Avian Influenza Virus (AIV)—Should the Mushroom Industry Be Concerned?
What is AIV?
Avian Influenza Virus (AIV) is a virus that is transmitted to birds through inhalation of influenza particles in nasal and respiratory secretions and from contact with the feces of infected birds. It has been detected in commercial poultry flocks, backyard poultry flocks, and wild waterfowl such as ducks, shorebirds, gulls, and other seabirds. Highly pathogenic avian influenza (HPAI) viruses are of particular concern to the domestic poultry industry because they can destroy flocks in just a few days. In many states, the spread of the disease is controlled by active surveillance programs that monitor birds for evidence of exposure to the virus and isolate and destroy infected flocks.
Can AIV Spread to Humans?
Avian influenza viruses do not usually cause disease in humans; however, human infections and outbreaks have been reported in Asia and Europe since 1997. Since the Fall of 2003, a growing number of Asian countries have reported outbreaks of avian influenza in chickens and ducks. H5N1 viruses have also been detected in some mammals, including both wild and domestic mammals. In 2024, multiple cases of AIV were reported in dairy cattle, and further spread to humans is of concern.
Many mushroom growers who use chicken litter in their compost are asking if they should be concerned about AIV on their farms. Like all viruses, AIV can only replicate inside an infected animal. Once it leaves a living host, it cannot remain active for very long.
Should the Mushroom Growers Be Concerned About AIV?
There are no studies on heat inactivation of AIV in poultry litter during mushroom composting. However, In 2003, researchers from the Penn State Animal Diagnostics Laboratory reported that AIV particles isolated from chicken manure can lose their infectivity when exposed to 56°C (133°F) for 60 minutes or 60°C (140°F) for 10 minutes (Lu et al. 2003). Also, research studies suggest that standard cooking and pasteurization treatments designed to ensure the rapid destruction of pathogenic bacteria in foods are also effective in destroying AIV. For instance, cooking eggs to 71°C (160°F) and chicken meat to between 57°C (135°F) and 60°C (140°F) was effective in killing the virus (Doyle et al. 2007). More recent reports from FDA (2024) and Kaiser et al. (2024) show that federally mandated pasteurization treatments of 63°C (145°F) for 30 minutes or 72°C (163°F) for 15 seconds are adequate for inactivating the HPAI virus in milk.
Based on this data, it is likely that, with those temperatures achieved during mushroom Phase I and II composting, there will be significant, if not complete, inactivation of the virus. Nevertheless, composters should obtain further protection by receiving assurances from their poultry manure suppliers that biosecurity control measures are followed on their farms and that they are participating in an active AIV surveillance program.
References and Information
- H. Lu, A. E. Castro, K. Pennick, J. Liu, Q. Yang P. Dunn, D. Weinstock, and D. Henzler. 2003. Survival of Avian Influenza Virus H7N2 in SPF Chickens and Their Environments. Avian Diseases 47:1015-1021. doi.org/10.1637/0005-2086-47.s3.1015.
- M. E. Doyle, S. Schultz-Cherry, M. Robach, and R. Weiss. 2007. Destruction of H5N1 Avian Influenza Virus in Meat and Poultry Products (PDF). FRI Briefings. Food Research Institute. University of Wisconsin-Madison.
- Using Heat Treatment for Virus Elimination (PDF). Animal Plant Health Inspection Service. U.S. Department of Agriculture. April 13, 2022.
- F. Kaiser et al. 2024. Inactivation of Avian Influenza A(H5N1) Virus in Raw Milk at 63°C and 72°C. Correspondence New England Journal of Medicine. June 28, 2024. doi:10.1056/NEJMc2405488.
- FDA 2024. Updates on Highly Pathogenic Avian Influenza (HPAI). U.S. Food and Drug Administration.
For additional information on AIV, visit the Penn State Extension Avian Influenza website.
