Abstract

West Nile virus (WNV) was first detected in North America in 1999 and has rapidly spread across the continent. An unusual characteristic of the North American epidemic is high avian mortality. The effect of WNV on wild bird populations was highlighted during the 2002 WNV season. Wildlife rehabilitation centers in 14 states reported a sudden increase in admissions of sick and dying raptors, particularly great horned owls and red-tailed hawks, at the height of the epidemic. Soon after, several anecdotal reports were received from rehabilitators who developed symptoms they believed to be due to WNV infection. Although mosquitoes are known to transmit the virus, many of these rehabilitators believed they acquired WNV while treating the sick birds (i.e., non-vector transmission). Some reported confirmation of WNV infection by their physician. Using the 2002 National Wildlife Rehabilitation Association (NWRA) directory, a telephone survey of randomly selected wildlife rehabilitators in the 14 states was conducted to determine the proportion of rehabilitators that had acquired WNV infection and to assess the possibility of direct bird-to-human transmission of the virus. Forty-two raptor rehabilitators participated in the survey. Thirty-four (81.0%) reported admitting WNV-suspect or WNV-confirmed raptor cases. Common personal protective measures taken included wearing gloves (leather and/or latex) and hand washing. Masks, face shields and/or goggles to protect against aerosol or body fluid exposure were used on an “as needed” basis, if at all. Half of the respondents reported using no protection against mosquito exposure, despite some reporting uncountable number of mosquito bites that season. Nonspecific symptoms that could have been due to WNV infection were reported in nine respondents, but only one (11.1%) sought medical care, after which the diagnosis was unknown. Based on this study, it is impossible to determine the likelihood illness occurred as a result of direct contact with sick birds. The states in which these rehabilitation facilities were located included those that experienced high WNV activity during the 2002 WNV season. It was impossible to determine whether illness was due to WNV and whether exposure occurred by route other than via mosquito. Further studies evaluating risk of WNV infection in personnel caring for wildlife are needed. The study does demonstrate the need for guidance to rehabilitators regarding protective practices to prevent injury and diseases they may acquire while treating sick animals. Veterinarians who provide services to wildlife rehabilitation facilities are in a unique position to provide guidance regarding protective measures needed while working with sick wildlife, as well as to emphasize the importance of personal health and the need to seek medical attention when symptoms arise.