Health authorities in the US have confirmed 4 new cases of bird flu in humans, bringing the number of people infected with this animal-borne disease since spring to 8.
The infected humans are four "farm workers" working on the same poultry farm, the Centers for Disease Control and Prevention (CDC) explained in a press release quoted by AFP.
There is also a suspected fifth case, which has not yet been confirmed.
The risk to the US population remains "low," the CDC stressed. Infected workers are suffering from "conjunctivitis" and "flu-like symptoms."
An outbreak of bird flu was detected in the United States in the spring, and the unusual development was that this disease, which initially affected mostly poultry and birds, is now also affecting cows.
On 1 April, an initial infection was declared in Texas, in the southern United States. It was then the world's first known case of avian influenza in humans via livestock.
After that, 2 more cases were reported in Michigan.
In early July, another case was found on a cow farm in Colorado. In this western US state, the disease is spreading to both cattle and poultry.
Experts are concerned about the increasing number of mammals infected with the disease, although human cases remain rare. They fear that the high level of circulation could facilitate mutation of the virus, allowing it to be transmitted from one person to another.
The CDC again urged workers who are in contact with infected cows or poultry to take precautions.
Further genetic analyses of these new cases in Colorado are to be conducted to detect a possible modification of the virus that could lead to a "change in the authorities' assessment of risk" to the population. | BGNES