SEROEPIDEMIOLOGY OF TRICHINOSIS IN FLORIDA SWINE

Surveys for swine trichinellosis, conducted in Florida using a commerc ial enzyme-linked immunosorbent assay (ELISA) kit with a modified prot ocol for screening and Western blot as a definitive test, revealed sig nificantly different seroprevalences of 0.3% (four of 1294 samples) an d 2.8% (five of 179 samples) in domestic breeding swine and feral swin e, respectively. Seropositive swine were identified in four of 114 (3. 5%) domestic swine herds and in three of six feral swine regions. The location of two domestic herds with seropositive swine within approxim ately 2 miles of one another, and adjacent to a region where a seropos itive feral hog was identified, suggests that a focus of trichinellosi s exists in this area. The occurrence of singleton reactors in domesti c herds may be explained by the absence of the common modes of transmi ssion and suggests that swine were infected incidentally by feeding on the infected carcasses of small wild mammals or rodents. Although the presence of Trichinella spiralis spiralis isolates cannot be excluded , it is more likely that a sylvatic Trichinella isolate occurs in Flor ida swine. This conclusion is supported by the low seroprevalence in d omestic swine, the failure to detect larvae in domestic or feral swine and the high prevalence in Florida panthers.