Study of the Dog Population and the Rabies Control Activities in the Mirigama Area of Sri Lanka

The national health authorities of Sri Lanka have adopted a combined strategy of rabies vaccination and stray dog removal to control endemic dog rabies. Despite the control efforts, an increase of animal and human rabies cases has occurred since 1994. As a consequence, a project to evaluate the national rabies control program has been started and a study focussing on the dog population and rabies control activities in a limited area of Mirigama was conducted. Information on canine abundance and the accessibility of dogs for rabies vaccination was obtained by a household survey, vaccination of dogs against rabies at several vaccination points, collar-marking, and transect line recapture. The number of unvaccinated dogs was estimated by using Bayesian methodology. The estimated number of dogs per square kilometre was 87 (95% credibility interval: 80, 93) for owned dogs and 108 (100, 116) for owned and ownerless dogs. Coverage after the immunisation campaign was 57.6% (53.3, 61.9%) if vaccination at the vaccination points was considered and 66% (60.4, 72.0%) if recently provided vaccination by private veterinarians was also taken into account. The proportion of households with at least one dog vaccinated varied between 59.1 and 94.2% within the catchment area of the different vaccination points. Unvaccinated dogs were puppies (12%), ownerless dogs (57%), and owned dogs, which were not presented for vaccination (31%). In order to improve the rabies immunisation coverage among dogs and to achieve complete elimination of rabies it was recommended that the 95% catchment area of each vaccination point be assessed, the distribution of vaccination points in the vaccination area be redefined if necessary, a system for the vaccination of dogs missing the vaccination campaign for dog owner-specific reasons be established, and an inexpensive marking system be used for vaccinated dogs.