TRACKING EMERGING VIRUSES – July 8, 2025 – Bird Flu
“The U.S. Centers for Disease Control and Prevention ended its emergency response for bird flu as the outbreak that sickened dozens of people, spread to cattle and drove up egg prices has abated.”
“The CDC merged its bird flu updates with those routinely reported for seasonal influenza starting on Monday, and will post the number of people monitored and tested for the virus, also known as H5N1, on a monthly basis, the agency said. It will no longer include infection rates found among animals on its website.”
“The CDC’s emergency bird flu response was deactivated to transition back to regular program activity, according to a spokesperson for the Department of Health and Human Services. Surveillance, readiness and response for bird flu will be included with existing efforts from the CDC’s Influenza Division and other agency programs, they said.” (1)
“Dr. Nirav Shah, who resigned this year from his position as CDC principal deputy director, says he would have also chosen to end the emergency response.
“This was not something that was imposed from the top down. It was initiated by the career scientists at CDC,” said Shah, now a visiting professor at Colby College in Maine. “The rationale is, in short, there haven’t been any human cases. And so there is not the need to sprint all-out every single day when there haven’t been human cases in a while. If there were to be more human cases, it is very easy to ratchet back up the level of the intensity of the response. It can literally be done in an afternoon.” (2)
“Writing in a new policy forum, a group of five experts ranging from veterinary medics to immunologists detailed their reasoning as to why letting the virus “run rampant”, as they described it, is far from a viable plan.
“This approach would be dangerous and unethical. Allowing a highly lethal, rapidly evolving, and contagious virus to run a natural course of infection in poultry would lead to unnecessary suffering of poultry and put other susceptible animals on and near affected farms at risk,” the authors state.
Kennedy’s reasoning for allowing bird flu to spread unmitigated, as an alternative to culling or vaccinating, is that it might allow us to identify and preserve only those birds with immunity to the virus.
Alongside unnecessary suffering, the authors point out that this plan would not only rapidly decrease the genetic diversity of poultry in the US – which might leave them more vulnerable in the event of future pathogens arising – but may also have another long-term impact.
“Such a ‘let-it-spread’ strategy may identify small numbers of poultry infected by H5 influenza virus that do not develop severe disease for unknown reasons; however, these birds could serve as a new longterm reservoir for the virus,” they explain.” (3)
“Here, Sorrell et al. critically evaluate the implications of the proposed strategy. According to the authors, allowing the virus to circulate freely in poultry flocks increases the risk of viral adaptation, which could create long-term reservoirs of infection that raises the risk of a future pandemic with serious public health consequences. The proposal may also have serious economic and food security implications. Poultry and eggs are vital, affordable sources of protein for Americans, and widespread infection would reduce production, increase prices, and disrupt access. Moreover, it could cost billions in animal losses and destabilize trade via global policies restricting the imports of U.S. poultry products….” (4)
“Coverage of bird flu should not be limited only to what’s happening in birds, cows and humans. Reporters can also start looking at local angles on environmental contributors to this current public health issue and to pandemics broadly.
Since 2022, bird flu in the U.S. has infected not only poultry, dairy cattle, cats and wild birds, but also many wild mammals, including skunks, brown bears, mountain lions, rats, foxes and bottlenose dolphins. It also recently was detected in a sheep in the United Kingdom.
The fact that bird flu has already spread to so many different species means the virus has many opportunities to evolve, a precursor to a pandemic. Unlike previous outbreaks of H5N1 in poultry, cows and wild animals — which have eventually fizzled out — this one appears to be here to stay.” (5)
“Cambodia has become adept at detecting cases, but now scientists are experimenting with a new line of attack that could revolutionise disease surveillance – making it safer, faster and cheaper to track zoonotic pathogens.
The approach? Rather than taking swabs directly from animals in high risk areas, virologists are analysing the air they breathe.
In wet markets teeming with live birds, slaughterhouses butchering pigs and even limestone caves home to millions of bats, scientists are deploying air samplers to capture a snapshot of the pathogens lurking in the atmosphere – from avian influenza to coronaviruses, and perhaps even the next ‘Disease X’.”
‘”Later, virologists in a lab will analyse these air samples, along with swabs from cages and the water used to wash birds. They’ll extract the nucleic acids present, then look for pathogens using a mix of methods – from targeted PCR to full-on metagenomic sequencing – to identify which diseases are lingering in the market.
“Imagine there are 10,000 birds going through this market in one day, and we are swabbing 20 or 40 of them. We miss things,” says Dr Erik Karlsson, head of the Virology Unit at Institut Pasteur du Cambodge (IPC) and director of the National Influenza Centre of Cambodia.
“But here, we can pick up multiple types of influenza in the air that we wouldn’t be able to pick up from a bird,” he says. “There have been days where we didn’t detect anything in the birds, but we found two different influenza types in the environment samples.”” (6)
“Bird flu remains a risk in the U.S., but we don’t know as much about its threat level because the CDC stopped conducting much surveillance some time ago. They never did the kind of studies some experts had wanted.”
“At the same time that we are cutting surveillance, some experts are concerned that Kennedy’s proposal to let bird flu spread through poultry could set us up for a pandemic. In fact, in this week’s Science, several argue that this “let ‘er rip” approach would be “dangerous and unethical.” Their concern is that by allowing the virus free rein, it will more likely spread and mutate, resulting in a pandemic. Gigi Gronvall, PhD, Johns Hopkins Center for Health Security, explains: “The thing that we are most concerned about is that H5N1 could reassort with a circulating flu virus and gain the ability to transmit between humans. Anything we could do to reduce that likelihood, we should be doing. That includes vaccinating people against what’s currently (influenza) circulating and also against H5N1.”
“Angela Rasmussen, PhD, a virologist now at the University of Saskatchewan, Canada, added to Gronvall’s concerns, stating in her Substack, “If they take another tip from Kennedy and start prophylactically dosing the birds with oseltamivir (Tamiflu), this will select for viruses that are resistant to our first line class of antiviral drugs. The “Let ‘Er Rip” plan for bird flu is a really, really bad idea that will have severe health, economic, agricultural, environmental, and food security consequences. Because this plan is to basically do nothing.” She is equally scathing in her comments about surveillance (or lack thereof) and why numbers of cases are decreasing.” (7)
(1).Bird flu emergency response ends in US as infections decline, by Jessica Nix, https://medicalxpress.com/news/2025-07-bird-flu-emergency-response-infections.html
(2). CDC ends emergency response to H5N1 bird flu, By Brenda Goodman, by Sarah Owermohle, https://www.cnn.com/2025/07/07/health/cdc-bird-flu-response
(3). RFK Jr Suggested Letting Bird Flu Run Through Farms – Experts Still Think It’s A Bad Idea, by Holly Large, https://www.iflscience.com/rfk-jr-suggested-letting-bird-flu-run-through-farms-experts-still-think-its-a-bad-idea-79873
(4). RFK’s proposal to let bird flu spread through poultry could set us up for a pandemic, experts warn, By Ben Turner, https://www.news-medical.net/news/20250704/Letting-bird-flu-run-its-course-could-spark-wider-pandemic.aspx
(5). Covering bird flu from an ecological angle, by Katie Burke, https://healthjournalism.org/blog/2025/06/covering-bird-flu-from-an-ecological-ang
(6). From coop to cave: Inside the high-tech hunt for H5N1 and Disease X, by Sarah Newey, https://www.telegraph.co.uk/global-health/science-and-disease/cambodia-bird-flu-h5n1-bats-pathogens-viruses-disease-x-pandemic-surveillance/
(7)CDC Bird Flu Response Cuts Could Lead To Another Pandemic, By Judy Stone, https://www.forbes.com/sites/judystone/2025/07/09/cdc-bird-flu-response-cuts-could-lead-to-another-pandemic/
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai
https://www.linkedin.com/in/jonathan-metsch-526290199/
jonathanmetsch@gmail.com