A second person in the U.S. — a farmworker in Michigan ― has been infected with bird flu linked to dairy cows, federal health officials announced Wednesday.
According to the Centers for Disease Control and Prevention, a nasal swab from the worker in Michigan had tested negative for the H5N1 virus, but an eye swab sent to the agency tested positive. Like the infected person in Texas, the Michigan patient only reported eye symptoms. He has recovered, according to officials.
Officials said in a press conference Wednesday they were investigating the case to determine whether the worker was wearing personal protective equipment and how exactly the person might have gotten sickened by a cow presumed to be infected.
Officials said the risk to the public from bird flu remains low but the risk to farmworkers is “elevated” as a growing number of cattle are infected with bird flu.
In March, a worker at a Texas dairy farm was diagnosed with bird flu. That was the first documented case of the flu spreading from a cow to a human.
Earlier this week, the CDC’s principal deputy director, Dr. Nirav D. Shah asked state health officials around the country to continue monitoring for flu “at enhanced levels” throughout the summer to help catch bird flu cases in humans.
Flu monitoring usually falls or stops during the summer months when temperatures rise and the spread of flu viruses falls to minimal levels in the United States. In Georgia, the Department of Public Health closely tracks flu activity from October through mid-May and scales back its monitoring during the summer months.
But in a meeting with state health officials, CDC officials said they want local health departments across the country to maintain a heightened awareness of circulating influenza viruses given the ongoing outbreak of H5N1 among poultry and U.S. dairy cattle.
Shah asked state health officials to maintain their peak-season levels to help detect “even rare” cases of bird flu in humans.
The bird flu now affecting dairy herds is an H5N1 virus, which is a subtype of influenza A, a common version of the flu infecting mostly people.
Standard testing can not distinguish human influenza A viruses (such as H1N1) from bird flu (H5N1). A special process in the lab is required to determine whether the influenza sample is a common seasonal influenza virus or the more worrisome H5N1.
Shah said the request from the federal agency wants state health officials to increase influenza samples analyzed in labs to help catch any human cases of H5N1.
DPH spokeswoman Nancy Nydam told The Atlanta Journal-Constitution Wednesday that in accordance to this new guidance from the CDC, the health department will maintain a high level of surveillance this summer and commercial labs in Georgia will now be asked to submit influenza A-positive specimens to the Georgia Public Health Laboratory for what is known as “subtyping” — a process to determine if the influenza A sample is a common virus or the bird flu strain.
It is rare for humans to get bird flu and currently, most cases of bird flu in people around the globe are linked to direct contact with infected animals. H5N1 bird flu is widespread in wild birds worldwide and has caused outbreaks in poultry and recently made the jump to dairy cows.
Scientists are paying close attention to how the virus is changing and are on high alert for any changes in the bird flu virus that might enable it to spread more easily among people.
As of Wednesday, the H5N1 virus has been detected in 51 dairy herds in nine states since March.
Georgia, however, has not reported any cases in cattle, nor in humans.
Just how much the increased surveillance will help remains to be seen. The CDC is on high alert for any uptick in activity this summer. And while Georgia DPH monitors flu activity by watching the percent of doctors’ visits that are for “influenza-like illness,” like other states, they don’t track each positive influenza case.
And many people with flu-like symptoms don’t get tested.
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