Why and how CT experts are monitoring the spread of bird flu

19.06.2024 15:31

For the past several months, news has been swirling about the spread of the H5N1 avian flu, with some reports questioning whether this could become the next global pandemic.

In early April, the Centers for Disease Control and Prevention reported the first case of bird flu in dairy cows. Since then, the agency has recorded cases in over one hundred herds across twelve states, as well as three human cases in Texas and Michigan.

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But Connecticut public health officials and infectious disease physicians say that the current risk of bird flu to the general public remains low.

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“The good news is the human cases are exceedingly low, and they’re all so far from people that have had direct contact with lactating cows,” said Manisha Juthani, commissioner of the Department of Public Health. “For a regular resident in the state of Connecticut, the risk is low.”

Scott Roberts, the associate director of infection prevention at Yale New Haven Health, said that the risk to humans through the consumption of animal products is also low.

“There’s no evidence that live virus is reaching consumers through eggs or milk, and pasteurization kills the virus. Cooking foods such as chicken and eggs kills the virus,” said Roberts, an expert on diseases like COVID-19 and flu.

The risk is slightly higher for farm workers, Juthani explained, but Connecticut is not currently one of the twelve states with an identified case in dairy cows.

Bryan Hurlburt, the commissioner of Connecticut’s Department of Agriculture, said in a written statement that the department has been working to protect the state’s livestock industry from an outbreak by monitoring lactating cows and working with DPH to distribute personal protective equipment to farmworkers and processors.

“The emergence of H5N1 is an opportunity to remind everyone — urban, suburban, rural — that animal health, environmental health, human health, and food accessibility/safety are all spokes of the One Health wheel,” wrote Hurlburt.

Monitoring the virus

While the short-term risk is low, Roberts said that two aspects of the virus concern him in the long-term: its mortality rate and its ability to jump from species to species.

“When it does reach humans, it’s very severe,” said Roberts. “Of the 900 or so cases that have been reported since this was first discovered in the late ’90s, about half of them, or 50%, have died.”

But so far in this outbreak, both humans and dairy cows have experienced only mild symptoms, said Juthani. In the three human cases, two people experienced conjunctivitis, or pink eye, and the third had symptoms of a mild upper respiratory infection. In cows, the primary symptom has been lower milk production for those that are lactating.

Roberts also worries that the current strain of the virus started out in wild birds but has since infected several species, including foxes, house mice, bears and domestic cats.

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“Clearly, this virus is evolving and learning how to jump across species. And so I think the natural question one has to ask is, ‘How long until it evolves and adapts to the point where it can infect humans?’ And the answer to that question might be ‘never,’” said Roberts.

Juthani said human and animal interactions have always concerned her, and not just when it comes to the bird flu. As a former practicing infectious disease physician, she advised patients to use caution, for example, when interacting with farm or exotic animals while traveling.

“If you look at traditionally where any of these more concerning viruses or bacteria have emerged from, it is from those types of interactions,” said Juthani. “In general, my advice would be that if you are concerned, then I would try to minimize those types of interactions.”

DPH is partnering with other state and federal agencies to monitor the evolution of the virus.

“There has been very good communication in terms of what information there is federally and what we have here locally,” said Juthani.

The department checks in weekly with the CDC and also stays in close contact with the Food and Drug Administration, Juthani said. DPH is also following the lead of the state’s Department of Agriculture, since the current outbreak is primarily in animals.

Agencies at the federal and state level are also using data to check for signs of an outbreak in humans.

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The CDC tracks wastewater data for influenza outbreaks and is watching for signs of an uptick in cases that would be unexpected for this time of year. DPH monitors symptoms for every patient that goes into ERs across the state and has been watching for upticks in symptoms related to this strain of the bird flu, like pink eye and upper respiratory issues.

“I want people in Connecticut to know that we are collaborating regularly so that we can be knowledgeable and be as best prepared to help people make informed choices as things potentially could evolve. And they might not, but if they do that’s what our job is — is to be prepared,” said Juthani.