H5N1 avian flu strikes South Dakota turkey farm

News brief

Marking the first H5N1 avian flu detection at a US commercial poultry farm since early July, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) on August 28 confirmed an outbreak at a South Dakota turkey farm.

turkey farm — *Morgan Lieberman/Mizzou CAFNR/Flickr cc*

The facility in Faulk County has 55,400 birds. The last detection at a commercial farm occurred in early July at a game bird facility in Lancaster County, Pennsylvania. Since then, there was a detection at a live-bird market in Los Angeles County and in backyard birds in St. Lawrence County, New York.

Detections often drop off in warmer months, but sporadic detections in wild birds, dairy cows, domestic cats, and wildlife have continued over the summer.

UK confirms 2 more H5N1 detections

Meanwhile, the United Kingdom has been experiencing an early rise in H5N1 outbreaks in poultry, with a spate of detections that began in late July.

The Department for Environment, Food, and Rural Affairs over the past few days reported two more, one at a facility in Devon and the other involving captive birds at a location near Somerset.

Wisconsin measles outbreak grows as Ohio reports family cluster

News brief

Lisa Schnirring

In Wisconsin, health officials in Oconto County have confirmed 9 more measles cases, raising the state's outbreak total to 23.

The outbreak in Oconto County, located in northeastern Wisconsin, began in early August. The Wisconsin Department of Health Services (WDHS) said in an August 29 update that two people have been hospitalized.

"The ongoing investigation indicates that measles is spreading locally. At this time, the investigation has not identified locations in public settings for which a full list of exposed people cannot be obtained," the WDHS said.

The state's measles dashboard reflects that all 23 of the confirmed case-patients are unvaccinated. The most affected group is children ages 5 to 17 years old (13 cases), followed by adults (7 cases).

Ohio reports family measles cluster

Elsewhere, the Zanesville-Muskingum County Health Department in Ohio on August 30 announced that it has identified three confirmed measles cases in children, all unvaccinated, the agency said in a Facebook post. All three are from the same family and are currently at home and are improving. Muskingum County, home to Zanesville, is located in east central Ohio.

Health officials said they are working with the family and hospital to identify and follow up on any exposures and contacts.

New antiviral application for COVID-19 preventive drug submitted to FDA

News brief

Stephanie Soucheray, MA

cold and flu — *Inside Creative House / iStock*

Shionogi has submitted its new drug application (NDA) to the Food and Drug Administration (FDA) for the approval of its oral pill for COVID (ensitrelvir), the first antiviral drug for the prevention of COVID-19 following exposure to an infected person, according to a company news release today.

Ensitrelvir, known as Xocova, is already approved for use in Japan. The drug is also available in Singapore and under review in Taiwan.

The NDA is based on results of a phase 3 trial of the drug, which studied ensitrelvir as post-exposure prophylaxis (PEP). In that trial, ensitrelvir demonstrated a statistically significant reduction (67%) in the risk of COVID-19, in uninfected individuals treated after exposure, compared to placebo at day 10.

Drug designed to prevent viral replication

Shionogi, based in Osaka, Japan, said that stopping viral replication after exposure is the best way to avoid potentially serious complications from COVID infections, and that current antivirals that target COVID-19 patients are administered after infection, when viral replication has already occurred.

If approved, ensitrelvir will be the first and only oral therapy to help protect people in the U.S. from COVID-19 following exposure.

"If approved, ensitrelvir will be the first and only oral therapy to help protect people in the U.S. from COVID-19 following exposure," said Nathan McCutcheon, MBA, president and CEO of Shionogi, in the press release.

Papua New Guinea confirms its first human polio case

News brief

Chris Dall, MA

Health officials in Papua New Guinea have confirmed the island nation's first human case of paralytic poliomyelitis, the World Health Organization (WHO) said late last week.

The case involves an unvaccinated 4-year-old boy from Morobe province who developed acute flaccid paralysis caused by circulating vaccine-derived poliovirus type 2 (cVDPV2).

"This marks a pivotal moment in the country's polio response, confirming that the virus has transitioned from environmental detection to direct impact on children," the WHO said in a news release. To combat the spread, the country's National Department of Health launched a nationwide supplementary immunization campaign on August 11 targeting children under 10 years old with the novel oral polio vaccine (nOPV2).

The first round of the campaign will continue to September 5, and a second round that will include nOPV2 and inactivated polio vaccine is scheduled from September 29 to October 17.

"Polio is preventable," said Sevil Huseynova, MD, MPH, WHO representative in Papua New Guinea. "The vaccines are safe, effective, and free. But we must act together—with urgency and unity."

Cases in 3 other countries

Meanwhile, three other countries reported polio cases last week, according to the latest update from the Global Polio Eradication Initiative (GPEI). Among them is Yemen, which reported 25 cVDPV2 cases, 23 of which date back to 2024. GPEI says the increase in reported cases isn't linked to an increase in transmission but rather to retrospective testing associated with a recent release of previously collected specimens. Yemen has 187 reported cVDPV2 cases for 2024 and 29 for 2025.

Chad also reported a cVDPV2 case, bringing its number of cases for the year to 15. Afghanistan reported one wild poliovirus type 1 case, bringing its total for the year to three cases.