Prevalence of antibodies against leptospires in small mammals in relation to age, sex and season

A total of 2,195 small mammals belonging to 8 species were captured in different districts of South Moravia, Czech Republic, and examined for antibodies against leptospires in the period from 2004 to 2008. Positive specimens amounting to 173 (9%) were found annually in five species of rodents such as Apodemus sp., Clethrionomys glareolus, Microtus arvalis, Mus musculus and Rattus norvegicus. The recognised leptospiral serotypes included L. grippotyphosa, L. bulgarica, L. sejroe and L. icterohaemorrhagiae/copenhageni. The highest prevalence of antibodies was against the L. grippotyphosa serotype (92.8%). Reactions with other serotypes of leptospires were exceptional. Reactions with L. bulgarica antigen were only due to coagglutination with L. grippotyphosa leptospires. The titres ranged from 100 to 12,800. However, lower values up to the titre of 800 predominated in 151 cases (83.4%). There were non-significant sex differences in seroprevalence with 8.1% and 7.6% prevalence in males and females, respectively. Marked differences were, however, found in seroprevalence of juveniles and adults with 3.3% and 10.2%, respectively. Adult males and females were seropositive in 10.9% and 9.5%, respectively; juveniles were seropositive only in 3.0% and 3.7%. The highest percentage of specimens (43.6%) was examined during July and August. The summer seroprevalence of 10.9% was higher than in spring and autumn. Our results revealed the persistence of both natural and synanthropic nidi of leptospirosis in the region under study and demonstrated epidemiological implications regarding health protection of animals and humans