Less than two months after a first case, a second person was infected with avian flu in the United States in connection with an epidemic of this virus in the country’s cows, health authorities announced Wednesday.
This person works on a farm where the H5N1 virus infected cows in the state of Michigan, the Centers for Disease Control and Prevention (CDC) said.
For this federal health agency, however, the risk assessment for the American population remains “low”.
A first case in Texas, in the south of the United States, was announced on 1er april. This was “probably” the first case of avian influenza infection via a cow worldwide, according to the CDC.
A first human case of avian flu was discovered in the country in 2022, in Colorado, but it was then an infection by poultry.
For the person infected in Michigan as in Texas, the patients only showed symptoms in the eyes, specifies the CDC. Both have recovered.
Experts are concerned about the growing number of mammals infected with the disease, although cases in humans remain rare.
There is no evidence of human-to-human transmission at this time, but scientists fear that high circulation could facilitate a mutation of the virus that would allow it to pass from one human to another.
The World Health Organization (WHO) expressed its “huge concern” in mid-April about the increasing spread of the H5N1 strain of avian flu to new species.
Additional possible cases
Cattle herds in at least nine US states are affected by this outbreak. The first report dates from March 25.
The CDC on Wednesday again emphasized the importance of precautionary measures for people exposed to sick or potentially infected animals.
These people must in particular avoid “close, prolonged and unprotected” contact with these animals, as well as with their excrement, or even with unpasteurized raw milk.
“Given the high levels of H5N1 virus in raw milk from infected cows, as well as the extent of spread of this virus among dairy cows, additional similar cases in humans may be identified,” the CDC said .
But “sporadic infections in humans – without continued spread – will not change the risk assessment for the general public,” they added.
At the end of April, the United States Medicines Agency (FDA) confirmed that milk sold in stores in the United States was “safe”, the pasteurization process being “effective” in killing the avian flu virus.