Prevalence and epidemiology of selected enteric infections of livestock in Trinidad

In a study of diarrhoeic and non-diarrhoeic livestock (cattle, pigs and sheep) from 50 farms in Trinidad, the prevalence of bacterial (Campylobacter, Salmonella, Yersinia and Escherichia coli), parasitic (coccidia, Cryptosporidium and enteric helminths) and viral (rotavirus) enteropathogens in faeces or rectal swabs was determined. Occurrence of the enteropathogens was tested for association with age, health status, animal species and mixed infections.

Of 423 diarrhoeic animals tested, Salmonella was isolated from 21 (5.0%), Campylobacter from 191 (45.2%) and Yersinia from three (0.7%), while the corresponding prevalence from 270 non-diarrhoeic controls was eight (3.0%) (χ² 1.19, P = 0.28), 119 (44.1%) (χ² 0.04, P = 0.85) and four (1.5%) (χ² 0.8, P = 0.39), respectively. Verocytotoxigenic E. coli and heat-labile toxin-producing E. coli were isolated from 51 (13.7%) and five (1.3%), respectively, of 373 diarrhoeic animals but the corresponding prevalence from 258 non-diarrhoeic animals was 39 (15.1%) (χ² 0.15, P = 0.7) and five (1.9%) (χ² 0.07, P = 0.8), respectively. Cryptosporidium oocytes were detected in 67 (16.5%) of 406 diarrhoeic animals and from 31 (12.1%) of 257 non-diarrhoeic animals (χ² 2.13, P = 0.15). For 147 diarrhoeic animals tested for coccidia, 64 (43.5%) were positive compared with 34 (37.8%) of 90 non-diarrhoeic animals (χ² 0.54, P = 0.49).

The prevalence of rotavirus infection was significantly (P 0.001, χ² 37.8) higher in diarrhoeic animals (39.9%, 112 of 281) than in non-diarrhoeic animals (13.4%, 26 of 194).