The highly pathogenic H5N2 avian influenza outbreak that first struck the United States in December 2014 and continued to affect U.S. poultry flocks through June is considered to be resolved, according to the the World Organisation for Animal Health (OIE).

According to a recent OIE report, the H5N2 avian influenza outbreaks in Arkansas, California, Idaho, Indiana, Iowa, Kansas, Minnesota, Missouri, Montana, Nebraska, North Dakota, Oregon, South Dakota, Washington and Wisconsin are now “final, closed, and resolved.” OIE further stated that in accordance with its Terrestrial Animal Health Code Chapter 10.4, the U.S. has completely fulfilled the necessary actions and surveillance requirements to self-declare itself free of H5N2 avian influenza.

The virus was first confirmed in the U.S. in December 2014 in wild pintail ducks found in Whatcom County, Washington, while the last case of H5N2 avian influenza was discovered in June a layer flock of about 1 million birds in Iowa.

While it has been more than five months since any new cases of the virus have been reported, the USDA’s Animal and Plant Health Inspection Service (APHIS) is preparing for its possible return in the coming weeks as wild birds make their southward migration. Officials with APHIS, as well as various state agriculture and wildlife agencies, continue to conduct surveillance in poultry and in wild birds.