Raw food testing and new public health funding emphasize need to better understand and get ahead of avian influenza outbreaks.
January 6, 2025
By Kristin Bakker
Several developments in the last couple of weeks demonstrate the widespread and rapidly changing nature of the bird flu outbreak and how it is affecting several different species and sectors. A number of actions and reports have been issued in an effort to mitigate the ripple effects.
The U.S. Food & Drug Administration announced that it has begun a domestic sampling assignment to collect and test aged raw cow’s milk cheese for the presence of H5N1 highly pathogenic avian influenza (HPAI).
The agency’s objectives are to determine whether viable H5N1 virus is present in the cheese and to take follow-up action(s) as needed to address contaminated product and protect consumers.
An outbreak of H5N1 in multiple states precipitated this assignment. FDA said it is working with the U.S. Department of Agriculture, the Centers for Disease Control & Prevention and state partners to investigate and respond to the outbreak, which is affecting poultry, dairy cows and people in the U.S.
FDA said its sampling assignment complements research efforts the agency is carrying out with its federal and state partners, as well as select research universities, but unlike the research efforts, the sampling assignment is a regulatory activity.
Raw milk cheese is made with unpasteurized milk, which, under U.S. regulations, must be aged for a minimum of 60 days to mitigate the risk from any pathogens that might be present. FDA field staff will collect samples of raw milk cheese aged for at least 60 days from warehouses and distribution hubs throughout the country and test the samples using polymerase chain reaction tests.
FDA’s sample collection was expected to begin as soon as the end of December 2024 and to be completed by the end of March 2025.
After a recent recall of raw frozen pet food from Northwest Naturals linked to the death of a pet cat in Oregon in December, another pet illness has been linked to consumption of raw food in California. The Los Angeles County Department of Public Health (LADPH) advised pet owners to avoid feeding pets raw food after tests found links between a cat's H5 avian flu illness and raw food sold by Monarch Raw Pet Food at several farmers markets in California.
In its news release, LADPH said H5 avian flu from product samples of Monarch Raw Pet Food was found during an investigation into an illness involving a house cat that had a lab-confirmed infection after consuming the product. Four other cats from the same household have presumed H5 infections after eating the same food.
Monarch Raw Pet Food lists on its website the locations of the farmers markets where its product is sold, although the company denied the allegations that its products were the cause of the recent illnesses.
LADPH said an investigation is still under way into fatal illnesses of cats from separate households that consumed raw milk, which resulted in a recall of raw milk and cream products from Raw Farm LLC.
No human infections have been identified in people with exposure to sick cats in the households.
Although emphasizing the risk of bird flu illness in people “remains low,” the U.S. Department of Health & Human Services (HHS) announced Jan. 3 it would award $306 million to continue its H5N1 avian influenza response.
HHS noted that while CDC’s assessment of the risk of avian influenza to the general public is low, USDA and HHS continue to closely collaborate with federal, state, local, industry and other stakeholders to protect human health, animal health and food safety.
HHS Secretary Xavier Becerra explained the agency is “always preparing for any possible scenario that could arise. These investments are critical to continuing our disease surveillance, laboratory testing and monitoring efforts alongside our partners at USDA. Preparedness is the key to keeping Americans healthy and our country safe. We will continue to ensure our response is strong, well equipped, and ready for whatever is needed.”
Since the first case of H5N1 was confirmed in cattle, USDA and HHS have worked with stakeholders across the nation to support state and local responses to the outbreak.
The new HHS funding comes in light of two recent reports published in the New England Journal of Medicine detailing investigators’ clinical findings and understanding of human patients who have been infected with H5N1 avian influenza.
One report investigated a case of critical illness of H5N1 in a British Columbia teen with underlying medical issues. The genome of the virus was sequenced and was found to be closely related to a strain circulating in wild birds in the area around the same time the patient became ill.
In the report, the investigators said they discovered mutations in the virus strain’s H5 HA gene that previously have been shown to “facilitate viral entry into cells in the human respiratory tract and enable viral replication.”
The report authors concluded that H5N1 HPAI infection acquired in North America “can cause severe human illness” and “may increase binding to human airway receptors is worrisome.”
In the second report, a team of CDC researchers and partners in several states analyzed influenza virus subtyping test kit results from human infections taken from March to October 2024 to determine the source of infection.
Of the 46 patients whose tests were studied, 20 were exposed to infected poultry, 25 were exposed to dairy cows and one had no identified exposure but was found to be infected with H5N1 virus through routine surveillance at the hospital. No patients died, and all cases linked to animal exposure experienced mild symptoms, according to the journal report. No evidence was found to suggest human-to-human transmission occurred.
The investigation also looked at the personal protective measures used by workers linked to animal exposure and found that 71% used gloves, 60% used eye protection and 47% used face masks. The report authors concluded that personal protective equipment (PPE) use was “suboptimal” and suggested that “additional strategies are needed to reduce exposure risk.”
A related editorial in the New England Journal of Medicine authored by Drs. Michael G. Ison and Jeanne Marrazzo with the National Institutes of Health noted that the case reports from the human HPAI studies point to a need to consider the best approach to take with a human health response.
They suggested, among several measures, taking a One Health approach that integrates veterinary, human and public health collaboration, as well as initiating more “vigilant surveillance of merging mutations and assessment of the threat of human-to-human transmission” and more consistent use of PPE in occupational settings paired with better education of its importance.
Ison and Marrazzo concluded that while the risk to public health currently remains low, “a balance between enhanced vigilance and ‘business as usual’ is needed.”
You May Also Like
Enter a zip code to see the weather conditions for a different location.
