Rabies postexposure prophylaxis was given to 200 US Air Force trainees at Joint Base San Antonio-Lackland in Texas after an investigation identified the presence of bats in seven dormitories housed in an older building on the base, according to a report in MMWR.
The bats were first reported in one dormitory on Jan. 17 during an inspection of the building when some trainees mentioned seeing bats. All 45 trainees in the affected dormitory (the index flight) started rabies postexposure prophylaxis (PEP) by receiving the first dose of vaccine that evening and the human rabies immune globulin 3 days later.
Additional investigations determined that another six dormitories in the building may also have a bat presence. Using recommendations by the Advisory Committee on Immunization Practices, health officials interviewed 866 trainees to assess their exposure risk. Those meeting the increased risk criteria were recommended PEP.
During the interviews, the investigators found that bats were observed at various times in seven dormitories from Dec. 22 to Jan. 16. Those in the index flight were found to have the highest risk. Another 157 trainees in three additional flights (organizational units within the US Air Force) were considered to be at moderate risk and initiated rabies PEP on Jan. 20. Two of the trainees discontinued after the first dose when they were reclassified as low risk.
In an investigation of the building by the civil engineering unit and a commercial bat control specialist, it was concluded that a small colony of 400 to 600 bats had been nesting inside the walls for several years. The building underwent remediation and the building was declared clear for reoccupation after 2 weeks.
“Despite numerous bat sightings involving multiple trainees and instructors over several days, no one had reported them to public health authorities,” the investigators from Joint Base San Antonio-Lackland wrote. “This supports previous reports that document an underappreciation of the health risk associated with indoor bat exposures.”
Disclosure: The investigators report no relevant financial disclosures.