Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-15 (of 15 Records) |
Query Trace: Tabu C [original query] |
---|
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. |
Assessment of missed opportunities for vaccination in Kenyan health facilities, 2016
Li AJ , Tabu C , Shendale S , Sergon K , Okoth PO , Mugoya IK , Machekanyanga Z , Onuekwusi IU , Sanderson C , Ogbuanu IU . PLoS One 2020 15 (8) e0237913 BACKGROUND: In November 2016, the Kenya National Vaccines and Immunization Programme conducted an assessment of missed opportunities for vaccination (MOV) using the World Health Organization (WHO) MOV methodology. A MOV includes any contact with health services during which an eligible individual does not receive all the vaccine doses for which he or she is eligible. METHODS: The MOV assessment in Kenya was conducted in 10 geographically diverse counties, comprising exit interviews with caregivers and knowledge, attitudes, and practices (KAP) surveys with health workers. On the survey dates, which covered a 4-day period in November 2016, all health workers and caregivers visiting the selected health facilities with children <24 months of age were eligible to participate. Health facilities (n = 4 per county) were purposively selected by size, location, ownership, and performance. We calculated the proportion of MOV among children eligible for vaccination and with documented vaccination histories (i.e., from a home-based record or health facility register), and stratified MOV by age and reason for visit. Timeliness of vaccine doses was also calculated. RESULTS: We conducted 677 age-eligible children exit interviews and 376 health worker KAP surveys. Of the 558 children with documented vaccination histories, 33% were visiting the health facility for a vaccination visit and 67% were for other reasons. A MOV was seen in 75% (244/324) of children eligible for vaccination with documented vaccination histories, with 57% (186/324) receiving no vaccinations. This included 55% of children visiting for a vaccination visit and 93% visiting for non-vaccination visits. Timeliness for multi-dose vaccine series doses decreased with subsequent doses. Among health workers, 25% (74/291) were unable to correctly identify the national vaccination schedule for vaccines administered during the first year of life. Among health workers who reported administering vaccines as part of their daily work, 39% (55/142) reported that they did not always have the materials they needed for patients seeking immunization services, such as vaccines, syringes, and vaccination recording documents. CONCLUSIONS: The MOV assessment in Kenya highlighted areas of improvement that could reduce MOV. The results suggest several interventions including standardizing health worker practices, implementing an orientation package for all health workers, and developing a stock management module to reduce stock-outs of vaccines and vaccination-related supplies. To improve vaccination coverage and equity in all counties in Kenya, interventions to reduce MOV should be considered as part of an overall immunization service improvement plan. |
Qualitative insights into reasons for missed opportunities for vaccination in Kenyan health facilities
Li AJ , Tabu C , Shendale S , Okoth PO , Sergon K , Maree E , Mugoya IK , Machekanyanga Z , Onuekwusi IU , Ogbuanu IU . PLoS One 2020 15 (3) e0230783 BACKGROUND: In 2016, Kenya conducted a study of missed opportunities for vaccination (MOV)-when eligible children have contact with the health system but are not fully vaccinated-to explore some of the reasons for persistent low vaccination coverage. This paper details the qualitative findings from that assessment. METHODS: Using the World Health Organization MOV methodology, teams conducted focus group discussions among caregivers and health workers and in-depth interviews of key informants in 10 counties in Kenya. Caregivers of children <24 months of age visiting the selected health facilities on the day of the assessment were requested to participate in focus group discussions. Health workers were purposively sampled to capture a broad range of perspectives. Key informants were selected based on their perceived insight on immunization services at the county, sub-county, or health facility level. RESULTS: Six focus group discussions with caregivers, eight focus group discussions with health workers, and 35 in-depth interviews with key informants were completed. In general, caregivers had positive attitudes toward healthcare and vaccination services, but expressed a desire for increased education surrounding vaccination. In order to standardize vaccination checks at all health facility visits, health workers and key informants emphasized the need for additional trainings for all staff members on immunization. Health workers and key informants also highlighted the negative impact of significant understaffing in health facilities, and the persistent challenge of stock-outs of vaccines and vaccination-related supplies. CONCLUSIONS: Identified factors that could contribute to MOV include a lack of knowledge surrounding vaccination among caregivers and health workers, inadequate number of health workers, and stock-outs of vaccines or vaccination-related materials. In addition, vaccination checks outside of vaccination visits lacked consistency, leading to MOV in non-vaccinating departments. Qualitative assessments could provide a starting point for understanding and developing interventions to address MOV in other countries. |
Impact of the introduction of rotavirus vaccine on hospital admissions for diarrhoea among children in Kenya: A controlled interrupted time series analysis
Otieno GP , Bottomley C , Khagayi S , Adetifa I , Ngama M , Omore R , Ogwel B , Owor BE , Bigogo G , Ochieng JB , Onyango C , Juma J , Mwenda J , Tabu C , Tate JE , Addo Y , Britton T , Parashar UD , Breiman RF , Verani JR , Nokes DJ . Clin Infect Dis 2019 70 (11) 2306-2313 INTRODUCTION: Monovalent rotavirus vaccine, RotarixTM, was introduced in Kenya in July 2014, is recommended to infants as oral doses at ages 6 and 10 weeks. A multi-site study was established in two population based surveillance sites to evaluate vaccine impact on the incidence of rotavirus-associated hospitalisations (RVH). METHODS: Hospital-based surveillance was conducted from January 2010 to June 2017 for acute diarrhoea hospitalisations among children aged <5 years in two health facilities in Kenya. A controlled interrupted time series analysis was undertaken to compare RVH pre and post vaccine introduction using rotavirus negative cases as a control series. The change in incidence post vaccine introduction was estimated from a negative binomial model that adjusted for secular trend, seasonality and multiple health worker industrial actions (strikes). RESULTS: Between January 2010 and June 2017 there were 1513 and 1652 diarrhoea hospitalisations in Kilifi and Siaya; among those tested for rotavirus, 28% (315/1142) and 23% (197/877) were positive, respectively. There was a 57% (95% CI: 8 to 80) reduction in RVH observed in the first year post vaccine introduction in Kilifi and a 59% (95% CI: 20 to 79) reduction in Siaya. In the second year, RVH decreased further at both sites, 80% (95% CI: 46 to 93) reduction in Kilifi and 82% reduction in Siaya (95% CI: 61 to 92), and this reduction was sustained at both sites into the third year. CONCLUSIONS: A substantial reduction of RVH and all-cause diarrhoea has been observed in two demographic surveillance sites in Kenya within 3 years of vaccine introduction. |
Effectiveness of monovalent rotavirus vaccine against hospitalization with acute rotavirus gastroenteritis in Kenyan children
Khagayi S , Omore R , Otieno GP , Ogwel B , Ochieng JB , Juma J , Apondi E , Bigogo G , Onyango C , Ngama M , Njeru R , Owor BE , Mwanga MJ , Addo Y , Tabu C , Amwayi A , Mwenda JM , Tate JE , Parashar UD , Breiman RF , Nokes DJ , Verani JR . Clin Infect Dis 2019 70 (11) 2298-2305 BACKGROUND: Rotavirus remains a leading cause of diarrheal illness and death among children worldwide. Data on rotavirus vaccine effectiveness in sub-Saharan Africa are limited. Kenya introduced monovalent rotavirus vaccine (RV1) in July 2014. We assessed RV1 effectiveness against rotavirus-associated hospitalization in Kenyan children. METHODS: Between July-2014 and December-2017, we conducted surveillance for acute gastroenteritis (AGE) in three hospitals across Kenya. We analysed data from children age-eligible for >/=1 RV1 dose, with stool tested for rotavirus and confirmed vaccination history. We compared RV1 coverage among those who tested rotavirus-positive (cases) versus rotavirus-negative (controls) using multivariable logistic regression; effectiveness was 1-adjusted odds ratio for vaccination x100%. RESULTS: Among 677 eligible children, 110 (16%) were rotavirus-positive. Vaccination data were available for 91 (83%) cases; 51 (56%) had received 2 RV1 doses and 33 (36%) 0 doses. Among 567 controls, 418 (74%) had vaccination data; 308 (74%) had 2 doses and 69 (16%) 0 doses. Overall 2-dose effectiveness was 64% (95% confidence interval [CI]: 35-80%); for children aged <12 months 67% (95%CI: 30-84%) and children aged >/=12 months 72% (95%CI: 10-91%). Significant effectiveness was seen in children with normal weight-for-age (84% [95%CI: 62-93%]), length/height-for-age (75% [95%CI: 48-88%]) and weight-for-length/height (84% [95%CI: 64-93%]); however, no protection was found among underweight, stunted nor wasted children. CONCLUSIONS: RV1 in the routine Kenyan immunization program provides significant protection against rotavirus AGE hospitalization. Protection was sustained beyond infancy. Malnutrition appears to diminish vaccine effectiveness. Efforts to improve rotavirus vaccine uptake and nutritional status are important to maximize vaccine benefit. |
Rates of hospitalization and death for all-cause and rotavirus acute gastroenteritis before rotavirus vaccine introduction in Kenya, 2010-2013
Omore R , Khagayi S , Ogwel B , Onkoba R , Ochieng JB , Juma J , Munga S , Tabu C , Kibet S , Nuorti JP , Odhiambo F , Mwenda JM , Breiman RF , Parashar UD , Tate JE . BMC Infect Dis 2019 19 (1) 47 BACKGROUND: Rotavirus vaccine was introduced in Kenya immunization program in July 2014. Pre-vaccine disease burden estimates are important for assessing vaccine impact. METHODS: Children with acute gastroenteritis (AGE) (>/=3 loose stools and/or >/= 1 episode of unexplained vomiting followed by loose stool within a 24-h period), hospitalized in Siaya County Referral Hospital (SCRH) from January 2010 through December 2013 were enrolled. Stool specimens were tested for rotavirus (RV) using an enzyme immunoassay (EIA). Hospitalization rates were calculated using person-years of observation (PYO) from the Health Demographic Surveillance System (HDSS) as a denominator, while adjusting for healthcare utilization at household level and proportion of stool specimen collected from patients who met the case definition at the surveillance hospital. Mortality rates were calculated using PYO as the denominator and number of deaths estimated using total deaths in the HDSS, proportion of deaths attributed to diarrhoea by verbal autopsy (VA) and percent positive for rotavirus AGE (RVAGE) hospitalizations. RESULTS: Of 7760 all-cause hospitalizations among children < 5 years of age, 3793 (49%) were included in the analysis. Of these, 21% (805) had AGE; RV was detected in 143 (26%) of 541 stools tested. Among children < 5 years, the estimated hospitalization rates per 100,000 PYO for AGE and RVAGE were 2413 and 429, respectively. Mortality rate associated with AGE and RVAGE were 176 and 45 per 100,000 PYO, respectively. CONCLUSION: AGE and RVAGE caused substantial health care burden (hospitalizations and deaths) before rotavirus vaccine introduction in Kenya. |
Developing a seasonal influenza vaccine recommendation in Kenya: Process and challenges faced by the National Immunization Technical Advisory Group (NITAG)
Dawa J , Chaves SS , Ba Nguz A , Kalani R , Anyango E , Mutie D , Muthoka P , Tabu C , Maritim M , Amukoye E , Were F . Vaccine 2018 37 (3) 464-472 Background: In 2014 the Kenya National Immunization Technical Advisory Group (KENITAG) was asked by the Ministry of Health to provide an evidence-based recommendation on whether the seasonal influenza vaccine should be introduced into the national immunization program (NIP). Methods: We reviewed KENITAG manuals, reports and meeting minutes generated between June 2014 and June 2016 in order to describe the process KENITAG used in arriving at that recommendation and the challenges encountered. Results: KENITAG developed a recommendation framework to identify critical, important and non-critical data elements that would guide deliberations on the subject. Literature searches were conducted in several databases and the quality of scientific articles obtained was assessed using the Critical Appraisal Skills Programme tool. There were significant gaps in knowledge on the national burden of influenza disease among key risk groups, i.e., pregnant women, individuals with co-morbidities, the elderly and health care workers. Insufficient funding and limited work force hindered KENITAG activities. In 2016 KENITAG recommended introduction of the annual seasonal influenza vaccine among children 6 to 23 months of age. However, the recommendation was contingent on implementation of a pilot study to address gaps in local data on the socio-economic impact of influenza vaccination programs, strategies for vaccine delivery, and the impact of the vaccination program on the healthcare workforce and existing immunization program. KENITAG did not recommend the influenza vaccine for any other risk group due to lack of local burden of disease data. Conclusion: Local data are a critical element in NITAG deliberations, however, where local data and in particular burden of disease data are lacking, there is need to adopt scientifically acceptable methods of utilizing findings from other countries to inform local decisions in a manner that is valid and acceptable to decision makers. |
Assessment of select electronic health information systems that support immunization data capture - Kenya, 2017
Namageyo-Funa A , Aketch M , Tabu C , MacNeil A , Bloland P . BMC Health Serv Res 2018 18 (1) 621 BACKGROUND: Although electronic health information systems (EHIS) with immunization components exist in Kenya, questions and concerns remain about their use and alignment with the Kenya Ministry of Health's (MOH) National Vaccine and Immunization Program (NVIP). This article reports on the findings of an assessment of select EHIS with immunization components in Kenya, specifically related to system design, development, and implementation. METHODS: We conducted a rapid assessment of select EHIS with immunization components in Kenya from January to May 2017 to understand the design, development, implementation of the EHIS including the lessons learned from their use. We also assessed how the data elements in the EHIS compared to the data elements in the Maternal and Child Health Booklet used in the existing paper based system in Kenya. RESULTS: The EHIS reviewed varied in purpose, content, and population covered. Only one system was built to focus specifically on immunization data. Substantial differences in system functionality and immunization-related data elements included in the EHIS were identified. None of the EHIS had all the data elements necessary to fully replace or operate independently from the standardized paper-based system for recording immunization data in Kenya. CONCLUSIONS: Overall, the findings of this assessment highlighted substantial variation in the EHIS with immunization components. The findings provide insights and lessons learned for the Kenya MOH NVIP, immunization partners, vendors of EHIS, and users of EHIS to consider as Kenya transitions from paper-based to electronic immunization information systems. |
Use of the revised World Health Organization cluster survey methodology to classify measles-rubella vaccination campaign coverage in 47 counties in Kenya, 2016
Subaiya S , Tabu C , N'Ganga J , Awes AA , Sergon K , Cosmas L , Styczynski A , Thuo S , Lebo E , Kaiser R , Perry R , Ademba P , Kretsinger K , Onuekwusi I , Gary H , Scobie HM . PLoS One 2018 13 (7) e0199786 INTRODUCTION: To achieve measles elimination, two doses of measles-containing vaccine (MCV) are provided through routine immunization services or vaccination campaigns. In May 2016, Kenya conducted a measles-rubella (MR) vaccination campaign targeting 19 million children aged 9 months-14 years, with a goal of achieving >/=95% coverage. We conducted a post-campaign cluster survey to estimate national coverage and classify coverage in Kenya's 47 counties. METHODS: The stratified multi-stage cluster survey included data from 20,011 children in 8,253 households sampled using the recently revised World Health Organization coverage survey methodology (2015). Point estimates and 95% confidence intervals (95% CI) of national campaign coverage were calculated, accounting for study design. County vaccination coverage was classified as 'pass,' 'fail,' or 'intermediate,' using one-sided hypothesis tests against a 95% threshold. RESULTS: Estimated national MR campaign coverage was 95% (95% CI: 94%-96%). Coverage differed significantly (p < 0.05) by child's school attendance, mother's education, household wealth, and other factors. In classifying coverage, 20 counties passed (>/=95%), two failed (<95%), and 25 were intermediate (unable to classify either way). Reported campaign awareness among caretakers was 92%. After the 2016 MR campaign, an estimated 93% (95% CI: 92%-94%) of children aged 9 months to 14 years had received >/=2 MCV doses; 6% (95% CI: 6%-7%) had 1 MCV dose; and 0.7% (95% CI: 0.6%-0.9%) remained unvaccinated. CONCLUSIONS: Kenya reached the MR campaign target of 95% vaccination coverage, representing a substantial achievement towards increasing population immunity. High campaign awareness reflected the comprehensive social mobilization strategy implemented in Kenya and supports the importance of including strong communications platforms in future vaccination campaigns. In counties with sub-optimal MR campaign coverage, further efforts are needed to increase MCV coverage to achieve the national goal of measles elimination by 2020. |
Reducing routine vaccination dropout rates: evaluating two interventions in three Kenyan districts, 2014
Haji A , Lowther S , Ngan'ga Z , Gura Z , Tabu C , Sandhu H , Arvelo W . BMC Public Health 2016 16 152 BACKGROUND: Globally, vaccine preventable diseases are responsible for nearly 20% of deaths annually among children <5 years old. Worldwide, many children dropout from the vaccination program, are vaccinated late, or incompletely vaccinated. We evaluated the impact of text messaging and sticker reminders to reduce dropouts from the vaccination program. METHODS: The evaluation was conducted in three selected districts in Kenya: Machakos, Langata and Njoro. Three health facilities were selected in each district, and randomly allocated to send text messages or provide stickers reminding parents to bring their children for second and third dose of pentavalent vaccine, or to the control group (routine reminder) with next appointment date indicated on the well-child booklet. Children aged <12 months presenting for their first dose of pentavalent vaccine were enrolled. A dropout was defined as not returning for vaccination ≥ 2 weeks after scheduled date for third dose of pentavalent vaccine. We calculated dropout rate as a percentage of the difference between first and third pentavalent dose. RESULTS: We enrolled 1,116 children; 372 in each intervention and 372 controls between February and October 2014. Median age was 45 days old (range: 31-99 days), and 574 (51%) were male. There were 136 (12%) dropouts. Thirteen (4%) children dropped out among those who received text messages, 60 (16%) among who received sticker reminders, and 63 (17%) among the controls. Having a caregiver with below secondary education [Odds Ratio (OR) 1.8, 95% Confidence Interval (CI) 1.1-3.2], and residing >5 km from health facility (OR 1.6, CI 1.0-2.7) were associated with higher odds of dropping out. Those who received text messages were less likely to drop out compared to controls (OR 0.2, CI 0.04-0.8). There was no statistical difference between those who received stickers and controls (OR 0.9, CI 0.5-1.6). CONCLUSION: Text message reminders can reduce vaccination dropout rates in Kenya. We recommend the extended implementation of text message reminders in routine vaccination services. |
Rotavirus enteritis in Dadaab refugee camps: implications for immunization programs in Kenya and Resettlement Countries
Ope M , Ochieng SB , Tabu C , Marano N . Clin Infect Dis 2014 59 (1) v-vi The section listed above, written by members of the CDC's Division of Global Migration and Quarantine and focusing on globally mobile populations and infectious disease outbreaks, is freely available online only, in this issue of Clinical Infectious Diseases at (http://cid.oxfordjournals.org). |
Differing burden and epidemiology of non-Typhi Salmonella bacteremia in rural and urban Kenya, 2006-2009
Tabu C , Breiman RF , Ochieng B , Aura B , Cosmas L , Audi A , Olack B , Bigogo G , Ongus JR , Fields P , Mintz E , Burton D , Oundo J , Feikin DR . PLoS One 2012 7 (2) e31237 BACKGROUND: The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. METHODS: As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0 degrees C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured. RESULTS: NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy. CONCLUSIONS: NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa. |
Population-based incidence of typhoid fever in an urban informal settlement and a rural area in Kenya: implications for typhoid vaccine use in Africa
Breiman RF , Cosmas L , Njuguna H , Audi A , Olack B , Ochieng JB , Wamola N , Bigogo GM , Awiti G , Tabu CW , Burke H , Williamson J , Oundo JO , Mintz ED , Feikin DR . PLoS One 2012 7 (1) e29119 BACKGROUND: High rates of typhoid fever in children in urban settings in Asia have led to focus on childhood immunization in Asian cities, but not in Africa, where data, mostly from rural areas, have shown low disease incidence. We set out to compare incidence of typhoid fever in a densely populated urban slum and a rural community in Kenya, hypothesizing higher rates in the urban area, given crowding and suboptimal access to safe water, sanitation and hygiene. METHODS: During 2007-9, we conducted population-based surveillance in Kibera, an urban informal settlement in Nairobi, and in Lwak, a rural area in western Kenya. Participants had free access to study clinics; field workers visited their homes biweekly to collect information about acute illnesses. In clinic, blood cultures were processed from patients with fever or pneumonia. Crude and adjusted incidence rates were calculated. RESULTS: In the urban site, the overall crude incidence of Salmonella enterica serovar Typhi (S. Typhi) bacteremia was 247 cases per 100,000 person-years of observation (pyo) with highest rates in children 5-9 years old (596 per 100,000 pyo) and 2-4 years old (521 per 100,000 pyo). Crude overall incidence in Lwak was 29 cases per 100,000 pyo with low rates in children 2-4 and 5-9 years old (28 and 18 cases per 100,000 pyo, respectively). Adjusted incidence rates were highest in 2-4 year old urban children (2,243 per 100,000 pyo) which were >15-fold higher than rates in the rural site for the same age group. Nearly 75% of S. Typhi isolates were multi-drug resistant. CONCLUSIONS: This systematic urban slum and rural comparison showed dramatically higher typhoid incidence among urban children <10 years old with rates similar to those from Asian urban slums. The findings have potential policy implications for use of typhoid vaccines in increasingly urban Africa. |
Does water hyacinth on East African lakes promote cholera outbreaks?
Feikin DR , Tabu CW , Gichuki J . Am J Trop Med Hyg 2010 83 (2) 370-3 Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate on the floating aquatic plant, water hyacinth, which is periodically widespread in East African lakes since the late 1980s. From 1994 to 2008, Nyanza Province, which is the Kenyan province bordering Lake Victoria, accounted for a larger proportion of cholera cases than expected by its population size (38.7% of cholera cases versus 15.3% of national population). Yearly water-hyacinth coverage on the Kenyan section of Lake Victoria was positively associated with the number of cholera cases reported in Nyanza Province (r = 0.83; P = 0.0010). Water hyacinth on freshwater lakes might play a role in initiating cholera outbreaks and causing sporadic disease in East Africa. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 22, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure