Volume 195 - Issue 6
Challenges in postexposure prophylaxis of a vaccinated bat carer
Authors: Heidi J Carroll, Bradley J McCall, David Looke and Bruce Fraser
Med J Aust 2011; 195 (6): 323-324. || doi: 10.5694/mja11.10776
Published online: 19 September 2011
Published online: 19 September 2011
To the Editor: Australian bat lyssavirus (ABL) has the potential to cause fatal encephalitis in humans exposed to infection through bat bites or scratches. There is no cure for rabies currently available, so postexposure prophylaxis with rabies vaccine and rabies immune globulin is recommended following potential human exposure, such as after bites or scratches.
People who work with or handle bats should be vaccinated, should regularly monitor their rabies antibody levels to ensure maximum protection, and should seek immediate medical attention for all potential ABL exposures.1
We report the case of a 42-year-old man bitten by a black flying fox (Pteropus alecto) during the retrieval of the bat from a suburban Brisbane, Queensland, backyard. The bat had been found on the ground in the daytime, vocalising and acting aggressively. The patient was a member of a local organisation which cares for injured bats.
The Logan and West Moreton Public Health Unit was notified the day after the incident. The patient reported that he had been vaccinated against rabies previously, and that his rabies virus-neutralising antibody titres were adequate. However, the patient’s available titres were below 0.50 IU/mL in 2002 and 0.43 IU/mL in 2008 (no boosters were given), both of which were below the World Health Organization recommended level that confers protection against rabies virus.2
The bat was euthanased for testing (because it had bitten a person, as per Qld Health protocol), and tests on the brain tissue showed it to be reactive for lyssavirus antigen (using an immuno-fluorescence antibody test) and lyssavirus RNA (using a TaqMan assay). In view of the patient’s recent serological tests indicating subprotective antibody levels and definite exposure to an ABL-positive bat, he was given postexposure prophylaxis comprising rabies immune globulin into the wound and five doses of rabies vaccine. He is currently well. The Public Health Unit determined that others were not potentially exposed to the bat.
The prompt reporting of all potential ABL exposures to public health units is especially important because bat carers may underreport potential ABL exposures.3 Current guidelines recommend that bat carers with ongoing potential exposure to ABL should check their rabies virus-neutralising antibody titres every 2 years and have a booster if the titre is reported as inadequate (< 0.5 IU/mL). Alternatively, booster doses may be offered every 2 years without determining antibody levels.1 Further education of the bat-handling community and their doctors is necessary to maintain awareness and best practice to protect the people who do this potentially dangerous work.
Competing interests
No relevant disclosures.
Acknowledgements
We thank Frederick Moore for testing of the bat.
References
- National Health and Medical Research Council. The Australian immunisation handbook. 9th ed. Canberra: Commonwealth of Australia, 2008. http://www.health.gov.au/internet/immunise/publishing.nsf/Content/Handbook–home (accessed Aug 2011).
- World Health Organization. Rabies vaccines: WHO position paper. Wkly Epidemiol Rec 2010; 85: 309-320. http://www.who.int/wer/2010/wer8532.pdf (accessed Aug 2011).
- Young MK, McCall BJ. Potential exposure to Australian bat lyssavirus in south east Queensland: what has changed in 12 years? Comm Dis Intell 2010; 34: 334-338. 0_CBBJEFEG