A shadow of concern hangs over Mexico with the confirmation of a death from bird flu. The victim, a 59-year-old man from the State of Mexico, suffered from chronic kidney disease, type 2 diabetes and hypertension, according to the Ministry of Health.
The news comes as a blow to the medical community and the population in general, generating a call for vigilance and caution. The patient lost his life on April 24 after facing several days of symptoms, which has raised justified alarm throughout the country.
Despite assurances from health authorities that there is no risk of direct contagion for the population, clear and urgent recommendations are being issued. Citizens urged to seek immediate medical attention if they experience any symptoms after having contact with animals, live or dead, of any type and species.
The mysterious death of a man in Mexico who had one type of bird flu is not related to outbreaks of a different type on U.S. dairy farms, experts say.
This is a look at the case and the different types of bird flu:
WHAT HAPPENED IN THE CASE OF BIRD FLU IN MEXICO?
A 59-year-old man in Mexico, who had been bedridden due to chronic health problems, developed fever, shortness of breath, and diarrhea in April. He died a week later, and this week the World Health Organization reported it.
The WHO said it was the first time that version of bird flu — H5N2 — had been seen in a person.
WHAT HAS HAPPENED IN THE UNITED STATES WITH BIRD FLU?
A different version of bird flu — H5N1 — has been infecting poultry farms for the past few years, leading to the culling of millions of birds. It has also been spreading among all types of animals around the world.
This year, that flu was detected on dairy farms in the United States. Dozens of herds have suffered infections, with the most recent cases reported in Iowa and Minnesota.
The outbreak in cows has been linked to three cases reported in farm workers, one in Texas and two in Michigan. Each had only mild symptoms.
WHAT DO THE LETTERS AND NUMBERS IN THE NAMES OF BIRD FLU MEAN?
The so-called influenza A viruses are the only viruses linked to human flu pandemics, so their appearance in animals and people is worrying. These viruses are divided into subtypes based on what types of proteins they have on their surface—hemagglutinin (H) and neuraminidase (N).
The scientists noted that there are 18 different subtypes of “H” and 11 subtypes of “N,” and they appear in dozens of combinations. H1N1 and H3N2 are common causes of seasonal flu among humans. There are many versions that are also seen in animals.
WHAT IS H5N2?
The H5N2 strain has long been seen in Mexican poultry, and farms vaccinate against it.
It is also known in the United States. An H5N2 outbreak affected a flock of 7,000 chickens in south-central Texas in 2004, the first time in two decades that a bird flu dangerous to birds appeared in the United States.
H5N2 was also primarily responsible for a wave of outbreaks in U.S. commercial poultry farms in 2014 and 2015.
HOW DANGEROUS IS H5N2?
Over the years, H5N2 has ranged from being considered a mild threat to birds to a serious threat, but it has not been considered a threat to humans at all.
A decade ago, researchers used mice and ferrets to study the strain affecting American poultry at the time, and concluded that it was less likely to spread and less lethal than H5N1. Officials also said there was no evidence it was spreading between people.
Unusual cases of infections in animals are reported every year, so it is not unexpected that a person would be diagnosed with H5N2.
“If you're a glass-half-full person, you'd say, 'This is the system doing exactly what it's supposed to do: detect and document these rare human infections, where years ago we were fumbling in the dark,'” he said. Matthew Ferrari, director of the Center for Infectious Disease Dynamics at Penn State.
In fact, Mexico's health secretary, Jorge Alcocer, noted that kidney and respiratory failure — and not the virus — were the real cause of the man's death.
Some experts said it is worth noting that it is not known how the man became infected with H5N2.
“The fact that there was no reported contact (with an infected bird) does raise the possibility that it was infected by someone else who visited it, but it's premature to jump to those conclusions,” said Richard Webby, a flu researcher at St. Jude Children's Research Hospital in Memphis.
WHAT ABOUT OTHER TYPES OF BIRD FLU?
At this point, H5N2 is still considered a minor threat compared to some other types of bird flu. Most human illnesses have been attributed to the H7N9, H5N6 and H5N1 avian influenza viruses.
From early 2013 to October 2017, five H7N9 outbreaks were blamed for killing more than 600 people in China. And at least 18 people in China died during an H5N6 outbreak in 2021, according to the US Centers for Disease Control and Prevention.
H5N1 was first identified in 1959, but began to worry health officials until an outbreak in Hong Kong in 1997 involving serious human illness and deaths.
H5N1 cases have continued since then, most of them involving direct contact between infected people and animals. Globally, more than 460 human deaths have been identified since 2003, according to WHO statistics that suggest it may kill up to half of people reported infected.
Like other viruses, H5N1 has evolved over time, generating new versions of itself. In recent years, the predominant version of the virus has spread rapidly among a wide range of animals, but human death tolls have fallen.
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