H7N9 avian flu strikes Mississippi broiler farm

News brief

The Mississippi Board of Animal Health (MBAH) late last week reported a highly pathogenic avian flu outbreak in commercial poultry, which involves the H7N9 strain—a virus type that hadn't been identified in poultry in the United States since 2017.

The MBAH said the outbreak occurred at a broiler facility in Noxubee County, which is in the eastern part of the state on the border with Alabama. It added that the state veterinary lab's findings were confirmed by the US Department of Agriculture (USDA) National Veterinary Services Laboratory in Ames, Iowa.

The birds have been depopulated and did not enter the food chain. The MBAH said it is working with federal veterinary officials on a joint incident response. Mississippi has experienced three avian flu outbreaks in commercial poultry since the spring of 2023, and since November 2024, the virus has been detected several times in migratory waterfowl in multiple parts of the state.

More than 47,000 birds depopulated

A notification on the outbreak submitted to the World Organization for Animal Health (WOAH) noted the H7N9 subtype, which it said belongs to a North American wild bird lineage. The outbreak began on March 8 when clinical signs were noticed, including increased deaths. Depopulation of 47,654 birds at the facility was completed on March 13.

The last high-path H7N9 confirmation in US poultry occurred in March 2017 when outbreaks struck two commercial poultry farms in Tennessee.

Newborns exposed in West Texas measles outbreak

News brief

Stephanie Soucheray, MA

Last week, a woman infected with measles gave birth at University Medical Center Children’s Hospital in Lubbock, Texas, possibly exposing newborns and their families to the highly infectious virus causing a large outbreak in West Texas and neighboring states.

According to NBC News, hospital officials are giving infants injections of immunoglobulin, an antibody that helps their immune system fight off infections. The exact number of newborns exposed has not yet been determined.

So far, the west Texas outbreak has resulted in 259 cases of measles, of which 201 have been in children. One unvaccinated child in Gaines County, Texas died from her infection.

Oklahoma, Michigan report new cases

In related news, Oklahoma has reported two more probable measles patients, raising its total to 4. The Oklahoma State Department of Health said the probable case-patients went to several public places, including multiple grocery and department stores, while infectious, potentially exposing many more to the virus.

Possibly exposed individuals who are not immune through vaccination or prior infection should exclude themselves from public settings for 21 days .

"Possibly exposed individuals who are not immune through vaccination or prior infection should exclude themselves from public settings for 21 days from the date of their potential exposure," state officials said in a press statement.

The two Oklahomans with suspected measles reported exposure to the ongoing Texas and New Mexico outbreak rather than to the two Oklahoma measles cases announced on March 11. All four were unvaccinated.

Michigan's health department has reported the state's first measles case of the year, which involves an adult who had recently traveled overseas. The Michigan Department of Health and Human Services (MDHHS) and the Oakland County Health Division said this is the first measles case in the state since July 2024.

"This case of measles is a reminder of how easily this highly contagious disease can spread, particularly with international travel," said Natasha Bagdasarian, MD, MDHHS chief medical executive.

Last week, the Centers for Disease Control and Prevention noted that the nation now had more than 300 measles cases. A total of 285 cases were reported in all of 2024.

New restrictions follow detection of CWD in 7th West Virginia county

News brief

Mary Van Beusekom, MS

White-tailed deer — Gary Yankech / Flickr cc

The West Virginia Division of Natural Resources (WVDNR) is implementing new restrictions on baiting deer and transporting high-risk carcasses after the first identification of chronic wasting disease (CWD) in a deer in Grant County.

Grant County, in the northeast part of the state, was added to the state's CWD containment area in 2015 because it is near other counties with CWD-positive cases, the WVDNR news release said.

While there is no evidence that CWD is harmful to humans, it is important that hunters abide by the carcass transport regulations to reduce risk factors that may affect our deer population.

Paul Johansen, MS

To slow transmission of the fatal neurodegenerative disease, the WVDNR has implemented restrictions on baiting and feeding deer and on transporting high-risk carcass parts outside of the CWD containment area. The transport restrictions will take effect in Grant County in the 2025 deer-hunting season.

"While there is no evidence that CWD is harmful to humans, it is important that hunters abide by the carcass transport regulations to reduce risk factors that may affect our deer population," Paul Johansen, MS, chief of the WVDNR’s Wildlife Resources Section, said in the news release.

Baiting restrictions will also be implemented in adjoining CWD-negative Pendleton County, where feeding restrictions are already in place, in the fall.

No vaccine or treatment has been developed

Grant County is the first new county in which CWD has been detected in free-ranging deer in West Virginia since 2023, when infected deer were found in Jefferson County. Previous cases were identified in Berkeley, Mineral, Morgan, Hardy, and Hampshire counties, the WVDNR said.

Caused by infectious misfolded proteins called prions, CWD affects cervids such as deer, moose, and elk. No vaccine or treatment is available.