The seroprevalence of antibodies to Leptospira species in dogs presented to Harare veterinary clinics and selected rural communities in Zimbabwe

Abstract

A cross sectional study was conducted to investigate the seroprevalence of leptospirosis, and the association between seropositivity and hepatic damage and/or renal insufficiency in dogs from Harare urban and five selected rural areas (Kariba, Machuchuta, Malipati, Marumani and Ndhlovu) in Zimbabwe. The awareness of dog owners on zoonotic importance of canine leptospirosis was also studied using an interviewer-administered structured questionnaire. Sera collected from a randomly selected dogs (both stray and communally- owned) were tested for leptospiral antibodies using an ImmunoComb ELISA kit which detects IgG antibodies to four pooled serovars; L. Canicola, L. Grippotyphosa, L. Icterohaemorrhagiae and L. Pomona. Data was analyzed by calculating proportions positive and assessment of associations using a Chisquared test. Of the 250 samples tested (116 males and 134 females), 39 (15.6%) tested positive for leptospiral IgG antibodies. Overall, urban dogs recorded a significantly (P < 0.05) higher seroprevalence (25%) compared to dogs from rural areas (11.2%). Urban female dogs (P < 0.05) recorded a significantly higher seroprevalence compared to rural female dogs but there was no significant difference between urban male (P > 0.05) and rural male dogs. No significant sex differences were observed in seroprevalence. There was a significant association (P < 0.01) between seropositivity and hepatic damage and/or renal insufficiency with dogs having hepatic damage and/or renal insufficiency being approximately 2 times (RR = 1.96; 1.3 < RR< 3.0) more likely to be seropositive. When asked on their awareness of dog zoonoses, 78.8% (119/151) of dog owners were aware. Of the 78.8% who were aware of zoonoses in dogs, a higher proportion (92.4%) knew rabies as a zoonotic disease in dogs compared to other named zoonoses. Other cited zoonoses were worms (6.7%), leptospirosis (5%), brucellosis (1.7%), ringworm (0.8%) and toxoplasmosis (0.8%). Those who named leptospirosis as a zoonotic disease in dogs were all from the veterinary profession. The results of this study indicated that leptospirosis was present in dogs from the selected areas in Zimbabwe, with a higher seroprevalence in Harare urban areas. Further studies are required to determine the serovars prevalent in these and other areas in the country. Teaching and training programmes for pet owners would improve awareness to leptospirosis and reduce the public health risk of pet zoonoses.