Stricter biosecurity measures helped to limit the spread of avian influenza in the U.S., according to a new report.
On June 23, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS) released its epidemiology report on the avian influenza outbreaks in Tennessee, Alabama, Kentucky and Georgia. The 44-page report can be read in full here.
The report, studying the outbreaks that popped up in the southeastern U.S. starting in March 2017, analyzed how the disease was spread and how it can be prevented in the future. It concluded the agency, and the poultry industry, have made strong progress since the 2014-2015 outbreaks.
A statement from Donna Karlsons, a spokeswoman for APHIS, said the states’ veterinary authorities and the poultry industry have collectively improved their response times since the major outbreak.
“In this case, rapid response and improved biosecurity practices helped to limit transmission between operations during this outbreak,” Karlsons said.
As for the disease characteristics, the agency said the results of genetic analyses determined that all H7N9 viruses detected from the outbreaks were of North American wild bird lineage. It added that genetic and epidemiologic evidence suggest the possibility of more than a single introduction of the virus at affected premises with limited transmission from farm to farm.
“Potential routes of lateral spread between farms, related to potential concerns such as the biosecurity of egg pickup, trucks, visitors, equipment and disposal activities, did not appear to be risk factors during this outbreak,” the report said. “However, factors such as the presence of rodents and other wild mammals and waterfowl near barns, the condition of the housing, and breaches in biosecurity protocols were identified as risk factors that could bring viruses into the barns from the environment.”
The release of the report should not be interpreted as a sign that the disease risk is over, however.
“We know that avian influenza viruses continue to circulate in migratory birds and waterfowl in North America,” Karlsons said. “For this reason, strict biosecurity measures are crucial to keep the disease from entering and spreading among poultry operations.”