Mass Human Exposure to Bats at a Volunteer Lodging Facility in Kentucky

BACKGROUND:  Bats are a domestic reservoir of rabies viruses and are consistently identified as the source of human rabies fatalities in the US.  In July of 2012 the Kentucky Department for Public Health (KDPH) was alerted to a situation involving potential bat exposures in a renovated brick building used as sleeping quarters of a non-profit organization for thousands of children and adults since 1999. Pest control professionals performing remediation in July reported a colony of 200-300 Big Brown bats (Eptesicus fuscus) roosting above the ceiling tiles of the sleeping quarters. CDC and KDPH performed risk assessments for all persons sleeping in the facility in 2012 to provide appropriate postexposure prophylaxis recommendations.

METHODS:  Telephone risk assessment surveys were done to collect demographic information, dates slept in the building, room(s) slept in, level of the bunk slept on, and whether the volunteer saw bats inside or outside of the building. For observed bats, respondents were asked about the health status of the bats, possible contact with bats, and additional situational details such as location of bat sightings. Pest control professionals were interviewed about bat exclusion dates and activities.

RESULTS:  A total of 257 out of 273 volunteers (94%) who slept in the building in 2012 completed a risk assessment and were categorized as low, moderate, or high risk for bat exposure. The age of volunteers ranged from 13 – 87 years with a median age of 21 years; 139/257 (54%) were female. Bats were reported in sleeping quarters on 13 nights between June 19 and July 24, 2012. Based on these sightings, a total of 48 (19%) volunteers were exposed to bats while they slept. Sixteen (6.3%) volunteers were assessed at elevated risk for rabies exposure and were recommended to receive rabies post-exposure prophylaxis (PEP), 3 high risk and 13 moderate risk. Two of three high risk exposure volunteers held a bat without gloves. The third high risk exposure volunteer was awakened when he rolled onto a bat in his bed and caught bats on two separate occasions without the use of gloves. No volunteers reported known bat bites or scratches.

CONCLUSIONS:  Bat infestation of sleeping quarters can result in significant bat-human interaction. This report highlights the need for official guidelines on conducting public health investigations of mass bat contacts, and the importance of collaborating with public health officials during bat exclusion efforts to minimize human-bat contact events.