The nation's steady stream of highly pathogenic avian flu outbreaks has now spread to commercial flocks in Maryland and South Dakota, federal officials said over the weekend, pushing the number of affected states this year to 12.
In related developments, the Centers for Disease Control and Prevention (CDC) said it is monitoring 140 people who were exposed to the virus, amid more positive findings from waterfowl surveillance.
Poultry outbreaks expand westward
Maryland's outbreak involves a commercial layer farm in Cecil County, which is located in the far northeastern corner of the state on the border with Pennsylvania and Delaware, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) said in a Mar 5 statement.
The Maryland Department of Agriculture said the virus was confirmed as H5N1 and that the outbreak comes 1 week after the virus was detected in Delaware, which prompted expanded surveillance in the Delmarva Peninsula.
In early February, live-waterfowl testing during surveillance activities turned up the virus in a bird from Maryland's Kent County.
South Dakota's outbreak involves a mixed species commercial farm in Charles Mix County, which is located in the southeastern part of the state near the Nebraska border, according to a separate statement yesterday from APHIS.
Following detections in waterfowl that began in the middle of January along the eastern seaboard, Indiana in early February reported the first related outbreak in poultry. South Dakota's outbreaks mark the westernmost spread to poultry so far, which followed recent detections in Iowa and Missouri.
In related developments, the USDA reported six more detections from wild bird surveillance, raising the total number of positives to 303. The new reports include the first two waterfowl detections from Tennessee, which were hunter harvested birds in Obion County. So far, the USDA has reported 303 positives in wild birds.
Monitoring and countermeasures
Meanwhile, in an update today, the CDC reiterated that the risk to humans is low, but some people with job or recreational exposure may be at higher risk. The current H5N1 virus has been linked to one human case in the United Kingdom, which involved someone who had very close contact with poultry and was asymptomatic.
So far, 140 people in the United States who were exposed to infected birds have been or are being monitored, and no cases have been found, the agency said.
Currently, H5N1 is primarily an animal health issue, the CDC said. It added that the USDA has posted genetic sequences of the H5N1 viruses recently detected in the United States, which reveal that they are related to the most common H5N1 clade circulating in other parts of the world, but are different than an earlier H5N1 virus that caused deadly infections in humans.
A new candidate vaccine virus against the strain has a nearly identical hemagglutinin protein and could be used to produce a vaccine for people, if needed, the CDC said. It added that antiviral medications used to treat flu would likely be effective and that tests for seasonal flu can detect H5N1.
Source : umn.edu