Knowledge and practices towards rabies and determinants of dog rabies vaccination in households: a cross sectional study in an area with high dog bite incidents in Kakamega County, Kenya, 2013

Introduction: an estimated 55,000 people die from rabies annually. Factors promoting dog vaccination, estimates of vaccination coverage and knowledge on rabies are important for effective rabies control. We sought to establish these estimates at household (HH) level and whether rabies knowledge is associated with proper control practices. Methods: cross-sectional cluster survey with two-stage sampling was employed in Kakamega County to enroll HH members above 18 years. A set of questions related to rabies knowledge and practice were used to score participant response. Score above the sample mean was equated to adequate knowledge and proper practices respectively. Independent t-test was used to evaluate the differences of sample mean scores based on dog vaccination status. Bivariate analysis was used to associate knowledge to practices. Results: three hundred and ninety HHs enrolled and had a population of 754 dogs with 35% (n=119) HH having vaccinated dogs within past 12 months. Overall mean score for knowledge was 7.0 (±2.8) with range (0-11) and 6.3 (±1.2) for practice with range (0-8). There was a statistically significant difference in mean knowledge (DF=288, p<0.01) and practice (DF=283, p=0.001) of HH with vaccinated dogs compared to ones with unvaccinated dogs. Participants with adequate rabies knowledge were more likely to have proper health seeking practices 139 (80%) (OR=3.0, 95% CI=1.4-6.8) and proper handling practices of suspected rabid dog 327 (88%) (OR=5.4, 95% CI=2.7-10.6). Conclusion: rabies vaccination below the 80% recommended for herd immunity. Mass vaccination campaign needed. More innovative ways of translating knowledge into proper rabies control practice are warranted

Preventing malaria during pregnancy: factors determining the use of insecticide-treated bednets and intermittent preventive therapy in Juba

The study was carried out among 334 pregnant and newly delivered women seen at Juba Teaching Hospital in 2009. The objective was to assess the coverage of insecticide-treated bed-nets (ITN) and Intermittent Preventive Therapy (IPT) among these women and the factors associated with their use. Overall 87% of the women used ITN and 61% used IPT. ITN use was positively associated with buying nets, indoor spraying of insecticide and higher household income. IPT use was positively associated with more frequent antenatal clinic visits, indoor spraying and buying ITN

Predicting Distribution of Aedes Aegypti and Culex Pipiens Complex, Potential Vectors of Rift Valley Fever Virus in Relation to Disease Epidemics in East Africa.

The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. DIVERSE ECOLOGICAL NICHE MODELLING TECHNIQUES HAVE BEEN DEVELOPED FOR THIS PURPOSE: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods

Effectiveness of monovalent rotavirus vaccine against hospitalization with acute rotavirus gastroenteritis in Kenyan children

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. 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%. 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. 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. [Abstract copyright: © The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America.

Randomized controlled field trial to assess the immunogenicity and safety of rift valley fever clone 13 vaccine in livestock

BACKGROUND:Although livestock vaccination is effective in preventing Rift Valley fever (RVF) epidemics, there are concerns about safety and effectiveness of the only commercially available RVF Smithburn vaccine. We conducted a randomized controlled field trial to evaluate the immunogenicity and safety of the new RVF Clone 13 vaccine, recently registered in South Africa. METHODS:In a blinded randomized controlled field trial, 404 animals (85 cattle, 168 sheep, and 151 goats) in three farms in Kenya were divided into three groups. Group A included males and non-pregnant females that were randomized and assigned to two groups; one vaccinated with RVF Clone 13 and the other given placebo. Groups B included animals in 1st half of pregnancy, and group C animals in 2nd half of pregnancy, which were also randomized and either vaccinated and given placebo. Animals were monitored for one year and virus antibodies titers assessed on days 14, 28, 56, 183 and 365. RESULTS:In vaccinated goats (N = 72), 72% developed anti-RVF virus IgM antibodies and 97% neutralizing IgG antibodies. In vaccinated sheep (N = 77), 84% developed IgM and 91% neutralizing IgG antibodies. Vaccinated cattle (N = 42) did not develop IgM antibodies but 67% developed neutralizing IgG antibodies. At day 14 post-vaccination, the odds of being seropositive for IgG in the vaccine group was 3.6 (95% CI, 1.5 - 9.2) in cattle, 90.0 (95% CI, 25.1 - 579.2) in goats, and 40.0 (95% CI, 16.5 - 110.5) in sheep. Abortion was observed in one vaccinated goat but histopathologic analysis did not indicate RVF virus infection. There was no evidence of teratogenicity in vaccinated or placebo animals. CONCLUSIONS:The results suggest RVF Clone 13 vaccine is safe to use and has high (>90%) immunogenicity in sheep and goats but moderate (> 65%) immunogenicity in cattle

Measuring the burden of arboviral diseases: the spectrum of morbidity and mortality from four prevalent infections

<p>Abstract</p> <p>Background</p> <p>Globally, arthropod-borne virus infections are increasingly common causes of severe febrile disease that can progress to long-term physical or cognitive impairment or result in early death. Because of the large populations at risk, it has been suggested that these outcomes represent a substantial health deficit not captured by current global disease burden assessments.</p> <p>Methods</p> <p>We reviewed newly available data on disease incidence and outcomes to critically evaluate the disease burden (as measured by disability-adjusted life years, or DALYs) caused by yellow fever virus (YFV), Japanese encephalitis virus (JEV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). We searched available literature and official reports on these viruses combined with the terms "outbreak(s)," "complication(s)," "disability," "quality of life," "DALY," and "QALY," focusing on reports since 2000. We screened 210 published studies, with 38 selected for inclusion. Data on average incidence, duration, age at onset, mortality, and severity of acute and chronic outcomes were used to create DALY estimates for 2005, using the approach of the current Global Burden of Disease framework.</p> <p>Results</p> <p>Given the limitations of available data, nondiscounted, unweighted DALYs attributable to YFV, JEV, CHIKV, and RVFV were estimated to fall between 300,000 and 5,000,000 for 2005. YFV was the most prevalent infection of the four viruses evaluated, although a higher proportion of the world's population lives in countries at risk for CHIKV and JEV. Early mortality and long-term, related chronic conditions provided the largest DALY components for each disease. The better known, short-term viral febrile syndromes caused by these viruses contributed relatively lower proportions of the overall DALY scores.</p> <p>Conclusions</p> <p>Limitations in health systems in endemic areas undoubtedly lead to underestimation of arbovirus incidence and related complications. However, improving diagnostics and better understanding of the late secondary results of infection now give a first approximation of the current disease burden from these widespread serious infections. Arbovirus control and prevention remains a high priority, both because of the current disease burden and the significant threat of the re-emergence of these viruses among much larger groups of susceptible populations.</p

The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya

Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5–1.3). The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1–1.4, p&lt;0.001), and slaughtering cattle at the homestead (OR 3.3; 95% CI 1.0–10.5, p = 0.047). A total of 553 slaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5–4.2). Being the slaughterman, the person who cuts the animal’s throat (OR 3.5; 95% CI 1.0–12.1, p = 0.047), was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further evidence for RVFV circulation in western Kenya

Prevalence and factors influencing consistent condom use among sexually active young people attending a youth friendly centre in Kenya, 2008

Objectives: Young people in Kenya engage in unprotected sexual intercourse with resultant high rates of unwanted pregnancy, STIs and HIV rates. To formulate effective and acceptable approaches that encourage safer sexual behavior, we need to understand young people sexual behavior. We thus conducted a study to determine prevalence and factors influencing consistent condom use among youths in Kenya.Methods: We carried out a cross-sectional study at the Youth Friendly Centre of Provincial General Hospital in Nakuru town. A self-administered questionnaire was used to collect data from persons aged 15 to 24 years using systematic random sampling method. Subjects who self reported positively on all three variables i.e.. ever condom use., \condom use within the last three months., and \condom use during the last sexual encounter. were defined as \consistent condom users.. Data analysis was performed using Chi-square test with alpha level of significance at 0.05.Results: Among the 223 enrolled subjects 196 (87%) were sexually active. The prevalence of consistent condom use was 36 %. Independently promoters of consistent condom use were; talking with parents about condom (OR=2.65; 95% CI=1.37-5.12; p = 0.004); attaining college level education (OR= 2.55; 95% CI=1.32-4.94; p = 0.006) and having multiple sexual partners (OR= 2.05; 95% CI=1.01-4.16; p = 0.048). Belief that condom diminishes pleasure (OR= 0.50; 95% CI=0.26-0.96; p = 0.037) and last sexual partner being a spouse (OR= 0.36; 95% CI=0.13-0.97; p = 0.044) were independent hindrances to consistent condom use.Conclusions: Majority of youths are sexually active with few of them not consistently using condom. Parents should be informed on the sexual behavior of the youth inorder to discuss about safer sexual behavior with their youths while encourage abstinence or postponement of sexually activity. Youth peer education need to be strengthened to foster safer sexual behaviors