Rabies in Wildlife in Latvia

In the Baltic States, lyssaviruses are often detected in wildlife and presumed to constitute an important public health hazard. In order to decrease rabies incidence and eradicate wildlife reservoirs, a national rabies eradication program has been in place. Since 1970 a vaccination program in dogs and cats has been executed, and in 1991 oral vaccination of foxes was started. However, due to an insufficient budget, the latter was not done regularly and nationwide before 2000. Now, the program in force consists of compulsory vaccination of all dogs and cats, and a tetracycline marker vaccine oral vaccination program of foxes in the whole country. In 2001, 151 of 285 (53%) fox jaws were tested positive for tetracycline. All animals showing rabies-like symptoms were killed and tested for rabies. In this way, 250–400 cases of rabies per year were diagnosed in wildlife. To molecularly characterize the prevalent lyssaviruses in wildlife, lyssavirus RNA of 25 recent rabies positive samples, collected in the year 1999, was amplified by RT-PCR. Direct sequencing of the RT-PCR-amplified products of the virus' nucleoprotein encoding region and subsequent sequence analyses resulted in a 99.3–100% homology between isolates and a 99.0–100% similarity with a 1995 genotype I, classical rabies virus (RABV) raccoon dog isolate from Estonia. These results confirmed that RABV is endemic in wildlife in Latvia and should be considered a serious public health threat. To successfully eradicate the wildlife reservoirs, the national rabies eradication program must be continued, and it may need to be intensified.