Prevalence and risk factors of GIARDIA infections in Dairy Cattle Herds in Lusaka and Chilanga Districts of Lusaka

Abstract

Giardia is an intestinal protozoan parasite of mammals including humans. The objectives of the cross sectional study conducted between May 2013 and April 2014 were to estimate the prevalence of Giardia infections in dairy herds on farms in Chilanga and Lusaka districts of Lusaka Province, Zambia, and to evaluate risk factors associated with the infections. Farms were grouped into smallholder and commercial farms. A total of 377 calves aged one day to one year were sampled from 34 farms. All the 377 faecal samples were analyzed for Giardia antigen using a commercially available monoclonal antibody-based Enzyme-linked immunosorbent assay kit. Chi square and Fisher’s exact tests were used and binary logistic regression was used to evaluate factors associated with infections. The overall prevalence of Giardia for the two districts was 34.5% (130/377; 95% CI= 29.7-39.3) while the overall farm prevalence was 79.4% (27/34). For individual smallholder farms, the animal level prevalence of Giardia ranged from zero to 100% and within commercial herds, it was 12.5% to 60.9%. The prevalence was significantly higher in calves up to three months old than in older ones (p = 0.010). There was no significant difference in the prevalence of Giardia between smallholder and commercial dairy farms (p = 0.300) and this was also the case between male and female calves (p = 0.633). The present study did not find a clear association between presence of Giardia in faecal samples and occurrence of diarrhoea in calves (p = 0.205). v Several management factors were evaluated, however, only husbandry system was found to be a significant risk factor for infection with the parasite. It was found that herds reared under intensive husbandry system were 2.083 (95% CI = 1.086-59.308, p = 0.041) times more likely to be positive for Giardia than those under free range system. The findings of the present study demonstrate that Giardia infections are common in dairy herds in Chilanga and Lusaka districts especially in calves up to three months of age which may play an important role in the epidemiology of giardiasis. Furthermore, husbandry system is an important factor in the perpetuation of the infections.