Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
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Query Trace: Njenga J [original query] |
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Seroconversion and seroprevalence of TORCH infections in a pregnant women cohort study, Mombasa, Kenya, 2017-2019
Hunsperger E , Osoro E , Munyua P , Njenga MK , Mirieri H , Kikwai G , Odhiambo D , Dayan M , Omballa V , Agogo GO , Mugo C , Widdowson MA , Inwani I . Epidemiol Infect 2024 1-24 |
Risk factors of adverse birth outcomes among a cohort of pregnant women in Coastal Kenya, 2017-2019
Mirieri H , Nduati R , Dawa J , Okutoyi L , Osoro E , Mugo C , Wamalwa D , Jin H , Mwaengo D , Otieno N , Marwanga D , Shabibi M , Munyua P , Kinuthia J , Clancey E , Widdowson MA , Njenga MK , Verani JR , Inwani I . BMC Pregnancy Childbirth 2024 24 (1) 127 INTRODUCTION: Adverse birth outcomes particularly preterm births and congenital anomalies, are the leading causes of infant mortality globally, and the burden is highest in developing countries. We set out to determine the frequency of adverse birth outcomes and the risk factors associated with such outcomes in a cohort of pregnant women in Kenya. METHODS: From October 2017 to July 2019, pregnant women < 28 weeks gestation were enrolled and followed up until delivery in three hospitals in coastal Kenya. Newborns were examined at delivery. Among women with birth outcome data, we assessed the frequency of congenital anomalies defined as gastroschisis, umbilical hernia, limb abnormalities and Trisomy 21, and adverse birth outcomes, defined as either stillbirth, miscarriage, preterm birth, small for gestational age, or microcephaly. We used log-binomial regression to identify maternal characteristics associated with the presence of at least one adverse outcome. RESULTS: Among the 2312 women enrolled, 1916 (82.9%) had birth outcome data. Overall, 402/1916 (20.9%; 95% confidence interval (CI): 19.1-22.8) pregnancies had adverse birth outcomes. Specifically, 66/1916 (3.4%; 95% CI: 2.7-4.4) were stillbirths, 34/1916 (1.8%; 95% CI: 1.2-2.4) were miscarriages and 23/1816 (1.2%; 95% CI: 0.8-1.9) had congenital anomalies. Among the participants with anthropometric measurements data, 142/1200 (11.8%; 95% CI: 10.1 - 13.8) were small for gestational age and among the participants with ultrasound records, 143/1711 (8.4%; 95% CI: 7.1-9.8) were preterm. Febrile illnesses in current pregnancy (adjusted risk ratio (aRR): 1.7; 95% CI: 1.1-2.8), a history of poor birth outcomes in prior pregnancy (aRR: 1.8; 95% CI: 1.3-2.4) and high blood pressure in pregnancy (aRR: 3.9, 95% CI: (1.7-9.2) were independently associated with adverse birth outcomes in a model that included age, education, human immunodeficiency virus status and high blood pressure at enrolment. CONCLUSION: We found similar rates of overall adverse birth outcomes, congenital anomalies, and small for gestational age but higher rates of stillbirths and lower rates of prematurity compared to the rates that have been reported in the sub-Saharan Africa region. However, the rates of adverse birth outcomes in this study were comparable to other studies conducted in Kenya. Febrile illnesses during the current pregnancy, previous history of poor birth outcomes and high blood pressure in pregnancy are predictive of an increased risk of adverse birth outcomes. |
Costs of seasonal influenza vaccine delivery in a pediatric demonstration project for children aged 6-23 months - Nakuru and Mombasa Counties, Kenya, 2019-2021
Gharpure R , Akumu AO , Dawa J , Gobin S , Adhikari BB , Lafond KE , Fischer LS , Mirieri H , Mwazighe H , Tabu C , Jalang'o R , Kamau P , Silali C , Kalani R , Oginga P , Jewa I , Njenga V , Ebama MS , Bresee JS , Njenga MK , Osoro E , Meltzer MI , Emukule GO . Vaccine 2023 BACKGROUND: During November 2019-October 2021, a pediatric influenza vaccination demonstration project was conducted in four sub-counties in Kenya. The demonstration piloted two different delivery strategies: year-round vaccination and a four-month vaccination campaign. Our objective was to compare the costs of both delivery strategies. METHODS: Cost data were collected using standardized questionnaires and extracted from government and project accounting records. We reported total costs and costs per vaccine dose administered by delivery strategy from the Kenyan government perspective in 2021 US$. Costs were separated into financial costs (monetary expenditures) and economic costs (financial costs plus the value of existing resources). We also separated costs by administrative level (national, regional, county, sub-county, and health facility) and program activity (advocacy and social mobilization; training; distribution, storage, and waste management; service delivery; monitoring; and supervision). RESULTS: The total estimated cost of the pediatric influenza demonstration project was US$ 225,269 (financial) and US$ 326,691 (economic) for the year-round delivery strategy (30,397 vaccine doses administered), compared with US$ 214,753 (financial) and US$ 242,385 (economic) for the campaign strategy (25,404 doses administered). Vaccine purchase represented the largest proportion of costs for both strategies. Excluding vaccine purchase, the cost per dose administered was US$ 1.58 (financial) and US$ 5.84 (economic) for the year-round strategy and US$ 2.89 (financial) and US$ 4.56 (economic) for the campaign strategy. CONCLUSIONS: The financial cost per dose was 83% higher for the campaign strategy than the year-round strategy due to larger expenditures for advocacy and social mobilization, training, and hiring of surge staff for service delivery. However, the economic cost per dose was more comparable for both strategies (year-round 22% higher than campaign), balanced by higher costs of operating equipment and monitoring activities for the year-round strategy. These delivery cost data provide real-world evidence to inform pediatric influenza vaccine introduction in Kenya. |
Comparing performance of year-round and campaign-mode influenza vaccination strategies among children aged 6-23 months in Kenya: 2019-2021
Dawa J , Jalang'o R , Mirieri H , Kalani R , Marwanga D , Lafond KE , Muriuki MM , Ejoi J , Chiguba F , Patta S , Amoth P , Okunga E , Tabu C , Chaves SS , Ebama MS , Muthoka P , Njenga V , Kiptoo E , Jewa I , Mwanyamawi R , Bresee J , Njenga MK , Osoro E , Mecca L , Emukule GO . Vaccine 2023 INTRODUCTION: In 2016, the Kenya National Immunization Technical Advisory Group requested additional programmatic and cost effectiveness data to inform the choice of strategy for a national influenza vaccination program among children aged 6-23 months of age. In response, we conducted an influenza vaccine demonstration project to compare the performance of a year-round versus campaign-mode vaccination strategy. Findings from this demonstration project will help identify essential learning lessons for a national program. METHODS: We compared two vaccine delivery strategies: (i) a year-round vaccination strategy where influenza vaccines were administered throughout the year at health facilities. This strategy was implemented in Njoro sub-county in Nakuru (November 2019 to October 2021) and Jomvu sub-county in Mombasa (December 2019 to October 2021), (ii) a campaign-mode vaccination strategy where vaccines were available at health facilities over four months. This strategy was implemented in Nakuru North sub-county in Nakuru (June to September 2021) and Likoni sub-county in Mombasa (July to October 2021). We assessed differences in coverage, dropout rates, vaccine wastage, and operational needs. RESULTS: We observed similar performance between strategies in coverage of the first dose of influenza vaccine (year-round strategy 59.7 %, campaign strategy 63.2 %). The coverage obtained in the year-round sub-counties was similar (Njoro 57.4 %; Jomvu 63.1 %); however, more marked differences between campaign sub-counties were observed (Nakuru North 73.4 %; Likoni 55.2 %). The campaign-mode strategy exceeded the cold chain capacity of participating health facilities, requiring thrice monthly instead of once monthly deliveries, and was associated with a two-fold increase in workload compared to the year-round strategy (168 vaccines administered per day in the campaign strategy versus 83 vaccines administered per day in the year-round strategy). CONCLUSION: Although both strategies had similar coverage levels, the campaign-mode strategy was associated with considerable operational needs that could significantly impact the immunization program. |
Resilience of routine childhood immunization services in two counties in Kenya in the face of the COVID-19 pandemic
Mirieri H , Nasimiyu C , Dawa J , Mburu C , Jalang'o R , Kamau P , Igboh L , Ebama M , Wainaina D , Gitonga J , Karanja J , Njenga E , Kariuki J , Machani J , Oginga P , Baraka I , Wamaru P , Muhula S , Ratemo P , Ayugi J , Kariuki Njenga M , Emukule GO , Osoro E , Otieno NA . Vaccine 2023 41 (52) 7695-7704 The recently emerged coronavirus disease 2019 (COVID-19) has caused considerable morbidity and mortality worldwide and disrupted health services. We describe the effect of the COVID-19 pandemic on utilization of childhood vaccination services during the pandemic. Using a mixed methods approach combining retrospective data review, a cross-sectional survey, focus group discussions among care givers and key informant interviews among nurses, we collected data between May and September 2021 in Mombasa and Nakuru counties. Overall, there was a <2 % decline in the number of vaccine doses administered during the pandemic period compared to the pre-pandemic period but this was statistically insignificant, both for the pentavalent-1 vaccine (ß = -0.013, p = 0.505) and the pentavalent-3 vaccine (ß = -0.012, p = 0.440). In government health facilities, there was 7.7 % reduction in the number of pentavalent-1 (ß = -0.08, p = 0.010) and 10.4 % reduction in the number of pentavalent-3 (ß = -0.11, p < 0.001) vaccine doses that were administered during the pandemic period. In non-government facilities, there was a 25.8 % increase in the number of pentavalent-1 (ß=0.23, p < 0.001) and 31.0 % increase in the number of pentavalent-3 (ß = -0.27, p < 0.001) vaccine doses that were administered facilities during the pandemic period. The strategies implemented to maintain immunization services during the pandemic period included providing messaging on the availability and importance of staying current with routine vaccination and conducting catch-up vaccinations and vaccination outreaches. Our findings suggest that the COVID-19 pandemic did not impact childhood vaccination services in Mombasa and Nakuru counties in Kenya. The private health facilities cushioned vaccination services against the effects of the pandemic and the strategies that were put in place by the ministry of health ensured continuation of vaccination services and encouraged uptake of the services during the pandemic period in the two counties in Kenya. These findings provide useful information to safeguard vaccination services during future pandemics. |
Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response (preprint)
Arnold BF , Kanyi H , Njenga SM , Rawago FO , Priest JW , Secor WE , Lammie PJ , Won KY , Odiere MR . medRxiv 2020 2020.04.10.20061101 Identifying populations with active transmission and monitoring changes in transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected in stool using microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to schistosomiasis soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. Serological measures of transmission closely aligned with stool-based measures of infection, and serological measures provided better resolution for between-community differences at lower levels of infection. Serology enabled fine- scale measures of heterogeneity in force of infection both geographically and by age. Our results show that serologic surveillance platforms represent an important new opportunity to guide and monitor schistosomiasis control programs.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was supported by the National Institutes of Allergy and Infectious Diseases (K01 AI119180 to BFA) and the Bill & Melinda Gates Foundation (OPP1022543 to PJL). The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services.Author DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData and replication files required to conduct the analyses are available through GitHub and the Open Science Framework: https://osf.io/rnme8. Community location data required to replicate the geostatistical model fits is not publicly available to protect participant confidentiality but is available from the corresponding author upon request, pending appropriate human subjects review and approval. https://osf.io/rnme8 |
High Real-time Reporting of Domestic and Wild Animal Diseases Following Rollout of Mobile Phone Reporting System in Kenya (preprint)
Njenga MK , Kemunto N , Kahariri S , Holmstrom L , Oyas H , Biggers K , Riddle A , Gachohi J , Muturi M , Mwatondo A , Gakuya F , Lekolool I , Sitawa R , Apamaku M , Osoro E , Widdowson MA , Munyua P . bioRxiv 2020 2020.12.04.411348 Background To improve early detection of emerging infectious diseases in sub-Saharan Africa (SSA), many of them zoonotic, numerous electronic animal disease-reporting systems have been piloted but not implemented because of cost, lack of user friendliness, and data insecurity. In Kenya, we developed and rolled out an open-source mobile phone-based domestic and wild animal disease reporting system and collected data over two years to demonstrate its robustness and ability to track disease trends.Methods The Kenya Animal Biosurveillance System (KABS) application was built on the Java® platform, freely downloadable for android compatible mobile phones, and supported by web-based account management, form editing and data monitoring. The application was integrated into the surveillance systems of Kenya’s domestic and wild animal sectors by adopting their existing data collection tools, and targeting disease syndromes prioritized by national, regional and international animal and human health agencies. Smartphone-owning government and private domestic and wild animal health officers were recruited and trained on the application, and reports received and analyzed by Kenya Directorate of Veterinary Services. The KABS application performed automatic basic analyses (frequencies, spatial distribution), which were immediately relayed to reporting officers as feedback.Results Over 95% of trained domestic animal officers downloaded the application, and >72% of them started reporting using the application within three months. Introduction of the application resulted in 2- to 10-fold increase in number of disease reports when compared the previous year (p<0.05), and reports were more spatially distributed. Among domestic animals, food animals (cattle, sheep, goats, camels, and chicken) accounted for >90% of the reports, with respiratory, gastrointestinal and skin diseases constituting >85% of the reports. Herbivore wildlife (zebra, buffalo, elephant, giraffe, antelopes) accounted for >60% of the wildlife disease reports, followed by carnivores (lions, cheetah, hyenas, jackals, and wild dogs). Deaths, traumatic injuries, and skin diseases were most reported in wildlife.Conclusions This open-source system was user friendly and secure, ideal for rolling out in other countries in SSA to improve disease reporting and enhance preparedness for epidemics of zoonotic diseases.Authors Summary Taking advantage of a recently developed freely downloadable disease reporting application in the United States, we customized it for android smartphones to collect and submit domestic and wild animal disease data in real-time in Kenya. To enhance user friendliness, the Kenya Animal Biosurveillance System (KABS) was installed with disease reporting tools currently used by the animal sector and tailored to collected data on transboundary animal disease important for detecting zoonotic endemic and emerging diseases. The KABS database was housed by the government of Kenya, providing important assurance on its security. The application had a feedback module that performed basics analysis to provide feedback to the end-user in real-time. Rolling out of KABS resulted in >70% of domestic and wildlife disease surveillance officers using it to report, resulting in exponential increase in frequency and spatial distributions of reports regions. Utility of the system was demonstrated by successful detected a Rift Valley fever outbreak in livestock in 2018, resulting in early response and prevention of widespread human infections. For the wildlife sector in Eastern Africa, the application provided the first disease surveillance system developed. This open-source system is ideal for rolling out in other countries in sub-Saharan Africa to improve disease reporting and enhance preparedness for epidemics of zoonotic diseases. |
Multiplex serologic testing within a cross-sectional lymphatic filariasis sentinel site survey in coastal Kenya reveals community-level differences in IgG antibody responses to parasitic diseases and vaccines (preprint)
Njenga SM , Kanyi HM , Arnold BF , Matendechero SH , Onsongo JK , Won KY , Priest JW . bioRxiv 2019 604181 Accurate, cost-effective measurement of the burden of co-endemic infections would enable public health managers to identify opportunities for implementation of integrated control programs. Dried blood spots (DBS) collected during a cross-sectional lymphatic filariasis sentinel site survey in the Kenyan coastal counties of Lamu, Tana River, Kilifi, Kwale, and Taita-Taveta were used for the integrated detection of serologic IgG antibodies against antigens from several parasitic infections (Wuchereria bancrofti, Schistosoma mansoni, Plasmodium spp, Ascaris lumbricoides, and Strongyloides stercoralis) as well as markers for immunity to vaccine-preventable diseases (measles, diphtheria, and tetanus) on a multiplex bead assay (MBA) platform. High heterogeneity was observed in antibody responses by pathogen and antigen across the sentinel sites. Antibody seroprevalence against Wb123, Bm14, and Bm33 recombinant filarial antigens were generally higher in Ndau Island (p<0.0001), which also had the highest prevalence of filarial antigenemia compared to other communities. Antibody responses to the Plasmodium species antigens CSP and MSP-119 were higher in Kilifi and Kwale counties, with Jaribuni community showing higher overall mean seroprevalence (p<0.0001). Kimorigo community in Taita-Taveta County was the only area where antibody responses against Schistosoma mansoni Sm25 recombinant antigen were detected. Seroprevalence rates to Strongyloides antigen NIE ranged between 3% and 26%, and there was high heterogeneity in immune responses against an Ascaris antigen among the study communities. Differences were observed between communities in terms of seroprevalence to vaccine-preventable diseases. Seroprotection to tetanus was lower in all 3 communities in Kwale County compared to the rest of the communities. This study has demonstrated that the MBA platform holds promise for rapid integrated monitoring of trends of infections of public health importance in endemic areas, and assessing the effectiveness of control and elimination programs.Author Summary Establishment of successful private-public partnerships in the recent past has led to an increase in resources available for control and elimination of malaria and Neglected Tropical Diseases (NTDs). Implementation of control and elimination programs and their subsequent monitoring and evaluation would be greatly facilitated by development of new tools and strategies for rapid identification of areas of transmission so that interventions could be prioritized to regions where they were most needed. Since development of antibody responses in a host depend on exposure to an infectious agent, assessment of such serologic markers provides a sensitive way to measure differences between populations in pathogen exposure. Our study applied a state-of-the-art multiplex bead assay platform to perform integrated measurement of antibody responses to multiple parasitic diseases and immunizing antigens for vaccine-preventable diseases (VPDs) in ten lymphatic filariasis sentinel sites across the Kenyan coastal region. A community-level analysis of age-specific and overall mean seroprevalence fit using a flexible model ensemble provided an improved understanding about the distributions of the various parasitic infections and seroprotection to VPDs. This study provides an important proof of concept for how we could dramatically increase the value of existing surveillance activities using small volumes of blood collected on filter paper and analyzed using a single multiplex laboratory assay and novel data analysis techniques. |
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. |
Mapping of cholera hotspots in Kenya using epidemiologic and water, sanitation, and hygiene (WASH) indicators as part of Kenya's new 2022-2030 cholera elimination plan
Kiama C , Okunga E , Muange A , Marwanga D , Langat D , Kuria F , Amoth P , Were I , Gachohi J , Ganda N , Martinez Valiente M , Njenga MK , Osoro E , Brunkard J . PLoS Negl Trop Dis 2023 17 (3) e0011166 Cholera is an issue of major public health importance. It was first reported in Kenya in 1971, with the country experiencing outbreaks through the years, most recently in 2021. Factors associated with the outbreaks in Kenya include open defecation, population growth with inadequate expansion of safe drinking water and sanitation infrastructure, population movement from neighboring countries, crowded settings such as refugee camps coupled with massive displacement of persons, mass gathering events, and changes in rainfall patterns. The Ministry of Health, together with other ministries and partners, revised the national cholera control plan to a multisectoral cholera elimination plan that is aligned with the Global Roadmap for Ending Cholera. One of the key features in the revised plan is the identification of hotspots. The hotspot identification exercise followed guidance and tools provided by the Global Task Force on Cholera Control (GTFCC). Two epidemiological indicators were used to identify the sub-counties with the highest cholera burden: incidence per population and persistence. Additionally, two indicators were used to identify sub-counties with poor WASH coverage due to low proportions of households accessing improved water sources and improved sanitation facilities. The country reported over 25,000 cholera cases between 2015 and 2019. Of 290 sub-counties, 25 (8.6%) sub-counties were identified as a high epidemiological priority; 78 (26.9%) sub-counties were identified as high WASH priority; and 30 (10.3%) sub-counties were considered high priority based on a combination of epidemiological and WASH indicators. About 10% of the Kenyan population (4.89 million) is living in these 30-combination high-priority sub-counties. The novel method used to identify cholera hotspots in Kenya provides useful information to better target interventions in smaller geographical areas given resource constraints. Kenya plans to deploy oral cholera vaccines in addition to WASH interventions to the populations living in cholera hotspots as it targets cholera elimination by 2030. |
Voluntary medical male circumcisions for HIV prevention - 13 countries in eastern and southern Africa, 2017-2021
Peck ME , Ong KS , Lucas T , Harvey P , Lekone P , Letebele M , Thomas VT , Maziya V , Mkhontfo M , Gultie T , Mulatu D , Shimelis M , Zegeye T , Juma AW , Odoyo-June E , Musingila PK , Njenga J , Auld A , Kapito M , Maida A , Msungama W , Canda M , Come J , Malimane I , Aupokolo M , Zemburuka B , Kankindi I , Malamba S , Remera E , Tubane E , Machava R , Maphothi N , Vranken P , Amuri M , Kazaura KJ , Simbeye D , Alamo S , Kabuye G , Chituwo O , Kamboyi R , Masiye J , Mandisarisa J , Xaba S , Toledo C . MMWR Morb Mortal Wkly Rep 2023 72 (10) 256-260 In 2007, voluntary medical male circumcision (VMMC) was endorsed by the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS after it was found to be associated with approximately a 60% reduction in the risk for female-to-male transmission of HIV (1). As a result of this endorsement, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR), through partnerships with U.S. government agencies, including CDC, the U.S. Department of Defense, and the U.S. Agency for International Development, started supporting VMMCs performed in prioritized countries in southern and eastern Africa. During 2010-2016, CDC supported 5,880,372 VMMCs in 12 countries (2,3). During 2017-2021, CDC supported 8,497,297 VMMCs performed in 13 countries. In 2020, the number of VMMCs performed declined 31.8% compared with the number in 2019, primarily because of COVID-19-related disruptions to VMMC service delivery. PEPFAR 2017-2021 Monitoring, Evaluation, and Reporting data were used to provide an update and describe CDC's contribution to the scale-up of the VMMC program, which is important to meeting the 2025 Joint United Nations Programme on HIV/AIDS (UNAIDS) target of 90% of males aged 15-59 years having access to VMMC services in prioritized countries to help end the AIDS epidemic by 2030 (4). |
A mixed methods assessment of knowledge, attitudes and practices related to aflatoxin contamination and exposure among caregivers of children under five years in Western Kenya
Awuor A , Wambura G , Ngere I , Hunsperger E , Onyango C , Bigogo G , Blum LS , Munyua P , Njenga MK , Widdowson MA . Public Health Nutr 2023 26 (12) 1-29 OBJECTIVE: Identifying factors that may influence aflatoxin exposure in children under five years of age living in farming households in western Kenya. DESIGN: We used a mixed methods design. The quantitative component entailed serial cross-sectional interviews in 250 farming households to examine crop processing and conservation practices, household food storage and consumption, and local understandings of aflatoxins. Qualitative data collection included focus group discussions (N=7) and key informant interviews (N=13) to explore explanations of harvesting and post-harvesting techniques and perceptions of crop spoilage. SETTING: The study was carried out in Asembo, a rural community where high rates of child stunting exist. PARTICIPANTS: A total of 250 female primary caregivers of children under five years of age and 13 experts in farming and food management participated. RESULTS: Study results showed that from a young age, children routinely ate maize-based dishes. Economic constraints and changing environmental patterns guided the application of sub-optimal crop practices involving early harvest, poor drying, mixing spoiled with good cereals, and storing cereals in polypropylene bags in confined quarters occupied by humans and livestock, raising risks of aflatoxin contamination. Most (80%) smallholder farmers were unaware of aflatoxins and their harmful economic and health consequences. CONCLUSIONS: Young children living in subsistence farming households may be at risk of exposure to aflatoxins and consequent ill health and stunting. Sustained efforts to increase awareness of the risks of aflatoxins and control measures among subsistence farmers could help to mitigate practices that raise exposure. |
Healthcare-seeking behavior for respiratory illnesses in Kenya: implications for burden of disease estimation
Emukule GO , Osoro E , Nyawanda BO , Ngere I , Macharia D , Bigogo G , Otieno NA , Chaves SS , Njenga MK , Widdowson MA . BMC Public Health 2023 23 (1) 353 BACKGROUND: Understanding healthcare-seeking patterns for respiratory illness can help improve estimation of disease burden and target public health interventions to control acute respiratory disease in Kenya. METHODS: We conducted a cross-sectional survey to determine healthcare utilization patterns for acute respiratory illness (ARI) and severe pneumonia in four diverse counties representing urban, peri-urban, rural mixed farmers, and rural pastoralist communities in Kenya using a two-stage (sub-locations then households) cluster sampling procedure. Healthcare seeking behavior for ARI episodes in the last 14 days, and severe pneumonia in the last 12 months was evaluated. Severe pneumonia was defined as reported cough and difficulty breathing for > 2 days and report of hospitalization or recommendation for hospitalization, or a danger sign (unable to breastfeed/drink, vomiting everything, convulsions, unconscious) for children < 5 years, or report of inability to perform routine chores. RESULTS: From August through September 2018, we interviewed 28,072 individuals from 5,407 households. Of those surveyed, 9.2% (95% Confidence Interval [CI] 7.9-10.7) reported an episode of ARI, and 4.2% (95% CI 3.8-4.6) reported an episode of severe pneumonia. Of the reported ARI cases, 40.0% (95% CI 36.8-43.3) sought care at a health facility. Of the74.2% (95% CI 70.2-77.9) who reported severe pneumonia and visited a medical health facility, 28.9% (95% CI 25.6-32.6) were hospitalized and 7.0% (95% CI 5.4-9.1) were referred by a clinician to the hospital but not hospitalized. 21% (95% CI 18.2-23.6) of self-reported severe pneumonias were hospitalized. Children aged < 5 years and persons in households with a higher socio-economic status were more likely to seek care for respiratory illness at a health facility. CONCLUSION: Our findings suggest that hospital-based surveillance captures less than one quarter of severe pneumonia in the community. Multipliers from community household surveys can account for underutilization of healthcare resources and under-ascertainment of severe pneumonia at hospitals. |
Sexual violence trends before and after rollout of COVID-19 mitigation measures, Kenya
Ochieng W , Sage EO , Achia T , Oluoch P , Kambona C , Njenga J , Bulterys M , Lor A . Emerg Infect Dis 2022 28 (13) S270-s276 COVID-19 mitigation measures such as curfews, lockdowns, and movement restrictions are effective in reducing the transmission of SARS-CoV-2; however, these measures can enable sexual violence. We used data from the Kenya Health Information System and different time-series approaches to model the unintended consequences of COVID-19 mitigation measures on sexual violence trends in Kenya. We found a model-dependent 73%-122% increase in reported sexual violence cases, mostly among persons 10-17 years of age, translating to 35,688 excess sexual violence cases above what would have been expected in the absence of COVID-19-related restrictions. In addition, during lockdown, the percentage of reported rape survivors receiving recommended HIV PEP decreased from 61% to 51% and STI treatment from 72% to 61%. Sexual violence mitigation measures might include establishing comprehensive national sexual violence surveillance systems, enhancing prevention efforts during school closures, and maintaining access to essential comprehensive services for all ages and sexes. |
Effects of COVID-19 pandemic on voluntary medical male circumcision services for HIV prevention, Sub-Saharan Africa, 2020
Peck ME , Ong KS , Lucas T , Prainito A , Thomas AG , Brun A , Kiggundu V , Yansaneh A , Busang L , Kgongwana K , Kelaphile D , Seipone K , Letebele MH , Makadzange PF , Marwiro A , Sesinyi M , Lapidos T , Lukhele N , Maziya V , Mkhontfo M , Gultie T , Mulatu D , Shimelis M , Zegeye T , Teka T , Bulterys M , Njenga JN , Odoyo-June E , Juma AW , Soo L , Talam N , Brown M , Chakare T , Nonyana N , Khoabane MA , Auld AF , Maida A , Msungama W , Kapito M , Nyirenda R , Matchere F , Odek J , Canda M , Malimane I , Come J , Gaspar N , Langa A , Aupokolo MA , Vejorerako KC , Kahindi L , Mali D , Zegeye A , Mangoya D , Zemburuka BL , Bamwesigye J , Kankindi I , Kayirangwa E , Malamba SS , Roels T , Kayonde L , Zimulinda E , Ndengo E , Nsanzimana S , Remera E , Rwibasira GN , Sangwayire B , Semakula M , Rugira E , Rugwizangoga E , Tubane E , Yoboka E , Lawrence J , Loykissoonlal D , Maphothi N , Achut V , Bunga S , Moi M , Amuri M , Kazaura K , Simbeye D , Fida N , Kayange AA , Seleman M , Akao J , Alamo ST , Kabuye G , Kyobutungi S , Makumbi FE , Mudiope P , Nantez B , Chituwo O , Godfrey L , Muyunda B , Kamboyi R , Masiye J , Lifuka E , Mandisarisa J , Mhangara M , Xaba S , Toledo C . Emerg Infect Dis 2022 28 (13) S262-s269 Beginning in March 2020, to reduce COVID-19 transmission, the US President's Emergency Plan for AIDS Relief supporting voluntary medical male circumcision (VMMC) services was delayed in 15 sub-Saharan African countries. We reviewed performance indicators to compare the number of VMMCs performed in 2020 with those performed in previous years. In all countries, the annual number of VMMCs performed decreased 32.5% (from 3,898,960 in 2019 to 2,631,951 in 2020). That reduction is largely attributed to national and local COVID-19 mitigation measures instituted by ministries of health. Overall, 66.7% of the VMMC global annual target was met in 2020, compared with 102.0% in 2019. Countries were not uniformly affected; South Africa achieved only 30.7% of its annual target in 2020, but Rwanda achieved 123.0%. Continued disruption to the VMMC program may lead to reduced circumcision coverage and potentially increased HIV-susceptible populations. Strategies for modifying VMMC services provide lessons for adapting healthcare systems during a global pandemic. |
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. |
Prevalence of microcephaly and Zika virus infection in a pregnancy cohort in Kenya, 2017-2019
Osoro E , Inwani I , Mugo C , Hunsperger E , Verani JR , Omballa V , Wamalwa D , Rhee C , Nduati R , Kinuthia J , Jin H , Okutoyi L , Mwaengo D , Maugo B , Otieno NA , Mirieri H , Shabibi M , Munyua P , Njenga MK , Widdowson MA . BMC Med 2022 20 (1) 291 BACKGROUND: Zika virus (ZIKV), first discovered in Uganda in 1947, re-emerged globally in 2013 and was later associated with microcephaly and other birth defects. We determined the incidence of ZIKV infection and its association with adverse pregnancy and fetal outcomes in a pregnancy cohort in Kenya. METHODS: From October 2017 to July 2019, we recruited and followed up women aged ≥ 15 years and ≤ 28 weeks pregnant in three hospitals in coastal Mombasa. Monthly follow-up included risk factor questions and a blood sample collected for ZIKV serology. We collected anthropometric measures (including head circumference), cord blood, venous blood from newborns, and any evidence of birth defects. Microcephaly was defined as a head circumference (HC) < 2 standard deviations (SD) for sex and gestational age. Severe microcephaly was defined as HC < 3 SD for sex and age. We tested sera for anti-ZIKV IgM antibodies using capture enzyme-linked immunosorbent assay (ELISA) and confirmed positives using the plaque reduction neutralization test (PRNT(90)) for ZIKV and for dengue (DENV) on the samples that were ZIKV neutralizing antibody positive. We collected blood and urine from participants reporting fever or rash for ZIKV testing. RESULTS: Of 2889 pregnant women screened for eligibility, 2312 (80%) were enrolled. Of 1916 recorded deliveries, 1816 (94.6%) were live births and 100 (5.2%) were either stillbirths or spontaneous abortions (< 22 weeks of gestation). Among 1236 newborns with complete anthropometric measures, 11 (0.9%) had microcephaly and 3 (0.2%) had severe microcephaly. A total of 166 (7.2%) participants were positive for anti-ZIKV IgM, 136 of whom became seropositive during follow-up. Among the 166 anti-ZIKV IgM positive, 3 and 18 participants were further seropositive for ZIKV and DENV neutralizing antibodies, respectively. Of these 3 and 18 pregnant women, one and 13 (72.2%) seroconverted with antibodies to ZIKV and DENV, respectively. All 308 samples (serum and urine samples collected during sick visits and samples that were anti-ZIKV IgM positive) tested by RT-PCR were negative for ZIKV. No adverse pregnancy or neonatal outcomes were reported among the three participants with confirmed ZIKV exposure. Among newborns from pregnant women with DENV exposure, four (22.2%) were small for gestational age and one (5.6%) had microcephaly. CONCLUSIONS: The prevalence of severe microcephaly among newborns in coastal Kenya was high relative to published estimates from facility-based studies in Europe and Latin America, but little evidence of ZIKV transmission. There is a need for improved surveillance for microcephaly and other congenital malformations in Kenya. |
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. |
Point-prevalence survey of antibiotic use at three public referral hospitals in Kenya
Omulo S , Oluka M , Achieng L , Osoro E , Kinuthia R , Guantai A , Opanga SA , Ongayo M , Ndegwa L , Verani JR , Wesangula E , Nyakiba J , Makori J , Sugut W , Kwobah C , Osuka H , Njenga MK , Call DR , Palmer GH , VanderEnde D , Luvsansharav UO . PLoS One 2022 17 (6) e0270048 Antimicrobial stewardship encourages appropriate antibiotic use, the specific activities of which will vary by institutional context. We investigated regional variation in antibiotic use by surveying three regional public hospitals in Kenya. Hospital-level data for antimicrobial stewardship activities, infection prevention and control, and laboratory diagnostic capacities were collected from hospital administrators, heads of infection prevention and control units, and laboratory directors, respectively. Patient-level antibiotic use data were abstracted from medical records using a modified World Health Organization point-prevalence survey form. Altogether, 1,071 consenting patients were surveyed at Kenyatta National Hospital (KNH, n = 579), Coast Provincial General Hospital (CPGH, n = 229) and Moi Teaching and Referral Hospital (MTRH, n = 263). The majority (67%, 722/1071) were ≥18 years and 53% (563/1071) were female. Forty-six percent (46%, 489/1071) were receiving at least one antibiotic. Antibiotic use was higher among children <5 years (70%, 150/224) than among other age groups (40%, 339/847; P < 0.001). Critical care (82%, 14/17 patients) and pediatric wards (59%, 155/265) had the highest proportion of antibiotic users. Amoxicillin/clavulanate was the most frequently used antibiotic at KNH (17%, 64/383 antibiotic doses), and ceftriaxone was most used at CPGH (29%, 55/189) and MTRH (31%, 57/184). Forty-three percent (326/756) of all antibiotic prescriptions had at least one missed dose recorded. Forty-six percent (204/489) of patients on antibiotics had a specific infectious disease diagnosis, of which 18% (37/204) had soft-tissue infections, 17% (35/204) had clinical sepsis, 15% (31/204) had pneumonia, 13% (27/204) had central nervous system infections and 10% (20/204) had obstetric or gynecological infections. Of these, 27% (56/204) had bacterial culture tests ordered, with culture results available for 68% (38/56) of tests. Missed antibiotic doses, low use of specimen cultures to guide therapy, high rates of antibiotic use, particularly in the pediatric and surgical population, and preference for broad-spectrum antibiotics suggest antibiotic use in these tertiary care hospitals is not optimal. Antimicrobial stewardship programs, policies, and guidelines should be tailored to address these areas. |
Comparable pregnancy outcomes for HIV-uninfected and HIV-infected women on antiretroviral treatment in Kenya
Mugo C , Nduati R , Osoro E , Nyawanda BO , Mirieri H , Hunsperger E , Verani JR , Jin H , Mwaengo D , Maugo B , Machoki J , Otieno NA , Ombok C , Shabibi M , Okutoyi L , Kinuthia J , Widdowson MA , Njenga K , Inwani I , Wamalwa D . J Infect Dis 2022 226 (4) 678-686 BACKGROUND: The impact of Human Immunodeficiency Virus (HIV) on pregnancy outcomes for women on antiretroviral therapy (ART) in sub-Saharan Africa remains unclear. METHODS: Pregnant women in Kenya were enrolled in the second trimester and followed up to delivery. We estimated effects of treated HIV with three pregnancy outcomes: loss, premature birth, and low birthweight and factors associated with HIV-positive status. RESULTS: Of 2,113 participants, 311 (15%) were HIV-infected and on ART. Ninety-one of 1,762 (5%) experienced a pregnancy loss, 169/1,725 (10%) a premature birth (<37 weeks), and 74/1,317 (6%) had a low birthweight newborn (<2500g).There was no evidence of associations between treated HIV infection and pregnancy loss (adjusted relative risk [aRR]: 1.19 [95% confidence interval: 0.65-2.16], p=0.57), prematurity (1.09 [0.70-1.70], p=0.69) and low birthweight (1.36 [0.77-2.40], p=0.27). Factors associated with an HIV-positive status included older age, food insecurity, lower education level, higher parity, lower gestation at first antenatal clinic, anemia, and syphilis. Women who were overweight or underweight were less likely to be HIV infected compared to those with normal weight. CONCLUSION: Currently treated HIV was not significantly associated with adverse pregnancy outcomes. HIV-infected women, however, had a higher prevalence of other factors associated with adverse pregnancy outcomes. |
Diagnostics to support elimination of lymphatic filariasis-Development of two target product profiles
Won KY , Gass K , Biamonte M , Dagne DA , Ducker C , Hanna C , Hoerauf A , Lammie PJ , Njenga SM , Noordin R , Ramaiah KD , Ramzy R , Scholte RGC , Solomon AW , Souza AA , Tappero J , Toubali E , Weil GJ , Williams SA , King JD . PLoS Negl Trop Dis 2021 15 (11) e0009968 As lymphatic filariasis (LF) programs move closer to established targets for validation elimination of LF as a public health problem, diagnostic tools capable of supporting the needs of the programs are critical for success. Known limitations of existing diagnostic tools make it challenging to have confidence that program endpoints have been achieved. In 2019, the World Health Organization (WHO) established a Diagnostic Technical Advisory Group (DTAG) for Neglected Tropical Diseases tasked with prioritizing diagnostic needs including defining use-cases and target product profiles (TPPs) for needed tools. Subsequently, disease-specific DTAG subgroups, including one focused on LF, were established to develop TPPs and use-case analyses to be used by product developers. Here, we describe the development of two priority TPPs for LF diagnostics needed for making decisions for stopping mass drug administration (MDA) of a triple drug regimen and surveillance. Utilizing the WHO core TPP development process as the framework, the LF subgroup convened to discuss and determine attributes required for each use case. TPPs considered the following parameters: product use, design, performance, product configuration and cost, and access and equity. Version 1.0 TPPs for two use cases were published by WHO on 12 March 2021 within the WHO Global Observatory on Health Research and Development. A common TPP characteristic that emerged in both use cases was the need to identify new biomarkers that would allow for greater precision in program delivery. As LF diagnostic tests are rarely used for individual clinical diagnosis, it became apparent that reliance on population-based surveys for decision making requires consideration of test performance in the context of such surveys. In low prevalence settings, the number of false positive test results may lead to unnecessary continuation or resumption of MDA, thus wasting valuable resources and time. Therefore, highly specific diagnostic tools are paramount when used to measure low thresholds. The TPP process brought to the forefront the importance of linking use case, program platform and diagnostic performance characteristics when defining required criteria for diagnostic tools. |
High real-time reporting of domestic and wild animal diseases following rollout of mobile phone reporting system in Kenya
Njenga MK , Kemunto N , Kahariri S , Holmstrom L , Oyas H , Biggers K , Riddle A , Gachohi J , Muturi M , Mwatondo A , Gakuya F , Lekolool I , Sitawa R , Apamaku M , Osoro E , Widdowson MA , Munyua P . PLoS One 2021 16 (9) e0244119 BACKGROUND: To improve early detection of emerging infectious diseases in sub-Saharan Africa (SSA), many of them zoonotic, numerous electronic animal disease-reporting systems have been piloted but not implemented because of cost, lack of user friendliness, and data insecurity. In Kenya, we developed and rolled out an open-source mobile phone-based domestic and wild animal disease reporting system and collected data over two years to investigate its robustness and ability to track disease trends. METHODS: The Kenya Animal Biosurveillance System (KABS) application was built on the Java® platform, freely downloadable for android compatible mobile phones, and supported by web-based account management, form editing and data monitoring. The application was integrated into the surveillance systems of Kenya's domestic and wild animal sectors by adopting their existing data collection tools, and targeting disease syndromes prioritized by national, regional and international animal and human health agencies. Smartphone-owning government and private domestic and wild animal health officers were recruited and trained on the application, and reports received and analyzed by Kenya Directorate of Veterinary Services. The KABS application performed automatic basic analyses (frequencies, spatial distribution), which were immediately relayed to reporting officers as feedback. RESULTS: Of 697 trained domestic animal officers, 662 (95%) downloaded the application, and >72% of them started reporting using the application within three months. Introduction of the application resulted in 2- to 14-fold increase in number of disease reports when compared to the previous year (relative risk = 14, CI 13.8-14.2, p<0.001), and reports were more widely distributed. Among domestic animals, food animals (cattle, sheep, goats, camels, and chicken) accounted for >90% of the reports, with respiratory, gastrointestinal and skin diseases constituting >85% of the reports. Herbivore wildlife (zebra, buffalo, elephant, giraffe, antelopes) accounted for >60% of the wildlife disease reports, followed by carnivores (lions, cheetah, hyenas, jackals, and wild dogs). Deaths, traumatic injuries, and skin diseases were most reported in wildlife. CONCLUSIONS: This open-source system was user friendly and secure, ideal for rolling out in other countries in SSA to improve disease reporting and enhance preparedness for epidemics of zoonotic diseases. |
sssHigh seroprevalence of SARS-CoV-2 but low infection fatality ratio eight months after introduction in Nairobi, Kenya.
Ngere I , Dawa J , Hunsperger E , Otieno N , Masika M , Amoth P , Makayotto L , Nasimiyu C , Gunn BM , Nyawanda B , Oluga O , Ngunu C , Mirieri H , Gachohi J , Marwanga D , Munywoki PK , Odhiambo D , Alando MD , Breiman RF , Anzala O , Njenga MK , Bulterys M , Herman-Roloff A , Osoro E . Int J Infect Dis 2021 112 25-34 BACKGROUND: The lower-than-expected COVID-19 morbidity and mortality in Africa has been attributed to multiple factors, including weak surveillance. We estimated the burden of SARS-CoV-2 infections eight months into the epidemic in Nairobi, Kenya. METHODS: We conducted a population-based cross-sectional survey using multi-stage random sampling to select households within Nairobi in November 2020. Sera from consenting household members were tested for antibodies to SARS-CoV-2. Seroprevalence was estimated after adjusting for population structure and test performance. Infection fatality ratios (IFRs) were calculated by comparing study estimates to reported cases and deaths. RESULTS: Among 1,164 individuals, the adjusted seroprevalence was 34.7% (95%CI 31.8-37.6). Half the enrolled households had at least one positive participant. Seropositivity increased in more densely populated areas (spearman's r=0.63; p=0.009). Individuals aged 20-59 years had at least 2-fold higher seropositivity than those aged 0-9 years. The IFR was 40 per 100,000 infections, with individuals ≥60 years old having higher IFRs. CONCLUSION: Over one-third of Nairobi residents had been exposed to SARS-CoV-2 by November 2020, indicating extensive transmission. However, the IFR was >10-fold lower than that reported in Europe and the United States, supporting the perceived lower morbidity and mortality in sub-Saharan Africa. |
Serological evidence of Rift Valley fever virus infection among domestic ruminant herds in Uganda
Ndumu DB , Bakamutumaho B , Miller E , Nakayima J , Downing R , Balinandi S , Monje F , Tumusiime D , Nanfuka M , Meunier N , Arinaitwe E , Rutebarika C , Kidega E , Kyondo J , Ademun R , Njenga KM , Veas F , Gonzalez JP . BMC Vet Res 2021 17 (1) 157 BACKGROUND: Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970's indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010-2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions. RESULTS: During the Yellow Fever outbreak investigation of 2010-2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region. CONCLUSIONS: The absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries. |
Low-Level Middle East Respiratory Syndrome Coronavirus among Camel Handlers, Kenya, 2019.
Munyua PM , Ngere I , Hunsperger E , Kochi A , Amoth P , Mwasi L , Tong S , Mwatondo A , Thornburg N , Widdowson MA , Njenga MK . Emerg Infect Dis 2021 27 (4) 1201-1205 Although seroprevalence of Middle East respiratory coronavirus syndrome is high among camels in Africa, researchers have not detected zoonotic transmission in Kenya. We followed a cohort of 262 camel handlers in Kenya during April 2018-March 2020. We report PCR-confirmed Middle East respiratory coronavirus syndrome in 3 asymptomatic handlers. |
Spatial clustering of livestock Anthrax events associated with agro-ecological zones in Kenya, 1957-2017
Nderitu LM , Gachohi J , Otieno F , Mogoa EG , Muturi M , Mwatondo A , Osoro EM , Ngere I , Munyua PM , Oyas H , Njagi O , Lofgren E , Marsh T , Widdowson MA , Bett B , Njenga MK . BMC Infect Dis 2021 21 (1) 191 BACKGROUND: Developing disease risk maps for priority endemic and episodic diseases is becoming increasingly important for more effective disease management, particularly in resource limited countries. For endemic and easily diagnosed diseases such as anthrax, using historical data to identify hotspots and start to define ecological risk factors of its occurrence is a plausible approach. Using 666 livestock anthrax events reported in Kenya over 60 years (1957-2017), we determined the temporal and spatial patterns of the disease as a step towards identifying and characterizing anthrax hotspots in the region. METHODS: Data were initially aggregated by administrative unit and later analyzed by agro-ecological zones (AEZ) to reveal anthrax spatio-temporal trends and patterns. Variations in the occurrence of anthrax events were estimated by fitting Poisson generalized linear mixed-effects models to the data with AEZs and calendar months as fixed effects and sub-counties as random effects. RESULTS: The country reported approximately 10 anthrax events annually, with the number increasing to as many as 50 annually by the year 2005. Spatial classification of the events in eight counties that reported the highest numbers revealed spatial clustering in certain administrative sub-counties, with 12% of the sub-counties responsible for over 30% of anthrax events, whereas 36% did not report any anthrax disease over the 60-year period. When segregated by AEZs, there was significantly greater risk of anthrax disease occurring in agro-alpine, high, and medium potential AEZs when compared to the agriculturally low potential arid and semi-arid AEZs of the country (p < 0.05). Interestingly, cattle were > 10 times more likely to be infected by B. anthracis than sheep, goats, or camels. There was lower risk of anthrax events in August (P = 0.034) and December (P = 0.061), months that follow long and short rain periods, respectively. CONCLUSION: Taken together, these findings suggest existence of certain geographic, ecological, and demographic risk factors that promote B. anthracis persistence and trasmission in the disease hotspots. |
High incidence of human brucellosis in a rural pastoralist community in Kenya, 2015
Munyua P , Osoro E , Hunsperger E , Ngere I , Muturi M , Mwatondo A , Marwanga D , Ngere P , Tiller R , Onyango CO , Njenga K , Widdowson MA . PLoS Negl Trop Dis 2021 15 (2) e0009049 BACKGROUND: Brucellosis occurs globally with highly variable incidence in humans from very low in North America and Western Europe to high in the Middle East and Asia. There are few data in Sub-Saharan Africa. This study estimated the incidence of human brucellosis in a pastoralist community in Kenya. METHODS: Between February 2015 and January 2016, we enrolled persons living in randomly selected households in Kajiado County. Free health care was offered at three facilities in the study area. Those who met the study clinical case definition completed a standardized questionnaire on demographics, clinical history and presentation. A blood sample was collected and tested by Rose Bengal test (RBT), then later tested at the Kenya Medical Research Institute laboratory for Brucella IgG and IgM by ELISA. Those who tested positive by both RBT and ELISA (IgG or IgM antibodies) were classified as confirmed while those that only tested positive for IgG or IgM antibodies were classified as probable. Further, sera were tested by polymerase chain reaction using a TaqMan Array Card (TAC) for a panel of pathogens causing AFI including Brucella spp. Annual incidence of brucellosis was calculated as the number of confirmed cases in one year/total number in the study population. RESULTS: We enrolled a cohort of 4746 persons in 804 households. Over half (52.3%) were males and the median age was 18 years (Interquartile range (IQR) 9 months- 32 years). A total of 236 patients were enrolled at three health facilities; 64% were females and the median age was 40.5 years (IQR 28-53 years). Thirty-nine (16.5%) were positive for Brucella antibodies by IgG ELISA, 5/236 (2.1%) by IgM ELISA and 4/236 (1.7%) by RBT. Ten percent 22/217 were positive by TAC. We confirmed four (1.7%) brucellosis cases giving an annual incidence of 84/100,000 persons/year (95% CI 82, 87). The incidence did not significantly vary by gender, age and location of residence. CONCLUSION: We report a high incidence of brucellosis in humans among members of this pastoralist community. Brucellosis was the most common cause febrile illness in this community. |
Carriage of antimicrobial-resistant bacteria in a high-density informal settlement in Kenya is associated with environmental risk-factors
Omulo S , Lofgren ET , Lockwood S , Thumbi SM , Bigogo G , Ouma A , Verani JR , Juma B , Njenga MK , Kariuki S , McElwain TF , Palmer GH , Call DR . Antimicrob Resist Infect Control 2021 10 (1) 18 BACKGROUND: The relationship between antibiotic use and antimicrobial resistance varies with cultural, socio-economic, and environmental factors. We examined these relationships in Kibera, an informal settlement in Nairobi-Kenya, characterized by high population density, high burden of respiratory disease and diarrhea. METHODS: Two-hundred households were enrolled in a 5-month longitudinal study. One adult (≥ 18 years) and one child (≤ 5 years) participated per household. Biweekly interviews (n = 1516) that included questions on water, sanitation, hygiene, and antibiotic use in the previous two weeks were conducted, and 2341 stool, 2843 hand swabs and 1490 drinking water samples collected. Presumptive E. coli (n = 34,042) were isolated and tested for susceptibility to nine antibiotics. RESULTS: Eighty percent of presumptive E. coli were resistant to ≥ 3 antibiotic classes. Stool isolates were resistant to trimethoprim (mean: 81%), sulfamethoxazole (80%), ampicillin (68%), streptomycin (60%) and tetracycline (55%). Ninety-seven households reported using an antibiotic in at least one visit over the study period for a total of 144 episodes and 190 antibiotic doses. Enrolled children had five times the number of episodes reported by enrolled adults (96 vs. 19). Multivariable linear mixed-effects models indicated that children eating soil from the household yard and the presence of informal hand-washing stations were associated with increased numbers of antimicrobial-resistant bacteria (counts increasing by 0·27-0·80 log(10) and 0·22-0·51 log(10) respectively, depending on the antibiotic tested). Rainy conditions were associated with reduced carriage of antimicrobial-resistant bacteria (1·19 to 3·26 log(10) depending on the antibiotic tested). CONCLUSIONS: Antibiotic use provided little explanatory power for the prevalence of antimicrobial resistance. Transmission of resistant bacteria in this setting through unsanitary living conditions likely overwhelms incremental changes in antibiotic use. Under such circumstances, sanitation, hygiene, and disease transmission are the limiting factors for reducing the prevalence of resistant bacteria. |
High MERS-CoV seropositivity associated with camel herd profile, husbandry practices and household socio-demographic characteristics in Northern Kenya
Ngere I , Munyua P , Harcourt J , Hunsperger E , Thornburg N , Muturi M , Osoro E , Gachohi J , Bodha B , Okotu B , Oyugi J , Jaoko W , Mwatondo A , Njenga K , Widdowson MA . Epidemiol Infect 2020 148 1-31 Despite high exposure to Middle East respiratory syndrome coronavirus (MERS-CoV), the predictors for seropositivity in the context of husbandry practices for camels in Eastern Africa are not well understood. We conducted a cross-sectional survey to describe the camel herd profile and determine the factors associated with MERS-CoV seropositivity in Northern Kenya. We enrolled 29 camel-owning households and administered questionnaires to collect herd and household data. Serum samples collected from 493 randomly selected camels were tested for anti-MERS-CoV antibodies using a microneutralisation assay, and regression analysis used to correlate herd and household characteristics with camel seropositivity. Households reared camels (median = 23 camels and IQR 16-56), and at least one other livestock species in two distinct herds; a home herd kept near homesteads, and a range/fora herd that resided far from the homestead. The overall MERS-CoV IgG seropositivity was 76.3%, with no statistically significant difference between home and fora herds. Significant predictors for seropositivity (P ⩽ 0.05) included camels 6-10 years old (aOR 2.3, 95% CI 1.0-5.2), herds with ⩾25 camels (aOR 2.0, 95% CI 1.2-3.4) and camels from Gabra community (aOR 2.3, 95% CI 1.2-4.2). These results suggest high levels of virus transmission among camels, with potential for human infection. |
Epidemiological investigation of a Rift Valley fever outbreak in humans and livestock in Kenya, 2018
Hassan A , Muturi M , Mwatondo A , Omolo J , Bett B , Gikundi S , Konongoi L , Ofula V , Makayotto L , Kasiti J , Oele E , Onyango C , Gura Z , Njenga K , Munyua P . Am J Trop Med Hyg 2020 103 (4) 1649-1655 On the last week of May of 2018, a community-based syndromic surveillance system detected mass abortions and deaths of young livestock in northeastern Kenya. Two weeks later, Rift Valley fever (RVF) was confirmed in humans presenting with febrile illness and hemorrhagic syndrome in the same region. A joint animal and human response team carried out an investigation to characterize the outbreak and identify drivers of disease transmission. Here, we describe the outbreak investigation and findings. A total of 106 human cases were identified in the months of May and June 2018: 92% (98) and 8% (8) of these cases occurring in the northern and western regions of Kenya, respectively. Seventy-six (72%) were probable cases, and 30 (28%) were laboratory confirmed by ELISA and/or PCR. Among the confirmed cases, the median age was 27.5 years (interquartile range = 20), and 60% (18) were males. Overall, the case fatality rate was 7% (n = 8). The majority of the confirmed cases, 19 (63%), reported contact with livestock during slaughter and consumption of meat from sick animals. All confirmed cases had fever, 40% (12) presented with hemorrhagic syndrome, and 23% (7) presented with jaundice. Forty-three livestock herds with at least one suspect and/or confirmed animal case were identified. Death of young animals was reported in 93% (40) and abortions in 84% (36) of livestock herds. The outbreak is indicative of the emergence potential of RVF in traditionally high- and low-risk areas and the risk posed by zoonosis to livestock keepers. |
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