USDA’s Animal and Plant Health Inspection Service (APHIS) has released an updated epidemiology report on the highly pathogenic avian influenza (HPAI) that has swept across the nation, killing millions of birds. According to USDA, the report has been updated to include:

-Interpretation of data from 81 turkey flocks investigated for HPAI

-Preliminary results from a case-control study conducted in layer operations in Iowa and Nebraska

-Preliminary results of a study of wildlife near affected and unaffected premises.

For months, USDA has conducted investigations to identify the transmission pathways of the virus. However, based on the data, the government agency concluded there is not substantial or significant enough evidence to point to a specific pathway or pathways for the current spread of the virus. But USDA Secretary Tom Vilsack told the Associated Press he is not ready to declare the outbreak over. Vilsack told the news agency that poultry producers have benefitted from the warm weather this summer since high temperatures can kill the virus. However, USDA officials feel the outbreak could return to the Midwest in the fall and spread to other regions as well.

The last case of the virus was detected in Iowa on June 17. Since December 2014, USDA has confirmed cases of HPAI H5 in the Pacific, Central and Mississippi flyways (or migratory bird paths). The disease has been found in wild birds, as well as more than 200 backyard and commercial poultry flocks, affecting approximately 48 million birds.

 The updated report can be read here.