Bangladesh notifies WHO of 2 recent human H5N1 avian flu infections

News brief

In its latest zoonotic flu update, the World Health Organization (WHO) said Bangladesh has notified it of two new human H5N1 avian flu infections, which appear to be the country’s first since 2015.

backyard chicken — *Rae Allen/Flickr cc*

Both patients are children from Khulna division in the country’s southwest. Both are boys who have recovered from their infections.

In one of the cases, H5N1 was detected in a sample collected from the child in April 2025. Bangladeshi officials notified the WHO on May 4. The month before the patient got sick, an H5N1 outbreak in poultry was reported from the same district where the child lives.

The other case was detected retrospectively in a sample collected from the child in February 2025. WHO was notified of the case on May 27.

Virus identified as older local H5N1 clade

In both instances, genetic sequencing conducted by Bangladesh’s Institute of Epidemiology, Disease Control, and Research revealed the older 2.3.2.1a clade, which is known to circulate in birds in India and Bangladesh.

The same clade was found during the investigation into a fatal H5N1 case reported in an Indian child in April, an 2021 fatal infection in an Indian child who had an underlying health condition, and a 2024 illness in an Australian child who had recently visited India and had a severe illness but recovered.

During a twice yearly deliberation on flu virus vaccine strains for pandemic preparedness, a WHO advisory group recommended 2.3.2.1a as one of its two picks, given ongoing circulation in birds and poultry in Bangladesh and India, despite the more recent introduction of the 2.3.4.4b global clade. Also, the advisory group noted that 2.3.2.1a had turned up in captive tigers, a captive leopard, and domestic cats in India.

More measles cases tied to domestic air travel in US

News brief

Stephanie Soucheray, MA

airport travel — an adult from Minnesota was confirmed to have measles after being exposed during domestic airline travel outside of Minnesota.

Yesterday an unvaccinated adult in Bell County, Texas, located in the central part of the state, became the county's first measles case.

The route of exposure is unknown, and county health officials said they are investigating any potential community exposures, including identifying whether the person recently traveled internationally or domestically.

Also yesterday, officials from San Juan County, New Mexico, reported that county's first measles case, and today shared more details. The case-patient is a child under 4 years who had received one measles, mumps, and rubella vaccine dose. The child had also recently traveled on a domestic flight.

This is the second US case in which a traveler was likely infected on a domestic flight, as opposed to an international one. Earlier this week an adult from Minnesota was confirmed to have measles after being exposed during domestic airline travel outside of Minnesota.

Three new cases in Kansas

Finally, today Kansas confirmed three more measles cases, raising the state's total to 71 as of June 2. Of the 71 cases, 69 are part of an outbreak in the southwestern part of the state, which has been linked to the West Texas outbreak first identified in January.

The three new cases were identified in Pawnee County, which recently reported its first case.

Ohio deer samples reveal COVID-19 Alpha variant more than 1 year after last human case

News brief

Mary Van Beusekom, MS

White-tailed buck — *Jen Goellnitz / Flickr cc*

Sampling free-ranging white-tailed deer (WTD) in northeastern Ohio in 2023 has identified six SARS-CoV-2 Omicron and Alpha strains—the latter of which hadn't been seen in Ohioans for more than a year, according to a study published yesterday in Emerging Infectious Diseases.

Ohio State University–led researchers collected nasal swabs from deer culled at 10 sites from January to March 2023. WTD are highly susceptible to SARS-CoV-2 infection. The same group published a similar analysis in 2021.

The swabs underwent real-time polymerase chain reaction (RT-PCR) and genomic sequencing, and positive samples were sent to a lab for virus isolation, characterization, and other experiments.

Half of samples at 1 site tested positive

In total, 12.3% of 519 swabs tested positive for SARS-CoV-2. Four of the 10 sites yielded positive samples, with prevalences of 6.5% to 50.0%, the latter of which was from a site next to a highly populated residential area. Viral isolation of 58 of the 64 positive samples produced 12 SARS-CoV-2 Omicron isolates.

We found evidence in northeast Ohio of extensive deer-to-deer transmission of >2 Omicron lineages (XBB.1.5.35 and BQ.1.1) that each spread between 2 sampling sites separated by interstate highways.

Whole-genome sequencing of 36 positive samples revealed that 86.1% were Omicron BQ.1.1, BQ.1.1.63, BQ.1.1.67, BQ.1.23, and XBB.1.5.35, which were still circulating in people. And five samples taken from a single site were Alpha B.1.1.7, which was last identified in Ohio more than 1 year earlier. The B.1.1.7 viruses amassed mutations at twice the rate of those in people.

"An apparent decrease in SARS-CoV-2 detections in North America WTD after emergence of the Omicron variant in humans in late 2021 led to speculation that the highly mutated and human-adapted Omicron variant could have reduced capacity to infect other species," the authors wrote.

"Instead, we found evidence in northeast Ohio of extensive deer-to-deer transmission of >2 Omicron lineages (XBB.1.5.35 and BQ.1.1) that each spread between 2 sampling sites separated by interstate highways," they added. "Evidence of sustained transmission of the Alpha variant in WTD, alongside more recent introductions of Omicron lineages in WTD, highlights the need for continued surveillance to monitor the long-term dynamics of SARS-CoV-2 in WTD and the associated zoonotic risks." They wondered if deer can become a reservoir for displaced variants.