Rabies surveillance-response in Mali in the past 18 years and requirements for the future.

ABSTRACT

CONTEXT Rabies is endemic in Mali, but little is known about the distribution of rabies and its surveillance across the country. Documenting the evolution of rabies and the problems related to surveillance is useful to facilitate elimination of human rabies by 2030. METHOD: Data collected at the Central Veterinary Laboratory (LCV) from 1999 to 2017 and through the surveillance system functioning at household, health and veterinary structure levels, as established by the Global Vaccine Alliance funded project on the burden of rabies, between 2016 and 2017 in Bamako and the Sikasso region were used in this study. All data on animals examined for rabies by the direct fluorescence antibody test (DFA) during the specified time period were summarized, and the proportion of rabies positive tested among animals suspected of rabies was estimated. From the number of dogs tested positive for rabies, a cumulative incidence was estimated for the total canine population. The number of positive tested samples was divided by the product of the estimated canine population and number of years (18). In addition, the number of human rabies cases was analyzed to estimate a cumulative incidence. RESULTS: Among all animal samples suspected for rabies, 93.2% [95% CI 90.6-95.3] were positive by the DFA test. From the 486 included animal samples, 94.7% [95% CI 92.3-96.5] were domestic dogs with 90.9% [95% CI 87.9-93.3] positive, which stands out as the main reservoir of rabies in Mali. Cats, cattle, sheep and donkeys also tested positive using the DFA test. The cumulative incidence of canine rabies was estimated at 0.371 [95% CI 0.336-0.408] / 10'000 dogs. The highest incidence was observed in Bamako, the capital of Mali, with a cumulative incidence of 2.242 [95% CI 2.001-2.504] / 10'000 dogs, followed by Koulikoro with 0.335 [95% CI 0.258-0.429] / 10'000 dogs. For other areas far from LCV, the cumulative incidence was low, with zero in Kidal. Nationally reported cases of human rabies declined in recent years with an average of 12.6 [95% CI 8.7-16.5] deaths per year. This result gives an annual incidence of 0.1047 [0.0742-0.1352] / 100'000 inhabitants. CONCLUSION: Over the past 18 years, rabies is endemically stable in Mali despite the decrease in reported human cases. The disparity among regions in number of samples tested indicates a low level of clinical and laboratory surveillance and likely a high level of underreporting. Dogs play the main role in rabies transmission in Mali. Monitoring of and decisions for post-exposure prophylaxis (PEP) includes other animals (cats, cattle, and monkeys) involved in transmission. Mali should develop a national rabies strategy to include better communication between the public health and animal health sectors, strengthening of laboratory surveillance capacity, mass vaccination of dogs and guaranteed access to PEP.