Associations between trematode infections in cattle and freshwater snails in highland and lowland areas of Iringa Rural District, Tanzania

Abstract

SUMMARYThe epidemiology of trematode infections in cattle was investigated within highland and lowland areas of Iringa Rural District, in southern Tanzania. Fecal samples were collected from 450 cattle in 15 villages at altitudes ranging from 696 to 1800 m above the sea level. Freshwater snails were collected from selected water bodies and screened for emergence of cercariae. The infection rates in cattle wereFasciola gigantica28·2%, paramphistomes 62·8% andSchistosoma bovis4·8%. Notably, prevalence of trematode infections in cattle was much higher in highland (altitude > 1500 m) as compared with lowland (altitude < 1500 m) areas and was statistically significant (P-value = 0·000) forF. giganticaand paramphistomes but not forS. bovis. The snails collected includedLymnaea natalensis, Bulinus africanus, Bulinus tropicus, Bulinus forskali, Biomphalaria pfeifferi, Melanoides tuberculataandBellamya constrictawith a greater proportion of highland (75%) than lowland (36%) water bodies harbouring snails. Altitude is a major factor shaping the epidemiology ofF. giganticaand paramphistomes infections in cattle in Iringa Rural District with greater emphasis upon control needed in highland areas.