Spatial distribution of sexual network locations used by long-distance truck drivers along the Northern Corridor highway, Kenya.

BACKGROUND: In Kenya, long-distance truck drivers (LDTDs) using the Northern Corridor highway have a high prevalence of HIV and other sexually transmitted infections (STIs) due to their risky sexual networks. However, the spatial distribution of the sexual network locations used by LDTDs is not well understood. Consequently, healthcare stakeholders have found it difficult to provide spatially targeted HIV/STI interventions among LDTDs. Thus, the study sought to establish the spatial distribution of sexual network locations used by LDTDs along the Northern Corridor highway, to inform efficient distribution and use of limited HIV/STI-prevention resources. METHODS: A cross-sectional study design was used. The study adopted a systematic sampling technique. 296 LDTDs were interviewed using interviewer-administered questionnaires at the Mlolongo weighbridge in Kenya. The LDTDs listed their history of sexual interactions and highway stopovers used during the week preceding data collection. Geospatial modelling techniques, using R statistical software packages for spatial mapping, were employed. Shapefiles were created and overlaid over a map of Kenya using R statistical software to create maps of sexual networks. RESULTS: Forty-two highway stopovers used by LDTDs were spatially distributed along the highway, from the Kenya coast to the Kenya-Uganda border. In general, LDTDs' sexual network hotspots were restricted to the outskirts of major cities along the Northern Corridor highway (Nairobi, Mombasa and Nakuru) as well as the Kenya-Uganda international border. CONCLUSIONS: On the Northern Corridor highway, stopovers situated proximal to major urban areas, as well as those at international border points, frequently serve as sexual network hotspots among LDTDs and their sexual partners. Thus, healthcare stakeholders should improve access to HIV/STI-prevention services targeted for LDTDs at the sexual network hotspots identified in this study.

Sero-epidemiological survey of Coxiella burnetii in livestock and humans in Tana River and Garissa counties in Kenya.

BACKGROUND: Coxiella burnetii is a widely distributed pathogen, but data on its epidemiology in livestock, and human populations remain scanty, especially in developing countries such as Kenya. We used the One Health approach to estimate the seroprevalance of C. burnetii in cattle, sheep, goats and human populations in Tana River county, and in humans in Garissa county, Kenya. We also identified potential determinants of exposure among these hosts. METHODS: Data were collected through a cross-sectional study. Serum samples were taken from 2,727 animals (466 cattle, 1,333 goats, and 928 sheep) and 974 humans and screened for Phase I/II IgG antibodies against C. burnetii using enzyme-linked immunosorbent assay (ELISA). Data on potential factors associated with animal and human exposure were collected using a structured questionnaire. Multivariable analyses were performed with households as a random effect to adjust for the within-household correlation of C. burnetii exposure among animals and humans, respectively. RESULTS: The overall apparent seroprevalence estimates of C. burnetii in livestock and humans were 12.80% (95% confidence interval [CI]: 11.57-14.11) and 24.44% (95% CI: 21.77-27.26), respectively. In livestock, the seroprevalence differed significantly by species (p < 0.01). The highest seroprevalence estimates were observed in goats (15.22%, 95% CI: 13.34-17.27) and sheep (14.22%, 95% CI: 12.04-16.64) while cattle (3.00%, 95% CI: 1.65-4.99) had the lowest seroprevalence. Herd-level seropositivity of C. burnetii in livestock was not positively associated with human exposure. Multivariable results showed that female animals had higher odds of seropositivity for C. burnetii than males, while for animal age groups, adult animals had higher odds of seropositivity than calves, kids or lambs. For livestock species, both sheep and goats had significantly higher odds of seropositivity than cattle. In human populations, men had a significantly higher odds of testing positive for C. burnetii than women. CONCLUSIONS: This study provides evidence of livestock and human exposure to C. burnetii which could have serious economic implications on livestock production and impact on human health. These results also highlight the need to establish active surveillance in the study area to reduce the disease burden associated with this pathogen.

Epidemiological study on foot-and-mouth disease in small ruminants: Sero-prevalence and risk factor assessment in Kenya.

Foot-and-mouth disease (FMD) is endemic in Kenya affecting cloven-hoofed ruminants. The epidemiology of the disease in small ruminants (SR) in Kenya is not documented. We carried out a cross-sectional study, the first in Kenya, to estimate the sero-prevalence of FMD in SR and the associated risk factors nationally. Selection of animals to be sampled used a multistage cluster sampling approach. Serum samples totaling 7564 were screened for FMD antibodies of non-structural-proteins using ID Screen® NSP Competition ELISA kit. To identify the risk factors, generalized linear mixed effects (GLMM) logistic regression analysis with county and villages as random effect variables was used. The country animal level sero-prevalence was 22.5% (95% CI: 22.3%-24.3%) while herd level sero-prevalence was 77.6% (95% CI: 73.9%-80.9%). The risk factor that was significantly positively associated with FMD sero-positivity in SR was multipurpose production type (OR = 1.307; p = 0.042). The risk factors that were significantly negatively associated with FMD sero-positivity were male sex (OR = 0.796; p = 0.007), young age (OR = 0.470; p = 0.010), and sedentary production zone (OR = 0.324; p<0.001). There were no statistically significant intra class correlations among the random effect variables but interactions between age and sex variables among the studied animals were statistically significant (p = 0.019). This study showed that there may be widespread undetected virus circulation in SR indicated by the near ubiquitous spatial distribution of significant FMD sero-positivity in the country. Strengthening of risk-based FMD surveillance in small ruminants is recommended. Adjustment of husbandry practices to control FMD in SR and in-contact species is suggested. Cross-transmission of FMD and more risk factors need to be researched.

Adherence to iron and folic acid supplementation during pregnancy among postnatal mothers seeking maternal and child healthcare at Kakamega level 5 hospital in Kenya: a cross-sectional study.

Background: Maternal anaemia is a public health problem worldwide, and its aetiology is linked to iron deficiency. The high nutrient demand during pregnancy exacerbates the condition. To meet the increased nutritional demand, supplementation of iron and folic acid (IFA) is key. The supplements are provided freely to pregnant women during antenatal visits at public health facilities, however, their uptake and adherence in Kenya remain unacceptably low. Methods: A hospital-based cross-sectional study involving 241 postnatal mothers seeking maternal and child healthcare (MCH) care at Kakamega level 5 hospital was conducted. Both quantitative and qualitative data were collected. Quantitative data were collected from 241 eligible postnatal mothers, while qualitative data were obtained through key informant interviews with community health volunteers and healthcare providers. Results: There was a moderate adherence to IFA supplementation (60.6%) during pregnancy among postnatal mothers seeking MCH care at Kakamega level 5 hospital. Some of the reasons for non-adherence stated by the respondents included; IFA related side effects (41.3%), forgetfulness (37.3%) and bad smell of the IFA supplements (10.3%). Higher IFA adherence was noted among the primigravida participants (OR=2.704; 95% CI: 1.262, 5.793; p=0.010) compared to multigravida participants, and those with a higher knowledge level of anaemia (OR=3.215; 95% CI: 1.346, 7.68; p=0.009) compared to their counterparts with low anaemia knowledge. Other factors that showed correlation with IFA adherence were: IFA education, pregnancy counselling before conception and the number of antenatal care visits attained. Conclusion: There is a moderate adherence to IFA supplementation during pregnancy among mothers seeking MCH at Kakamega level 5 hospital. The greatest impediments of IFA compliance during pregnancy are IFA side effects, forgetfulness and the bad smell of the IFA tablets. Therefore, providing IFA education to pregnant mothers incorporated with probable ways of managing the IFA side effects would contribute to IFA supplementation adherence.

Frequency of sexual interactions and associated factors among long-distance truck drivers operating along the Northern Corridor Highway, Kenya.

INTRODUCTION: harsh working conditions among long-distance truck drivers (LDTDs) expose them to risky sexual interactions while on transit. As a result, the risky sexual interactions among the LDTDs place them at a high risk of contracting human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). This study sought to assess the sexual interactions and associated factors among the LDTDs in Kenya. METHODS: two hundred ninety-six (296) LDTDs were interviewed using interviewer-administered questionnaires. A systematic sampling technique was adopted. The number of sexual acts reported by the respondents was used to generate an ordered outcome variable (frequency of sexual interactions), in the order of; no sexual acts (zero), one to three sexual acts (1), and four to six sexual acts (2). Association between the predictor variables and the outcome variable was analysed using ordered logistic regression analysis in R statistical software. RESULTS: the mean age of the study participants was 38.4 years, with the youngest being 24 years and the oldest 57 years. Slightly above half of the participants (52.4%) reported no sexual interactions, while the rest (47.6%) had sexual interactions with either casual or regular sexual partners on the week preceding the survey. Age, the number of weeks spent on a transit journey, and drug use were independently associated with the frequency of sexual interactions among LDTDs involved in the study. CONCLUSION: the frequencies of sexual interactions are likely to be higher among the younger LDTDs, those who spent more than one week on transit, and those who use alcohol and khat, hence a high exposure risk to HIV/STIs among them.

Relative Distribution, Diversity, and Bloodmeal Sources of Mosquitoes and Known Vectors of Rift Valley Fever Phlebovirus in Three Differing Ecosystems in Bura, Tana River County, Kenya.

Environmental modifications disturb the equilibrium of mosquito populations, altering the risk of mosquito-borne diseases. Mosquito distribution, diversity, and bloodmeal sources were examined to compare Rift Valley fever (RVF) risk among irrigated, riverine, and pastoral ecosystems in Bura, Tana River County, Kenya, between September 2014 and June 2015. Thirty-eight households and 21 irrigation fields were selected for the study. Mosquitoes were trapped with carbon dioxide-impregnated CDC traps, one trap per household and three traps per irrigated field, and morphologically identified using taxonomic keys. Host DNA was extracted from engorged females and cytochrome b genes amplified by PCR to identify sources of bloodmeals. A total of 21,015 mosquitoes were collected; 5742 within households in the 3 ecosystems and 15,273 within irrigated fields. Mosquitoes collected within irrigated fields belonged to 8 genera and 37 species, while those from households within the irrigation scheme belonged to 6 genera and 29 species. Collections from riverine and pastoral households belonged to five and four genera, respectively. The most abundant genera in the irrigated fields were Aedes (21%) and Mansonia (22%), while Anopheles (43%) was the most abundant within households. Most mosquitoes in riverine and pastoral households belonged to Anopheles (76%) and Aedes (65%) genera, respectively. Seasonal variation driven by rainfall was evidenced by spikes in mosquito numbers within irrigated and riverine ecosystems. Host species identification revealed that goats and humans were the main sources of bloodmeal. There was an overall increase in mosquito abundance and diversity as a result of the presence of the irrigated ecosystem in this county, and an increased availability of highly RVF-susceptible hosts as a result of the establishment and concentration of residential areas, promoting potential vector-host contacts. These results highlight the impact of anthropogenic changes on mosquito ecology, potentially heightening the risk of transmission and maintenance of RVF in this region.

Positive association between Brucella spp. seroprevalences in livestock and humans from a cross-sectional study in Garissa and Tana River Counties, Kenya.

BACKGROUND: Brucella spp. is a zoonotic bacterial agent of high public health and socio-economic importance. It infects many species of animals including wildlife, and people may get exposed through direct contact with an infected animal or consumption of raw or undercooked animal products. A linked livestock-human cross-sectional study to determine seroprevalences and risk factors of brucellosis in livestock and humans was designed. Estimates were made for intra-cluster correlation coefficients (ICCs) for these observations at the household and village levels. METHODOLOGY: The study was implemented in Garissa (specifically Ijara and Sangailu areas) and Tana River (Bura and Hola) counties. A household was the unit of analysis and the sample size was derived using the standard procedures. Serum samples were obtained from selected livestock and people from randomly selected households. Humans were sampled in both counties, while livestock could be sampled only in Tana River County. Samples obtained were screened for anti-Brucella IgG antibodies using ELISA kits. Data were analyzed using generalized linear mixed effects logistic regression models with the household (herd) and village being used as random effects. RESULTS: The overall Brucella spp. seroprevalences were 3.47% (95% confidence interval [CI]: 2.72-4.36%) and 35.81% (95% CI: 32.87-38.84) in livestock and humans, respectively. In livestock, older animals and those sampled in Hola had significantly higher seroprevalences than younger ones or those sampled in Bura. Herd and village random effects were significant and ICC estimates associated with these variables were 0.40 (95% CI: 0.22-0.60) and 0.24 (95% CI: 0.08-0.52), respectively. In humans, Brucella spp. seroprevalence was significantly higher in older people, males, and people who lived in pastoral areas than younger ones, females or those who lived in irrigated or riverine areas. People from households that had at least one seropositive animal were 3.35 (95% CI: 1.51-7.41) times more likely to be seropositive compared to those that did not. Human exposures significantly clustered at the household level; the ICC estimate obtained was 0.21 (95% CI: 0.06-0.52). CONCLUSION: The presence of a Brucella spp.-seropositive animal in a household significantly increased the odds of Brucella spp. seropositivity in humans in that household. Exposure to Brucella spp. of both livestock and humans clustered significantly at the household level. This suggests that risk-based surveillance measures, guided by locations of primary cases reported, either in humans or livestock, can be used to detect Brucella spp. infections in livestock or humans, respectively.

Willingness to pay for contagious bovine pleuropneumonia vaccination in Narok South District of Kenya.

Contagious bovine pleuropneumonia (CBPP) is an economically important trans-boundary cattle disease which affects food security and livelihoods. A conjoint analysis-contingent valuation was carried out on 190 households in Narok South District of Kenya to measure willingness to pay (WTP) and demand for CBPP vaccine and vaccination as well as factors affecting WTP. The mean WTP was calculated at Kenya Shillings (KSh) 212.48 (USD 3.03) for vaccination using a vaccine with the characteristics that were preferred by the farmers (preferred vaccine and vaccination) and KSh -71.45 (USD -1.02) for the currently used vaccine and vaccination. The proportion of farmers willing to pay an amount greater than zero was 66.7% and 34.4% for the preferred and current vaccine and vaccination respectively. About one third (33.3%) of farmers would need to be compensated an average amount of KSh 1162.62 (USD 13.68) per animal to allow their cattle to be vaccinated against CBPP using the preferred vaccine and vaccination. About two-thirds (65.6%) of farmers would need to be compensated an average amount of KSh 853.72 (USD 12.20) per animal to allow their cattle to be vaccinated against CBPP using the current vaccine and vaccination. The total amount of compensation would be KSh 61.39 million (USD 0.88 million) for the preferred vaccine and vaccination and KSh 90.15 million (USD 1.29 million) for the current vaccine and vaccination. Demand curves drawn from individual WTP demonstrated that only 59% and 27% of cattle owners with a WTP greater than zero were willing to pay a benchmark cost of KSh 34.60 for the preferred and current vaccine respectively. WTP was negatively influenced by the attitude about household economic situation (p=0.0078), presence of cross breeds in the herd (p<0.0001) and years since CBPP had been experienced in the herd (p=0.0375). It was positively influenced by education (p=0.0251) and the practice of treating against CBPP (p=0.0432). The benefit cost ratio (BCR) for CBPP vaccination was 2.9-6.1 depending on the vaccination programme. In conclusion, although a proportion of farmers was willing to pay, participation levels may be lower than those required to interrupt transmission of CBPP. Households with characteristics that influence WTP negatively need persuasion to participate in CBPP vaccination. It is economically worthwhile to vaccinate against CBPP. A benefit cost analysis (BCA) using aggregated WTP as benefits can be used as an alternative method to the traditional BCA which uses avoided production losses (new revenue) and costs saved as benefits.

Establishing a One Health office in Kenya.

A One Health (OH) approach that integrates human,animal and environmental approaches to management of zoonotic diseases has gained momentum in the last decadeas part of a strategy to prevent and control emerging infectious diseases. However, there are few examples of howan OH approach can be established in a country. Kenya establishment of an OH office, referred to asthe Zoonotic Disease Unit (ZDU) in 2011. The ZDU bridges theanimal and human health sectors with a senior epidemiologist deployed from each ministry; and agoal of maintaining collaboration at the animal and human health interface towards better prevention and control of zoonoses. The country is adding an ecologist to the ZDU to ensure that environmental risks are adequately addressed in emerging disease control.

Exploring farmer preferences for contagious bovine pleuropneumonia vaccination: a case study of Narok District of Kenya.

Contagious bovine pleuropneumonia (CBPP) is an economically important disease in most of sub-Saharan Africa. A conjoint analysis and ordered probit regression models were used to measure the preferences of farmers for CBPP vaccine and vaccination attributes. This was with regard to inclusion or not of an indicator in the vaccine, vaccine safety, vaccine stability as well as frequency of vaccination, vaccine administration and the nature of vaccination. The analysis was carried out in 190 households in Narok District of Kenya between October and December 2006 using structured questionnaires, 16 attribute profiles and a five-point Likert scale. The factors affecting attribute valuation were shown through a two-way location interaction model. The study also demonstrated the relative importance (RI) of attributes and the compensation value of attribute levels. The attribute coefficient estimates showed that farmers prefer a vaccine that has an indicator, is 100% safe and is administered by the government (p<0.0001). The preferences for the vaccine attributes were consistent with expectations. Preferences for stability, frequency of vaccination and nature of vaccination differed amongst farmers (p>0.05). While inclusion of an indicator in the vaccine was the most important attribute (RI=43.6%), price was the least important (RI=0.5%). Of the 22 household factors considered, 15 affected attribute valuation. The compensation values for a change from non inclusion to inclusion of an indicator, 95-100% safety, 2h to greater than 2h stability and from compulsory to elective vaccination were positive while those for a change from annual to biannual vaccination and from government to private administration were negative. The study concluded that the farmers in Narok District had preferences for specific vaccine and vaccination attributes. These preferences were conditioned by various household characteristics and disease risk factors. On average the farmers would need to be compensated or persuaded to accept biannual and private vaccination against CBPP. There is need for consideration of farmer preferences for vaccine attribute levels during vaccine formulations and farmer preferences for vaccination attribute levels when designing delivery of vaccines.