Vaccine should not be administered in the gluteal area because this may result in lower antibody titers. The deltoid is the only acceptable intramuscular site of vaccine administration in adults and older children; the outer thigh can be used in young children. Vaccines cost about $300 per dose. Vaccine shortages have occurred, and the Centers for Disease Control and Prevention (CDC) maintains a website for rabies vaccine availability, www.cdc.gov/rabies/resources/availability.html.

Because of the cost, some public health experts have been concerned about ED overprescription. However, when we studied RPEP from more than 2,000 animal exposures presenting to our CDC EMERGEncy ID NET sites, we found that emergency physicians were in fact conservative in their use based on local guidelines.³

Back to our friend, the emergency physician “batted” in the head. Human rabies epidemiology in the United States helps provide the answer.

According to the CDC, the most common rabies virus variants responsible for human rabies in the United States are bat-related.2 During 1990–2007, 34 bat-associated human cases of rabies were reported in the United States. In six cases, a bite was reported; in two cases, contact with a bat and a probable bite were reported; in 15 cases, physical contact was reported (eg, the removal of a bat from the home or workplace or the presence of a bat in the room where the person had been sleeping), but no bite was documented; and in 11 cases, no bat encounter was reported. In these cases, an unreported or undetected bat bite remains the most plausible hypothesis because the genetic sequences of the rabies virus closely matched those of specific species of bats.

Rabid bats are more aggressive and have difficulty flying. The little sono-geeks do not normally fly flat into the foreheads of people, not once and especially not twice. So the bat in question was very likely rabid. And since bat bites can be imperceptible, this type of exposure requires RPEP. When in doubt, call the local health department, which is available 24-7 for these sometimes difficult and expensive ED decisions. My friend’s hospital bill was $16,240.

Acknowledgment: I would like to thank Dr. Brett Petersen and Dr. Andrea McCollum at the CDC for their review and suggestions.

Read the drug summary for HyperRAB, then complete the CME activity.

Dr. Talan is professor of medicine in residence (emeritus) at the David Geffen School of Medicine at UCLA and chairman emeritus of the department of emergency medicine and faculty in the Division of Infectious Diseases at the Olive View-UCLA Medical Center.

References

1. Red Book Online [database online]. Greenwood Village, CO: Truven Health Analytics. Accessed July 14, 2018.
2. Manning SE, Rupprecht CE, Fishbein D, et al. Human rabies prevention—United States, 2008: recommendations of the Advisory Committee of Immunization Practices. MMWR Recomm Rep. 2008;57(RR-3):1-28.
3. Moran GJ, Talan, DA, Newdow M, et al. Appropriateness of emergency department rabies postexposure prophylaxis for animal exposures. Emergency ID Net Study Group. JAMA. 2000;284(8):1001-1007.