Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
Records 1-30 (of 92 Records) |
Query Trace: Herman K[original query] |
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Impact of malaria diagnostic choice on monitoring of Plasmodium falciparum prevalence estimates in the Democratic Republic of the Congo and relevance to control programs in high-burden countries
Diallo AO , Banek K , Kashamuka MM , Bala JAM , Nkalani M , Kihuma G , Nseka TM , Atibu JL , Mahilu GE , McCormick L , White SJ , Sendor R , Sinai C , Keeler C , Herman C , Emch M , Sompwe E , Thwai KL , Dinglasan RR , Rogier E , Juliano JJ , Tshefu AK , Parr JB . PLOS Glob Public Health 2023 3 (7) e0001375 Malaria programs rely upon a variety of diagnostic assays, including rapid diagnostic tests (RDTs), microscopy, polymerase chain reaction (PCR), and bead-based immunoassays (BBA), to monitor malaria prevalence and support control and elimination efforts. Data comparing these assays are limited, especially from high-burden countries like the Democratic Republic of the Congo (DRC). Using cross-sectional and routine data, we compared diagnostic performance and Plasmodium falciparum prevalence estimates across health areas of varying transmission intensity to illustrate the relevance of assay performance to malaria control programs. Data and samples were collected between March-June 2018 during a cross-sectional household survey across three health areas with low, moderate, and high transmission intensities within Kinshasa Province, DRC. Samples from 1,431 participants were evaluated using RDT, microscopy, PCR, and BBA. P. falciparum parasite prevalence varied between diagnostic methods across all health areas, with the highest prevalence estimates observed in Bu (57.4-72.4% across assays), followed by Kimpoko (32.6-53.2%), and Voix du Peuple (3.1-8.4%). Using latent class analysis to compare these diagnostic methods against an "alloyed gold standard," the most sensitive diagnostic method was BBA in Bu (high prevalence) and Voix du Peuple (low prevalence), while PCR diagnosis was most sensitive in Kimpoko (moderate prevalence). RDTs were consistently the most specific diagnostic method in all health areas. Among 9.0 million people residing in Kinshasa Province in 2018, the estimated P. falciparum prevalence by microscopy, PCR, and BBA were nearly double that of RDT. Comparison of malaria RDT, microscopy, PCR, and BBA results confirmed differences in sensitivity and specificity that varied by endemicity, with PCR and BBA performing best for detecting any P. falciparum infection. Prevalence estimates varied widely depending on assay type for parasite detection. Inherent differences in assay performance should be carefully considered when using community survey and surveillance data to guide policy decisions. |
The effect of COVID-19 pandemic on healthcare seeking in an urban informal settlement in Nairobi and a rural setting in western Kenya
Agogo GO , Munywoki PK , Audi A , Auko J , Aol G , Oduor C , Kiplangat S , Ouma A , Komo T , Herman-Roloff A , Munyua P , Bigogo G . PLOS Glob Public Health 2024 4 (4) e0002968 The COVID-19 pandemic caused widespread changes and disruptions to healthcare seeking behavior. There are limited studies on the effect of the COVID-19 pandemic on healthcare seeking patterns in low-and middle-income countries (LMICs), especially in settings with inequitable access to healthcare in rural and urban informal settlements. We investigated the effect of the COVID-19 pandemic on reported healthcare seeking at health facilities and chemists using morbidity data from participants in an ongoing population-based infectious disease surveillance platform in Asembo in Siaya County, a rural setting in western Kenya and Kibera, an urban informal settlement in Nairobi County. We described healthcare seeking patterns before (from 1st January 2016 to 12th March 2020) and during the pandemic (from 13th March 2020 to 31st August 2022) by gender and age for any reported illness and select clinical syndromes using frequencies and percentages. We used a generalized estimating equation with an exchangeable correlation structure to assess the effect of the pandemic on healthcare seeking adjusting for gender and age. Overall, there was a 19% (adjusted odds ratio, aOR: 0.81; 95% Confidence Interval, CI: 0.79-0.83) decline in odds of seeking healthcare at health facilities for any illness in Asembo during the pandemic, and a 30% (aOR: 0.70; 95% CI: 0.67-0.73) decline in Kibera. Similarly, there was a decline in seeking healthcare by clinical syndromes, e.g., for ARI, aOR: 0.76; 95% CI:0.73-0.79 in Asembo, and aOR: 0.68; 95% CI:0.64-0.72 in Kibera. The pandemic resulted in increased healthcare seeking at chemists (aOR: 1.23; 95% CI: 1.20-1.27 in Asembo, and aOR: 1.40; 95% CI: 1.35-1.46 in Kibera). This study highlights interruptions to healthcare seeking in resource-limited settings due to the COVID-19 pandemic. The pandemic resulted in a substantial decline in seeking care at health facilities, and an increase of the same at chemists. |
Mapping the overlap of poverty level and prevalence of diagnosed chronic kidney disease among Medicare beneficiaries in the United States
Han Y , Xu F , Morgenstern H , Bragg-Gresham J , Gillespie BW , Steffick D , Herman WH , Pavkov ME , Veinot T , Saran R . Prev Chronic Dis 2024 21 E23 |
Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions among patients enrolled at 100 health facilities throughout Tanzania: February to July 2021
Rogier E , Battle N , Bakari C , Seth MD , Nace D , Herman C , Barakoti A , Madebe RA , Mandara CI , Lyimo BM , Giesbrecht DJ , Popkin-Hall ZR , Francis F , Mbwambo D , Garimo I , Aaron S , Lusasi A , Molteni F , Njau R , Cunningham JA , Lazaro S , Mohamed A , Juliano JJ , Bailey JA , Udhayakumar V , Ishengoma DS . Sci Rep 2024 14 (1) 8158 Plasmodium falciparum with the histidine rich protein 2 gene (pfhrp2) deleted from its genome can escape diagnosis by HRP2-based rapid diagnostic tests (HRP2-RDTs). The World Health Organization (WHO) recommends switching to a non-HRP2 RDT for P. falciparum clinical case diagnosis when pfhrp2 deletion prevalence causes ≥ 5% of RDTs to return false negative results. Tanzania is a country of heterogenous P. falciparum transmission, with some regions approaching elimination and others at varying levels of control. In concordance with the current recommended WHO pfhrp2 deletion surveillance strategy, 100 health facilities encompassing 10 regions of Tanzania enrolled malaria-suspected patients between February and July 2021. Of 7863 persons of all ages enrolled and providing RDT result and blood sample, 3777 (48.0%) were positive by the national RDT testing for Plasmodium lactate dehydrogenase (pLDH) and/or HRP2. A second RDT testing specifically for the P. falciparum LDH (Pf-pLDH) antigen found 95 persons (2.5% of all RDT positives) were positive, though negative by the national RDT for HRP2, and were selected for pfhrp2 and pfhrp3 (pfhrp2/3) genotyping. Multiplex antigen detection by laboratory bead assay found 135/7847 (1.7%) of all blood samples positive for Plasmodium antigens but very low or no HRP2, and these were selected for genotyping as well. Of the samples selected for genotyping based on RDT or laboratory multiplex result, 158 were P. falciparum DNA positive, and 140 had sufficient DNA to be genotyped for pfhrp2/3. Most of these (125/140) were found to be pfhrp2+/pfhrp3+, with smaller numbers deleted for only pfhrp2 (n = 9) or only pfhrp3 (n = 6). No dual pfhrp2/3 deleted parasites were observed. This survey found that parasites with these gene deletions are rare in Tanzania, and estimated that 0.24% (95% confidence interval: 0.08% to 0.39%) of false-negative HRP2-RDTs for symptomatic persons were due to pfhrp2 deletions in this 2021 Tanzania survey. These data provide evidence for HRP2-based diagnostics as currently accurate for P. falciparum diagnosis in Tanzania. |
Geospatial analysis of Plasmodium falciparum serological indicators: school versus community sampling in a low-transmission malaria setting
Jaramillo-Underwood A , Herman C , Jean SE , Nace D , Elder ES , Robinson K , Knipes A , Worrell CM , Fox LM , Desir L , Fayette C , Javel A , Monestime F , Mace KE , Udhayakumar V , Won KY , Chang MA , Lemoine JF , Rogier E . BMC Med 2024 22 (1) 31 BACKGROUND: Due to low numbers of active infections and persons presenting to health facilities for malaria treatment, case-based surveillance is inefficient for understanding the remaining disease burden in low malaria transmission settings. Serological data through the detection of IgG antibodies from previous malaria parasite exposure can fill this gap by providing a nuanced picture of where sustained transmission remains. Study enrollment at sites of gathering provides a potential approach to spatially estimate malaria exposure and could preclude the need for more intensive community-based sampling. METHODS: This study compared spatial estimates of malaria exposure from cross-sectional school- and community-based sampling in Haiti. A total of 52,405 blood samples were collected from 2012 to 2017. Multiplex bead assays (MBAs) tested IgG against P. falciparum liver stage antigen-1 (LSA-1), apical membrane antigen 1 (AMA1), and merozoite surface protein 1 (MSP1). Predictive geospatial models of seropositivity adjusted for environmental covariates, and results were compared using correlations by coordinate points and communes across Haiti. RESULTS: Consistent directional associations were observed between seroprevalence and environmental covariates for elevation (negative), air temperature (negative), and travel time to urban centers (positive). Spearman's rank correlation for predicted seroprevalence at coordinate points was lowest for LSA-1 (ρ = 0.10, 95% CI: 0.09-0.11), but improved for AMA1 (ρ = 0.36, 95% CI: 0.35-0.37) and MSP1 (ρ = 0.48, 95% CI: 0.47-0.49). CONCLUSIONS: In settings approaching P. falciparum elimination, case-based prevalence data does not provide a resolution of ongoing malaria transmission in the population. Immunogenic antigen targets (e.g., AMA1, MSP1) that give higher population rates of seropositivity provide moderate correlation to gold standard community sampling designs and are a feasible approach to discern foci of residual P. falciparum transmission in an area. |
Kenya's experience implementing event-based surveillance during the COVID-19 pandemic
Ndegwa L , Ngere P , Makayotto L , Patel NN , Nzisa L , Otieno N , Osoro E , Oreri E , Kiptoo E , Maigua S , Crawley A , Clara AW , Arunmozhi Balajee S , Munyua P , Herman-Roloff A . BMJ Glob Health 2023 8 (12) Event-based surveillance (EBS) can be implemented in most settings for the detection of potential health threats by recognition and immediate reporting of predefined signals. Such a system complements existing case-based and sentinel surveillance systems. With the emergence of the COVID-19 pandemic in early 2020, the Kenya Ministry of Health (MOH) modified and expanded an EBS system in both community and health facility settings for the reporting of COVID-19-related signals. Using an electronic reporting tool, m-Dharura, MOH recorded 8790 signals reported, with 3002 (34.2%) verified as events, across both community and health facility sites from March 2020 to June 2021. A subsequent evaluation found that the EBS system was flexible enough to incorporate the addition of COVID-19-related signals during a pandemic and maintain high rates of reporting from participants. Inadequate resources for follow-up investigations to reported events, lack of supportive supervision for some community health volunteers and lack of data system interoperability were identified as challenges to be addressed as the EBS system in Kenya continues to expand to additional jurisdictions. |
Estimating county-level vaccination coverage using small area estimation with the National Immunization Survey-Child
Seeskin ZH , Ganesh N , Maitra P , Herman P , Wolter KM , Copeland KR , English N , Chen MP , Singleton JA , Santibanez TA , Yankey D , Elam-Evans LD , Sterrett N , Smith CS , Gipson K , Meador S . Vaccine 2023 The National Immunization Survey-Child (NIS-Child) provides annual vaccination coverage estimates in the United States for children aged 19 through 35 months, nationally, for each state, and for select local areas and territories. There is a need for vaccination coverage estimates for smaller geographic areas to support local authority planning and identify counties with potentially low vaccination coverage for possible further intervention. We describe small area estimation methods using 2008-2018 NIS-Child data to generate county-level estimates for children up to two years of age born 2007-2011 and 2012-2016. We applied an empirical best linear unbiased prediction method to combine direct estimates of vaccination coverage with model-based prediction using county-level predictors regarding health and demographic characteristics. We review the predictors commonly selected for the small area models and note multiple predictors related to barriers to vaccination. |
Heterogenous transmission and seroprevalence of SARS-CoV-2 in two demographically diverse populations with low vaccination uptake in Kenya, March and June 2021
Munywoki PK , Bigogo G , Nasimiyu C , Ouma A , Aol G , Oduor CO , Rono S , Auko J , Agogo GO , Njoroge R , Oketch D , Odhiambo D , Odeyo VW , Kikwai G , Onyango C , Juma B , Hunsperger E , Lidechi S , Ochieng CA , Lo TQ , Munyua P , Herman-Roloff A . Gates Open Res 2023 7 101 BACKGROUND: SARS-CoV-2 has extensively spread in cities and rural communities, and studies are needed to quantify exposure in the population. We report seroprevalence of SARS-CoV-2 in two well-characterized populations in Kenya at two time points. These data inform the design and delivery of public health mitigation measures. METHODS: Leveraging on existing population based infectious disease surveillance (PBIDS) in two demographically diverse settings, a rural site in western Kenya in Asembo, Siaya County, and an urban informal settlement in Kibera, Nairobi County, we set up a longitudinal cohort of randomly selected households with serial sampling of all consenting household members in March and June/July 2021. Both sites included 1,794 and 1,638 participants in the March and June/July 2021, respectively. Individual seroprevalence of SARS-CoV-2 antibodies was expressed as a percentage of the seropositive among the individuals tested, accounting for household clustering and weighted by the PBIDS age and sex distribution. RESULTS: Overall weighted individual seroprevalence increased from 56.2% (95%CI: 52.1, 60.2%) in March 2021 to 63.9% (95%CI: 59.5, 68.0%) in June 2021 in Kibera. For Asembo, the seroprevalence almost doubled from 26.0% (95%CI: 22.4, 30.0%) in March 2021 to 48.7% (95%CI: 44.3, 53.2%) in July 2021. Seroprevalence was highly heterogeneous by age and geography in these populations-higher seroprevalence was observed in the urban informal settlement (compared to the rural setting), and children aged <10 years had the lowest seroprevalence in both sites. Only 1.2% and 1.6% of the study participants reported receipt of at least one dose of the COVID-19 vaccine by the second round of serosurvey-none by the first round. CONCLUSIONS: In these two populations, SARS-CoV-2 seroprevalence increased in the first 16 months of the COVID-19 pandemic in Kenya. It is important to prioritize additional mitigation measures, such as vaccine distribution, in crowded and low socioeconomic settings. |
Estimating excess mortality during the COVID-19 pandemic from a population-based infectious disease surveillance in two diverse populations in Kenya, March 2020-December 2021
Oduor C , Audi A , Kiplangat S , Auko J , Ouma A , Aol G , Nasimiyu C , Agogo GO , Lo T , Munyua P , Herman-Roloff A , Bigogo G , Munywoki PK . PLOS Glob Public Health 2023 3 (8) e0002141 Robust data on the impact of the COVID-19 pandemic on mortality in Africa are relatively scarce. Using data from two well-characterized populations in Kenya we aimed to estimate excess mortality during the COVID-19 pandemic period. The mortality data arise from an ongoing population-based infectious disease surveillance (PBIDS) platform, which has been operational since 2006 in rural western Kenya (Asembo, Siaya County) and an urban informal settlement (Kibera, Nairobi County), Kenya. PBIDS participants were regularly visited at home (2-3 times a year) by field workers who collected demographic data, including deaths. In addition, verbal autopsy (VA) interviews for all identified deaths are conducted. We estimated all-cause and cause-specific mortality rates before and during the height of the COVID-19 pandemic, and we compared associated mortality rates between the periods using incidence rate ratios. Excess deaths during the COVID-19 period were also estimated by modelling expected deaths in the absence of COVID-19 by applying a negative binomial regression model on historical mortality data from January 2016. Overall and monthly excess deaths were determined using the P-score metric. Spearman correlation was used to assess whether there is a relationship between the generated P-score and COVID-19 positivity rate. The all-cause mortality rate was higher during the COVID-19 period compared to the pre-COVID-19 period in Asembo [9.1 (95% CI, 8.2-10.0) vs. 7.8 (95% CI, 7.3-8.3) per 1000 person-years of observation, pyo]. In Kibera, the all-cause mortality rate was slightly lower during the COVID-19 period compared to the pre-COVID-19 period [2.6 (95% CI, 2.2-3.2 per 1000 pyo) vs. 3.1; 95% CI, 2.7-3.4 per 1000 pyo)]. An increase in all-cause mortality was observed (incidence rate ratio, IRR, 1.16; 95% CI, 1.04-1.31) in Asembo, unlike in Kibera (IRR, 0.88; 95% CI, 0.71-1.09). The notable increase in mortality rate in Asembo was observed among persons aged 50 to 64 years (IRR, 2.62; 95% CI, 1.95-3.52), persons aged 65 years and above (5.47; 95% CI, 4.60-6.50) and among females (IRR, 1.25; 95% CI, 1.07-1.46). These age and gender differences were not observed in Kibera. We observed an increase in the mortality rate due to acute respiratory infection, including pneumonia (IRR, 1.45;95% CI, 1.03-2.04), and a reduction in the mortality rate due to pulmonary tuberculosis (IRR, 0.22; 95% CI, 0.05-0.87) among older children and adults in Asembo. There was no statistically significant change in mortality rates due to leading specific causes of death in Kibera. Overall, during the COVID-19 period observed deaths were higher than expected deaths in Asembo (P-score = 6.0%) and lower than expected in Kibera (P-score = -22.3%).Using well-characterized populations in the two diverse geographic locations, we demonstrate a heterogenous impact of the COVID-19 pandemic on all-cause and cause-specific mortality rates in Kenya. We observed more deaths than expected during the COVID-19 period in our rural site in western Kenya contrary to the urban site in Nairobi, the capital city in Kenya. |
Community-based surveys for Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions in selected regions of mainland Tanzania (preprint)
Bakari C , Jones S , Subramaniam G , Mandara CI , Chiduo MG , Rumisha S , Chacky F , Molteni F , Mandike R , Mkude S , Njau R , Herman C , Nace DP , Mohamed A , Udhayakumar V , Kibet CK , Nyanjom SG , Rogier E , Ishengoma DS . medRxiv 2020 2020.05.12.20097766 Background Despite recent reports of false negative results among histidine-rich protein 2 (HRP2) based-malaria rapid diagnostic tests (mRDTs) caused by pfhrp2/3 gene deletions in different countries, there is paucity of data in Tanzania.Methods This study assessed the status of pfhrp2/3 deletions in 7,543 blood samples using laboratory multiplex antigen detection (Plasmodium lactate dehydrogenase - pLDH, aldolase, and HRP2). Samples showing mRDT false negativity or aberrant relationship of HRP2 to pan-Plasmodium antigens were genotyped for pfhrp2/3genes.Results Of all samples, 2,417 (32.0%) were positive for any Plasmodium antigens while 5,126 (68.0%) were negative. About 99.8% (n=2,411) of antigen positive samples had HRP2, but 6 (0.2%) had only pLDH and/or pAldolase. Thirteen samples had atypical relationships between pan-Plasmodium antigens and HRP2, but were positive by PCR. An additional 16 samples with negative HRP2 mRDTs but positive by microscopy were also chosen; all giving 35 samples genotyped for pfhrp2/3. Of 35 samples, 4 (11.4%) failed to consistently amplify positive control genes (pfmsp1 and pfmsp2), and pfhrp2 and pfhrp3 genes were successfully amplified in 31 (88.6%) samples.Conclusions Lack of pfhrp2 and/or pfhrp3 genes deletions in Plasmodium falciparum parasites supports continued use of HRP2-based mRDTs for routine malaria diagnosis in Tanzania.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThe field component of this study was supported by The Global Fund through National Malaria Control Programme of the Tanzanian Ministry of Health. The CDC laboratory work was supported by Malaria Branch and Catherine Bakari’s MSc studies was funded by the Developing Excellence in Leadership and Genomics for Malaria Elimination (DELGEME) project with funding from the Developing Excellence in Leadership and Training (DELTAS) Africa Initiative, of the African Academy of Sciences (AAS).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.YesThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request |
Anti-inflammatory SARS-CoV-2 T cell immunity in asymptomatic seronegative Kenyan adults (preprint)
Samandari T , Ongalo J , McCarthy K , Biegon RK , Madiega P , Mithika A , Orinda J , Mboya GM , Mwaura P , Anzala O , Onyango C , Oluoch FO , Osoro E , Dutertre CA , Tan N , Hang SK , Hariharaputran S , Lye DC , Herman-Roloff A , Le Bert N , Bertoletti A . medRxiv 2023 18 Antibodies are used to estimate prevalence of past infection. However, T cell responses against SARSCoV-2 may more accurately define prevalence because SARS-CoV-2-specific antibodies wane. In November-December 2021, we studied serological and cellular immune responses in residents of rural Kenya who had not experienced any respiratory symptom nor had contact with COVID-19 cases. Among participants we detected anti-spike antibodies in 41.0% and T cell responses against >=2 SARSCoV-2 proteins in 82.5%, which implies that serosurveys underestimate SARS-CoV-2 prevalence in settings where asymptomatic infections prevail. Distinct from cellular immunity in European and Asian COVID-19 convalescents, strong T cell immunogenicity was observed against viral accessory proteins in these asymptomatic Africans, as well as a higher IL-10/IFN-gamma ratio cytokine profile, suggesting that environmental or genetic factors modulate pro-inflammatory responses. 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. |
Transmission of SARS-CoV-2 in standardised first few X cases and household transmission investigations: A systematic review and meta-analysis
Lewis HC , Marcato AJ , Meagher N , Valenciano M , Villanueva-Cabezas JP , Spirkoska V , Fielding JE , Karahalios A , Subissi L , Nardone A , Cheng B , Rajatonirina S , Okeibunor J , Aly EA , Barakat A , Jorgensen P , Azim T , Wijesinghe PR , Le LV , Rodriguez A , Vicari A , Van Kerkhove M , McVernon J , Pebody R , Price DJ , Bergeri I , Alemu MA , Alvi Y , Bukusi EA , Chung PS , Dambadarjaa D , Das AK , Dub T , Dulacha D , Ebrahim F , Gonzalez-Duarte MA , Guruge D , Heredia-Melo DC , Herman-Roloff A , Herring BL , Islam F , Jeewandara KC , Kant S , Lako R , Leite J , Malavige GN , Mandakh U , Mariam W , Mend T , Mize VA , Musa S , Nohynek H , Olu OO , Osorio-Merchan MB , Pereyaslov D , Ransom J , Ariqi LA , Khan W , Saxena S , Sharma P , Sreedevi A , Satheesh M , Subhashini KJ , Tippet-Barr BA , Usha A , Wamala JF , Watare SH , Yadav K , Inbanathan FY . Influenza Other Respir Viruses 2022 16 (5) 803-819 Abstract We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for “Unity-aligned” First Few X cases (FFX) and HHTIs published 1 December 2019 to 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review; 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2% to 90% (95% prediction interval: 3%–71%; I2 = 99.7%); I2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses. |
Transmission of SARS-CoV-2 in standardised First Few X cases and household transmission investigations: a systematic review and meta-analysis (preprint)
Lewis HC , Marcato AJ , Meagher N , Valenciano M , Villanueva-Cabezas JP , Spirkoska V , Fielding JE , Karahalios A , Subissi L , Nardone A , Cheng B , Rajatonirina S , Okeibunor J , Aly EA , Barakat A , Jorgensen P , Azim T , Wijesinghe PR , Le LV , Rodriguez A , Vicari A , Van Kerkhove M , McVernon J , Pebody R , Price DJ , Bergeri I , Alemu MA , Alvi Y , Bukusi EA , Chung PS , Dambadarjaa D , Das AK , Dub T , Dulacha D , Ebrahim F , Gonzalez-Duarte MA , Guruge D , Heredia-Melo DC , Herman-Roloff A , Herring BL , Islam F , Jeewandara KC , Kant S , Lako R , Leite J , Malavige GN , Mandakh U , Mariam W , Mend T , Mize VA , Musa S , Nohynek H , Olu OO , Osorio-Merchan MB , Pereyaslov D , Ransom J , Ariqi LA , Khan W , Saxena S , Sharma P , Sreedevi A , Satheesh M , Subhashini KJ , Tippet-Barr BA , Usha A , Wamala JF , Watare SH , Yadav K , Inbanathan FY . medRxiv 2022 03 (5) 803-819 We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies Household Transmission Investigations (HHTI) protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for 'Unity-aligned' First Few X cases (FFX) and HHTIs published between 1 December 2019 and 26 July 2021. Standardised early results were shared by WHO Unity Studies collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases; 16 provided by Unity Studies collaborators) were retained in the systematic review and 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2%-90% (95% prediction interval: 3%-71%; I2=99.7%); I2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. FFX and HHTI remain critical epidemiological tools for early and ongoing characterisation of novel infectious pathogens. The large, unexplained variance in hSAR estimates emphasises the need to further support standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs in time and place, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses. 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. |
Prevalence and functional profile of SARS-CoV-2 T cells in asymptomatic Kenyan adults
Samandari T , Ongalo J , McCarthy K , Biegon RK , Madiega P , Mithika A , Orinda J , Mboya GM , Mwaura P , Anzala O , Onyango C , Oluoch FO , Osoro EM , Dutertre CA , Tan N , Hang SK , Hariharaputran S , Lye DC , Herman-Roloff A , Le Bert N , Bertoletti A . J Clin Invest 2023 133 (13) BACKGROUND: SARS-CoV-2 infection in Africa has been characterized by less severe disease than elsewhere but the profile of SARS-CoV-2 specific adaptive immunity in this largely asymptomatic spread has not been studied. METHODS: We collected blood and nasopharyngeal samples from rural Kenyans (n=80) without respiratory symptoms since 2019, had no contact with COVID-19 cases or received COVID-19 vaccines and were negative for current SARS-CoV-2 infection. We analyzed spike-specific antibodies and T cells specific for SARS-CoV-2 structural (membrane, nucleocapsid and spike) and accessory (ORF3a, ORF7, ORF8) proteins. Pre-pandemic samples collected in urban Nairobi, Kenya (n=13) between 2015-2016 and samples of mild-moderately symptomatic COVID-19 convalescents (n=36) living in the urban environment of Singapore were also studied. RESULTS: Among asymptomatic Kenyans, we detected anti-spike antibodies in 41.0% and T cell responses against ≥2 SARS-CoV-2 proteins in 82.5%. The pre-pandemic samples from Nairobi had low-level, monospecific responses. Furthermore, distinct from cellular immunity in European and Asian COVID-19 convalescents, strong T cell immunogenicity was observed against viral accessory proteins (ORF3a, ORF8) and not structural proteins, as well as a higher IL-10/IFN-γ ratio cytokine profile. CONCLUSIONS: The high incidence of T cell responses against different SARS-CoV-2 proteins in largely seronegative participants suggests that serosurveys underestimate SARS-CoV-2 prevalence in settings where asymptomatic infections prevail. Similar observations have been made with other coronavirus infections such as MERS and SARS-CoV-1. The functional and antigen-specific profile of SARS-CoV-2 specific T cells in these African individuals suggests that genetic or environmental factors play a role in the development of protective antiviral immunity. FUNDINGS: U.S. Centers for Disease Control and Prevention, Division of Global Health Protection; the Singapore Ministry of Health's National Medical Research Council. |
Acceptability, feasibility, drug safety, and effectiveness of a pilot mass drug administration with a single round of sulfadoxine-pyrimethamine plus primaquine and indoor residual spraying in communities with malaria transmission in Haiti, 2018
Chang MA , Impoinvil D , Hamre KES , Dalexis PE , Mérilien JB , Dismer AM , Fouché B , Desir L , Holmes K , Lafortune W , Herman C , Rogier E , Noland GS , Young AJ , Druetz T , Ashton R , Eisele TP , Cohen J , van den Hoogen L , Stresman G , Drakeley C , Pothin E , Cameron E , Battle KE , Williamson J , Telfort MA , Lemoine JF . Am J Trop Med Hyg 2023 108 (6) 1127-1139 For a malaria elimination strategy, Haiti's National Malaria Control Program piloted a mass drug administration (MDA) with indoor residual spraying (IRS) in 12 high-transmission areas across five communes after implementing community case management and strengthened surveillance. The MDA distributed sulfadoxine-pyrimethamine and single low-dose primaquine to eligible residents during house visits. The IRS campaign applied pirimiphos-methyl insecticide on walls of eligible houses. Pre- and post-campaign cross-sectional surveys were conducted to assess acceptability, feasibility, drug safety, and effectiveness of the combined interventions. Stated acceptability for MDA before the campaign was 99.2%; MDA coverage estimated at 10 weeks post-campaign was 89.6%. Similarly, stated acceptability of IRS at baseline was 99.9%; however, household IRS coverage was 48.9% because of the high number of ineligible houses. Effectiveness measured by Plasmodium falciparum prevalence at baseline and 10 weeks post-campaign were similar: 1.31% versus 1.43%, respectively. Prevalence of serological markers were similar at 10 weeks post-campaign compared with baseline, and increased at 6 months. No severe adverse events associated with the MDA were identified in the pilot; there were severe adverse events in a separate, subsequent campaign. Both MDA and IRS are acceptable and feasible interventions in Haiti. Although a significant impact of a single round of MDA/IRS on malaria transmission was not found using a standard pre- and post-intervention comparison, it is possible there was blunting of the peak transmission. Seasonal malaria transmission patterns, suboptimal IRS coverage, and low baseline parasitemia may have limited the effectiveness or the ability to measure effectiveness. |
Diabetes care barriers, use, and health outcomes in younger adults with type 1 and type 2 diabetes
Pihoker C , Braffett BH , Songer TJ , Herman WH , Tung M , Kuo S , Bellatorre A , Isganaitis E , Jensen ET , Divers J , Zhang P , Nathan DM , Drews K , Dabelea D , Zeitler PS . JAMA Netw Open 2023 6 (5) e2312147 IMPORTANCE: Treatment challenges exist for younger adults with type 1 (T1D) and type 2 diabetes (T2D). Health care coverage, access to, and use of diabetes care are not well delineated in these high-risk populations. OBJECTIVE: To compare patterns of health care coverage, access to, and use of diabetes care and determine their associations with glycemia among younger adults with T1D and with T2D. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed data from a survey that was jointly developed by 2 large, national cohort studies: the SEARCH for Diabetes in Youth (SEARCH) study, an observational study of individuals with youth-onset T1D or T2D, and the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study, a randomized clinical trial (2004-2011) followed by an observational study (2012-2020). The interviewer-directed survey was administered during in-person study visits in both studies between 2017 and 2019. Data analyses were performed between May 2021 and October 2022. MAIN OUTCOMES AND MEASURES: Survey questions addressed health care coverage, usual sources of diabetes care, and frequency of care use. Glycated hemoglobin (HbA1c) levels were assayed in a central laboratory. Patterns of health care factors and HbA1c levels were compared by diabetes type. RESULTS: The analysis included 1371 participants (mean [range] age, 25 [18-36] years; 824 females [60.1%]), of whom 661 had T1D and 250 had T2D from the SEARCH study and 460 had T2D from the TODAY study. Participants had a mean (SD) diabetes duration of 11.8 (2.8) years. More participants with T1D than T2D in both the SEARCH and TODAY studies reported health care coverage (94.7%, 81.6%, and 86.7%), access to diabetes care (94.7%, 78.1%, and 73.4%), and use of diabetes care (88.1%, 80.5%, and 73.6%). Not having health care coverage was associated with significantly higher mean (SE) HbA1c levels in participants with T1D in the SEARCH study (no coverage, 10.8% [0.5%]; public, 9.4% [0.2%]; private, 8.7% [0.1%]; P < .001) and participants with T2D from the TODAY study (no coverage, 9.9% [0.3%]; public, 8.7% [0.2%]; private, 8.7% [0.2%]; P = .004). Medicaid expansion vs without expansion was associated with more health care coverage (participants with T1D: 95.8% vs 90.2%; participants with T2D in SEARCH: 86.1% vs 73.9%; participants with T2D in TODAY: 93.6% vs 74.2%) and lower HbA1c levels (participants with T1D: 9.2% vs 9.7%; participants with T2D in SEARCH: 8.4% vs 9.3%; participants with T2D in TODAY: 8.7% vs 9.3%). The T1D group incurred higher median (IQR) monthly out-of-pocket expenses than the T2D group ($74.50 [$10.00-$309.00] vs $10.00 [$0-$74.50]). CONCLUSIONS AND RELEVANCE: Results of this study suggested that lack of health care coverage and of an established source of diabetes care were associated with significantly higher HbA1c levels for participants with T1D, but inconsistent results were found for participants with T2D. Increased access to diabetes care (eg, through Medicaid expansion) may be associated with improved health outcomes, but additional strategies are needed, particularly for individuals with T2D. |
Seroprevalence and risk factors of SARS-CoV-2 infection in an urban informal settlement in Nairobi, Kenya, December 2020 (preprint)
Munywoki PK , Nasimiyu C , Alando MD , Otieno N , Ombok C , Njoroge R , Kikwai G , Odhiambo D , Osita MP , Ouma A , Odour C , Juma B , Ochieng CA , Mutisya I , Ngere I , Dawa J , Osoro E , Njenga MK , Bigogo G , Munyua P , Lo TQ , Hunsperger E , Herman-Roloff A . F1000Res 2021 10 853 Introduction: Urban informal settlements may be disproportionately affected by the COVID-19 pandemic due to overcrowding and other socioeconomic challenges that make adoption and implementation of public health mitigation measures difficult. We conducted a seroprevalence survey in the Kibera informal settlement, Nairobi, Kenya, to determine the extent of SARS-CoV-2 infection. Methods: Members of randomly selected households from an existing population-based infectious disease surveillance (PBIDS) provided blood specimens between 27 (th) November and 5 (th) December 2020. The specimens were tested for antibodies to the SARS-CoV-2 spike protein. Seroprevalence estimates were weighted by age and sex distribution of the PBIDS population and accounted for household clustering. Multivariable logistic regression was used to identify risk factors for individual seropositivity. Results: Consent was obtained from 523 individuals in 175 households, yielding 511 serum specimens that were tested. The overall weighted seroprevalence was 43.3% (95% CI, 37.4 - 49.5%) and did not vary by sex. Of the sampled households, 122(69.7%) had at least one seropositive individual. The individual seroprevalence increased by age from 7.6% (95% CI, 2.4 - 21.3%) among children (<5 years), 32.7% (95% CI, 22.9 - 44.4%) among children 5 - 9 years, 41.8% (95% CI, 33.0 - 51.1%) for those 10-19 years, and 54.9%(46.2 - 63.3%) for adults (≥20 years). Relative to those from medium-sized households (3 and 4 individuals), participants from large (≥5 persons) households had significantly increased odds of being seropositive, aOR, 1.98(95% CI, 1.17 - 1.58), while those from small-sized households (≤2 individuals) had increased odds but not statistically significant, aOR, 2.31 (95% CI, 0.93 - 5.74). Conclusion: In densely populated urban settings, close to half of the individuals had an infection to SARS-CoV-2 after eight months of the COVID-19 pandemic in Kenya. This highlights the importance to prioritize mitigation measures, including COVID-19 vaccine distribution, in the crowded, low socioeconomic settings. |
A Public Health Research Agenda for Managing Infodemics: Methods and Results of the First WHO Infodemiology Conference.
Calleja N , AbdAllah A , Abad N , Ahmed N , Albarracin D , Altieri E , Anoko JN , Arcos R , Azlan AA , Bayer J , Bechmann A , Bezbaruah S , Briand SC , Brooks I , Bucci LM , Burzo S , Czerniak C , De Domenico M , Dunn AG , Ecker UKH , Espinosa L , Francois C , Gradon K , Gruzd A , Gülgün BS , Haydarov R , Hurley C , Astuti SI , Ishizumi A , Johnson N , Johnson Restrepo D , Kajimoto M , Koyuncu A , Kulkarni S , Lamichhane J , Lewis R , Mahajan A , Mandil A , McAweeney E , Messer M , Moy W , Ndumbi Ngamala P , Nguyen T , Nunn M , Omer SB , Pagliari C , Patel P , Phuong L , Prybylski D , Rashidian A , Rempel E , Rubinelli S , Sacco P , Schneider A , Shu K , Smith M , Sufehmi H , Tangcharoensathien V , Terry R , Thacker N , Trewinnard T , Turner S , Tworek H , Uakkas S , Vraga E , Wardle C , Wasserman H , Wilhelm E , Würz A , Yau B , Zhou L , Purnat TD . JMIR Infodemiology 2021 1 (1) e30979 BACKGROUND: An infodemic is an overflow of information of varying quality that surges across digital and physical environments during an acute public health event. It leads to confusion, risk-taking, and behaviors that can harm health and lead to erosion of trust in health authorities and public health responses. Owing to the global scale and high stakes of the health emergency, responding to the infodemic related to the pandemic is particularly urgent. Building on diverse research disciplines and expanding the discipline of infodemiology, more evidence-based interventions are needed to design infodemic management interventions and tools and implement them by health emergency responders. OBJECTIVE: The World Health Organization organized the first global infodemiology conference, entirely online, during June and July 2020, with a follow-up process from August to October 2020, to review current multidisciplinary evidence, interventions, and practices that can be applied to the COVID-19 infodemic response. This resulted in the creation of a public health research agenda for managing infodemics. METHODS: As part of the conference, a structured expert judgment synthesis method was used to formulate a public health research agenda. A total of 110 participants represented diverse scientific disciplines from over 35 countries and global public health implementing partners. The conference used a laddered discussion sprint methodology by rotating participant teams, and a managed follow-up process was used to assemble a research agenda based on the discussion and structured expert feedback. This resulted in a five-workstream frame of the research agenda for infodemic management and 166 suggested research questions. The participants then ranked the questions for feasibility and expected public health impact. The expert consensus was summarized in a public health research agenda that included a list of priority research questions. RESULTS: The public health research agenda for infodemic management has five workstreams: (1) measuring and continuously monitoring the impact of infodemics during health emergencies; (2) detecting signals and understanding the spread and risk of infodemics; (3) responding and deploying interventions that mitigate and protect against infodemics and their harmful effects; (4) evaluating infodemic interventions and strengthening the resilience of individuals and communities to infodemics; and (5) promoting the development, adaptation, and application of interventions and toolkits for infodemic management. Each workstream identifies research questions and highlights 49 high priority research questions. CONCLUSIONS: Public health authorities need to develop, validate, implement, and adapt tools and interventions for managing infodemics in acute public health events in ways that are appropriate for their countries and contexts. Infodemiology provides a scientific foundation to make this possible. This research agenda proposes a structured framework for targeted investment for the scientific community, policy makers, implementing organizations, and other stakeholders to consider. |
Non-falciparum malaria infection and IgG seroprevalence among children under 15 years in Nigeria, 2018
Herman C , Leonard CM , Uhomoibhi P , Maire M , Moss D , Inyang U , Abubakar A , Ogunniyi A , Mba N , Greby SM , Okoye MI , Iriemenam NC , Maikore I , Steinhardt L , Rogier E . Nat Commun 2023 14 (1) 1360 Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples (n = 31,234) were collected from children aged 0-14 years during a 2018 nationwide HIV survey and assayed for Plasmodium antigenemia, Plasmodium DNA, and IgG against Plasmodium MSP1-19 antigens. Of all children, 6.6% were estimated to have Pm infection and 1.4% Po infection with no Pv infections detected. The highest household wealth quintile was strongly protective against infection with Pm (aOR: 0.11, 95% CI: 0.05-0.22) or Po (aOR= 0.01, 0.00-0.10). Overall Pm seroprevalence was 34.2% (95% CI: 33.3-35.2) with lower estimates for Po (12.1%, 11.6-12.5) and Pv (6.3%, 6.0-6.7). Pm seropositivity was detected throughout the country with several local government areas showing >50% seroprevalence. Serological and DNA indicators show widespread exposure of Nigerian children to Pm with lower rates to Po and Pv. |
Adopting World Health Organization Multimodal Infection Prevention and Control Strategies to Respond to COVID-19, Kenya
Kimani D , Ndegwa L , Njeru M , Wesangula E , Mboya F , Macharia C , Oliech J , Weyenga H , Owiso G , Irungu K , Luvsansharav UO , Herman-Roloff A . Emerg Infect Dis 2022 28 (13) S247-s254 The World Health Organization advocates a multimodal approach to improving infection prevention and control (IPC) measures, which Kenya adopted in response to the COVID-19 pandemic. The Kenya Ministry of Health formed a national IPC committee for policy and technical leadership, coordination, communication, and training. During March-November 2020, a total of 69,892 of 121,500 (57.5%) healthcare workers were trained on IPC. Facility readiness assessments were conducted in 777 health facilities using a standard tool assessing 16 domains. A mean score was calculated for each domain across all facilities. Only 3 domains met the minimum threshold of 80%. The Ministry of Health maintained a national list of all laboratory-confirmed SARS-CoV-2 infections. By December 2020, a total of 3,039 healthcare workers were confirmed to be SARS-CoV-2-positive, an infection rate (56/100,000 workers) 12 times higher than in the general population. Facility assessments and healthcare workers' infection data provided information to guide IPC improvements. |
Incorporating COVID-19 into acute febrile illness surveillance systems, Belize, Kenya, Ethiopia, Peru, and Liberia, 2020-2021
Shih DC , Silver R , Henao OL , Alemu A , Audi A , Bigogo G , Colston JM , Edu-Quansah EP , Erickson TA , Gashu A , Gbelee GB Jr , Gunter SM , Kosek MN , Logan GG , Mackey JM , Maliga A , Manzanero R , Morazan G , Morey F , Munoz FM , Murray KO , Nelson TV , Olortegui MP , Yori PP , Ronca SE , Schiaffino F , Tayachew A , Tedasse M , Wossen M , Allen DR , Angra P , Balish A , Farron M , Guerra M , Herman-Roloff A , Hicks VJ , Hunsperger E , Kazazian L , Mikoleit M , Munyua P , Munywoki PK , Namwase AS , Onyango CO , Park M , Peruski LF , Sugerman DE , Gutierrez EZ , Cohen AL . Emerg Infect Dis 2022 28 (13) S34-s41 Existing acute febrile illness (AFI) surveillance systems can be leveraged to identify and characterize emerging pathogens, such as SARS-CoV-2, which causes COVID-19. The US Centers for Disease Control and Prevention collaborated with ministries of health and implementing partners in Belize, Ethiopia, Kenya, Liberia, and Peru to adapt AFI surveillance systems to generate COVID-19 response information. Staff at sentinel sites collected epidemiologic data from persons meeting AFI criteria and specimens for SARS-CoV-2 testing. A total of 5,501 patients with AFI were enrolled during March 2020-October 2021; >69% underwent SARS-CoV-2 testing. Percentage positivity for SARS-CoV-2 ranged from 4% (87/2,151, Kenya) to 19% (22/115, Ethiopia). We show SARS-CoV-2 testing was successfully integrated into AFI surveillance in 5 low- to middle-income countries to detect COVID-19 within AFI care-seeking populations. AFI surveillance systems can be used to build capacity to detect and respond to both emerging and endemic infectious disease threats. |
The National Clinical Care Commission Report to Congress: Recommendations to better leverage federal policies and programs to prevent and control diabetes
Herman WH , Schillinger D , Bolen S , Boltri JM , Bullock A , Chong W , Conlin PR , Cook JW , Dokun A , Fukagawa N , Gonzalvo J , Greenlee MC , Hawkins M , Idzik S , Leake E , Linder B , Lopata AM , Schumacher P , Shell D , Strogatz D , Towne J , Tracer H , Wu S . Diabetes Care 2023 46 (2) 255-261 The National Clinical Care Commission (NCCC) was established by Congress to make recommendations to leverage federal policies and programs to more effectively prevent and treat diabetes and its complications. The NCCC developed a guiding framework that incorporated elements of the Socioecological and Chronic Care Models. It surveyed federal agencies and conducted follow-up meetings with representatives from 10 health-related and 11 non-health-related federal agencies. It held 12 public meetings, solicited public comments, met with numerous interested parties and key informants, and performed comprehensive literature reviews. The final report, transmitted to Congress in January 2022, contained 39 specific recommendations, including 3 foundational recommendations that addressed the necessity of an all-of-government approach to diabetes, health equity, and access to health care. At the general population level, the NCCC recommended that the federal government adopt a health-in-all-policies approach so that the activities of non-health-related federal agencies that address agriculture, food, housing, transportation, commerce, and the environment be coordinated with those of health-related federal agencies to affirmatively address the social and environmental conditions that contribute to diabetes and its complications. For individuals at risk for type 2 diabetes, including those with prediabetes, the NCCC recommended that federal policies and programs be strengthened to increase awareness of prediabetes and the availability of, referral to, and insurance coverage for intensive lifestyle interventions for diabetes prevention and that data be assembled to seek approval of metformin for diabetes prevention. For people with diabetes and its complications, the NCCC recommended that barriers to proven effective treatments for diabetes and its complications be removed, the size and competence of the workforce to treat diabetes and its complications be increased, and new payment models be implemented to support access to lifesaving medications and proven effective treatments for diabetes and its complications. The NCCC also outlined an ambitious research agenda. The NCCC strongly encourages the public to support these recommendations and Congress to take swift action. |
The National Clinical Care Commission Report to Congress: Leveraging federal policies and programs to prevent diabetes in people with prediabetes
Boltri JM , Tracer H , Strogatz D , Idzik S , Schumacher P , Fukagawa N , Leake E , Powell C , Shell D , Wu S , Herman WH . Diabetes Care 2023 46 (2) e39-e50 Individuals with an elevated fasting glucose level, elevated glucose level after glucose challenge, or elevated hemoglobin A1c level below the diagnostic threshold for diabetes (collectively termed prediabetes) are at increased risk for type 2 diabetes. More than one-third of U.S. adults have prediabetes but fewer than one in five are aware of the diagnosis. Rigorous scientific research has demonstrated the efficacy of both intensive lifestyle interventions and metformin in delaying or preventing progression from prediabetes to type 2 diabetes. The National Clinical Care Commission (NCCC) was a federal advisory committee charged with evaluating and making recommendations to improve federal programs related to the prevention of diabetes and its complications. In this article, we describe the recommendations of an NCCC subcommittee that focused primarily on prevention of type 2 diabetes in people with prediabetes. These recommendations aim to improve current federal diabetes prevention activities by 1) increasing awareness of and diagnosis of prediabetes on a population basis; 2) increasing the availability of, referral to, and insurance coverage for the National Diabetes Prevention Program and the Medicare Diabetes Prevention Program; 3) facilitating Food and Drug Administration review and approval of metformin for diabetes prevention; and 4) supporting research to enhance the effectiveness of diabetes prevention. Cognizant of the burden of type 1 diabetes, the recommendations also highlight the importance of research to advance our understanding of the etiology of and opportunities for prevention of type 1 diabetes. |
Diagnostic accuracy of the Panbio COVID-19 antigen rapid test device for SARS-CoV-2 detection in Kenya, 2021: A field evaluation
Irungu JK , Munyua P , Ochieng C , Juma B , Amoth P , Kuria F , Kiiru J , Makayotto L , Abade A , Bulterys M , Hunsperger E , Emukule GO , Onyango C , Samandari T , Barr BAT , Akelo V , Weyenga H , Munywoki PK , Bigogo G , Otieno NA , Kisivuli JA , Ochieng E , Nyaga R , Hull N , Herman-Roloff A , Aman R . PLoS One 2023 18 (1) e0277657 BACKGROUND: Accurate and timely diagnosis is essential in limiting the spread of SARS-CoV-2 infection. The reference standard, rRT-PCR, requires specialized laboratories, costly reagents, and a long turnaround time. Antigen RDTs provide a feasible alternative to rRT-PCR since they are quick, relatively inexpensive, and do not require a laboratory. The WHO requires that Ag RDTs have a sensitivity ≥80% and specificity ≥97%. METHODS: This evaluation was conducted at 11 health facilities in Kenya between March and July 2021. We enrolled persons of any age with respiratory symptoms and asymptomatic contacts of confirmed COVID-19 cases. We collected demographic and clinical information and two nasopharyngeal specimens from each participant for Ag RDT testing and rRT-PCR. We calculated the diagnostic performance of the Panbio™ Ag RDT against the US Centers for Disease Control and Prevention's (CDC) rRT-PCR test. RESULTS: We evaluated the Ag RDT in 2,245 individuals where 551 (24.5%, 95% CI: 22.8-26.3%) tested positive by rRT-PCR. Overall sensitivity of the Ag RDT was 46.6% (95% CI: 42.4-50.9%), specificity 98.5% (95% CI: 97.8-99.0%), PPV 90.8% (95% CI: 86.8-93.9%) and NPV 85.0% (95% CI: 83.4-86.6%). Among symptomatic individuals, sensitivity was 60.6% (95% CI: 54.3-66.7%) and specificity was 98.1% (95% CI: 96.7-99.0%). Among asymptomatic individuals, sensitivity was 34.7% (95% CI 29.3-40.4%) and specificity was 98.7% (95% CI: 97.8-99.3%). In persons with onset of symptoms <5 days (594/876, 67.8%), sensitivity was 67.1% (95% CI: 59.2-74.3%), and 53.3% (95% CI: 40.0-66.3%) among those with onset of symptoms >7 days (157/876, 17.9%). The highest sensitivity was 87.0% (95% CI: 80.9-91.8%) in symptomatic individuals with cycle threshold (Ct) values ≤30. CONCLUSION: The overall sensitivity and NPV of the Panbio™ Ag RDT were much lower than expected. The specificity of the Ag RDT was high and satisfactory; therefore, a positive result may not require confirmation by rRT-PCR. The kit may be useful as a rapid screening tool only for symptomatic patients in high-risk settings with limited access to rRT-PCR. A negative result should be interpreted based on clinical and epidemiological information and may require retesting by rRT-PCR. |
Adapting Longstanding Public Health Collaborations between Government of Kenya and CDC Kenya in Response to the COVID-19 Pandemic, 2020-2021.
Herman-Roloff A , Aman R , Samandari T , Kasera K , Emukule GO , Amoth P , Chen TH , Kisivuli J , Weyenga H , Hunsperger E , Onyango C , Juma B , Munyua P , Wako D , Akelo V , Kimanga D , Ndegwa L , Mohamed AA , Okello P , Kariuki S , DeCock KM , Bulterys M . Emerg Infect Dis 2022 28 (13) S159-s167 Kenya's Ministry of Health (MOH) and the US Centers for Disease Control and Prevention in Kenya (CDC Kenya) have maintained a 40-year partnership during which measures were implemented to prevent, detect, and respond to disease threats. During the COVID-19 pandemic, the MOH and CDC Kenya rapidly responded to mitigate disease impact on Kenya's 52 million residents. We describe activities undertaken jointly by the MOH and CDC Kenya that lessened the effects of COVID-19 during 5 epidemic waves from March through December 2021. Activities included establishing national and county-level emergency operations centers and implementing workforce development and deployment, infection prevention and control training, laboratory diagnostic advancement, enhanced surveillance, and information management. The COVID-19 pandemic provided fresh impetus for the government of Kenya to establish a national public health institute, launched in January 2022, to consolidate its public health activities and counter COVID-19 and future infectious, vaccine-preventable, and emerging zoonotic diseases. |
Improving water, sanitation, and hygiene (WASH), with a focus on hand hygiene, globally for community mitigation of COVID-19
Berendes D , Martinsen A , Lozier M , Rajasingham A , Medley A , Osborne T , Trinies V , Schweitzer R , Prentice-Mott G , Pratt C , Murphy J , Craig C , Lamorde M , Kesande M , Tusabe F , Mwaki A , Eleveld A , Odhiambo A , Ngere I , Kariuki Njenga M , Cordon-Rosales C , Contreras APG , Call D , Ramay BM , Ramm RES , Paulino CJT , Schnorr CD , Aubin M , Dumas D , Murray KO , Bivens N , Ly A , Hawes E , Maliga A , Morazan GH , Manzanero R , Morey F , Maes P , Diallo Y , Ilboudo M , Richemond D , Hattab OE , Oger PY , Matsuhashi A , Nsambi G , Antoine J , Ayebare R , Nakubulwa T , Vosburgh W , Boore A , Herman-Roloff A , Zielinski-Gutierrez E , Handzel T . PLOS Water 2022 1 (6) Continuity of key water, sanitation, and hygiene (WASH) infrastructure and WASH practices-for example, hand hygiene-are among several critical community preventive and mitigation measures to reduce transmission of infectious diseases, including COVID-19 and other respiratory diseases. WASH guidance for COVID-19 prevention may combine existing WASH standards and new COVID-19 guidance. Many existing WASH tools can also be modified for targeted WASH assessments during the COVID-19 pandemic. We partnered with local organizations to develop and deploy tools to assess WASH conditions and practices and subsequently implement, monitor, and evaluate WASH interventions to mitigate COVID-19 in low- and middle-income countries in Latin America and the Caribbean and Africa, focusing on healthcare, community institution, and household settings and hand hygiene specifically. Employing mixed-methods assessments, we observed gaps in access to hand hygiene materials specifically despite most of those settings having access to improved, often onsite, water supplies. Across countries, adherence to hand hygiene among healthcare providers was about twice as high after patient contact compared to before patient contact. Poor or non-existent management of handwashing stations and alcohol-based hand rub (ABHR) was common, especially in community institutions. Markets and points of entry (internal or external border crossings) represent congregation spaces, critical for COVID-19 mitigation, where globally-recognized WASH standards are needed. Development, evaluation, deployment, and refinement of new and existing standards can help ensure WASH aspects of community mitigation efforts that remain accessible and functional to enable inclusive preventive behaviors. |
Spatial, environmental, and individual associations with Anopheles albimanus salivary antigen IgG in Haitian children
Jaramillo-Underwood A , Herman C , Impoinvil D , Sutcliff A , Knipes A , Worrell CM , Fox LM , Desir L , Fayette C , Javel A , Monestime F , Mace KE , Chang MA , Lemoine JF , Won K , Udhayakumar V , Rogier E . Front Cell Infect Microbiol 2022 12 1033917 IgG serology can be utilized to estimate exposure to Anopheline malaria vectors and the Plasmodium species they transmit. A multiplex bead-based assay simultaneously detected IgG to Anopheles albimanus salivary gland extract (SGE) and four Plasmodium falciparum antigens (CSP, LSA-1, PfAMA1, and PfMSP1) in 11,541 children enrolled at 350 schools across Haiti in 2016. Logistic regression estimated odds of an above-median anti-SGE IgG response adjusting for individual- and environmental-level covariates. Spatial analysis detected statistically significant clusters of schools with students having high anti-SGE IgG levels, and spatial interpolation estimated anti-SGE IgG levels in unsampled locations. Boys had 11% (95% CI: 0.81, 0.98) lower odds of high anti-SGE IgG compared to girls, and children seropositive for PfMSP1 had 53% (95% CI: 1.17, 2.00) higher odds compared to PfMSP1 seronegatives. Compared to the lowest elevation, quartiles 2-4 of higher elevation were associated with successively lower odds (0.81, 0.43, and 0.34, respectively) of high anti-SGE IgG. Seven significant clusters of schools were detected in Haiti, while spatially interpolated results provided a comprehensive picture of anti-SGE IgG levels in the study area. Exposure to malaria vectors by IgG serology with SGE is a proxy to approximate vector biting in children and identify risk factors for vector exposure. |
First cases of SARS-CoV-2 infection and secondary transmission in Kisumu, Kenya
Tippett Barr Beth A , Herman-Roloff Amy , Mburu Margaret , Murnane Pamela M , Sang Norton , Bukusi Elizabeth , Oele Elizabeth , Odhiambo Albert , Lewis-Kulzer Jayne , Onyango Clayton O , Hunsperger Elizabeth , Odhiambo Francesca , Joseph Rachel H , Munyua Peninah , Othieno Kephas , Mulwa Edwin , Akelo Victor , Muok Erick , Bulterys Marc , Nzioka Charles , Cohen Craig R . PLoS Glob Public Health 2022 2 (9) e0000951 We investigated the first 152 laboratory-confirmed SARS-CoV-2 cases (125 primary and 27 secondary) and their 248 close contacts in Kisumu County, Kenya. Conducted June 10–October 8, 2020, this study included interviews and sample collection at enrolment and 14–21 days later. Median age was 35 years (IQR 28–44); 69.0% reported COVID-19 related symptoms, most commonly cough (60.0%), headache (55.2%), fever (53.3%) and loss of taste or smell (43.8%). One in five were hospitalized, 34.4% >25 years of age had at least one comorbidity, and all deaths had comorbidities. Adults ≥25 years with a comorbidity were 3.15 (95% CI 1.37–7.26) times more likely to have been hospitalized or died than participants without a comorbidity. Infectious comorbidities included HIV, tuberculosis, and malaria, but no current cases of influenza, respiratory syncytial virus, dengue fever, leptospirosis or chikungunya were identified. Thirteen (10.4%) of the 125 primary infections transmitted COVID-19 to 27 close contacts, 158 (63.7%) of whom resided or worked within the same household. Thirty-one percent (4 of 13) of those who transmitted COVID-19 to secondary cases were health care workers; no known secondary transmissions occurred between health care workers. This rapid assessment early in the course of the COVID-19 pandemic identified some context-specific characteristics which conflicted with the national line-listing of cases, and which have been substantiated in the year since. These included over two-thirds of cases reporting the development of symptoms during the two weeks after diagnosis, compared to the 7% of cases reported nationally; over half of cases reporting headaches, and nearly half of all cases reporting loss of taste and smell, none of which were reported at the time by the World Health Organization to be common symptoms. This study highlights the importance of rapid in-depth assessments of outbreaks in understanding the local epidemiology and response measures required. |
Plasmodium falciparum pfhrp2 and pfhrp3 Gene Deletions and Relatedness to Other Global Isolates, Djibouti, 2019-2020
Rogier E , McCaffery JN , Mohamed MA , Herman C , Nace D , Daniels R , Lucchi N , Jones S , Goldman I , Aidoo M , Cheng Q , Kemenang EA , Udhayakumar V , Cunningham J . Emerg Infect Dis 2022 28 (10) 2043-2050 Deletions of pfhrp2 and paralogue pfhrp3 (pfhrp2/3) genes threaten Plasmodium falciparum diagnosis by rapid diagnostic test. We examined 1,002 samples from suspected malaria patients in Djibouti City, Djibouti, to investigate pfhrp2/3 deletions. We performed assays for Plasmodium antigen carriage, pfhrp2/3 genotyping, and sequencing for 7 neutral microsatellites to assess relatedness. By PCR assay, 311 (31.0%) samples tested positive for P. falciparum infection, and 296 (95.2%) were successfully genotyped; 37 (12.5%) samples were pfhrp2+/pfhrp3+, 51 (17.2%) were pfhrp2+/pfhrp3-, 5 (1.7%) were pfhrp2-/pfhrp3+, and 203 (68.6%) were pfhrp2-/pfhrp3-. Histidine-rich protein 2/3 antigen concentrations were reduced with corresponding gene deletions. Djibouti P. falciparum is closely related to Ethiopia and Eritrea parasites (pairwise G(ST) 0.68 [Ethiopia] and 0.77 [Eritrea]). P. falciparum with deletions in pfhrp2/3 genes were highly prevalent in Djibouti City in 2019-2020; they appear to have arisen de novo within the Horn of Africa and have not been imported. |
Outbreak of Middle East Respiratory Syndrome Coronavirus in Camels and Probable Spillover Infection to Humans in Kenya.
Ngere I , Hunsperger EA , Tong S , Oyugi J , Jaoko W , Harcourt JL , Thornburg NJ , Oyas H , Muturi M , Osoro EM , Gachohi J , Ombok C , Dawa J , Tao Y , Zhang J , Mwasi L , Ochieng C , Mwatondo A , Bodha B , Langat D , Herman-Roloff A , Njenga MK , Widdowson MA , Munyua PM . Viruses 2022 14 (8) The majority of Kenya's > 3 million camels have antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV), although human infection in Africa is rare. We enrolled 243 camels aged 0-24 months from 33 homesteads in Northern Kenya and followed them between April 2018 to March 2020. We collected and tested camel nasal swabs for MERS-CoV RNA by RT-PCR followed by virus isolation and whole genome sequencing of positive samples. We also documented illnesses (respiratory or other) among the camels. Human camel handlers were also swabbed, screened for respiratory signs, and samples were tested for MERS-CoV by RT-PCR. We recorded 68 illnesses among 58 camels, of which 76.5% (52/68) were respiratory signs and the majority of illnesses (73.5% or 50/68) were recorded in 2019. Overall, 124/4692 (2.6%) camel swabs collected from 83 (34.2%) calves in 15 (45.5%) homesteads between April-September 2019 screened positive, while 22 calves (26.5%) recorded reinfections (second positive swab following ≥ 2 consecutive negative tests). Sequencing revealed a distinct Clade C2 virus that lacked the signature ORF4b deletions of other Clade C viruses. Three previously reported human PCR positive cases clustered with the camel infections in time and place, strongly suggesting sporadic transmission to humans during intense camel outbreaks in Northern Kenya. |
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