The U.S. Department of Agriculture’s Animal & Plant Health Inspection Service (APHIS) released a preliminary epidemiology report for the cases of highly pathogenic avian influenza (HPAI) and low-pathogenic avian influenza (LPAI) confirmed in Indiana.

Animal health officials confirmed one case of HPAI H7N8 and eight cases of LPAI H7N8 in Indiana in January. This was a short incident in which the cases were reported quickly.

Following these avian influenza cases, APHIS joined forces with the Indiana Board of Animal Health and the poultry industry to complete a series of epidemiological, geospatial and laboratory-based investigations.

In the report, APHIS outlines the findings of those investigations, which, to date, include:

* Genetic analyses of these viruses indicate that all viruses were of North American wild bird lineage, the HPAI and LPAI viruses were highly similar and the LPAI virus mutated to HPAI at a single farm.

* APHIS sampled wildlife on infected premises but did not detect the new H7N8 virus.

* APHIS said one of the factors examined was the weather. The weather in Dubois County, Ind., was warmer and wetter than in past years, which may have contributed to the introduction and persistence of the virus. More detailed geospatial analysis is ongoing.

* APHIS used an in-person questionnaire to examine physical and management characteristics of infected premises. Specific practices were identified as risk factors in the 2015 outbreak. The initial analysis showed that farmers in Indiana had eliminated some of these practices from their routine, but a few of those practices were still seen on the affected farms. APHIS is now collecting similar information on non-infected farms to help further interpret the data from the infected cases.

Click here to view the full epidemiology report.

APHIS emphasized that the preliminary findings reinforce the need for producers to remain vigilant in the upcoming months and to maintain good biosecurity practices. Biosecurity is one of the most important steps producers can take to protect the health of their birds. Biosecurity information, training resources and a producer self-assessment are all available through the APHIS website.

APHIS will continue to provide updates to this report and investigate how the HPAI/LPAI virus was introduced and spread in Indiana.