Highly pathogenic avian influenza was identified in three more states—Missouri, Maryland, and South Dakota—said the Agriculture Department. Since the first case was confirmed on February 8 on a turkey farm in southern Indiana, HPAI has been found in 21 domestic flocks in 12 states.
Nearly 1.9 million birds, mostly chickens and turkeys, have died, either from the disease or from exterminations intended to prevent the spread of it. Agricultural officials act quickly and ruthlessly because “high path” bird flu can wipe out a flock swiftly.
This year’s outbreaks are the first appearance of HPAI in domestic flocks in two years.
More than 50 million chickens and turkeys died in an HPAI epidemic that ran from December 2014 through June 2015. “These birds accounted for about 12% of the US table-egg laying population and 8% of the estimated inventory of turkeys grown for meat, ” said a 2017 USDA report. “In response to this historic animal-disease event, many destination markets for US poultry commodities levied trade restrictions on US poultry exports, distorting markets and exacerbating economic losses.”
Over the weekend, the Animal and Plant Health Inspection Service confirmed HPAI in a flock of 240,000 broiler chickens, being raised for human consumption, in Stoddard County in southeastern Missouri; in a flock of egg-laying hens in Cecil County, in the northeastern corner of Maryland; and in a “commercial mixed species flock” in Charles Mix County in southeastern South Dakota. The agency did not say how large the flocks were in Maryland and South Dakota.
The largest loss so far was 1.2 million “commercial poultry” in New Castle County in northern Delaware. New Castle County adjoins Cecil County, Maryland. Federal and state surveillance and testing of birds was stepped up after the Delaware outbreak on February 22 to protect the poultry industry on the Delmarva Peninsula, said the Maryland Department of Agriculture (MDA).
“All poultry growers, operators, and owners, including those who manage backyard flocks, must remain vigilant,” said Maryland agriculture secretary Joe Bartenfelder. “MDA, USDA and other partner agencies are working diligently to address and localize the situation, including quarantining and testing nearby flocks.” The infected farm was put in quarantine and the flock will be culled.
The Missouri and South Dakota outbreaks were the second and third west of the Mississippi River; the first was on March 1 in a backyard flock in Pottawattamie County in western Iowa.
To date, Indiana has the largest number of outbreaks—six flocks in Dubois and Greene counties.
Avian influenza is highly contagious and can be spread by migratory waterfowl and their droppings, but also through contact with infected poultry and by contaminated equipment and clothing of farmworkers. Wild birds are seemingly unaffected by HPAI. The virus is not considered a health risk for humans.
More than 300 cases of HPAI in wild birds have been confirmed by the USDA this year.