NBC News
An aviar flu strain that is spreading between Nevada dairy cows infected a worker from a state’s dairy farm, as the centers for disease control and prevention reported Monday.
It was discovered that the patient, who had been working with sick cows, had an aviar flu strain called D1.1, which has been circulating between wild birds. It is different from the strain of the virus that has caused most human infections in the United States, called B3.13.
D1.1 has a mutation that could make the virus spread more easily in mammals.
It was found in dairy cows for the first time last month, also in Nevada, through the National Milk Analysis Strategy that monitors the avian flu in dairy cows analyzing its milk.
It is the second time that a strain of the avian flu virus was “propagates” from the birds to cows.
“It is very important something,” said Michael Osterholm, an expert in infectious diseases and director of the Research and Policy Center for Infectious Diseases of the University of Minnesota. It is another indication that the virus continues to mutate.
It is not clear how long the D1.1 has been circulating between the dairy cows or which are its implications, said Andrea García, vice president of Science, Medicine and Public Health of the American Medical Association, in a YouTube video published by the East Group Monday.
“Some experts fear that it can mark a new chapter at the outbreak or that avian flu can become endemic in the United States,” Garcia said. “This is something we follow very closely.”
In general, the virus has not caused deaths in dairy cows, according to the American Association of Veterinary Medicine. The California Food and Agriculture Department said that 236 of the 738 herds infected in that state have recovered. (At the national level, there have been a total of 962 cases in livestock, according to the Department of Agriculture).
But the virus has wreaked havoc on poultry farms. Millions of chickens have been sacrificed, which has contributed to the vertiginous rise in prices and the shortage of eggs.
The only symptom of a dairy worker in Nevada was conjunctivitis and the person has recovered, according to CDC. None of the person near the person became ill, said the Health District of Central Nevada.
Like the Nevada patient, almost all people infected with avian flu during the past year have had mild symptoms, regardless of the type they suffered.
A person in Louisiana who had the strain D1.1 died last month. The individual, who was over 65 and underlying health problems, became ill in December after coming into contact with a flock of poultry and wild birds.
CDC estimate that strain D1.1 was responsible for 15 of the 68 human cases of avian flu found last year. In addition to Louisiana, cases of D1.1 have been detected in Iowa, Oregon, Washington and Wisconsin.
Last month, CDC said that the United States should intensify avian flu tests in hospitalized patients, ideally within 24 hours after admission.
However, almost all human cases of avian flu have been slight. The Nevada patient was not hospitalized.
CDC argue that the risk of avian flu for the general population is low and that there is no evidence that the virus is spreading from person to person.
But now is the time for scientists and public health officials to prepare to change, said Osterholm, the expert in infectious diseases.
“We are going to have another flu pandemic, and when it happens, we should not surprise ourselves,” he said. “But will it be H5 or not? I don’t know.”
