Bat Rabies in Indiana.

Our objective was to determine rates of rabies infection in bats submitted to the Indiana State Department of Health (ISDH) between species, over time, and in normally behaving bats. Those are important questions for public health reasons and also for protection of bats. Bats were tested by ISDH by using the immunofluorescent method. We tested 8,262 bats for rabies at the ISDH from 1966 to 2003, of which 445 (5.4%) tested positive. The 2 most common species, the big brown bat (Eptesicus fuscus; n = 5,584; 173 [3.1%] rabid), and the red bat (Lasiurus borealis; n = 1,512; 169 [11.2%] rabid), accounted for 85.9% of submissions. We found the highest rates of rabies in the hoary bat (L. cinereus; 54 of 178 [30.3%] rabid) and eastern pipistrelle (Pipistrellus subflavus; 41 of 314 [13.1%] rabid). Rates of rabies in other species ranged from 3.7% in the silver-haired bat (Lasionycteris noctivagans) to zero in Indiana myotis (Myotis sodalis) and evening bats (Nycticeius humeralis). The above data were mostly for incapacitated bats that people found sick or dead rather than normally behaving bets. None of 259 normally behaving big brown bats examined from areas where rabid bets had occurred were rabid. Levels of rabies in the big brown bat remained relatively stable throughout the study period with peak activity during late summer and fall. [ABSTRACT FROM AUTHOR]