A strain of influenza deadly to chickens and other fowl has spread to poultry operations in Kentucky and Virginia, widening an outbreak detected at a turkey farm in Indiana last week. 

Mexico is among countries that have reportedly banned or limited poultry imports from Indiana after the virus was detected there, and the wider spread raises the possibility of additional curbs.

The U.S. Agriculture Department’s Animal and Plant Health Inspection Service said in a statement Monday that tests show the virus present in a flock of commercial broiler chickens in Fulton County, Kentucky, and a backyard flock of mixed species birds in Fauquier County, Virginia.

Birds in the two flocks have been quarantined and will be killed, APHIS said in the statement. No human cases of the virus have been detected in the U.S., the agency said. According to the U.S. Centers for Disease Control and Prevention, these avian influenza detections do not present an immediate public health concern, the USDA said.