Last data update: Jun 03, 2024. (Total: 46935 publications since 2009)
Records 1-29 (of 29 Records) |
Query Trace: Omolo J [original query] |
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Predictors of never testing for HIV among sexually active individuals aged 15-56 years in Rwanda
Niyompano H , Biracyaza E , Hakizayezu F , Niyoyita JC , Ndayisenga J , Omolo J , Umubyeyi A . Sci Rep 2024 14 (1) 2259 Human Immunodeficiency Virus (HIV) testing services are known as the primary step in preventing the spread of HIV. However, access to these crucial services varies across regions within continents due to disparities in healthcare infrastructure, resources, and awareness. Approximately one in every five people living with HIV (PLWH) encounters obstacles in accessing HIV testing, notably in Eastern and Southern Africa, where geographical, resource, awareness, and infrastructure limitations prevail. Consequently, HIV remains a significant public health concern in these regions, necessitating expanded testing efforts to combat the HIV/AIDS disaster. Despite these challenges, there is a lack of scientific evidence on the prevalence of HIV testing and its determining factors in Rwanda. This study determined the prevalence of never being tested for HIV and its associated factors among sexually active individuals aged 15-56 who participated in the Rwanda AIDS Indicators and HIV Incidence Survey (RAIHIS). This cross-sectional study enrolled 1846 participants. The variables were extracted from the RAIHIS dataset and statistically analyzed using STATA software version 13. Bivariate and multivariate logistic regression models were employed to identify predictors of never having undergone HIV testing, with a 95% confidence interval and a 5% statistical significance level applied. The prevalence of non-testing for HIV was 17.37%. Being aged 15-30 years (aOR 2.57, 95%CI 1.49-4.43, p < 0.001) and male (aOR 2.44, 95%CI 1.77-3.36, p < 0.001) was associated with an increase in the odds of never testing for HIV. Further, those from urban area were less likely than those living in rural areas to have never tested for HIV (aOR 0.31; 95% CI 0.38-0.67; p < 0.001). Participants who were not aware of HIV test facilitates were more likely to have never undergone HIV testing (aOR 1.75; 95% CI 1.25-2.47; p = 0.031) than their counterparts. While the prevalence of HIV non-testing remains modest, the significance of youth, male gender, lack of awareness, and rural residence as influential factors prompts a call for inventive strategies to tackle the reasons behind never having undergone HIV testing. Further exploration using mixed methodologies is advocated to better comprehend socio-cultural impacts and causation relating to these identified factors. |
Prevalence and factors associated with hypertension among HIV positive patients on antiretroviral therapy: A hospital-based cross-sectional study in Rwanda
Uwanyirigira D , Biracyaza E , Uzabakiriho I , Omolo J , Hakizayezu F , Nzayirambaho M . Vasc Health Risk Manag 2023 19 857-870 INTRODUCTION: The human immunodeficiency virus (HIV) and the use of antiretroviral therapy (ART) are influential elements contributing to hypertension, which is a public health concern particularly in sub-Saharan Africa where its underdiagnosis and limited investigation persist. Moreover, hypertension prevails at higher rates among individuals living with HIV (PLWH) in comparison to the general population. Therefore, our study determined the prevalence of hypertension and its associated factors among PLWH who are undergoing ART treatment at Byumba District Hospital. METHODS: A cross-sectional study design was conducted among 406 PLWH over the age of 14 years who were undergoing ART within the HIV department. We performed statistical analyses using STATA version 13. Significant independent variables identified in the bivariate analysis were further exported in a multivariable logistic regression model to ascertain their association with hypertension. This model elucidated factors associated with hypertension, presenting outcomes through odds ratios and their respective 95% confidence intervals, with statistical significance set at p < 0.05. RESULTS: The prevalence of hypertension was 24.7%, which means that roughly 1 in 4 PLWH were hypertensive. Notably, individuals aged 41 years and above demonstrated a significant association with heightened hypertension [AOR = 4.49; 95% CI = 2.45-8.21, p < 0.001] in contrast to those aged between 14 and 40 years. Additionally, smokers [AOR = 12.12; 95% CI = 4.48-32.74, p < 0.001] and individuals with a family history of hypertension [AOR = 4.28; 95% CI = 1.01-18.13, p = 0.049] demonstrated a higher likelihood of hypertension than their counterparts. Moreover, alcohol consumers [AOR = 5.5; 95% CI = 2.75-10.9, p < 0.001] had an increased likelihoods of hypertension compared to non-drinkers. Lastly, diabetics were almost 6 times more likely to be hypotensive [AOR = 4.50; 95% CI = 2.55-7.95, p = 0.018] when compared to those without diabetes. CONCLUSION: Our findings strongly underscore the urgency for the implementation of targeted programs aimed at enhancing awareness and comprehension of the factors and potential complications tied to hypertension among PLWH. Such programs could be integrated into routine HIV care services to provide patients with the information and skills required to manage their hypertension effectively. |
Incidence and factors associated with being lost to follow-up among people living with HIV and receiving antiretroviral therapy in Nyarugenge the central business district of Kigali city, Rwanda
Ntabanganyimana D , Rugema L , Omolo J , Nsekuye O , Malamba SS . PLoS One 2022 17 (10) e0275954 BACKGROUND: Lost to follow-up (LTFUP) continues to threaten the sustainability of antiretroviral therapy (ART) benefits and success of ART programs. We determined the incidence and predictors of LTFUP among people living with HIV (PLHIV) on ART in Nyarugenge the Central Business District of Kigali city. METHODS: A cohort of PLHIV who initiated ART in 2018 was retrospectively studied for 24 months. Using health facility records, a person who had no record of contact with the health facility for at least three consecutive months was considered LTFUP. LTFUP incidence rates were computed, and the Fine-Gray's competing risk regression models were used to determine factors associated with time to first LTFUP. Generalized estimating equations (GEEs) were used to analyze repeated measurement outcomes of LTFUP and predictors of LTFUP. RESULTS: Of 950 participants, 581 (61.2%) were females and 866 (91.2%) were 15 to 49 years old. From 1,586.1 person years of observation (pyo), 148 participants got LTFUP for 451 times. The incidence rate to first event was 9.4 per 100 pyo (95%CI:7.9-10.9) and 31.8 per 100 pyo (95%CI:29.0-34.4) to multiple events. WHO stage, marital status, employment status and person to contact when PLHIV is not reachable were associated with time to first LTFUP event. However, an average participant with a contact person who was not a Community Health Worker (CHW) or a peer educator had higher incidence of LTUP (aIRR = 2.69, 95%CI: 1.43-5.06), an average single patients had higher incidence of LTFUP (aIRR = 1.74, 95%CI: 1.28-2.34) compared to married/co-habiting, and an average self-employed had higher incidence of LTFUP (aIRR = 1.51, 95%CI: 1.14-2.01) compared to participants employed by others. Furthermore, an average PLHIV living out-of-the health facility catchment area had higher incidence of LTFUP (aIRR = 1.55, 95%CI: 1.19-2.01) compared to an average PLHIV living in the health facility catchment area whereas, an average children initiated on first line had lower incidence of LTUP (aIRR = 0.43, 95%CI: 0.21-0.86) compared to adults. CONCLUSION: Using CHW and peer educators as contact persons can help to reduce LTFUP while, targeted sensitization and service delivery are needed for single, self-employed and, patients living out of the health facility catchment area. |
Treatment outcome and factors associated with mortality due to malaria in Munini District Hospital, Rwanda in 2016-2017: Retrospective cross-sectional study
Hakizayezu F , Omolo J , Biracyaza E , Ntaganira J . Front Public Health 2022 10 898528 INTRODUCTION: Malaria is a major public health burden in developing countries despite efforts made by several countries. This disease leads to high morbidity and mortality among Rwandans, particularly in the Southern Province where it was the sixth national cause of morality; at Munini hospital it is the first cause of mortality, but the associated factors remain unknown. In this study, we determined the factors associated with deaths among patients with severe malaria to come up with evidence-based interventions to prevent malaria and its factors. METHODS: A retrospective cross-sectional study was conducted on malaria patients who were treated at the Munini District Hospital from 2016 to 2017. Data were collected from the hospital records or registers relating to patients who were admitted with severe malaria. The odds ratio was estimated by bivariate logistic regression and multivariate hierarchical regression models for determining the associated factors of deaths. Data were analyzed using STATA/MP Version 14.1 and Epi-info with proportions. RESULTS: The study population were mostly women (n = 237, 59.1%), farmers (n = 313, 78.05%), aged 16-30 years (n = 107, 26.68%). Our results indicated that the majority of deaths were women (56.25%). Socio-economic and clinical determinants are important predictors of death among patients with severe malaria. Patients with coma had higher odds of dying (AOR = 7.31, 95% CI :3.33-16.1, p < 0.001) than those who were not. The possibility of mortality increased by almost four times in patients who delayed consultation by a day (AOR = 3.7, 95%CI:1.8-4.1; p < 0.001) compared to those who came in very early. Patients who had severe malaria in the dry season were at a lower risk of mortality (AOR = 0.23, 95%CI:0.08-0.64, p = 0.005) compared to those with severe malaria during the rainy season. CONCLUSION: Lack of health insurance, age of the patient, delayed diagnosis, coma, proximity and access to healthcare services, and weather conditions were the major factors associated with mortality among patients with severe malaria. Comprehensive, long-term, equity-based healthcare interventions and immediate care strategies are recommended. |
HIV incidence and prevalence among adults aged 15-64 years in Rwanda: Results from the Rwanda Population-based HIV Impact Assessment (RPHIA) and District-level Modeling, 2019
Nsanzimana S , Rwibasira G , Malamba SS , Musengimana G , Kayirangwa E , Jonnalagadda S , Fazito E , Eaton J , Mugisha V , Remera E , Semakula M , Mulindabigwi A , Omolo FJ , Wiesner L , Moore C , Patel H , Justman J . Int J Infect Dis 2022 116 245-254 OBJECTIVES: The 2018-19 Rwanda Population-based HIV Impact Assessment (RPHIA) was conducted to measure national HIV incidence and prevalence. District-level estimates were modeled to inform resources allocation. METHODS: RPHIA was a nationally representative cross-sectional household survey. Consenting adults were interviewed and tested for HIV using the national diagnostic algorithm followed by laboratory-based confirmation of HIV status, and testing for viral load (VL), limiting antigen (LAg) avidity and presence of antiretrovirals. Incidence was calculated using normalized optical density ≤ 1•5, VL ≥ 1,000 copies/mL, and undetectable antiretrovirals. Survey and programmatic data were used to model district-level HIV incidence and prevalence. RESULTS: Of 31,028 eligible adults, 98•7% participated in RPHIA and 934 tested HIV positive. HIV prevalence among adults in Rwanda was 3•0% (95% CI:2•7-3•3). National HIV incidence was 0•08% (95% CI:0•02-0•14) and 0•11% (95% CI:0•00-0•26) in the City of Kigali (CoK). Based on district-level modeling, HIV incidence was greatest in the three CoK districts (0•11% to 0•15%) and varied across other districts (0•03% to 0•10%). CONCLUSIONS: HIV prevalence among adults in Rwanda is 3.0%; HIV incidence is low at 0.08%. District-level modeling has identified disproportionately affected urban hotspots: areas to focus resources. |
Recent infections among individuals with a new HIV diagnosis in Rwanda, 2018-2020
Rwibasira GN , Malamba SS , Musengimana G , Nkunda RCM , Omolo J , Remera E , Masengesho V , Mbonitegeka V , Dzinamarira T , Kayirangwa E , Mugwaneza P . PLoS One 2021 16 (11) e0259708 BACKGROUND: Despite Rwanda's progress toward HIV epidemic control, 16.2% of HIV-positive individuals are unaware of their HIV positive status. Tailoring the public health strategy could help reach these individuals with new HIV infection and achieve epidemic control. Recency testing is primarily for surveillance, monitoring, and evaluation but it's not for diagnostic purposes. However, it's important to know what proportion of the newly diagnosed are recent infections so that HIV prevention can be tailored to the profile of people who are recently infected. We therefore used available national data to characterize individuals with recent HIV infection in Rwanda to inform the epidemic response. METHODS: We included all national-level data for recency testing reported from October 2018 to June 2020. Eligible participants were adults (aged ≥15 years) who had a new HIV diagnosis, who self-reported being antiretroviral therapy (ART) naïve, and who had consented to recency testing. Numbers and proportions of recent HIV infections were estimated, and precision around these estimates was calculated with 95% confidence intervals (CI). Logistic regression was used to assess factors associated with being recently (within 12 months) infected with HIV. RESULTS: Of 7,785 eligible individuals with a new HIV-positive diagnosis, 475 (6.1%) met the criteria for RITA recent infection. The proportion of RITA recent infections among individuals with newly identified HIV was high among those aged 15-24 years (9.6%) and in men aged ≥65 years (10.3%) compared to other age groups; and were higher among women (6.7%) than men (5.1%). Of all recent cases, 68.8% were women, and 72.2% were aged 15-34 years. The Northern province had the fewest individuals with newly diagnosed HIV but had the highest proportion of recent infections (10.0%) compared to other provinces. Recent infections decreased by 19.6% per unit change in time (measured in months). Patients aged ≥25 years were less likely to have recent infection than those aged 15-24 years with those aged 35-49 years being the least likely to have recent infection compared to those aged 15-24 years (adjusted odds ratio [aOR], 0.415 [95% CI: 0.316-0.544]). CONCLUSION: Public health surveillance targeting the areas and the identified groups with high risk of recent infection could help improve outcomes. |
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. |
Building global epidemiology and response capacity with field epidemiology training programs
Jones DS , Dicker RC , Fontaine RE , Boore AL , Omolo JO , Ashgar RJ , Baggett HC . Emerg Infect Dis 2017 23 (13) S158-65 More than ever, competent field epidemiologists are needed worldwide. As known, new, and resurgent communicable diseases increase their global impact, the International Health Regulations and the Global Health Security Agenda call for sufficient field epidemiologic capacity in every country to rapidly detect, respond to, and contain public health emergencies, thereby ensuring global health security. To build this capacity, for >35 years the US Centers for Disease Control and Prevention has worked with countries around the globe to develop Field Epidemiology Training Programs (FETPs). FETP trainees conduct surveillance activities and outbreak investigations in service to ministry of health programs to prevent and control infectious diseases of global health importance such as polio, cholera, tuberculosis, HIV/AIDS, malaria, and emerging zoonotic infectious diseases. FETP graduates often rise to positions of leadership to direct such programs. By training competent epidemiologists to manage public health events locally and support public health systems nationally, health security is enhanced globally. |
The national burden of influenza-associated severe acute respiratory illness hospitalization in Rwanda, 2012-2014
Nyamusore J , Rukelibuga J , Mutagoma M , Muhire A , Kabanda A , Williams T , Mutoni A , Kamwesiga J , Nyatanyi T , Omolo J , Kabeja A , Koama JB , Mukarurangwa A , Umuringa JD , Granados C , Gasana M , Moen A , Tempia S . Influenza Other Respir Viruses 2017 12 (1) 38-45 BACKGROUND: Estimates of influenza-associated hospitalization are severely limited in low- and middle-income countries, especially in Africa. OBJECTIVES: To estimate the national number of influenza-associated severe acute respiratory illness (SARI) hospitalization in Rwanda. METHODS: We multiplied the influenza virus detection rate from influenza surveillance conducted at 6 sentinel hospitals by the national number of respiratory hospitalization obtained from passive surveillance after adjusting for underreporting and reclassification of any respiratory hospitalizations as SARI during 2012-2014. The population at risk was obtained from projections of the 2012 census. Bootstrapping was used for the calculation of confidence intervals (CI) to account for the uncertainty associated with all levels of adjustment. Rates were expressed per 100 000 population. A sensitivity analysis using a different estimation approach was also conducted. RESULTS: SARI cases accounted for 70.6% (9759/13 813) of respiratory admissions at selected hospitals: 77.2% (6783/8786) and 59.2% (2976/5028) among individuals aged <5 and ≥5 years, respectively. Overall, among SARI cases tested, the influenza virus detection rate was 6.3% (190/3022): 5.7% (127/2220) and 7.8% (63/802) among individuals aged <5 and ≥5 years, respectively. The estimated mean annual national number of influenza-associated SARI hospitalizations was 3663 (95% CI: 2930-4395-rate: 34.7; 95% CI: 25.4-47.7): 2637 (95% CI: 2110-3164-rate: 168.7; 95% CI: 135.0-202.4) among children aged <5 years and 1026 (95% CI: 821-1231-rate: 11.3; 95% CI: 9.0-13.6) among individuals aged ≥5 years. The estimates obtained from both approaches were not statistically different (overlapping CIs). CONCLUSIONS: The burden of influenza-associated SARI hospitalizations was substantial and was highest among children aged <5 years. |
Non-disclosure to male partners and incomplete PMTCT regimens associated with higher risk of mother-to-child HIV transmission: a national survey in Kenya
McGrath CJ , Singa B , Langat A , Kinuthia J , Ronen K , Omolo D , Odongo BE , Wafula R , Muange P , Katana A , Ng'anga L , John-Stewart GC . AIDS Care 2017 30 (6) 1-9 Health worker experience and community support may be higher in high HIV prevalence regions than low prevalence regions, leading to improved prevention of mother-to-child HIV transmission (PMTCT) programs. We evaluated 6-week and 9-month infant HIV transmission risk (TR) in a high prevalence region and nationally. Population-proportionate-to-size sampling was used to select 141 clinics in Kenya, and mobile teams surveyed mother-infant pairs attending 6-week and 9-month immunizations. HIV DNA testing was performed on HIV-exposed infants. Among 2521 mother-infant pairs surveyed nationally, 2423 (94.7%) reported HIV testing in pregnancy or prior diagnosis, of whom 200 (7.4%) were HIV-infected and 188 infants underwent HIV testing. TR was 8.8% (4.0%-18.3%) in 6-week and 8.9% (3.2%-22.2%) in 9-month cohorts including mothers with HIV diagnosed postpartum, of which 53% of infant infections were due to previously undiagnosed mothers. Of 276 HIV-exposed infants in the Nyanza survey, TR was 1.4% (0.4%-5.3%) at 6-week and 5.1% (2.5%-9.9%) at 9-months. Overall TR was lower in Nyanza, high HIV region, than nationally (3.3% vs. 7.2%, P = 0.02). HIV non-disclosure to male partners and incomplete ARVs were associated with TR in both surveys [aOR = 12.8 (3.0-54.3); aOR = 5.6 (1.2-27.4); aOR = 4.5 (1.0-20.0), aOR = 2.5, (0.8-8.4), respectively]. TR was lower in a high HIV prevalence region which had better ARV completion and partner HIV disclosure, possibly due to programmatic efficiencies or community/peer/partner support. Most 9-month infections were among infants of mothers without prior HIV diagnosis. Strategies to detect incident or undiagnosed maternal infections will be important to achieve PMTCT. |
Implementing One Health as an integrated approach to health in Rwanda
Nyatanyi T , Wilkes M , McDermott H , Nzietchueng S , Gafarasi I , Mudakikwa A , Kinani JF , Rukelibuga J , Omolo J , Mupfasoni D , Kabeja A , Nyamusore J , Nziza J , Hakizimana JL , Kamugisha J , Nkunda R , Kibuuka R , Rugigana E , Farmer P , Cotton P , Binagwaho A . BMJ Glob Health 2017 2 (1) e000121 It is increasingly clear that resolution of complex global health problems requires interdisciplinary, intersectoral expertise and cooperation from governmental, non-governmental and educational agencies. 'One Health' refers to the collaboration of multiple disciplines and sectors working locally, nationally and globally to attain optimal health for people, animals and the environment. One Health offers the opportunity to acknowledge shared interests, set common goals, and drive toward team work to benefit the overall health of a nation. As in most countries, the health of Rwanda's people and economy are highly dependent on the health of the environment. Recently, Rwanda has developed a One Health strategic plan to meet its human, animal and environmental health challenges. This approach drives innovations that are important to solve both acute and chronic health problems and offers synergy across systems, resulting in improved communication, evidence-based solutions, development of a new generation of systems-thinkers, improved surveillance, decreased lag time in response, and improved health and economic savings. Several factors have enabled the One Health movement in Rwanda including an elaborate network of community health workers, existing rapid response teams, international academic partnerships willing to look more broadly than at a single disease or population, and relative equity between female and male health professionals. Barriers to implementing this strategy include competition over budget, poor communication, and the need for improved technology. Given the interconnectedness of our global community, it may be time for countries and their neighbours to follow Rwanda's lead and consider incorporating One Health principles into their national strategic health plans. |
Laboratory-based performance evaluation of PIMA CD4+ T-lymphocyte count point-of-care by lay-counselors in Kenya
Zeh C , Rose CE , Inzaule S , Desai MA , Otieno F , Humwa F , Akoth B , Omolo P , Chen RT , Kebede Y , Samandri T . J Immunol Methods 2017 448 44-50 BACKGROUND: CD4+ T-lymphocyte count testing at the point-of-care (POC) may improve linkage to care of persons diagnosed with HIV-1 infection, but the accuracy of POC devices when operated by lay-counselors in the era of task-shifting is unknown. We examined the accuracy of Alere's Pima POC device on both capillary and venous blood when performed by lay-counselors and laboratory technicians. METHODS: In Phase I, we compared the perfomance of POC against FACSCalibur for 280 venous specimens by laboratory technicians. In Phase II we compared POC performance by lay-counselors versus laboratory technicians using 147 paired capillary and venous specimens, and compared these to FACSCalibur. Statistical analyses included Bland-Altman analyses, concordance correlation coefficient, sensitivity, and specificity at treatment eligibility thresholds of 200, 350, and 500cells/mul. RESULTS: Phase I: POC sensitivity and specificity were 93.0% and 84.1% at 500cells/mul, respectively. Phase II: Good agreement was observed for venous POC results from both lay-counselors (concordance correlation coefficient (CCC)=0.873, bias -86.4cells/mul) and laboratory technicians (CCC=0.920, bias -65.7cells/mul). Capillary POC had good correlation: lay-counselors (CCC=0.902, bias -71.2cells/mul), laboratory technicians (CCC=0.918, bias -63.0cells/mul). Misclassification at the 500 cells/mul threshold for venous blood was 13.6% and 10.2% for lay-counselors and laboratory technicians and 12.2% for capillary blood in both groups. POC tended to under-classify the CD4 values with increasingly negative bias at higher CD4 values. CONCLUSIONS: Pima results were comparable to FACSCalibur for both venous and capillary specimens when operated by lay-counselors. POC CD4 testing has the potential to improve linkage to HIV care without burdening laboratory technicians in resource-limited settings. |
Sero-prevalence for hepatitis B virus among pregnant women attending antenatal clinic in Juba Teaching Hospital, Republic of South Sudan
Kirbak ALS , Ng'ang'a Z , Omolo J , Idris H , Usman A , Mbabazi WB . Pan Afr Med J 2017 26 72 INTRODUCTION: Hepatitis B virus infection is a major public health problem worldwide and in Africa. This would be the first ever documented study on epidemiology of Hepatitis B infections in the newly formed Republic of South Sudan. This study was designed to estimate the sero-prevalence of Hepatitis B virus infection amongst pregnant women attending antenatal services in Juba. METHODS: A cross-sectional study was conducted among pregnant women attending antenatal clinic services in Juba Teaching Hospital, in the period between December 2012 and March 2013. Any pregnant woman, attending antenatal care services at Juba Teaching Hospital, was included if she was a resident of Juba County for at least 1 year before pregnancy. A Hepatitis B case was defined as any women participating in the study and was found to be positive for HbsAg and confirmed by ELISA. RESULTS: This study documented that the prevalence of Hepatitis B surface antigen (HBsAg) among pregnant women attending ANC in Juba was 11% (31 out of the 280 samples). Other samples tested were indeterminate (36%), naturally immune (27.1%), susceptible (23%) and the remaining 1.8% was immune due to vaccination. Significant risk factors for Hepatitis B infection were loss of partner (OR 4.4 and CI of 1.4-13.9) and history of Jaundice (OR 1.7 and CI of 1.2-2.1). CONCLUSION: These study findings show that only 29% of infants in Juba county are born to immune mothers (naturally or vaccine induced). The remaining 70% of babies would be at risk of infection, if a birth dose of Hepatitis B is not provided. We therefore recommended introduction of Hepatitis B Vaccine birth dose into routine infants' vaccination series to eliminate this risk. |
Establishment of reference intervals during normal pregnancy through six months postpartum in western Kenya
Odhiambo C , Omolo P , Oyaro B , Williamson J , Kinuthia J , Matemo D , Drake A , John-Stewart G , Zeh C . PLoS One 2017 12 (4) e0175546 BACKGROUND: Pregnancy is associated with changes in hematological and biochemistry values, yet there are no African reference intervals for clinical management of pregnant women. We sought to 1) develop laboratory reference intervals during pregnancy and up to 24 weeks postpartum and 2) determine the proportion of women in a previous clinical trial who would be misclassified as having out-of-range values using reference intervals from a United States (U.S.) population. METHODS AND FINDINGS: This was a longitudinal sub-study of 120 clinically healthy, HIV-uninfected, self-selected pregnant women seeking antenatal care services at either of two public hospitals in western Kenya. Blood specimens were obtained from consented women at gestational ages 28 and 36 weeks and at 2, 6, 14 and 24 weeks postpartum. Median and 95% reference intervals were calculated for immune-hematological and biochemistry parameters and compared to reference intervals from a Kenyan and United States (U.S.) population, using Wilcoxon tests. Differences with p≤0.05 were considered significant. Some hematological parameters, including hemoglobin and neutrophils showed significant variations compared to reference intervals for non-pregnant women. Hemoglobin values were significantly lower during pregnancy but were comparable to the values in non-pregnant women by 6 weeks postpartum. CD4, CD8 and platelets were significantly elevated in early postpartum but declined gradually, reaching normal levels by 24 weeks postpartum. Using the new hemoglobin reference levels from this study to estimate prevalence of 'out of range' values in a prior Kisumu research cohort of pregnant/postpartum women, resulted in 0% out of range values, in contrast to 96.3% using US non-pregnant reference values. CONCLUSION: There were substantial differences in U.S. and Kenyan values for immune-hematological parameters among pregnant/postpartum women, specifically in red blood cell parameters in late pregnancy and 2 weeks postpartum. Use of U.S. reference intervals markedly increases likelihood of out of range values, highlighting the need for suitable locally developed reference intervals. |
Gaps in adolescent engagement in antenatal care and prevention of mother-to-child HIV transmission services in Kenya
Ronen K , McGrath CJ , Langat AC , Kinuthia J , Omolo D , Singa B , Katana AK , Ng'Ang ALw , John-Stewart G . J Acquir Immune Defic Syndr 2016 74 (1) 30-37 BACKGROUND: Rates of pregnancy and HIV infection are high among adolescents. However, their engagement in prevention of mother-to-child HIV transmission (PMTCT) services is poorly characterized. We compared engagement in the PMTCT cascade between adult and adolescent mothers in Kenya. METHODS: We conducted a nationally representative cross-sectional survey of mother-infant pairs attending 120 maternal child health clinics selected by probability-proportionate-to-size-sampling, with a secondary survey oversampling HIV-positive mothers in 30 clinics. ANC attendance, HIV testing and ARV use were compared between adolescent (age ≤19) and adult mothers using Chi-square tests and logistic regression. RESULTS: Among 2521 mothers, 278 (12.8%) were adolescents. Adolescents were less likely than adults to be employed (16.5% vs. 37.9%), married (66.1% vs. 88.3%), have intended pregnancy (40.5% vs. 58.6%), or have disclosed their HIV status (77.5% vs. 90.7%) (p<0.01 for all). Adolescents were less likely than adults to attend ≥4 ANC visits (35.2% vs. 45.6%, p=0.002). This effect remained significant when adjusting for employment, household crowding, pregnancy intention, gravidity and HIV status (aOR[95% CI]=0.54[0.37-0.97], p=0.001). Among 2359 women without previous HIV testing, 96.1% received testing during pregnancy; testing levels did not differ between adolescents and adults. Among 288 HIV-positive women not on ART prior to pregnancy, adolescents were less likely than adults to be on ARVs (65.0% vs. 85.8%, p=0.01) or to have infants on ARVs (85.7% vs. 97.7%, p=0.005). CONCLUSIONS: Adolescent mothers had poorer ANC attendance and uptake of ARVs for PMTCT. Targeted interventions are needed to improve retention of this vulnerable population in the PMTCT cascade. |
Clinical evaluation of the BD FACSPresto Near-Patient CD4 Counter in Kenya
Angira F , Akoth B , Omolo P , Opollo V , Bornheimer S , Judge K , Tilahun H , Lu B , Omana-Zapata I , Zeh C . PLoS One 2016 11 (8) e0157939 BACKGROUND: The BD FACSPresto Near-Patient CD4 Counter was developed to expand HIV/AIDS management in resource-limited settings. It measures absolute CD4 counts (AbsCD4), percent CD4 (%CD4), and hemoglobin (Hb) from a single drop of capillary or venous blood in approximately 23 minutes, with throughput of 10 samples per hour. We assessed the performance of the BD FACSPresto system, evaluating accuracy, stability, linearity, precision, and reference intervals using capillary and venous blood at KEMRI/CDC HIV-research laboratory, Kisumu, Kenya, and precision and linearity at BD Biosciences, California, USA. METHODS: For accuracy, venous samples were tested using the BD FACSCalibur instrument with BD Tritest CD3/CD4/CD45 reagent, BD Trucount tubes, and BD Multiset software for AbsCD4 and %CD4, and the Sysmex KX-21N for Hb. Stability studies evaluated duration of staining (18-120-minute incubation), and effects of venous blood storage <6-24 hours post-draw. A normal cohort was tested for reference intervals. Precision covered multiple days, operators, and instruments. Linearity required mixing two pools of samples, to obtain evenly spaced concentrations for AbsCD4, total lymphocytes, and Hb. RESULTS: AbsCD4 and %CD4 venous/capillary (N = 189/ N = 162) accuracy results gave Deming regression slopes within 0.97-1.03 and R2 ≥0.96. For Hb, Deming regression results were R2 ≥0.94 and slope ≥0.94 for both venous and capillary samples. Stability varied within 10% 2 hours after staining and for venous blood stored less than 24 hours. Reference intervals results showed that gender-but not age-differences were statistically significant (p<0.05). Precision results had <3.5% coefficient of variation for AbsCD4, %CD4, and Hb, except for low AbsCD4 samples (<6.8%). Linearity was 42-4,897 cells/muL for AbsCD4, 182-11,704 cells/muL for total lymphocytes, and 2-24 g/dL for Hb. CONCLUSIONS: The BD FACSPresto system provides accurate, precise clinical results for capillary or venous blood samples and is suitable for near-patient CD4 testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT02396355. |
A mixed outbreak of epidemic typhus fever and trench fever in a youth rehabilitation center: Risk factors for illness from a case-control study, Rwanda, 2012
Umulisa I , Omolo J , Muldoon KA , Condo J , Habiyaremye F , Uwimana JM , Muhimpundu MA , Galgalo T , Rwunganira S , Dahourou AG , Tongren E , Koama JB , McQuiston J , Raghunathan PL , Massung R , Gatei W , Boer K , Nyatanyi T , Mills EJ , Binagwaho A . Am J Trop Med Hyg 2016 95 (2) 452-6 In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1-5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6-9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0-11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10-0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks. |
Anemia and red blood cell abnormalities in HIV-infected and HIV-exposed breastfed infants: a secondary analysis of the Kisumu Breastfeeding Study
Odhiambo C , Zeh C , Ondoa P , Omolo P , Akoth B , Lwamba H , Lando R , Williamson J , Otieno J , Masaba R , Weidle P , Thomas T . PLoS One 2015 10 (11) e0141599 BACKGROUND: Anemia results in increased morbidity and mortality, underscoring the need to better understand its pathophysiology amongst HIV-exposed and infected children in sub-Saharan Africa, the region where most infant HIV exposure and infections occur. METHODS: This analysis used samples obtained from children in the Kisumu Breastfeeding Study (KiBS). KiBS was a longitudinal phase IIB, open-label, one-arm clinical trial, designed to investigate the safety, tolerability and effectiveness of a maternal triple-antiretroviral (ARV) regimen for prevention of mother-to-child transmission (PMTCT) of HIV, during late pregnancy and early infancy while breastfeeding. Blood samples from 482 children were obtained at birth, 2, 6, 10 and 14 weeks and 6, 9, 12, 18 and 24 months. Severity of anemia was graded using the NIH Division of AIDS (DAIDS) toxicity tables. We describe the proportion of children with anemia and anomalies in red blood cell parameters at various time points over 24 months and compare rates of anemia between HIV-infected and HIV-uninfected children and by mothers' ARV regimen and infant malaria infection. RESULTS: The proportion of children with anemia significantly increased after the breastfeeding period in both HIV-infected and HIV-uninfected children with higher proportion among HIV-infected children compared to HIV-uninfected children (RR: 1.72; CI: 1.22-2.44, p = 0.002). Maternal triple-antiretroviral regimen was not associated with infant anemia (p = 0.11). There was no significant difference in mean hemoglobin between HIV-uninfected children with and without malaria at each time point except at 24 months. CONCLUSION: A relatively lower proportion of children with severe anemia during the breastfeeding period suggest that exposure to mother's triple antiretroviral combinations through breast milk, posed minimal risk of hematologic toxicity. |
A rapid assessment of drinking water quality in informal settlements after a cholera outbreak in Nairobi, Kenya
Blanton E , Wilhelm N , O'Reilly C , Muhonja E , Karoki S , Ope M , Langat D , Omolo J , Wamola N , Oundo J , Hoekstra R , Ayers T , De Cock K , Breiman R , Mintz E , Lantagne D . J Water Health 2015 13 (3) 714-25 Populations living in informal settlements with inadequate water and sanitation infrastructure are at risk of epidemic disease. In 2010, we conducted 398 household surveys in two informal settlements in Nairobi, Kenya with isolated cholera cases. We tested source and household water for free chlorine residual (FCR) and Escherichia coli in approximately 200 households. International guidelines are ≥0.5 mg/L FCR at source, ≥0.2 mg/L at household, and <1 E. coli/100 mL. In these two settlements, 82% and 38% of water sources met FCR guidelines; and 7% and 8% were contaminated with E. coli, respectively. In household stored water, 82% and 35% met FCR guidelines and 11% and 32% were contaminated with E. coli, respectively. Source water FCR ≥0.5 mg/L (p = 0.003) and reported purchase of a household water treatment product (p = 0.002) were associated with increases in likelihood that household stored water had ≥0.2 mg/L FCR, which was associated with a lower likelihood of E. coli contamination (p < 0.001). These results challenge the assumption that water quality in informal settlements is universally poor and the route of disease transmission, and highlight that providing centralized water with ≥0.5 mg/L FCR or (if not feasible) household water treatment technologies reduces the risk of waterborne cholera transmission in informal settlements. |
Establishing a field epidemiology elective for medical students in Kenya: a strategy for increasing public health awareness and workforce capacity
Arvelo W , Gura Z , Amwayi S , Wiersma P , Omolo J , Becknell S , Jones D , Ongore D , Dicker R . J Epidemiol Glob Health 2015 5 (1) 33-9 Medical students have limited exposure to field epidemiology, even though will assume public health roles after graduation. We established a 10-week elective in field epidemiology during medical school. Students attended one-week didactic sessions on epidemiology, and nine weeks in field placement sites. We administered pre- and post-tests to evaluate the training. We enrolled 34 students in 2011 and 2012. In 2011, we enrolled five of 24 applicants from a class of 280 medical students. In 2012, we enrolled 18 of 81 applicants from a class of 360 students; plus 11 who participated in the didactic sessions only. Among the 34 students who completed the didactic sessions, 74% were male, and their median age was 24 years (range: 22-26). The median pre-test score was 64% (range: 47-88%) and the median post-test score was 82% (range: 72-100%). Successful completion of the field projects was 100%. Six (30%) students were not aware of public health as a career option before this elective, 56% rated the field experience as outstanding, and 100% reported it increased their understanding of epidemiology. Implementing an elective in field epidemiology within the medical training is a highly acceptable strategy to increase awareness for public health among medical students. |
Assessing the prevalence of spina bifida and encephalocele in a Kenyan hospital from 2005-2010: implications for a neural tube defects surveillance system
Githuku JN , Azofeifa A , Valencia D , Ao T , Hamner H , Amwayi S , Gura Z , Omolo J , Albright L , Guo J , Arvelo W . Pan Afr Med J 2014 18 60 INTRODUCTION: Neural tube defects such as anencephaly, spina bifida, and encephalocele are congenital anomalies of the central nervous system. Data on the prevalence of neural tube defects in Kenya are limited. This study characterizes and estimates the prevalence of spina bifida and encephalocele reported in a referral hospital in Kenya from 2005-2010. METHODS: Cases were defined as a diagnosis of spina bifida or encephalocele. Prevalence was calculated as the number of cases by year and province of residence divided by the total number of live-births per province. RESULTS: From a total of 6,041 surgical records; 1,184 (93%) had reported diagnosis of spina bifida and 88 (7%) of encephalocele. Estimated prevalence of spina bifida and encephalocele from 2005-2010 was 3.3 [95% Confidence Interval (CI): 3.1-3.5] cases per 10,000 live-births. The highest prevalence of cases were reported in 2007 with 4.4 (95% CI: 3.9-5.0) cases per 10,000 live-births. Rift Valley province had the highest prevalence of spina bifida and encephalocele at 6.9 (95% CI: 6.3-7.5) cases per 10,000 live-births from 2005-2010. CONCLUSION: Prevalence of spina bifida and encephalocele is likely underestimated, as only patients seeking care at the hospital were included. Variations in regional prevalence could be due to referral patterns and healthcare access. Implementation of a neural tube defects surveillance system would provide a more thorough assessment of the burden of neural tube defects in Kenya. |
A national cholera epidemic with high case fatality rates--Kenya 2009
Loharikar A , Briere E , Ope M , Langat D , Njeru I , Gathigi L , Makayotto L , Ismail AM , Thuranira M , Abade A , Amwayi S , Omolo J , Oundo J , De Cock KM , Breiman RF , Ayers T , Mintz E , O'Reilly CE . J Infect Dis 2013 208 Suppl 1 S69-77 BACKGROUND: Cholera remains endemic in sub-Saharan Africa. We characterized the 2009 cholera outbreaks in Kenya and evaluated the response. METHODS: We analyzed surveillance data and estimated case fatality rates (CFRs). Households in 2 districts, East Pokot (224 cases; CFR = 11.7%) and Turkana South (1493 cases; CFR = 1.0%), were surveyed. We randomly selected 15 villages and 8 households per village in each district. Healthcare workers at 27 health facilities (HFs) were surveyed in both districts. RESULTS:. In 2009, cholera outbreaks caused a reported 11 425 cases and 264 deaths in Kenya. Data were available from 44 districts for 6893 (60%) cases. District CFRs ranged from 0% to 14.3%. Surveyed household respondents (n = 240) were aware of cholera (97.5%) and oral rehydration solution (ORS) (87.9%). Cholera deaths were reported more frequently from East Pokot (n = 120) than Turkana South (n = 120) households (20.7% vs. 12.3%). The average travel time to a HF was 31 hours in East Pokot compared with 2 hours in Turkana South. Fewer respondents in East Pokot (9.8%) than in Turkana South (33.9%) stated that ORS was available in their village. ORS or intravenous fluid shortages occurred in 20 (76.9%) surveyed HFs. CONCLUSIONS: High CFRs in Kenya are related to healthcare access disparities, including availability of rehydration supplies. |
Molecular epidemiology of geographically dispersed Vibrio cholerae, Kenya, January 2009-May 2010
Mohamed AA , Oundo J , Kariuki SM , Boga HI , Sharif SK , Akhwale W , Omolo J , Amwayi AS , Mutonga D , Kareko D , Njeru M , Li S , Breiman RF , Stine OC . Emerg Infect Dis 2012 18 (6) 925-31 Numerous outbreaks of cholera have occurred in Kenya since 1971. To more fully understand the epidemiology of cholera in Kenya, we analyzed the genetic relationships among 170 Vibrio cholerae O1 isolates at 5 loci containing variable tandem repeats. The isolates were collected during January 2009-May 2010 from various geographic areas throughout the country. The isolates grouped genetically into 5 clonal complexes, each comprising a series of genotypes that differed by an allelic change at a single locus. No obvious correlation between the geographic locations of the isolates and their genotypes was observed. Nevertheless, geographic differentiation of the clonal complexes occurred. Our analyses showed that multiple genetic lineages of V. cholerae were simultaneously infecting persons in Kenya. This finding is consistent with the simultaneous emergence of multiple distinct genetic lineages of V. cholerae from endemic environmental reservoirs rather than recent introduction and spread by travelers. |
Nevirapine-associated hepatotoxicity and rash among HIV-infected pregnant women in Kenya
Peters PJ , Polle N , Zeh C , Masaba R , Borkowf CB , Oyaro B , Omolo P , Ogindo P , Ndivo R , Angira F , Lando R , Fowler MG , Weidle PJ , Thomas TK . J Int Assoc Physicians AIDS Care (Chic) 2012 11 (2) 142-9 BACKGROUND: Few studies have evaluated the risk of nevirapine (NVP)-associated hepatotoxicity among HIV-infected pregnant women with a CD4 count ≥250 cells/mm(3). METHODS: We enrolled HIV-infected pregnant Kenyan women who initiated triple antiretroviral therapy (ART) at 34 weeks gestation. We compared the rates of severe hepatotoxicity (grades 3-4 hepatotoxicity) and rash-associated hepatotoxicity (rash with ≥grade 2 hepatotoxicity) with NVP and nelfinavir (NFV), respectively. RESULTS: We initiated triple ART in 522 pregnant women; severe hepatotoxicity and rash-associated hepatotoxicity occurred in 14 (3%) and 9 (2%) women, respectively. Women who initiated NVP had higher rates of severe hepatotoxicity (5% vs 1%; P = .03) and rash-associated hepatotoxicity (4% vs 0%; P = .003) when compared with NFV. Among women who initiated NVP (n = 254), a baseline CD4 count ≥250 cells/mm(3) was not associated with severe hepatotoxicity (5% vs 3%; P = .52) or rash-associated hepatotoxicity (4% vs 3%; P = .69). CONCLUSION: Nevirapine use but not CD4 count ≥250 cells/mm(3) was associated with hepatotoxicity. |
Relationship of climate, geography, and geology to the incidence of Rift Valley fever in Kenya during the 2006-2007 outbreak
Hightower A , Kinkade C , Nguku PM , Anyangu A , Mutonga D , Omolo J , Njenga MK , Feikin DR , Schnabel D , Ombok M , Breiman RF . Am J Trop Med Hyg 2012 86 (2) 373-380 We estimated Rift Valley fever (RVF) incidence as a function of geological, geographical, and climatological factors during the 2006-2007 RVF epidemic in Kenya. Location information was obtained for 214 of 340 (63%) confirmed and probable RVF cases that occurred during an outbreak from November 1, 2006 to February 28, 2007. Locations with subtypes of solonetz, calcisols, solonchaks, and planosols soil types were highly associated with RVF occurrence during the outbreak period. Increased rainfall and higher greenness measures before the outbreak were associated with increased risk. RVF was more likely to occur on plains, in densely bushed areas, at lower elevations, and in the Somalia acacia ecological zone. Cases occurred in three spatial temporal clusters that differed by the date of associated rainfall, soil type, and land usage. |
Hospitalized patients with pandemic (H1N1) 2009, Kenya
Osoro EM , Munyua P , Muthoka P , Gikundi S , Njenga MK , Lifumo S , Achilla R , Waiboci L , Nzioka C , Omolo J , Feikin DR , Breiman RF , Katz MA . Emerg Infect Dis 2011 17 (9) 1744-6 To describe the epidemiology and clinical course of patients hospitalized with pandemic (H1N1) 2009 in Kenya, we reviewed medical records of 49 such patients hospitalized during July-November 2009. The median age (7 years) was lower than that in industrialized countries. More patients had HIV than the general Kenyan population. |
Sequential Rift Valley fever outbreaks in eastern Africa caused by multiple lineages of the virus
Nderitu L , Lee JS , Omolo J , Omulo S , O'Guinn ML , Hightower A , Mosha F , Mohamed M , Munyua P , Nganga Z , Hiett K , Seal B , Feikin DR , Breiman RF , Njenga MK . J Infect Dis 2011 203 (5) 655-65 BACKGROUND: During the Rift Valley fever (RVF) epidemic of 2006-2007 in eastern Africa, spatial mapping of the outbreaks across Kenya, Somalia, and Tanzania was performed and the RVF viruses were isolated and genetically characterized. METHODS: Following confirmation of the RVF epidemic in Kenya on 19 December 2006 and in Tanzania on 2 February 2007, teams were sent to the field for case finding. Human, livestock, and mosquito specimens were collected and viruses isolated. The World Health Organization response team in Kenya worked with the WHO's polio surveillance team inside Somalia to collect information and specimens from Somalia. RESULTS: Seven geographical foci that reported hundreds of livestock and >25 cases in humans between December 2006 and June 2007 were identified. The onset of RVF cases in each epidemic focus was preceded by heavy rainfall and flooding for at least 10 days. Full-length genome analysis of 16 RVF virus isolates recovered from humans, livestock, and mosquitoes in 5 of the 7 outbreak foci revealed 3 distinct lineages of the viruses within and across outbreak foci. CONCLUSION: The findings indicate that the sequential RVF epidemics in the region were caused by multiple lineages of the RVF virus, sometimes independently activated or introduced in distinct outbreak foci. |
Risk factors for severe Rift Valley fever infection in Kenya, 2007
Anyangu AS , Gould LH , Sharif SK , Nguku PM , Omolo JO , Mutonga D , Rao CY , Lederman ER , Schnabel D , Paweska JT , Katz M , Hightower A , Njenga MK , Feikin DR , Breiman RF . Am J Trop Med Hyg 2010 83 14-21 A large Rift Valley fever (RVF) outbreak occurred in Kenya from December 2006 to March 2007. We conducted a study to define risk factors associated with infection and severe disease. A total of 861 individuals from 424 households were enrolled. Two hundred and two participants (23%) had serologic evidence of acute RVF infection. Of these, 52 (26%) had severe RVF disease characterized by hemorrhagic manifestations or death. Independent risk factors for acute RVF infection were consuming or handling products from sick animals (odds ratio [OR] = 2.53, 95% confidence interval [CI] = 1.78-3.61, population attributable risk percentage [PAR%] = 19%) and being a herds person (OR 1.77, 95% CI = 1.20-2.63, PAR% = 11%). Touching an aborted animal fetus was associated with severe RVF disease (OR = 3.83, 95% CI = 1.68-9.07, PAR% = 14%). Consuming or handling products from sick animals was associated with death (OR = 3.67, 95% CI = 1.07-12.64, PAR% = 47%). Exposures related to animal contact were associated with acute RVF infection, whereas exposures to mosquitoes were not independent risk factors. |
An investigation of a major outbreak of Rift Valley fever in Kenya: 2006-2007
Nguku PM , Sharif SK , Mutonga D , Amwayi S , Omolo J , Mohammed O , Farnon EC , Gould LH , Lederman E , Rao C , Sang R , Schnabel D , Feikin DR , Hightower A , Njenga MK , Breiman RF . Am J Trop Med Hyg 2010 83 5-13 An outbreak of Rift Valley fever (RVF) occurred in Kenya during November 2006 through March 2007. We characterized the magnitude of the outbreak through disease surveillance and serosurveys, and investigated contributing factors to enhance strategies for forecasting to prevent or minimize the impact of future outbreaks. Of 700 suspected cases, 392 met probable or confirmed case definitions; demographic data were available for 340 (87%), including 90 (26.4%) deaths. Male cases were more likely to die than females, Case Fatality Rate Ratio 1.8 (95% Confidence Interval [CI] 1.3-3.8). Serosurveys suggested an attack rate up to 13% of residents in heavily affected areas. Genetic sequencing showed high homology among viruses from this and earlier RVF outbreaks. Case areas were more likely than non-case areas to have soil types that retain surface moisture. The outbreak had a devastatingly high case-fatality rate for hospitalized patients. However, there were up to 180,000 infected mildly ill or asymptomatic people within highly affected areas. Soil type data may add specificity to climate-based forecasting models for RVF. |
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