Rabies Detected in Keen’s Myotis Bat – Prince of Wales Island, Alaska

On July 13, biologists working on Prince of Wales Island trapped several Keen’s myotis bats near Harris River. One bat that appeared to be potentially ill and was acting more aggressively than the others was later euthanized and submitted to the Alaska State Virology Laboratory (ASVL) for rabies testing. This bat tested positive for rabies on July 17 and is only the third bat ever found to have rabies in Alaska.

There are several objectives for this Health Advisory:

1. To update what is known about bat rabies occurrence in Alaska;
2. To reinforce that people bitten by or exposed to bats should be evaluated promptly for possible rabies post-exposure prophylaxis; and
3. To encourage people finding sick or dead bats to contact wildlife and/or health authorities.

Prior bat rabies cases in Alaska

Six species of bats live in Alaska. Prior to July 2014, only two bats had been confirmed with rabies in Alaska. In 1993, a little brown bat found near Ketchikan in the Tongass Forest tested positive for rabies; the Centers for Disease Control and Prevention (CDC) characterized the virus strain as a silver-haired bat rabies virus variant. In 2006, a Keen’s myotis bat from northeastern Prince of Wales Island tested positive; that strain was characterized as a red bat rabies virus variant. There have been no cases of bat variant rabies among non-bats in Alaska.

In general, migratory patterns of bats in Alaska are not well-documented. It is reasonable to assume that rabies circulates among bat populations in southeastern Alaska, although we cannot exclude the possibility that any of the rabies-infected bats originated from outside Alaska. Bats from other regions in Alaska, including the Kenai Peninsula and the Anchorage-Mat-Su Valley area, have all tested negative for rabies. Samples from this third rabid bat will be sent to CDC for rabies virus variant characterization.

Potential bat exposures

Anyone who may have been bitten or scratched by a bat should contact a health care provider immediately to be evaluated for rabies post-exposure prophylaxis. If the bat is still available, it should be submitted to ASVL for rabies testing. Health care providers can contact the Alaska Section of Epidemiology (SOE) for assistance with rabies exposure consultations and for routing bats to ASVL for rabies testing. Call Epidemiology at 907-269-8000 M-F 8AM-5PM, or 800-478-0084 after hours.