(Bloomberg) — It’s spreading quickly among cows. It also infects skunks, mountain lions and red foxes.
Most read on Bloomberg
Yet while the highly contagious avian flu affects mammals throughout the United States, only one human case has been reported so far.
But that’s probably only because the testing of people to detect it is extremely limited. State governments and farm owners have blocked Centers for Disease Control and Prevention teams from conducting field surveys that would offer a more complete picture of the virus’s prevalence in humans.
That threatens to undermine federal officials’ response to an outbreak that many experts see as the biggest test for pandemic preparedness systems since Covid-19. The recent patient is recovering after experiencing eye redness as the only symptom. However, bird flu typically kills half of those infected, suggesting the danger it poses if it were to spread widely.
The CDC is not allowed to conduct field investigations without an invitation, and states that have confirmed the presence of infected cattle say they have made no such overture to the agency.
Private dairy farms would also have to host CDC investigators, a difficult proposition in an industry heavily dependent on immigrant workers who are often reluctant to interact with government officials and fear losing their income if they test positive. Farms may also be reluctant to look for infected cows, out of fear that it could have downsides to their low-profit-margin businesses.
“The CDC is not able to do the type of testing and investigative work that it needs to do,” said Abraar Karan, an infectious disease researcher at Stanford University. “It’s a huge problem and it’s a glaring problem.”
The CDC says the current risk of bird flu to the general public is low because it is not known to spread effectively from person to person. But each infection in a cow or in a human offers the virus the opportunity to mutate and better adapt to mammalian respiratory cells.
The key to understanding this risk – and preventing the emergence of a deadly pandemic – is the ability to detect infection and track molecular changes in the virus.
“We’re playing with fire,” said Sam Scarpino, a professor at Northeastern University who helped lead pathogen surveillance at the Rockefeller Foundation during the coronavirus pandemic. “We really don’t do any monitoring to say it’s not here.”
Field testing
CDC Director Mandy Cohen said her agency was prepared to conduct field avian flu testing and other forms of surveillance.
“We are ready to deploy,” Cohen said in an interview Monday. “We have been for weeks.” Among those waiting at the CDC are multilingual, multidisciplinary epidemiological teams.
Yet all nine states with infected cattle – Texas, New Mexico, Michigan, Kansas, Idaho, Colorado, North Carolina, Ohio and South Dakota – said in statements that they had not invited the CDC.
In New Mexico and Texas, the only two states to have conducted their own testing, the scope of this work has been limited. New Mexico has tested three people for bird flu, a spokesperson said in an email.
The Texas Department of State Health Services has tested about 20 people, with one positive case in a dairy farm worker. The worker showed signs of conjunctivitis with red, swollen eyes and returned to work the day after the test. A ministry spokesperson said it did not invite the CDC “because we have not found any dairy farms interested in participating in an epidemiological field study.”
Since March, more than 30 people have been tested for novel influenza A, the broad category of flu that includes H5N1, and more than 220 have been monitored for symptoms, many of whom are asked to self-report signs of the disease, depending on the organism. CDC.
The CDC monitors several flu indicators, and Cohen notes that data from emergency rooms and commercial laboratories across the United States currently show no concerning trends.
“The good news is we’re not seeing anything unusual,” Cohen said, such as an increase in doctors ordering flu tests.
But she also highlighted the need to continue working with agricultural partners – particularly given the novel nature of the spread of this strain of bird flu.
“We’ve worked very rigorously with our poultry producers, but this is new in the cattle business,” Cohen said.
‘Huge problem’
The FDA has found traces of the H5N1 virus in 1 in 5 retail milk samples. Although pasteurization has been shown to render the pathogen harmless, this incidence shows that it has spread widely among cows. In the United States, some 36 dairy herds are believed to have been affected.
The USDA recently said it was looking for manufacturers interested in making a safe and effective vaccine for cattle that targets the virus.
The people most likely to be infected — dairy farm workers who regularly touch cows — won’t necessarily seek medical care, community health workers say.
Testing of wastewater in Texas revealed traces of H5N1, which could be traced to humans or animals carrying the virus. Of hundreds of sites examined each week by a research group, three were tested for H5N1 genetic markers, and all three were confirmed to have them. The researchers wrote that cow’s milk entering sewage systems is a likely explanation for these findings.
“We almost certainly missed human cases,” Scarpino said, referring to the Texas wastewater findings. “The real question we need to answer is: Are there thousands of flu cases we’ve missed, or a handful?
Reluctance of workers
Even if the CDC were to obtain permission from states and farms to conduct on-site testing, it would face an additional challenge: Workers would have to agree to participate, and many of them would likely be reluctant to do so.
Fear of job loss, language barriers, transportation costs and distrust of public health systems are all factors that could deter migrants from consenting to testing, said Bethany Alcauter, research director at National Center for Farmworker Health. She said the situation reminds her of the early days of the coronavirus pandemic, when workers were reluctant to get tested and the disease was not well understood.
Lus Chavez, director of rural outreach at Family Support Services in Amarillo, Texas, said she spoke with dairy workers in late February with flu-like symptoms, including congestion, but that they had been tested negative for flu and Covid. Farmworkers, she said, were convinced it was a new strain of Covid that wasn’t showing up in tests.
Chavez said she was contacted by the Texas Department of Health to say it could offer voluntary testing, but workers are reluctant to do so for fear of retaliation if they raise concerns or of their fear of losing their salary.
Even if workers choose to get tested, there is no requirement to reveal where they work, another challenge for authorities trying to track and contain the virus.
The CDC is engaged in discussions with several states about setting up field investigations to answer questions about the ongoing outbreak, including examining anti-flu antibodies in blood samples from farmworkers to see if any of them had already been infected. The CDC would help establish study protocols that would standardize data across states. Such an effort could also face hesitation from farms and staff.
It’s not just the lack of testing for bird flu that worries public health experts. A lack of funding and research, some say, also left the United States unprepared if a broader outbreak of bird flu — or any other deadly virus — took hold.
“We won’t be ready,” said Katrine Wallace, an epidemiologist at the University of Illinois. “We don’t even care about what’s right in front of us.”
–With help from Madison Muller.
(Updates with USDA announcement, adds details on wastewater treatment study)
Most read from Bloomberg Businessweek
©2024 Bloomberg LP
News Source : finance.yahoo.com
Gn Health
