California Fish and Game Tells Hunters to “Keep It Clean” / Avoid Disease
“Wild animals are natural reservoirs for a variety of bacteria and viruses. Anyone coming into contact with wild birds needs to practice good hygiene in the field and at home,” said Dr. Pam Swift, DFG wildlife veterinarian. “Hunters can be exposed to bacteria and viruses in blinds, at harvest and collection, during field dressing and when cooking wild game.”
Some avian diseases that occur naturally in California include avian botulism, avian cholera, mycoplasmosis, salmonellosis and trichomoniasis. Of heightened concern during the past several years has been the risk of exposure to Highly Pathogenic H5N1 Avian Influenza (HPAI H5N1).
HPAI H5N1 is primarily a bird disease that is particular to domestic poultry, but can also infect most other birds both domestic and wild, and to a lesser extent, mammals. It is one of many types of avian influenza viruses. The HPAI H5N1 virus caused high mortality in poultry and wild birds in 55 countries around the world but has not been detected in North America. Long-term surveillance of more than 30 years by the U.S. Geological Survey and U.S. Fish and Wildlife Service (USFWS) in cooperation with DFG, has not established the presence of any HPAI virus in North American wild birds. Surveillance for avian influenza viruses has become a standard procedure in addition to the testing for a variety of other avian diseases.
While there is currently no known risk of being exposed to the HPAI H5N1 in the United States, anyone coming into contact with birds should know that there are other diseases and bacteria they may encounter.
“Hunters are not the only people who are exposed to wild birds,” said Dan Yparraguirre, DFG wildlife biologist. “Backyard bird feeders, wildlife rehabilitators, gamebird breeders, licensed game bird clubs, falconers, restricted species permit holders, scientific collectors, zookeepers and field biologists are examples of people who can have contact with wild birds.”
Good hygiene is the best defense against exposure to any number of diseases that wild birds carry. To prevent exposure to bacteria and viruses, people should:
Not handle birds that are obviously sick
Keep game birds cool, clean and dry
Place harvested birds in a washable container for transport (ice chest, etc. that can be sanitized)
Wash hands before eating, smoking, drinking (use hand sanitizer in duck blinds)
Use rubber gloves when cleaning game and wash hands with soap and water or alcohol wipes after dressing birds
Clean all tools and surfaces immediately afterward; use hot soapy water, then disinfect with a 10 percent chlorine bleach solution
Clean clothes, boots, back of truck, bird prep station well
Properly dispose of feathers/innards
Cook game meat thoroughly (155-165°F)
Some avian diseases like avian cholera and avian botulism do not pose a threat to humans, but can cause large bird die-offs. These diseases occur in a cyclic manner depending on numerous environmental factors such as ambient temperature, water availability and bird concentrations. When a die-off occurs, DFG and USFWS respond quickly.
“We are ready to rapidly investigate and collect samples for necropsy and disease testing should a die-off occur in California,” said Yparraguirre. “With rapid response, we can ensure the public safety and maybe slow the effect of the die-off.”
To help with the statewide surveillance and response to wild bird die-offs, the public is encouraged to report dead wild birds to 877-968-2473 or at the California West Nile virus Web site at www.WestNile.ca.gov.
Over the past 30 years in California, documented bird losses due to diseases and pollution ranged from a low of 10,500 in 1977-78 to a high of 169,300 in 1991-92. The majority of the bird losses in 1991-92 consisted of 150,000 eared grebes that died due to avian cholera at the Salton Sea. Average annual loss of migratory birds to disease in California is about 25,000 birds. These figures are for birds picked up and disposed of, and the actual losses are greater. In 2005, the last full year of available data from the National Wildlife Health Center, of the nearly 12,000 birds picked up in California, most diagnosed causes of mortality were petroleum spills (5,000), salmonellosis (2,400), botulism (1,800) and starvation (1,500).
For more information on avian influenza and clean and safe practices for all varietys of contact with wild birds, please visit www.dfg.ca.gov/wildlife/avianflu.