Flock-level seroprevalence of, and risk factors for, Neospora caninum among sheep and goats in northern Jordan

Abstract

During the period January 2002 to December 2003, serum samples were collected from 104 small ruminant flocks consisting of 18 sheep flocks, 27 goat flocks and 59 mixed flocks containing both sheep and goats in northern Jordan. Only female animals were sampled. At least 5 females aged over 2 years per flock per species were sampled and examined for anti-Neospora caninum antibodies using ELISA. To increase the chances of detecting positive flocks, sick or older ewes were sampled. Also, N. caninum DNA was investigated in 7 sheep brains using PCR technique and 1 was found positive. The flock-level true seroprevalence in small ruminants was 53% (95% CI: 43,63). The true flock-level seroprevalence was higher in sheep (92%) than goats (12%) (OR=55; 95% CI: 17,197). Similarly, the individual-level seroprevalence in sheep and goat was 63% and 2% respectively (OR=25; 95% CI: 16,39). Out of 32 production and health management variables, the presence of dogs with the flock (OR=3.6, 95% CI: 1.2,10) enhanced seropositivity. Cold temperate climate (OR=0.1, 95% CI: 0.03,0.4), veterinary supervision (OR=0.2, 95% CI: 0.06,0.6) and buying healthy animals to replace those culled (OR=0.3, 95% CI: 0.1,0.97) reduced the risk of seropositivity. Both sheep and goats in Jordan are exposed to N. caninum infection with higher seroprevalence in sheep than goats. The contribution of N. caninum to abortion in small ruminant flock needs to be evaluated. Educating the farmers with regard to the role of dogs in transmitting N. caninum infection is expected to enhance small ruminant health in Jordan.