Missouri has been declared free of avian influenza after a low pathogenic H5N1 form of the virus was found in a commercial turkey flock there in April, the World Organisation for Animal Health (OIE) reported.

A turkey flock at a farm in Japser County tested positive for the virus, which led to the stamping out of 39,000 birds. Since that time, the USDA Animal and Plant Health Inspection Service (APHIS) and the Missouri Department of Agriculture conducted a comprehensive epidemiological investigation and implemented enhanced surveillance and testing.

Control measures, including quarantine and the establishment of a protection zone, were put in place after the avian flu outbreak was discovered.

The virus did not spread beyond the affected farm, which has since been depopulated and disinfected. All tests in the immediate geographical area conducted since April have proven negative for avian influenza. As a result, OIE considers the Missouri outbreak to be “final, closed and resolved,” and will not submit any further reports on the matter.

However, the OIE stated that additional surveillance activities may continue in the state and the area as an added precaution.

The source of the low pathogenic H5N1 avian influenza outbreak in Missouri is still considered unknown.