Seroepidemiology of leptospirosis in livestock in Trinidad

A study was conducted to determine the seroprevalence of leptospirosis and infecting serovars across livestock (cattle, sheep, goats, and pigs) in Trinidad using the microscopic agglutination test with an international panel of 23 serovars. Of a total of 590 cattle tested, 21.5% were seropositive with agglutinations to 13 of the 23 antigens used in the panel. Icterohaemorrhagiae (9.3%), Sejroe (4.1%), Ballum (4.1%), and Autumnalis (1.9%) were the predominant serogroups detected in the cattle sampled (n = 590). Of 222 sheep tested, 5.0% were seropositive with agglutinations to five serovars belonging to two serogroups. These serogroups were Autumnalis at 2.7%, and Icterohaemorrhagiae at 2.3% of all sheep tested (n = 222). Of a total of 180 goats tested, 3.3% were seropositive, all agglutinating to the Icterohaemorrhagiae serogroup, 1.7% to serovar Copenhageni, 1.1% to serovar Mankarso, and 0.6% to serovar Icterohaemorrhagiae. Among pigs (n = 200), 5.0% were seropositive for five serovars belonging to three serogroups. These serogroups were Icterohaemorrhagiae at 2.5%, Australis at 2%, and Ballum at 0.5%. Overall, age and sex of animals were not significantly associated with leptospirosis with the exception of cattle where age was a significant factor for seropositivity. It was concluded that for livestock, leptospirosis may be an important zoonotic and economic disease, particularly in the case of cattle. It is imperative that the impact of leptospirosis on abortion, stillbirths, and decreased milk production in livestock in the country be assessed.