Serological survey of canine leptospirosis in three countries of tropical Africa: Sudan, Gabon and Ivory Coast

• There is a lack of data on canine leptospirosis in Africa.
• Large number of apparently healthy dog (n = 475) in natural conditions in three African countries.
• High prevalence of different Leptospira serogroups on low titres: 95.4% [CI95: 93.4–97.2].
• 40.8% [CI95: 36.4–45.2] are positive on high titres without evidence of clinical leptospirosis.
• Diversity of serovars detected indicates possible existence of a variety of animal reservoirs.

A cross-sectional survey was conducted to estimate the presence of leptospiral antibodies among 475 dogs from three countries of tropical Africa: Sudan (n = 62), Gabon (n = 255) and Ivory Coast (n = 158). Sixteen reference strains belonging to seven serogroups were used as antigen in the microscopic agglutination test. Overall, considering titres ≥1:40, 453 samples were positive towards one or several serovars of pathogenic leptospires. Focusing on high titres, i.e. ≥1:320, the seroprevalence was 40.8%. In Gabon, the seroprevalence was higher in rural areas than in an urban environment (p < 0.001). In Ivory Coast, the seroprevalence for serogroups Icterohaemorrhagiae and Canicola was not statistically different according to the vaccinal status. Predominant serogroups varied according to the countries but Grippotyphosa and Sejroë were the most common, while Icterohaemorragiae and Canicola were dominant in Sudan. In these three countries, dogs are heavily exposed to pathogenic Leptospira and humans living in the same environment are also at risk of infection.