 75 mL (168.9 °C). Flavor types significantly influenced MMADs, total mass of particles, and VCCs (µg/puff: 2.15-2.30) in Puff Bar™ emissions (p < 0.05). Increasing puff volume (mL:55 < 65 < 75) significantly increased total mass (mg/puff: 4.6 < 5.6 < 6.2) of particles without substantially changing MMADs (∼1µm:1.02 ∼ 0.99 ∼ 0.98). Aerosol emissions were estimated to deposit in the pulmonary region of e-cigarette user (41–44%), which could have toxicological importance. More than 2/3 (67–77%) of inhaled particles were estimated to be exhaled by users, which could affect bystanders. The VCCs measured contained carcinogens—formaldehyde (29.6%) and acetaldehyde (16.4%)—as well as respiratory irritants: acetone (23.9%), isovaleraldehyde (14.5%), and acrolein (4.9%). As Puff Bar™ emissions contain respirable particles and harmful chemicals, efforts should be made to minimize exposures, especially in indoor settings where people (including vulnerable populations) spend most of their life-time. Copyright © 2023 American Association for Aerosol Research. ©, This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 USC. 105, no copyright protection is available for such works under US Law. |
Influence of puff topographies on e-liquid heating temperature, emission characteristics and modeled lung deposition of Puff Bar
Ranpara A , Stefaniak AB , Fernandez E , Bowers LN , Arnold ED , LeBouf RF . Aerosol Sci Technol 2023 57 (5) 450-466 Puff Bar, one of the latest designs of e-cigarettes, heats a mixture of liquid using a battery-powered coil at certain temperatures to emit aerosol. This study presents a mass-based characterization of emissions from seven flavors of Puff Bar devices by aerosolizing with three puff topographies [(puff volume: 55 < 65 < 75-mL) within 4-seconds at 30-seconds interval]. We evaluated the effects of puff topographies on heating temperatures; characterized particles using a cascade impactor; and measured volatile carbonyl compounds (VCCs). Modeled dosimetry and calculated mass median aerodynamic diameters (MMADs) were used to estimate regional, total respiratory deposition of the inhaled aerosol and exhaled fractions that could pose secondhand exposure risk. Temperatures of Puff Bar e-liquids increased with increasing puff volumes: 55 mL (116.6 C), 65 mL (128.3 C), and 75 mL (168.9 C). Flavor types significantly influenced MMADs, total mass of particles, and VCCs (g/puff: 2.15-2.30) in Puff Bar emissions (p < 0.05). Increasing puff volume (mL:55 < 65 < 75) significantly increased total mass (mg/puff: 4.6 < 5.6 < 6.2) of particles without substantially changing MMADs (1m:1.02 0.99 0.98). Aerosol emissions were estimated to deposit in the pulmonary region of e-cigarette user (4144%), which could have toxicological importance. More than 2/3 (6777%) of inhaled particles were estimated to be exhaled by users, which could affect bystanders. The VCCs measured contained carcinogensformaldehyde (29.6%) and acetaldehyde (16.4%)as well as respiratory irritants: acetone (23.9%), isovaleraldehyde (14.5%), and acrolein (4.9%). As Puff Bar emissions contain respirable particles and harmful chemicals, efforts should be made to minimize exposures, especially in indoor settings where people (including vulnerable populations) spend most of their life-time. Copyright 2023 American Association for Aerosol Research. , This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 USC. 105, no copyright protection is available for such works under US Law. |
Acute reactions after a homologous primary COVID-19 vaccination series: Analysis of Taiwan V-Watch data
Su WJ , Arnold Chan K , Chuang JH , Wang TA , Chen SF , Chang YC , Chen MY , Chang CC , Yang CH . Vaccine 2023 41 (17) 2853-2859 INTRODUCTION: The ChAdOx1 nCoV-19 (ChAd), mRNA-1273 (m1273), MVC-COV1901 (MVC), and BNT162b2 (BNT) COVID-19 vaccines received authorization for emergency use in Taiwan beginning in February 2021. We investigated acute reactions to homologous primary COVID-19 vaccination series in adults aged ≥ 18 years. METHODS: In this prospective observational study based on smartphone data (Taiwan V-Watch), we calculated the frequencies of self-reported local and systemic acute reactions within 7 days of a COVID-19 vaccination, and the health effects up to 3 weeks after each dose. Those who reported adverse reactions after both doses were assessed by the McNemar test. RESULTS: During 22 March 2021-13 December 2021, 77,468 adults were enrolled; 59.0 % were female and 77.8 % were aged 18-49 years. For both doses of all four vaccines, the local and systemic reactions were minor in severity and highest on days 1 and 2 after vaccination, and declined markedly until day 7. For 65,367 participants who provided data after the first and second doses, systemic reactions were more frequent after dose 2 of the BNT and m1273 vaccines (McNemar tests: both p < 0.001), while local reactions were more frequent after dose 2 of the m1273 and MVC vaccines (both p < 0.001), compared with dose 1 of the homologous vaccine. Among the participants aged 18-49 years, the percentage who missed work on the day after vaccination was slightly higher among women (9.3 %) than among men (7.0 %). CONCLUSIONS: Acute reactogenicity and impact of work absenteeism for the four COVID vaccines in the V-Watch survey were mild and of short duration. |
COVID-19 vaccine reactogenicity and vaccine attitudes among children and parents/guardians after multisystem inflammatory syndrome in children or COVID-19 hospitalization: September 2021-May 2022
Yousaf AR , Kunkel A , Abrams JY , Shah AB , Hammett TA , Arnold KE , Beltran YL , Laham FR , Kao CM , Hunstad DA , Hussaini L , Baida N , Salazar L , Perez MA , Rostad CA , Godfred-Cato S , Campbell AP , Belay ED . Pediatr Infect Dis J 2023 42 (3) 252-259 BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a multiorgan hyperinflammatory condition following SARS-CoV-2 infection. Data on COVID-19 vaccine adverse events and vaccine attitudes in children with prior MIS-C are limited. We described characteristics associated with COVID-19 vaccination, vaccine adverse events and vaccine attitudes in children with a history of MIS-C or COVID-19 and their parents/guardians. METHODS: We enrolled children previously hospitalized for MIS-C or COVID-19 from 3 academic institutions. We abstracted charts and interviewed children and parents/guardians regarding vaccine adverse events and acceptability. RESULTS: Of 163 vaccine-eligible children enrolled with a history of MIS-C and 70 with history of COVID-19, 51 (31%) and 34 (49%), respectively, received mRNA COVID-19 vaccine a median of 10 (Interquartile Range 6-13) months after hospital discharge. Among 20 children with MIS-C and parents/guardians who provided interviews, local injection site reaction of brief duration (mean 1.8 days) was most commonly reported; no children required medical care within 2 weeks postvaccination. Vaccine survey results of interviewed, vaccinated children and their parents/guardians: of 20 children with MIS-C and 15 children with COVID-19, 17 (85%) and 13 (87%), respectively, listed doctors in the top 3 most trusted sources for vaccine information; 13 (65%) and 9 (60%) discussed vaccination with their doctor. CONCLUSIONS: COVID-19 vaccination was well tolerated in children with prior MIS-C or COVID-19 participating in our investigation. Parents/guardians regarded their children's doctors as a trusted source of information for COVID-19 vaccines, and most vaccinated children's parents/guardians had discussed COVID-19 vaccination for their child with their doctor. |
The relationship between ferritin and BMI is mediated by inflammation among women in higher-income countries, but not in most lower-income countries nor among young children: A multi-country analysis
Davis JN , Williams A , Arnold CD , Rohner F , Wirth JP , Addo Y , Flores-Ayala RC , Oaks BM , Young MF , Suchdev PS , Engle-Stone R . Curr Dev Nutr 2022 6 (10) nzac139 BACKGROUND: In the presence of inflammation, the serum or plasma ferritin concentration ("ferritin" hereafter) transiently increases, confounding its interpretation as an iron status marker. The extent to which adiposity-related inflammation may influence ferritin interpretation is uncertain. OBJECTIVES: We describe relationships between weight status, inflammation, and ferritin among nonpregnant women of reproductive age (WRA; 15-49 years) and preschool-age children (PSC; 6-59 months) with normal weight to overweight or obesity (OWOB) in differing geographic settings. METHODS: Cross-sectional data were separately analyzed from 18 surveys (WRA) and 25 surveys (PSC) from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project, excluding observations with underweight, wasting, pregnancy, or malaria. Relationships were assessed between BMI (in WRA) or BMI-for-age z-score (BAZ; in PSC), inflammatory biomarkers of C-reactive protein (CRP) and/or α-1-acid glycoprotein (AGP), ferritin by linear regression, and potential mediation by CRP and/or AGP in relationships between BMI or BAZ and ferritin with structural equation modeling. Regression and mediation models accounted for complex survey designs. Results were grouped by World Bank income classifications. RESULTS: In 5 of 6 surveys among WRA from upper-middle and high-income countries, ferritin was significantly positively associated with BMI, and this relationship was partially (or fully, in the United States) mediated by CRP and/or AGP. Mediation was present in 4 of 12 surveys for WRA in low- and lower-middle income countries. Among PSC, ferritin was positively associated with CRP and/or AGP in all surveys, but there were no significant CRP- or AGP-mediated relationships between ferritin and BAZ, except a negative relationship in the Philippines. CONCLUSIONS: Where having OWOB is common among WRA, measurements of inflammatory biomarkers and their uses in interpreting ferritin may improve iron status assessments. While these relationships were inconsistent among PSC, inflammation was common and should be measured to interpret iron status. Included Kenyan trial data are registered at clinicaltrials.gov as NCT01088958. |
Effect of biannual mass azithromycin distributions to preschool-aged children on trachoma prevalence in Niger: A cluster randomized clinical trial
Arzika AM , Mindo-Panusis D , Abdou A , Kadri B , Nassirou B , Maliki R , Alsoudi AF , Zhang T , Cotter SY , Lebas E , O'Brien KS , Callahan EK , Bailey RL , West SK , Goodhew EB , Martin DL , Arnold BF , Porco TC , Lietman TM , Keenan JD . JAMA Netw Open 2022 5 (8) e2228244 IMPORTANCE: Because transmission of ocular strains of Chlamydia trachomatis is greatest among preschool-aged children, limiting azithromycin distributions to this age group may conserve resources and result in less antimicrobial resistance, which is a potential advantage in areas with hypoendemic trachoma and limited resources. OBJECTIVE: To determine the efficacy of mass azithromycin distributions to preschool-aged children as a strategy for trachoma elimination in areas with hypoendemic disease. DESIGN, SETTING, AND PARTICIPANTS: In this cluster randomized clinical trial performed from November 23, 2014, until July 31, 2017, thirty rural communities in Niger were randomized at a 1:1 ratio to biannual mass distributions of either azithromycin or placebo to children aged 1 to 59 months. Participants and study personnel were masked to treatment allocation. Data analyses for trachoma outcomes were performed from October 19, 2021, through June 10, 2022. INTERVENTIONS: Every 6 months, a single dose of either oral azithromycin (20 mg/kg using height-based approximation for children who could stand or weight calculation for small children) or oral placebo was provided to all children aged 1 to 59 months. MAIN OUTCOMES AND MEASURES: Trachoma was a prespecified outcome of the trial, assessed as the community-level prevalence of trachomatous inflammation-follicular and trachomatous inflammation-intense through masked grading of conjunctival photographs from a random sample of 40 children per community each year during the 2-year study period. A secondary outcome was the seroprevalence of antibodies to C trachomatis antigens. RESULTS: At baseline, 4726 children in 30 communities were included; 1695 children were enrolled in 15 azithromycin communities and 3031 children were enrolled in 15 placebo communities (mean [SD] proportions of boys, 51.8% [4.7%] vs 52.0% [4.2%]; mean [SD] age, 30.8 [2.8] vs 30.6 [2.6] months). The mean coverage of study drug for the 4 treatments was 79% (95% CI, 75%-83%) in the azithromycin group and 82% (95% CI, 79%-85%) in the placebo group. The mean prevalence of trachomatous inflammation-follicular at baseline was 1.9% (95% CI, 0.5%-3.5%) in the azithromycin group and 0.9% (95% CI, 0-1.9%) in the placebo group. At 24 months, trachomatous inflammation-follicular prevalence was 0.2% (95% CI, 0-0.5%) in the azithromycin group and 0.8% (95% CI, 0.2%-1.6%) in the placebo group (incidence rate ratio adjusted for baseline: 0.18 [95% CI, 0.01-1.20]; permutation P = .07). CONCLUSIONS AND RELEVANCE: The findings of this trial do not show that biannual mass azithromycin distributions to preschool-aged children were more effective than placebo, although the underlying prevalence of trachoma was low. The sustained absence of trachoma even in the placebo group suggests that trachoma may have been eliminated as a public health problem in this part of Niger. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02048007. |
Red blood cell distribution width and pediatric community-acquired pneumonia disease severity
Lee J , Zhu Y , Williams DJ , Self WH , Arnold SR , McCullers JA , Ampofo K , Pavia AT , Anderson EJ , Jain S , Edwards KM , Grijalva CG . Hosp Pediatr 2022 12 (9) 798-805 BACKGROUND AND OBJECTIVES: No standardized risk assessment tool exists for community-acquired pneumonia (CAP) in children. This study aims to investigate the association between red blood cell distribution width (RDW) and pediatric CAP. METHODS: Data prospectively collected by the Etiology of Pneumonia in the Community study (2010-2012) was used. Study population was pediatric patients admitted to tertiary care hospitals in Nashville and Memphis, Tennessee with clinically and radiographically confirmed CAP. The earliest measured RDW value on admission was used, in quintiles and also as a continuous variable. Outcomes analyzed were: severe CAP (requiring ICU, mechanical ventilation, vasopressor support, or death) or moderate CAP (hospital admission only). Analysis used multivariable logistic regression and restricted cubic splines modeling. RESULTS: In 1459 eligible children, the median age was 29 months (interquartile range: 12-73), median RDW was 13.3% (interquartile range: 12.5-14.3), and 289 patients (19.8%) developed severe disease. In comparison with the lowest RDW quintile (Q1), the adjusted odds ratio (95% CI) for severe CAP in subsequent quintiles were, Q2: 1.20 (0.72-1.99); Q3: 1.28 (0.76-2.14); Q4: 1.69 (1.01-2.82); Q5: 1.25 (0.73-2.13). Consistently, RDW restricted cubic splines demonstrated an independent, nonlinear, positive association with CAP severity (P = .027), with rapid increases in the risk of severe CAP with RDW values up to 15%. CONCLUSIONS: Higher presenting RDW was associated with an increased risk of severe CAP in hospitalized children. Widely available and inexpensive, RDW can serve as an objective data point to help with clinical assessments. |
Changes in spina bifida lesion level after folic acid fortification in the United States
Mai CT , Evans J , Alverson CJ , Yue X , Flood T , Arnold K , Nestoridi E , Denson L , Adisa O , Moore CA , Nance A , Zielke K , Rice S , Shan X , Dean JH , Ethen M , Hansen B , Isenburg J , Kirby RS . J Pediatr 2022 249 59-66 e1 OBJECTIVE: To assess whether the severity of cases of spina bifida changed after mandatory folic acid fortification in the United States. STUDY DESIGN: Six active population-based birth defects programs provided data on cases of spina bifida for 1992-1996 (pre-fortification) and 1999-2016 (post-fortification); programs contributed varying years of data. Case information included both medical record verbatim text description of the spina bifida diagnosis and spina bifida codes (International Classification of Diseases, Clinical Modification, or a modified birth defects surveillance coding system). Comparing pre- with post-fortification periods, adjusted odds ratios (aOR) for case severity [upper-level (cervical, thoracic) to lower-level (lumbar, sacral) lesion cases] and prevalence ratios (PR) were estimated. RESULTS: A total of 2,593 cases of spina bifida (7,816,062 live births) met inclusion criteria, with 573 and 2,020 cases from the pre- and post-fortification periods respectively. Case severity decreased 70% (aOR: 0.30; 95% confidence interval [CI] 0.26, 0.35) between the fortification periods. The decrease was most pronounced for non-Hispanic white mothers. Overall spina bifida prevalence declined 23% (PR=0.77, 95% CI=0.71, 0.85), with similar reduction seen across early, mid, and recent post-fortification periods. A statistically significant decrease in upper-level lesions occurred in the post-fortification compared with pre-fortification periods (PR=0.28, 95% CI=0.22, 0.34), while prevalence of lower-level lesions remained relatively similar (PR: 0.94, 95% CI: 0.84, 1.05). CONCLUSIONS: Severity of cases of spina bifida decreased after mandatory folic acid fortification in the United States. Further examination is warranted to understand better the potential effect of folic acid on spina bifida severity. |
Comparison of product safety data sheet ingredient lists with skin irritants and sensitizers present in a convenience sample of light-curing resins used in additive manufacturing
Bowers LN , Ranpara AC , Roach KA , Knepp AK , Arnold ED , Stefaniak AB , Virji MA . Regul Toxicol Pharmacol 2022 133 105198 Material jetting and vat photopolymerization additive manufacturing (AM) processes use liquid resins to build objects. These resins can contain skin irritants and/or sensitizers but product safety data sheets (SDSs) might not declare all ingredients. We characterized elemental and organic skin irritants and sensitizers present in 39 commercial products; evaluated the influence of resin manufacturer, system, color, and AM process type on the presence of irritants and sensitizers; and compared product SDSs to results. Among all products, analyses identified 23 irritant elements, 54 irritant organic substances, 22 sensitizing elements, and 23 sensitizing organic substances; SDSs listed 3, 9, 4, and 6 of these ingredients, respectively. Per product, the number and total mass (an indicator of potential dermal loading) of ingredients varied: five to 17 irritant elements (8.32-4756.65mg/kg), one to 17 irritant organics (3273 to 356,000mg/kg), four to 17 sensitizing elements (8.27-4755.63mg/kg), and one to seven sensitizing organics (15-382,170mg/kg). Median numbers and concentrations of irritants and sensitizers were significantly influenced by resin system and AM process type. The presence of undeclared irritants and sensitizers in these resins supports the need for more complete information on product SDSs for comprehensive dermal risk assessments. |
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