Rabies serum neutralizing antibody in mongooses from Grenada

Abstract

During a four-year study on Grenada, 4,754 mongooses were examined, of which 100 (2·1%) were rabid. Of 1,675 mongooses tested for rabies serum neutralizing (SN) antibody, 498 (30%) were positive. During these four years (1971–1974) the antibody prevalence rate increased from 20·8% to 43·2%, whereas the number of rabid mongooses decreased from 3·5% to 0·6%. Naturally acquired antibody was monitored in 20 captive mongooses for up to 35 months, and it was still circulating in 18 when monitoring ceased. The highest titre recorded was 1:1,400, and the rate of fall was greatest in mongooses with high initial titres. High titres of naturally acquired antibody suggest recent rabies activity. 14 mongooses vaccinated parenterally with 1·0 ml of attenuated ERA vaccine showed substantial increases in antibody titres; most had titres greater than 1:1,000 one month later and maintained a high titre for several months. The highest recorded was 1:34,800. The virus titres of brain material from rabid mongooses ranged from 10 1·8 to 10 4·3 and, in some cases, were only slightly lower than those of salivary gland tissue (range, 10 1 to 10 5·6).