America's H5N1 bird flu outbreak grows as CDC confirms third case in California

California has recorded its third case of bird flu in dairy farmers in just three weeks, making it the 17th human case of H5N1 flu in the US since March.

CDC officials announced that the latest patient is experiencing mild symptoms, including eye redness and eye infection, and none of the three cases have required hospitalization.

Experts believe the infection was spread from the dairy cows that each patient comes in close contact with daily. The patients did not know each other and there is so far no indication that the infection is spreading from person to person.

More cases are likely to arise in the coming months, according to the CDC, given the speed at which bird flu is spreading among hundreds of dairy cattle herds across at least 14 states.

The agency has received more specimens from two other Californians who are likely to have bird flu, but they need to undergo confirmatory testing by the CDC to verify the results.

While the agency insists risk to the public remains low, experts have expressed fears that all signs point to the virus' capacity to drive a potential pandemic not dissimilar to Covid-19.  

CDC researchers studied the genetic makeup of each virus specimen taken from patients and did not find signs of any mutations that would make the virus more likely to infect or spread between people, or that would make it resistant to antiviral medications. 

Infections in people who have close contact with animals is to be expected, the CDC said, and doesn't alter its messaging to the public that the general risk is low. 

But outside experts are becoming increasingly worried that as the virus continues to spread, it will not only get more farmers sick, but also gain the ability to better infect humans on a wider scale. 

Dr Rick Bright, former deputy preparedness secretary at the Department of Health and Human Services, said that because the virus is spreading amongst both birds and cows on farms, 'the opportunity for infecting a human is increasing.' 

Dr Bright added: 'We don’t know how many cows are infected, we don’t know how many people have been exposed... If we haven’t caught the virus before it mutates to efficiently transmit person-to-person, all bets are off in terms of being able to control it.'   

The virus has been running rampant in dairy herds in California, raising the spectre of a wider-reaching outbreak among farmworkers in the state. 

Farms are reporting as many as 50 to 60 percent of their herds have been infected, and around 15 percent of cows are dying. 

According to the the California Dairy Quality Assurance Program: 'As the number of infected herds climbs, producers are understandably concerned, wanting to know how to prevent the disease from entering their herd and how to best manage the disease if it does.' 

Nationwide, the virus has infected more than 100 million birds across 48 states as well as 295 dairy herds in 14 states. 

The patients in California have experienced watery, infected eyes, mild fever, and runny nose. 

When five poulty workers were infect in July, they experienced the same symptoms as well as some respiratory distress and, like those in California, did not need to go to the hospital. 

Symptoms can range in severity, though, and include flu-like symptoms, achiness, shortness of breath, eye inflammation, diarrhea, nausea, and vomiting. It may look similar to an upper respiratory infection of the flu. 

In the most severe cases, bird flu can lead to pneumonia and respiratory failure. 

Infected animals shed the virus in their saliva, mucus, and feces that can get into water, soil, and various hard surfaces where it can linger for up to 48 hours depending on air temperature and humidity.