Epidemiological surveillance of rabies in Lithuania from 1986 to 1996

Rabies has been endemic in Lithuania for centuries. The objective of this study was to evaluate rabies incidence and seasonal trends in domestic and wild animals in Lithuania from 1986 to 1996. Annual rabies reports and data on cattle numbers were collected. Descriptive epidemiology and time series data analyses were performed to detect seasonal trends. A total of 1,475 specimens were submitted for rabies testing. Of these, 1,248 (84.6%) were confirmed as rabies cases by immunofluorescence antibody testing. Domestic animals accounted for 73.8% (921/1,248) of all rabies cases, with cattle accounting for 61.1% (563/921) of domestic animal cases. Wildlife cases were reported principally in red foxes (56%; 183/327) and raccoon dogs (31.2%; 102/327). Time series analysis indicated a strong association between the occurrence of rabies in cattle and the season of the year (P = 0.0032), with the highest incidence of rabies occurring in autumn. The incidence declined from 3.4 to 4.8 cases per 100,000 cattle in the mid-1980s to < 1.5 cases per 100,000 cattle in 1994, but increased to 4.2 cases per 100,000 cattle in 1996. However, as the cattle population dramatically decreased (by 54%) over the eleven-year period of the study, the reduction in the total number of rabies cases in cattle was not reflected in the annual incidence rate of cattle rabies.