Rabies seroprevalence of street dogs from Sao Paulo City, Brazil

A sample of 602 street dogs captured by the Sao Paulo zoonosis-control municipal service was analyzed for the presence of serum antibodies against the rabies virus and compared to a control sample of 37 dogs from the kennel of the police of Sao Paulo. Data were stratified into 4 age intervals and the age from the street-dog sample was estimated by general aspects and dental observation according to standard techniques. We assumed that seropositivity was due to previous vaccination (no sub-clinical infection). From the prevalence data, we estimated the age-dependent incidence-density rate of vaccination by a simple mathematical model, which also allowed the estimation of the period of antibody protection given by the supposed vaccination. Crude seroprevalence in the street-dog sample was 16.5% and in the sample from the police-kennel dogs was 80%. The average age of first vaccination calculated for the street-dog sample was 5 years of age (if we assumed an average period of vaccine protection of 3 years) - but 5 months of age for the police-kennel sample. (C) 2000 Elsevier Science B.V. All rights reserved.