Cryptosporidium species detected in calves and cattle in Dagoretti, Nairobi, Kenya.

A total of 1,734 cattle faecal samples from 296 dairy-keeping households were collected from urban settings in Nairobi, Kenya. Modified Ziehl-Neelsen staining method and an immunofluorescence assay were used to identify those samples with Cryptosporidium oocyst infection. Oocysts from positive faecal samples were isolated by Sheather's sucrose flotation method and picked from the concentrate using cover slips. Genomic DNA was extracted from 124 of the faecal samples that were positive for Cryptosporidium and was used as template for nested PCR of the 18S rRNA gene. Twenty-five samples (20 %) were PCR-positive for Cryptosporidium, and 24 of the PCR products were successfully cloned and sequenced. Sequence and phylogenetic analysis identified 17 samples (68 %) as Cryptosporidium parvum-like, four samples (16 %) as Cryptosporidium ryanae, three samples (12 %) as Cryptosporidium andersoni and one sample (4 %) as Cryptosporidium hominis. To the best of our knowledge, this is the first genotyping study to report C. parvum-like, C. andersoni and C. hominis in cattle from Kenya. The results of this study show Cryptosporidium infections in calves and cattle may be potential zoonotic reservoirs of the parasite that infects humans.

Prevalence of cryptosporidiosis in dairy cattle, cattle-keeping families, their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division, Nairobi, Kenya.

This paper reports a study estimating the prevalence of cryptosporidiosis, an emerging zoonosis, in people and cattle in Dagoretti, Nairobi. A repeated cross-sectional survey was carried out among randomly selected cattle keepers in Dagoretti, their dairy cattle and their non-cattle-keeping neighbours in the dry and wet seasons of 2006. A survey was also carried out among a group of people living with human immunodeficiency virus (HIV). Faecal samples were examined for Cryptosporidium oocysts using the modified Ziehl-Neelsen method; 16 % of the samples were also examined using immunofluorescence antibody (IFA) technique. Quality control consisted of blind reviews of slides, examining split samples and confirming slide results with IFA. We found that members of dairy households had a dry season cryptosporidiosis prevalence of 4 % and wet season prevalence of 0.3 %, and non-dairy households, a prevalence of 5 and 0 %, respectively. The cattle dry season prevalence was 15 %, and the wet season prevalence, 11 %. The prevalence in people living with HIV was 5 %. The laboratory quality control system showed some inconsistency within and between different tests, indicating challenges in obtaining consistent results under difficult field and working conditions. In conclusion, this is the first reported study to simultaneously survey livestock, livestock keepers and their neighbours for cryptosporidiosis. We failed to find evidence that zoonotic cryptosporidiosis is important overall in this community. This study also draws attention to the importance of quality control and its reporting in surveys in developing countries.

Development and delivery of evidence-based messages to reduce the risk of zoonoses in Nairobi, Kenya.

This paper describes a trans-disciplinary process of co-generating and disseminating evidence-based messages for reducing the risk from cryptosporidiosis and other zoonoses in an urban community in Nairobi. Research findings about disease prevalence, risk factors and observed risky and risk-mitigating practices were analysed by a team comprising researchers, community members and local policy- and decision-makers. Using participatory planning, multiple strategies were developed for disseminating key information. We identified five vulnerable groups at higher risk of exposure to cryptosporidiosis and other cattle zoonoses with similar transmission pathways (women, children, elderly people, immunosuppressed people and male farm workers). For each group, targeted messages were developed. Good practices already in use, as were also practices as practices to improve environmental conditions. These messages were disseminated through printed material, in a workshop, through community campaigners and also an edutainment soap opera episode broadcast on Kenyan television. In conclusion, a participatory and trans-disciplinary process can help transform the findings of research into messages that are targeted, attractive and understandable.