Cryptosporidium parasites are leading causes of enteric disease, especially in children. A prospective survey on the prevalence of cryptosporidiosis in children less than five years of age was undertaken at six microbiology laboratories in Kenya on fecal samples submitted for routine parasite and ova investigations. Analysis of 4,899 samples over a two-year study period showed an overall prevalence of cryptosporidiosis of 4% that was highest between November to February. Investigations on the nature of enteric diseases prompting ova and cyst examination requests showed 66.4% had acute diarrhea, 9% had persistent diarrhea, and 21% had recurrent diarrhea. The main symptoms were abdominal pain (51.1%), vomiting (51.6%), and abdominal swelling (11%). The prevalence of cryptosporidiosis was highest among children 13-24 months of age (5.2%) and least among those 48-60 months of age (2%). No significant differences were observed by sex but vomiting was slightly higher in males than in females (65% males and 52% females; P = 0.07). Cryptosporidiosis was significantly associated with persistent diarrhea (P = 0.0001, odds ratio [OR] = 2.193, 95% confidence interval [CI] = 1.463-3.29), vomiting (P = 0.0273, OR = 1.401, 95% CI = 1.04-1.893), and abdominal swelling (P = 0.0311, OR = 1.56, 95% CI = 1.04-2.34). Genotype analysis based on polymerase chain reaction-restriction fragment length polymorphism of the 18S rRNA gene fragment showed that 87% (153 of 175) of the Cryptosporidium isolates were C. hominis, 9% (15 of 175) were C. parvum, and remaining 4% were C. canis, C. felis, C. meleagridis, and C. muris. The most common protozoa in coinfected patients were Entamoeba histolytica/E. dispar, E. coli, and Giardia intestinalis (6%, 5%, and 2%, respectively). Our results show that Cryptosporidium is among the most common protozoan parasites in children with enteric diseases and that anthroponotic species are the leading cause of human cryptosporidiosis in Kenya, which suggests that human-to-human transmission is the main mode of spread.

Evidence suggests that the intracellular bacterial pathogen Coxiella burnetii (which causes Q fever) is widespread, with a near global distribution. While there has been increasing attention to Q fever epidemiology in high-income settings, a recent systematic review highlighted significant gaps in our understanding of the prevalence, spatial distribution and risk factors for Q fever infection across Africa. This research aimed to provide a One Health assessment of Q fever epidemiology in parts of Western and Nyanza Provinces, Western Kenya, in cattle and humans. A cross-sectional survey was conducted: serum samples from 2049 humans and 955 cattle in 416 homesteads were analysed for C. burnetii antibodies. Questionnaires covering demographic, socio-economic and husbandry information were also administered. These data were linked to environmental datasets based on geographical locations (e.g., land cover). Correlation and spatial-cross correlation analyses were applied to assess the potential link between cattle and human seroprevalence. Multilevel regression analysis was used to assess the relationships between a range of socio-economic, demographic and environmental factors and sero-positivity in both humans and animals. The overall sero-prevalence of C. burnetii was 2.5% in humans and 10.5% in cattle, but we found no evidence of correlation between cattle and human seroprevalence either within households, or when incorporating spatial proximity to other households in the survey. Multilevel modelling indicated the importance of several factors for exposure to the organism. Cattle obtained from market (as opposed to those bred in their homestead) and those residing in areas with lower precipitation levels had the highest sero-prevalence. For humans, the youngest age group had the highest odds of seropositivity, variations were observed between ethnic groups, and frequent livestock contact (specifically grazing and dealing with abortion material) was also a risk factor. These results illustrate endemicity of C. burnetii in western Kenya, although prevalence is relatively low. The analysis indicates that while environmental factors may play a role in cattle exposure patterns, human exposure patterns are likely to be driven more strongly by livestock contacts. The implication of livestock markets in cattle exposure risks suggests these may be a suitable target for interventions.

BackgroundThe neglected zoonotic diseases (NZD) are an understudied group that are a major cause of illness throughout the developing world. In general, little is known about the prevalence and burden of NZDs in affected communities, particularly in relation to other infectious diseases with which they are often co-endemic. We describe the design and descriptive epidemiological outputs from an integrated study of human and animal zoonotic and non-zoonotic disease in a rural farming community in western Kenya.MethodsThis cross-sectional survey involved 2113 people, their cattle (n = 983) and pigs (n = 91). People and animals were tested for infection or exposure to a wide range of zoonotic and non-zoonotic pathogens. Prevalence estimates, with adjustment for the complex study design, were derived. Evidence for spatial clustering in exposure or infection was identified using the spatial scan statistic.ResultsThere was a high prevalence of human parasitism in the community, particularly with hookworm (Ancylostoma duodenale or Necator americanus) (36.3% (95% CI 32.8–39.9)), Entamoeba histolytica/dispar (30.1% (95% CI 27.5–32.8)), and Plasmodium falciparum (29.4% (95% CI 26.8–32.0)). Human infection with Taenia spp. was also prevalent (19.7% (95% CI 16.7–22.7)), while exposure to other zoonotic pathogens was comparatively rarer (Brucella spp., 0.6% (95% CI 0.2–0.9); Coxiella burnetii, 2.2% (95% CI 1.5–2.9); Rift Valley fever, 0.5% (95% CI 0.2–0.8)). A low prevalence of exposure to Brucella spp. was observed in cattle (0.26% (95% CI 0–0.56). This was higher for Rift Valley fever virus (1.4% (95% CI 0.5–2.22)) and C. burnetii (10.0% (95% CI 7.7–12.2)). The prevalence of Taenia spp. cysticercosis was 53.5% (95% CI 48.7–58.3) in cattle and 17.2% (95% CI 9.1–25.3) in pigs. Mycobacterium bovis infection was found in 2.2% of cattle (95% CI 1.3–3.2), while the prevalence of infection with Mycobacterium spp. was 8.2% (95% CI 6.8–9.6) in people.ConclusionZoonotic infections in people and animals occur in the context of a wide range of co-endemic pathogens in a rural community in western Kenya. The wide diversity of pathogens under study provides a unique opportunity to explore the distribution and determinants of infection in a multi-pathogen, multi-host system.