JONATHAN M. METSCH, Dr,P.H. – Tracking Emerging Public Health Challenges – July 19, 2026 – BIRD FLU
During the COVID-19 pandemic, many countries closed their borders to stop the spread of the disease. This is not an option when infectious wild birds routinely migrate across thousands of miles with ease.
Second, bird flu is much more deadly than COVID-19. Infectious disease experts at the U.S. Centers for Disease Control and Prevention (CDC) cite a historical fatality rate of 52% for bird flu in humans. Most recently, a study of 12 human cases of bird flu reported worldwide over the past 10 months found that a quarter of those infected died of the disease. These are huge percentages when compared to COVID-19, which had a fatality rate of roughly one percent.
Third, experts are concerned because there are so many vectors – or carriers – for the disease. COVID-19 would very rarely infect pets and other animals, and there was minimal to no risk that those animals would infect humans. This is not true of bird flu, which has already been documented to have been transmitted from dairy cattle to humans, and from cats to humans as well as other mammals.
And finally, concern is great because bird flu is already in our food supply. Health officials have documented the presence of bird flu virus in raw cat food chicken, uncooked eggs and unpasteurized milk. A broken, deactivated virus has been found in 1 out of 5 samples of pasteurized milk. While COVID-19 may have disrupted the supply chain and caused food prices to rise, it was never present in the food supply and never threatened to infect people through their nourishment.
Influenza, or “flu,” is a form of viral infection of mammals. There are several types of flu, and some originate in humans while others originate in other animals. The dangerous thing about flus is that they have a propensity to be “zoonotic,” meaning they can infect humans as well as animals. And once they get into a human, they ‘look under the hood’ and study our physiology, looking for ways to make it easier to infect, or transfer themselves, to other hosts, including other human beings. Which is why every time an animal flu crosses the divide and infects a human, the experts get a little more worried.” (1)
“A nine-month-old girl in Cambodia has tested positive for H5N1 avian influenza, marking the country’s fifth human case of 2026, the Ministry of Health said in a statement late on Saturday.
The infant, from Prek Takong village, Meanchey district, Phnom Penh, was confirmed positive for the virus on Thursday, the statement said.
A team of doctors is providing the patient with intensive care, it added.
Health authorities “are investigating the infection’s source and tracing contacts to prevent community transmission,” the statement said.” (2)
1.Can your cat give you bird flu? What experts say about human risk and the likelihood that bird flu will cause a pandemic., by Michelle Dally, https://www.uchealth.org/today/bird-flu-cats-can-they-infect-humans/
2.Cambodia confirms 5th human case of bird flu in 2026, by Xinhua, https://english.news.cn/asiapacific/20260711/b97c21fccec647ceab3ef0a550d75084/c.html
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai