Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Sebastian V [original query] |
---|
Key population size estimation to guide HIV epidemic responses in Nigeria: Bayesian analysis of 3-source capture-recapture data
McIntyre AF , Mitchell A , Stafford KA , Nwafor SU , Lo J , Sebastian V , Schwitters A , Swaminathan M , Dalhatu I , Charurat M . JMIR Public Health Surveill 2022 8 (10) e34555 BACKGROUND: Nigeria has the fourth largest burden of HIV globally. Key populations, including female sex workers, men who have sex with men, and people who inject drugs, are more vulnerable to HIV than the general population due to stigmatized and criminalized behaviors. Reliable key population size estimates are needed to guide HIV epidemic response efforts. OBJECTIVE: The objective of our study was to use empirical methods for sampling and analysis to improve the quality of population size estimates of female sex workers, men who have sex with men, and people who inject drugs in 7 states (Akwa Ibom, Benue, Cross River, Lagos, Nasarawa, Rivers, and the Federal Capital Territory) of Nigeria for program planning and to demonstrate improved statistical estimation methods. METHODS: From October to December 2018, we used 3-source capture-recapture to produce population size estimates in 7 states in Nigeria. Hotspots were mapped before 3-source capture-recapture started. We sampled female sex workers, men who have sex with men, and people who inject drugs during 3 independent captures about one week apart. During hotspot encounters, key population members were offered inexpensive, memorable objects unique to each capture round. In subsequent rounds, key population members were offered an object and asked to identify objects received during previous rounds (if any). Correct responses were tallied and recorded on tablets. Data were aggregated by key population and state for analysis. Median population size estimates were derived using Bayesian nonparametric latent-class models with 80% highest density intervals. RESULTS: Overall, we sampled approximately 310,000 persons at 9015 hotspots during 3 independent captures. Population size estimates for female sex workers ranged from 14,500 to 64,300; population size estimates for men who have sex with men ranged from 3200 to 41,400; and population size estimates for people who inject drugs ranged from 3400 to 30,400. CONCLUSIONS: This was the first implementation of these 3-source capture-recapture methods in Nigeria. Our population size estimates were larger than previously documented for each key population in all states. The Bayesian models account for factors, such as social visibility, that influence heterogeneous capture probabilities, resulting in more reliable population size estimates. The larger population size estimates suggest a need for programmatic scale-up to reach these populations, which are at highest risk for HIV. |
Computable guidelines and clinical decision support for cervical cancer screening and management to improve outcomes and health equity
Saraiya M , Colbert J , Bhat GL , Almonte R , Winters DW , Sebastian S , O'Hanlon M , Meadows G , Nosal MR , Richards TB , Michaels M , Townsend JS , Miller JW , Perkins RB , Sawaya GF , Wentzensen N , White MC , Richardson LC . J Womens Health (Larchmt) 2022 31 (4) 462-468 Cervical cancer is highly preventable when precancerous lesions are detected early and appropriately managed. However, the complexity of and frequent updates to existing evidence-based clinical guidelines make it challenging for clinicians to stay abreast of the latest recommendations. In addition, limited availability and accessibility to information technology (IT) decision supports make it difficult for groups who are medically underserved to receive screening or receive the appropriate follow-up care. The Centers for Disease Control and Prevention (CDC), Division of Cancer Prevention and Control (DCPC), is leading a multiyear initiative to develop computer-interpretable ("computable") version of already existing evidence-based guidelines to support clinician awareness and adoption of the most up-to-date cervical cancer screening and management guidelines. DCPC is collaborating with the MITRE Corporation, leading scientists from the National Cancer Institute, and other CDC subject matter experts to translate existing narrative guidelines into computable format and develop clinical decision support tools for integration into health IT systems such as electronic health records with the ultimate goal of improving patient outcomes and decreasing disparities in cervical cancer outcomes among populations that are medically underserved. This initiative meets the challenges and opportunities highlighted by the President's Cancer Panel and the President's Cancer Moonshot 2.0 to nearly eliminate cervical cancer. |
SARS-CoV-2 Variants of Interest and Concern naming scheme conducive for global discourse.
Konings F , Perkins MD , Kuhn JH , Pallen MJ , Alm EJ , Archer BN , Barakat A , Bedford T , Bhiman JN , Caly L , Carter LL , Cullinane A , de Oliveira T , Druce J , El Masry I , Evans R , Gao GF , Gorbalenya AE , Hamblion E , Herring BL , Hodcroft E , Holmes EC , Kakkar M , Khare S , Koopmans MPG , Korber B , Leite J , MacCannell D , Marklewitz M , Maurer-Stroh S , Rico JAM , Munster VJ , Neher R , Munnink BO , Pavlin BI , Peiris M , Poon L , Pybus O , Rambaut A , Resende P , Subissi L , Thiel V , Tong S , van der Werf S , von Gottberg A , Ziebuhr J , Van Kerkhove MD . Nat Microbiol 2021 6 (7) 821-823 A group convened and led by the Virus Evolution Working Group of the World Health Organization reports on its deliberations and announces a naming scheme that will enable clear communication about SARS-CoV-2 variants of interest and concern. | | Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has a linear, unsegmented, positive-sense RNA genome. As with all viruses, SARS-CoV-2 continuously adapts to changing environments in real time via random genome mutations that are subject to natural selection. Most mutations are neutral or detrimental to the virus; however, a small number of mutations may provide a selective advantage, such as escape from the host immune system or resistance to antiviral drugs. Such mutations may also lead to increased fitness for transmissibility. As mutated forms of viruses or variants spread from person to person, they will eventually be detected at the population level. |
Trends in Racial and Ethnic Disparities in COVID-19 Hospitalizations, by Region - United States, March-December 2020.
Romano SD , Blackstock AJ , Taylor EV , El Burai Felix S , Adjei S , Singleton CM , Fuld J , Bruce BB , Boehmer TK . MMWR Morb Mortal Wkly Rep 2021 70 (15) 560-565 Persons from racial and ethnic minority groups are disproportionately affected by COVID-19, including experiencing increased risk for infection (1), hospitalization (2,3), and death (4,5). Using administrative discharge data, CDC assessed monthly trends in the proportion of hospitalized patients with COVID-19 among racial and ethnic groups in the United States during March-December 2020 by U.S. Census region. Cumulative and monthly age-adjusted COVID-19 proportionate hospitalization ratios (aPHRs) were calculated for racial and ethnic minority patients relative to non-Hispanic White patients. Within each of the four U.S. Census regions, the cumulative aPHR was highest for Hispanic or Latino patients (range = 2.7-3.9). Racial and ethnic disparities in COVID-19 hospitalization were largest during May-July 2020; the peak monthly aPHR among Hispanic or Latino patients was >9.0 in the West and Midwest, >6.0 in the South, and >3.0 in the Northeast. The aPHRs declined for most racial and ethnic groups during July-November 2020 but increased for some racial and ethnic groups in some regions during December. Disparities in COVID-19 hospitalization by race/ethnicity varied by region and became less pronounced over the course of the pandemic, as COVID-19 hospitalizations increased among non-Hispanic White persons. Identification of specific social determinants of health that contribute to geographic and temporal differences in racial and ethnic disparities at the local level can help guide tailored public health prevention strategies and equitable allocation of resources, including COVID-19 vaccination, to address COVID-19-related health disparities and can inform approaches to achieve greater health equity during future public health threats. |
Key population hotspots in Nigeria for targeted HIV program planning: Mapping, validation, and reconciliation
Lo J , Nwafor SU , Schwitters AM , Mitchell A , Sebastian V , Stafford KA , Ezirim I , Charurat M , McIntyre AF . JMIR Public Health Surveill 2021 7 (2) e25623 BACKGROUND: With the fourth highest HIV burden globally, Nigeria is characterized as having a mixed HIV epidemic with high HIV prevalence among key populations, including female sex workers, men who have sex with men, and people who inject drugs. Reliable and accurate mapping of key population hotspots is necessary for strategic placement of services and allocation of limited resources for targeted interventions. OBJECTIVE: We aimed to map and develop a profile for the hotspots of female sex workers, men who have sex with men, and people who inject drugs in 7 states of Nigeria to inform HIV prevention and service programs and in preparation for a multiple-source capture-recapture population size estimation effort. METHODS: In August 2018, 261 trained data collectors from 36 key population-led community-based organizations mapped, validated, and profiled hotspots identified during the formative assessment in 7 priority states in Nigeria designated by the United States President's Emergency Plan for AIDS Relief. Hotspots were defined as physical venues wherein key population members frequent to socialize, seek clients, or engage in key population-defining behaviors. Hotspots were visited by data collectors, and each hotspot's name, local government area, address, type, geographic coordinates, peak times of activity, and estimated number of key population members was recorded. The number of key population hotspots per local government area was tabulated from the final list of hotspots. RESULTS: A total of 13,899 key population hotspots were identified and mapped in the 7 states, that is, 1297 in Akwa Ibom, 1714 in Benue, 2666 in Cross River, 2974 in Lagos, 1550 in Nasarawa, 2494 in Rivers, and 1204 in Federal Capital Territory. The most common hotspots were those frequented by female sex workers (9593/13,899, 69.0%), followed by people who inject drugs (2729/13,899, 19.6%) and men who have sex with men (1577/13,899, 11.3%). Although hotspots were identified in all local government areas visited, more hotspots were found in metropolitan local government areas and state capitals. CONCLUSIONS: The number of key population hotspots identified in this study is more than that previously reported in similar studies in Nigeria. Close collaboration with key population-led community-based organizations facilitated identification of many new and previously undocumented key population hotspots in the 7 states. The smaller number of hotspots of men who have sex with men than that of female sex workers and that of people who inject drugs may reflect the social pressure and stigma faced by this population since the enforcement of the 2014 Same Sex Marriage (Prohibition) Act, which prohibits engaging in intimate same-sex relationships, organizing meetings of gays, or patronizing gay businesses. |
Nigeria's public health response to the COVID-19 pandemic: January to May 2020.
Dan-Nwafor C , Ochu CL , Elimian K , Oladejo J , Ilori E , Umeokonkwo C , Steinhardt L , Igumbor E , Wagai J , Okwor T , Aderinola O , Mba N , Hassan A , Dalhat M , Jinadu K , Badaru S , Arinze C , Jafiya A , Disu Y , Saleh F , Abubakar A , Obiekea C , Yinka-Ogunleye A , Naidoo D , Namara G , Muhammad S , Ipadeola O , Ofoegbunam C , Ogunbode O , Akatobi C , Alagi M , Yashe R , Crawford E , Okunromade O , Aniaku E , Mba S , Agogo E , Olugbile M , Eneh C , Ahumibe A , Nwachukwu W , Ibekwe P , Adejoro OO , Ukponu W , Olayinka A , Okudo I , Aruna O , Yusuf F , Alex-Okoh M , Fawole T , Alaka A , Muntari H , Yennan S , Atteh R , Balogun M , Waziri N , Ogunniyi A , Ebhodaghe B , Lokossou V , Abudulaziz M , Adebiyi B , Abayomi A , Abudus-Salam I , Omilabu S , Lawal L , Kawu M , Muhammad B , Tsanyawa A , Soyinka F , Coker T , Alabi O , Joannis T , Dalhatu I , Swaminathan M , Salako B , Abubakar I , Fiona B , Nguku P , Aliyu SH , Ihekweazu C . J Glob Health 2020 10 (2) 020399 The novel coronavirus disease 2019, COVID-19, which is caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2) [1] was first reported in December 2019 by Chinese Health Authorities following an outbreak of pneumonia of unknown origin in Wuhan, Hubei Province [2,3]. SARS-CoV-2 is likely of zoonotic origin, similar to SARS and Middle East Respiratory Syndrome (MERS), and transmitted between humans through respiratory droplets and fomites. Since its emergence, it has rapidly spread globally [4]. |
Top food category contributors to sodium and potassium intake - United States, 2015-2016
Woodruff RC , Zhao L , Ahuja JKC , Gillespie C , Goldman J , Harris DM , Jackson SL , Moshfegh A , Rhodes D , Sebastian RS , Terry A , Cogswell ME . MMWR Morb Mortal Wkly Rep 2020 69 (32) 1064-1069 Most U.S. adults consume too much sodium and not enough potassium (1,2). For apparently healthy U.S. adults aged ≥19 years, guidelines recommend reducing sodium intake that exceeds 2,300 mg/day and consuming at least 3,400 mg/day of potassium for males and at least 2,600 mg/day for females* (1). Reducing population-level sodium intake can reduce blood pressure and prevent cardiovascular diseases, the leading causes of death in the United States (1,3). Adequate potassium intake might offset the hypertensive effects of excessive sodium intake (1). Data from the 2015-2016 What We Eat in America (WWEIA) dietary interview component of the National Health and Nutrition Examination Survey (NHANES)(†) were analyzed to identify top food categories contributing to sodium and potassium intake for U.S. residents aged ≥1 year. During 2015-2016, 40% of sodium consumed came from the top 10 food categories, which included prepared foods with sodium added (e.g., deli meat sandwiches and pizza). Approximately 43% of potassium consumed was from 10 food categories, which included foods naturally low in sodium (e.g., unflavored milk, fruit, vegetables) and prepared foods. These results can inform efforts to encourage consumption of foods naturally low in sodium, which might have the dual benefit of reducing sodium intake and increasing potassium intake, contributing to cardiovascular disease prevention. |
Probabilistic reconstruction of measles transmission clusters from routinely collected surveillance data.
Robert A , Kucharski AJ , Gastanaduy PA , Paul P , Funk S . J R Soc Interface 2020 17 (168) 20200084 Pockets of susceptibility resulting from spatial or social heterogeneity in vaccine coverage can drive measles outbreaks, as cases imported into such pockets are likely to cause further transmission and lead to large transmission clusters. Characterizing the dynamics of transmission is essential for identifying which individuals and regions might be most at risk. As data from detailed contact-tracing investigations are not available in many settings, we developed an R package called o2geosocial to reconstruct the transmission clusters and the importation status of the cases from their age, location, genotype and onset date. We compared our inferred cluster size distributions to 737 transmission clusters identified through detailed contact-tracing in the USA between 2001 and 2016. We were able to reconstruct the importation status of the cases and found good agreement between the inferred and reference clusters. The results were improved when the contact-tracing investigations were used to set the importation status before running the model. Spatial heterogeneity in vaccine coverage is difficult to measure directly. Our approach was able to highlight areas with potential for local transmission using a minimal number of variables and could be applied to assess the intensity of ongoing transmission in a region. |
Influenza passaging annotations: what they tell us and why we should listen.
DuPai CD , McWhite CD , Smith CB , Garten R , Maurer-Stroh S , Wilke CO . Virus Evol 2019 5 (1) vez016 Influenza databases now contain over 100,000 worldwide sequence records for strains influenza A(H3N2) and A(H1N1). Although these data facilitate global research efforts and vaccine development practices, they also represent a stumbling block for researchers because of their confusing and heterogeneous annotation. Unclear passaging annotations are particularly concerning given the recent work highlighting the presence and risk of false adaptation signals introduced by cell passaging of viral isolates. With this in mind, we aim to provide a concise outline of why viruses are passaged, a clear overview of passaging annotation nomenclature currently in use, and suggestions for a standardized nomenclature going forward. Our hope is that this summary will empower researchers and clinicians alike to more easily understand a virus sample's passage history when analyzing influenza sequences. |
National health information systems for achieving the Sustainable Development Goals
Suthar AB , Khalifa A , Joos O , Manders EJ , Abdul-Quader A , Amoyaw F , Aoua C , Aynalem G , Barradas D , Bello G , Bonilla L , Cheyip M , Dalhatu IT , De Klerk M , Dee J , Hedje J , Jahun I , Jantaramanee S , Kamocha S , Lerebours L , Lobognon LR , Lote N , Lubala L , Magazani A , Mdodo R , Mgomella GS , Monique LA , Mudenda M , Mushi J , Mutenda N , Nicoue A , Ngalamulume RG , Ndjakani Y , Nguyen TA , Nzelu CE , Ofosu AA , Pinini Z , Ramirez E , Sebastian V , Simanovong B , Son HT , Son VH , Swaminathan M , Sivile S , Teeraratkul A , Temu P , West C , Xaymounvong D , Yamba A , Yoka D , Zhu H , Ransom RL , Nichols E , Murrill CS , Rosen D , Hladik W . BMJ Open 2019 9 (5) e027689 OBJECTIVES: Achieving the Sustainable Development Goals will require data-driven public health action. There are limited publications on national health information systems that continuously generate health data. Given the need to develop these systems, we summarised their current status in low-income and middle-income countries. SETTING: The survey team jointly developed a questionnaire covering policy, planning, legislation and organisation of case reporting, patient monitoring and civil registration and vital statistics (CRVS) systems. From January until May 2017, we administered the questionnaire to key informants in 51 Centers for Disease Control country offices. Countries were aggregated for descriptive analyses in Microsoft Excel. RESULTS: Key informants in 15 countries responded to the questionnaire. Several key informants did not answer all questions, leading to different denominators across questions. The Ministry of Health coordinated case reporting, patient monitoring and CRVS systems in 93% (14/15), 93% (13/14) and 53% (8/15) of responding countries, respectively. Domestic financing supported case reporting, patient monitoring and CRVS systems in 86% (12/14), 75% (9/12) and 92% (11/12) of responding countries, respectively. The most common uses for system-generated data were to guide programme response in 100% (15/15) of countries for case reporting, to calculate service coverage in 92% (12/13) of countries for patient monitoring and to estimate the national burden of disease in 83% (10/12) of countries for CRVS. Systems with an electronic component were being used for case reporting, patient monitoring, birth registration and death registration in 87% (13/15), 92% (11/12), 77% (10/13) and 64% (7/11) of responding countries, respectively. CONCLUSIONS: Most responding countries have a solid foundation for policy, planning, legislation and organisation of health information systems. Further evaluation is needed to assess the quality of data generated from systems. Periodic evaluations may be useful in monitoring progress in strengthening and harmonising these systems over time. |
The phylogeography and incidence of multi-drug resistant typhoid fever in sub-Saharan Africa.
Park SE , Pham DT , Boinett C , Wong VK , Pak GD , Panzner U , Espinoza LMC , von Kalckreuth V , Im J , Schutt-Gerowitt H , Crump JA , Breiman RF , Adu-Sarkodie Y , Owusu-Dabo E , Rakotozandrindrainy R , Soura AB , Aseffa A , Gasmelseed N , Keddy KH , May J , Sow AG , Aaby P , Biggs HM , Hertz JT , Montgomery JM , Cosmas L , Fields B , Sarpong N , Razafindrabe TJL , Raminosoa TM , Kabore LP , Sampo E , Teferi M , Yeshitela B , El Tayeb MA , Sooka A , Meyer CG , Krumkamp R , Dekker DM , Jaeger A , Poppert S , Tall A , Niang A , Bjerregaard-Andersen M , Valborg Løfberg S , Seo HJ , Jeon HJ , Deerin JF , Park J , Konings F , Ali M , Clemens JD , Hughes P , Sendagala JN , Vudriko T , Downing R , Ikumapayi UN , Mackenzie GA , Obaro S , Argimon S , Aanensen DM , Page A , Keane JA , Duchene S , Dyson Z , Holt KE , Dougan G , Marks F , Baker S . Nat Commun 2018 9 (1) 5094 There is paucity of data regarding the geographical distribution, incidence, and phylogenetics of multi-drug resistant (MDR) Salmonella Typhi in sub-Saharan Africa. Here we present a phylogenetic reconstruction of whole genome sequenced 249 contemporaneous S. Typhi isolated between 2008-2015 in 11 sub-Saharan African countries, in context of the 2,057 global S. Typhi genomic framework. Despite the broad genetic diversity, the majority of organisms (225/249; 90%) belong to only three genotypes, 4.3.1 (H58) (99/249; 40%), 3.1.1 (97/249; 39%), and 2.3.2 (29/249; 12%). Genotypes 4.3.1 and 3.1.1 are confined within East and West Africa, respectively. MDR phenotype is found in over 50% of organisms restricted within these dominant genotypes. High incidences of MDR S. Typhi are calculated in locations with a high burden of typhoid, specifically in children aged <15 years. Antimicrobial stewardship, MDR surveillance, and the introduction of typhoid conjugate vaccines will be critical for the control of MDR typhoid in Africa. |
Viral factors in influenza pandemic risk assessment.
Lipsitch M , Barclay W , Raman R , Russell CJ , Belser JA , Cobey S , Kasson PM , Lloyd-Smith JO , Maurer-Stroh S , Riley S , Beauchemin CA , Bedford T , Friedrich TC , Handel A , Herfst S , Murcia PR , Roche B , Wilke CO , Russell CA . Elife 2016 5 The threat of an influenza A virus pandemic stems from continual virus spillovers from reservoir species, a tiny fraction of which spark sustained transmission in humans. To date, no pandemic emergence of a new influenza strain has been preceded by detection of a closely related precursor in an animal or human. Nonetheless, influenza surveillance efforts are expanding, prompting a need for tools to assess the pandemic risk posed by a detected virus. The goal would be to use genetic sequence and/or biological assays of viral traits to identify those non-human influenza viruses with the greatest risk of evolving into pandemic threats, and/or to understand drivers of such evolution, to prioritize pandemic prevention or response measures. We describe such efforts, identify progress and ongoing challenges, and discuss three specific traits of influenza viruses (hemagglutinin receptor binding specificity, hemagglutinin pH of activation, and polymerase complex efficiency) that contribute to pandemic risk. |
Outcomes among children enrolled in HIV care in Mozambique 2009-2013
Teasdale CA , Yang J , Thome B , Yersin I , Sebastian T , Brusamento S , Lahuerta M , Jobarteh KM , Abrams EJ . Pediatr Infect Dis J 2016 35 (10) 1117-25 BACKGROUND: Scale-up of HIV care and antiretroviral therapy (ART) services for children has expanded access, but significant gaps and challenges remain. We examined lost to follow-up (LTF) and mortality in a large cohort of children enrolled in HIV care in Mozambique. METHODS: Routinely collected medical data on children 0-14 years enrolled in care 2009-2013 at ICAP-supported health facilities in 5 provinces of Mozambique were used. Children not receiving ART (pre-ART) were considered LTF if they did not a have a visit within 12 months of the end of data collection; for those receiving ART, LTF was no visit within 6 months. Competing risk and Kaplan-Meier estimators were used, respectively, to estimate pre-ART and on ART LTF and mortality. RESULTS: A total of 13,695 children enrolled in HIV care at 64 health facilities (48.6%, <2 years), and 7733 (56.5%) initiated ART during follow-up. Cumulative incidence of pre-ART LTF was 32.9% [95% confidence interval (CI): 32.1-33.7] and 34.4% (95% CI: 33.6-35.2) by 12 and 24 months, respectively, and was highest in children <5 years (12-month LTF in children 2-4 years, 34.2%, 95% CI: 32.6-35.9). Pre-ART mortality at 12 months was 3.3% (95% CI: 3.0-3.6) and was highest in children <2 years (4.1%, 95% CI: 3.6-4.6). On ART, LTF was 28.6% (95% CI: 27.6-29.7) and 37.6 (95% CI: 36.4-38.8) at 12 and 24 months, and 12 months mortality after ART was 8.0% (95% CI: 7.3-8.7). CONCLUSIONS: High rates of LTF were observed in this large cohort of HIV-infected children accessing care in Mozambique both before and after ART initiation highlighting the urgent need for interventions to improve retention in routine care settings. |
Pressure drop of filtering facepiece respirators: how low should we go?
Kim JH , Roberge RJ , Powell JB , Shaffer RE , Ylitalo CM , Sebastian JM . Int J Occup Med Environ Health 2015 28 (1) 71-80 INTRODUCTION: This study was undertaken to determine the mean peak filter resistance to airflow (Rfilter) encountered by subjects while wearing prototype filtering facepiece respirators (PRs) with low Rfilter during nasal and oral breathing at sedentary and low-moderate work rates. MATERIAL AND METHODS: In-line pressure transducer measurements of mean Rfilteracross PRs with nominal Rfilter of 29.4 Pa, 58.8 Pa and 88.2 Pa (measured at 85 l/min constant airflow) were obtained during nasal and oral breathing at sedentary and low-moderate work rates for 10 subjects. RESULTS: The mean Rfilter for the 29.4 PR was significantly lower than the other 2 PRs (p < 0.000), but there were no significant differences in mean Rfilter between the PRs with 58.8 and 88.2 Pa filter resistance (p > 0.05). The mean Rfilter was greater for oral versus nasal breathing and for exercise compared to sedentary activity (p < 0.001). CONCLUSIONS: Mean oral and nasal Rfilter for all 3 PRs was at, or below, the minimal threshold level for detection of inspiratory resistance (the 58.8-74.5 Pa/lxs-1), which may account for the previously-reported lack of significant subjective or physiological differences when wearing PRs with these low Rfilter. Lowering filtering facepiece respirator Rfilter below 88.2 Pa (measured at 85 l/min constant airflow) may not result in additional subjective or physiological benefit to the wearer. |
Isolation and functional characterization of the novel Clostridium botulinum neurotoxin A8 subtype.
Kull S , Schulz KM , Strotmeier JW , Kirchner S , Schreiber T , Bollenbach A , Dabrowski PW , Nitsche A , Kalb SR , Dorner MB , Barr JR , Rummel A , Dorner BG . PLoS One 2015 10 (2) e0116381 Botulism is a severe neurological disease caused by the complex family of botulinum neurotoxins (BoNT). Based on the different serotypes known today, a classification of serotype variants termed subtypes has been proposed according to sequence diversity and immunological properties. However, the relevance of BoNT subtypes is currently not well understood. Here we describe the isolation of a novel Clostridium botulinum strain from a food-borne botulism outbreak near Chemnitz, Germany. Comparison of its botulinum neurotoxin gene sequence with published sequences identified it to be a novel subtype within the BoNT/A serotype designated BoNT/A8. The neurotoxin gene is located within an ha-orfX+ cluster and showed highest homology to BoNT/A1, A2, A5, and A6. Unexpectedly, we found an arginine insertion located in the HC domain of the heavy chain, which is unique compared to all other BoNT/A subtypes known so far. Functional characterization revealed that the binding characteristics to its main neuronal protein receptor SV2C seemed unaffected, whereas binding to membrane-incorporated gangliosides was reduced in comparison to BoNT/A1. Moreover, we found significantly lower enzymatic activity of the natural, full-length neurotoxin and the recombinant light chain of BoNT/A8 compared to BoNT/A1 in different endopeptidase assays. Both reduced ganglioside binding and enzymatic activity may contribute to the considerably lower biological activity of BoNT/A8 as measured in a mouse phrenic nerve hemidiaphragm assay. Despite its reduced activity the novel BoNT/A8 subtype caused severe botulism in a 63-year-old male. To our knowledge, this is the first description and a comprehensive characterization of a novel BoNT/A subtype which combines genetic information on the neurotoxin gene cluster with an in-depth functional analysis using different technical approaches. Our results show that subtyping of BoNT is highly relevant and that understanding of the detailed toxin function might pave the way for the development of novel therapeutics and tailor-made antitoxins. |
Improving pandemic influenza risk assessment.
Russell CA , Kasson PM , Donis RO , Riley S , Dunbar J , Rambaut A , Asher J , Burke S , Davis CT , Garten RJ , Gnanakaran S , Hay SI , Herfst S , Lewis NS , Lloyd-Smith JO , Macken CA , Maurer-Stroh S , Neuhaus E , Parrish CR , Pepin KM , Shepard SS , Smith DL , Suarez DL , Trock SC , Widdowson MA , George DB , Lipsitch M , Bloom JD . Elife 2014 3 e03883 Assessing the pandemic risk posed by specific non-human influenza A viruses is an important goal in public health research. As influenza virus genome sequencing becomes cheaper, faster, and more readily available, the ability to predict pandemic potential from sequence data could transform pandemic influenza risk assessment capabilities. However, the complexities of the relationships between virus genotype and phenotype make such predictions extremely difficult. The integration of experimental work, computational tool development, and analysis of evolutionary pathways, together with refinements to influenza surveillance, has the potential to transform our ability to assess the risks posed to humans by non-human influenza viruses and lead to improved pandemic preparedness and response. |
Assessment of potential zoonotic disease exposure and illness related to an annual bat festival - Idanre, Nigeria
Vora NM , Osinubi M , Wallace RM , Aman-Oloniyo A , Gbadegesin YH , Sebastian YK , Saliman OA , Niezgoda M , Davis L , Recuenco S . MMWR Morb Mortal Wkly Rep 2014 63 (15) 334 Bats provide vital ecologic services that humans benefit from, such as seed dispersal and pest control, and are a food source for some human populations. However, bats also are reservoirs for a number of high-consequence zoonoses, including paramyxoviruses, filoviruses, and lyssaviruses. The variety of viruses that bats harbor might be related to their evolutionary diversity, ability to fly large distances, long lifespans, and gregarious roosting behaviors. Every year a festival takes place in Idanre, Nigeria, in which males of all ages enter designated caves to capture bats; persons are forbidden from entering the caves outside of these festivities. Festival participants use a variety of techniques to capture bats, but protective equipment rarely is used, placing hunters at risk for bat scratches and bites. Many captured bats are prepared as food, but some are transported to markets in other parts of the country for sale as bushmeat. Bats also are presented to dignitaries in elaborate rituals. The health consequences of contact with these bats are unknown, but a number of viruses have been previously identified among Nigerian bats, including lyssaviruses, pegiviruses, and coronaviruses. Furthermore, the caves are home to Rousettus aegyptiacus bats, which are reservoirs for Marburg virus in other parts of Africa. |
Impact of low filter resistances on subjective and physiological responses to filtering facepiece respirators
Roberge RJ , Kim JH , Powell JB , Shaffer RE , Ylitalo CM , Sebastian JM . PLoS One 2013 8 (12) e84901 Ten subjects underwent treadmill exercise at 5.6 km/h over one hour while wearing each of three identical appearing, cup-shaped, prototype filtering facepiece respirators that differed only in their filter resistances (3 mm, 6 mm, and 9 mm H2O pressure drop). There were no statistically significant differences between filtering facepiece respirators with respect to impact on physiological parameters (i.e., heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide levels, tympanic membrane temperature), pulmonary function variables (i.e., tidal volume, respiratory rate, volume of carbon dioxide production, oxygen consumption, or ventilation), and subjective ratings (i.e., exertion, thermal comfort, inspiratory effort, expiratory effort and overall breathing comfort). The nominal filter resistances of the prototype filtering facepiece respirators correspond to airflow resistances ranging from 2.1 - 6.6 mm H2O/L/s which are less than, or minimally equivalent to, previously reported values for the normal threshold for detection of inspiratory breathing resistance (6 - 7.6 mm H2O/L/sec). Therefore, filtering facepiece respirators with filter resistances at, or below, this level may not impact the wearer differently physiologically or subjectively from those with filter resistances only slightly above this threshold at low-moderate work rates over one hour. |
Genome sequences for five strains of the emerging pathogen Haemophilus haemolyticus.
Jordan IK , Conley AB , Antonov IV , Arthur RA , Cook ED , Cooper GP , Jones BL , Knipe KM , Lee KJ , Liu X , Mitchell GJ , Pande PR , Petit RA , Qin S , Rajan VN , Sarda S , Sebastian A , Tang S , Thapliyal R , Varghese NJ , Ye T , Katz LS , Wang X , Rowe L , Frace M , Mayer LW . J Bacteriol 2011 193 (20) 5879-80 We report the first whole-genome sequences for five strains, two carried and three pathogenic, of the emerging pathogen Haemophilus haemolyticus. Preliminary analyses indicate that these genome sequences encode markers that distinguish H. haemolyticus from its closest Haemophilus relatives and provide clues to the identity of its virulence factors. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 29, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure