Avian flu numbers drop as summer nears

COLUMBIA, Mo. — Numbers are dropping for Avian influenza, informally known as avian flu or bird flu, according to Robert Pierce, University of Missouri Extension wildlife and fisheries specialist.

Fewer reports of dead and sick birds point to an end to the current outbreak of avian influenza, Pierce says. Rising summer temperatures will also likely lead to a decrease in avian influenza. There is evidence that the AI virus does not tolerate high temperatures well. Numbers could move upward again in the fall as temperatures drop.

Pierce says it is not necessary to remove bird feeders as a precaution; transmission of avian influenza from birds to humans is very rare. However, it is important to practice good sanitary measures such as regularly cleaning birdbaths and bird feeders.

Pierce also notes that songbirds do not appear to be a major carrier of avian influenza. (For more information, Avian Influenza Outbreak: Should You Take Down Your Bird Feeders? from the Cornell Lab of Ornithology.)

MU Veterinary Medical Diagnostic Laboratory confirmed avian flu cases as early as March. The lab first confirmed avian influenza in a commercial poultry flock in Stoddard County on March 3. Avian influenza was reported in a backyard flock in Bates County on March 4. The Missouri Department of Conservation confirmed cases in at least 23 Missouri counties as of May 11.

The flu occurs naturally in bird populations, especially waterfowl, shorebirds and domestic birds such as chickens and turkeys. According to MDC, avian influenza spreads as birds along North American flyways mingle with infected birds from Europe and Asia.

The virus moves from bird to bird through fecal droppings, saliva and nasal discharges. There is a risk for spillover from wild birds into domestic poultry and then back again from poultry to wild birds, resulting in further spread. While often fatal in domestic poultry, it rarely infects other domestic animals or humans.

Infected birds exhibit symptoms such as tremors, head tilting, lethargy, loss of coordination, inability to fly or walk properly and trouble standing upright, according to MDC.

Dead or sick birds can be reorted to MDC at wildlifehealth@mdc.mo.gov. The MU Veterinary Medical Diagnostic Lab offers testing for avian influenza. Visit vmdl.Missouri.edu for details.

Missouri Department of Agriculture has information and updates on avian influenza at agriculture.mo.gov/avian-influenza.php.

Missouri Department of Conservation map can be viewed at https://mdc.mo.gov/sites/default/files/styles/media_large/public/2022-05/HPAI%20map_WILD%20ONLY_5-11-2022.png. It shows the 23 Missouri counties with confirmed cases of avian flu as of May 11.