Epidemiology of cryptosporidiosis in dogs in Lusaka District, Zambia
Cryptosporidium is an intracellular zoonotic protozoan parasite that causes cryptosporidiosis, a diarrhoeal disease of humans and domestic animals. The parasite has been reported in a variety of domestic animals including dogs. Several species of Cryptosporidium infecting animals have also been reported in humans highlighting the zoonotic nature of the disease. This study was aimed at determining the prevalence and associated risk factors of Cryptosporidium infection in domestic dogs in Lusaka district of Zambia. It was a prospective cross-sectional descriptive study carried out from October, 2015 to May, 2016 in three Veterinary Clinics as well as Kalingalinga and Kabanana residential areas within Lusaka District. A total of 390 dog faecal samples were collected and analyzed at the University of Zambia, School of Veterinary Medicine laboratory and at the parasitology laboratory at the University Teaching Hospital. The modified Ziehl Neelsen and fluorochrome (Auramine) staining techniques were used to identify positive samples. A sample was considered positive if at least one oocyst was identified under the microscope. Proportions were compared using chi-square, fisher’s exact test and logistic regression, where appropriate. Overall, 390 dogs ranging from 2 months to 13 years were examined for the presence of Cryptosporidium. Out of these, 280 (71.8%) were of mixed breed while 110 (28.2%) were pure breeds; and 75.6% (295/390) were vaccinated while 24.4% (95/390) were not. Majority of the dogs (62.3%; 243/390) were males compared to only 37.7% (147/390) females. Most of the dogs (89. 2%; 348/390) were fed leftovers while the rest were fed pet food (5.9%; 23/390), sawdust (2.1%; 8/390) or both leftovers and pet food (2.8%; 11/390). The overall prevalence of Cryptosporidium infection in the dogs was 5.9% (23/390). Of the 23 positive dogs, 21 (5.4%) were detected by both Ziehl Neelsen and fluorochrome methods, while the other two were detected by fluorochrome method only, giving a prevalence of 5.9% (23/390) for the latter. The prevalence of Cryptosporidium in males was 5.3% (13/243) while that for females was 6.8% (10/147) but the difference was not significant (P= 0.658). There was a statistically significant difference in Cryptosporidium infection between mixed breed and pure breed dogs (P=0.012), with prevalence being higher in the mixed breed type. Water source was another variable found to be significantly associated with Cryptosporidium infection (P=0.041). Other factors investigated were not associated with Cryptosporidium infection. There was no statistically significant difference in the detection of Cryptosporidium using Auramine and Modified Ziehl Neelsen as the results obtained from the two methods were found to be in almost perfect agreement (Kappa=0.95). The study detected Cryptosporidium oocysts in dogs with most of them being asymptomatic. Most of the factors investigated apart from breed and water source were not associated with the Cryptosporidium infection. The two compared techniques, namely; Modified Ziehl Neelsen and Auramine can be adopted for routine examination of Cryptosporidium oocysts since both showed similar analytical results.
- Veterinary Medicine