SI (EMERGING ZOONOSES) Prevalence of cryptosporidiosis in dairy cattle, cattle-keeping families, their non-cattle-keeping neighbours and HIV-positive individuals in Dagoretti Division, Nairobi, Kenya Erastus Kange’the & Brigid McDermott & Delia Grace & Cecilia Mbae & Erastus Mulinge & Joseph Monda & Concepta Nyongesa & Julie Ambia & Alice Njehu Accepted: 30 May 2012 / Published online: 10 August 2012 # Springer Science+Business Media B.V. 2012 Abstract 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. Keywords Cryptosporidiosis . Dairy cattle . Nairobi . HIV Introduction Cryptosporidiosis, caused by protozoa of the genus Cryptospordia, is an emerging disease of people and animals. Cryptosporidium was first identified as a cause of gastrointestinal disease in humans in 1976, and in the 1980s, it was recognised as a common cause of diarrhoea in people infected with human immunodeficiency virus (HIV). In 1993, it was responsible for the largest water-borne disease outbreak ever documented in the USA, affecting over 400,000 people (MacKenzie et al. 1994). From the 1990s on, numerous studies have shown the importance of cryptosporidiosis in developing countries (summarised in Mor and Tzipori 2008). Humans are mainly infected by two species of Crypto- sporidium: Cryptosporidium parvum which is zoonotic and This paper is part of a special supplement on assessing and managing urban zoonoses and food-borne disease in two African cities (Nairobi, Kenya and Ibadan, Nigeria). E. Kange’the : J. Monda : C. Nyongesa : J. Ambia : A. Njehu Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya B. McDermott Biometry Unit, Department of Crop Science, University of Nairobi, Nairobi, Kenya D. Grace (*) International Livestock Research Institute, P.O. Box 29053, Nairobi, Kenya e-mail: d.grace@cgiar.org C. Mbae : E. Mulinge Centre for Microbiological Research, Kenya Medical Research Institute, Nairobi, Kenya Trop Anim Health Prod (2012) 44 (Suppl 1):S11–S16 DOI 10.1007/s11250-012-0201-6