Over the last few days the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service has reported four more H5N1 avian flu detections in dairy cattle, two from California and two from Idaho, lifting the national total to 1,009 from 17 states since March 2024.

Also, APHIS has confirmed more H5N1 detections in poultry flocks from two states. They include two more detections in live bird markets in New York’s Queens County and a backyard location in Jefferson County. The virus was also detected at two locations in New Mexico, including a poultry farm in Curry County and a backyard flock in Roosevelt County.

WHO H5 surveillance guidance, USDA livestock disease funding

In other H5N1 developments, the World Health Organization (WHO) on April 11 released new guidance on surveillance for human infections with H5 avian influenza viruses.  It said the goal is to rapidly detect and characterize any human H5 infections to allow prompt response actions, assess trends and health risks, and guide global flu pandemic preparedness.

The group emphasized that under the International Health Regulations, countries are required to notify the WHO within 24 hours of any lab-confirmed human case involving a new subtype, based on the WHO case definition of being unusual or unexpected and potentially posing a serious public health impact. The new guidance also included a data reporting guide.

In a related US development, the USDA’s APHIS last week announced $15.3 million in funding for research projects to enhance preparedness, early detection, and rapid response to the diseases that threaten US livestock. The funding will support 68 projects led by 24 state agriculture departments, five tribal entities, 35 universities, three livestock groups, and one federal partner. One third of the funding is geared toward enhanced biosecurity. 

Older adults and other groups at risk for severe complications from influenza infections often do not receive flu antiviral prescriptions in urgent care (UC) and emergency department (ED) settings, according to a recent study in Clinical Infectious Diseases. 

The study was based on findings from 10,700 patient encounters for acute respiratory illness at urgent cares or emergency departments and with positive influenza virus test results during the 2023-24 flu season at four large US healthcare systems. 

All patients were considered higher risk for severe influenza, the median age was 65 years, with 59% female, 36% Hispanic, 37% non-Hispanic White, and 16% Medicaid recipients.

Overall, 58% were prescribed antivirals during their UC or ED visit, with 67% of prescribing occurring on the encounter date. Among those prescribed antivirals, 3,050 (80%) had them dispensed, with 65% of dispensing occurring on the prescription date. 

Those 50 to 64 had more antivirals dispensed

Among the 7,138 eligible encounters with an antiviral medication prescription, 7,135 (99.96%) were prescribed oseltamivir (Tamiflu).

Older age (65 and older) was associated with lower odds of same-day prescribing  (0.57; 95% confidence interval [CI], 0.42 to 0.78). For same-day dispensing, the odds were 0.58 (95% CI, 0.36 to 0.94), compared to those 18 to 49 years.

Those aged 50–64 years had the highest proportion dispensed antivirals (85%) among those prescribed,

"Patient encounters aged ≥65 years had the highest proportion prescribed antivirals (63%); however, those aged 50–64 years had the highest proportion dispensed antivirals (85%) among those prescribed,” the authors said. 

The authors said their study points to gaps in the antiviral prescription timeline.

"Strategies to improve earlier initiation of influenza antivirals for older, chronically ill patients along with expanded use of rapid and highly sensitive point-of-care testing in ED and UC settings could improve treatment initiation among patients with influenza," the authors concluded.

Many cases of tuberculosis (TB) in prisons in Europe and the Americas during the COVID-19 pandemic were likely missed, putting both inmates and the community at risk for the deadly bacterial disease, Boston University (BU)-led researchers propose in The Lancet Public Health. 

The study team analyzed data from the World Health Organization's (WHO's) Pan American Health Organization (PAHO; 22 of 39 countries) and WHO Europe (25 of 53 countries) to model and predict prison populations and TB infections among 4.9 million inmates from 2020 to 2022. 

Case notifications fall up to 100%

TB notifications in prisons were much lower than predicted in 2020 (-26.2%), 2021 (-46.4%), and 2022 (-48.9%). These trends were consistent across Europe and the Americas, but larger drops occurred in countries with lower TB rates (low burden) in 2020 (-54.8%) and 2021 (-68.4%), high-burden settings in 2021 (-89.4%), and Central and North America in 2021 (-100.3%).

Reasons for this change in tuberculosis notifications might be multifactorial and include missed diagnoses and implementation of COVID-19 pandemic measures, reducing transmission.

Incarceration rates were similar to predicted levels (under 10% overall difference) during the entire pandemic.

"Reasons for this change in tuberculosis notifications might be multifactorial and include missed diagnoses and implementation of COVID-19 pandemic measures, reducing transmission," the authors wrote.

In a BU news release, first author Amy Zheng, MPH, a PhD student, said, "When countries are unable to detect tuberculosis in high-risk populations—such as people who are incarcerated—it increases the risk of transmission, both within prisons and to the broader community, when people are released from prison."

In a related commentary, Emma Plugge, MD, PhD, of the University of Southampton in England, and Nicola Cocco, MD, of ASST Santi Paolo e Carlo in Milan, Italy, said that while prisons released some inmates to slow COVID-19 transmission, the efforts were inconsistent across countries and didn't result in meaningful population decreases.

"Efforts to tackle tuberculosis inside prisons must be redoubled as they have outside," they wrote. "Such actions will have a positive effect on the whole community; no one is safe until we are all safe."