A new dashboard from the U.S. Centers for Disease Control and Prevention (CDC) aims to help track the spread of bird flu as the federal government works to monitor and contain the virus.
So far, the virus has mainly affected dairy cows and has not posed a significant threat to humans. However, given the virus’s ability to transfer between species, the CDC is increasing its response efforts.
On Tuesday, the agency released a variety of data, including information on wastewater sampling sites that have tested positive for influenza A, which includes the avian influenza subtype H5N1.
The new dashboard displays data in graphs and charts, comparing current positive tests in a region to those from the same time last year.
“By tracking the percentage of specimens tested that are positive for influenza A viruses, we can monitor for unusual increases in influenza activity that may be an early sign of the spread of novel influenza A viruses, including H5N1,” the CDC stated in its report.
What Data Does the CDC Dashboard Include?
While the CDC monitors flu cases year-round, the new dashboard is intended to enhance surveillance of bird flu cases at national, state, and local levels.
The agency is currently monitoring 260 people who have been exposed to dairy cows infected with H5N1. For the week ending May 10, the agency’s surveillance system showed no indications of unusual flu activity in people, including the H5N1 virus.
The first-ever reported case of bird flu infecting a human occurred in 2022 following exposure to infected poultry. A second case was reported this year in Texas following exposure to infected dairy cattle.
The CDC is also testing wastewater from sewers to detect mutations in the virus that could increase its transmissibility among humans. For the week ending May 4, 189 wastewater sampling sites across the U.S. showed higher-than-average levels of influenza A, requiring further analysis. Notably, Saline County, Kansas, had particularly high levels.
“The data from these sites are being closely monitored by CDC and its partners to identify potential contributing factors, including assessing whether any of the high levels are related to human illness,” the CDC noted.
However, the CDC cautioned that current wastewater monitoring methods cannot distinguish between subtypes of influenza A, meaning that bird flu cannot be accurately detected this way. Additionally, wastewater testing cannot determine the source of the influenza A virus, which could come from humans, animals, or animal products like milk.
“Efforts to monitor influenza A virus activity using wastewater data are likely to evolve as methodologies and interpretation are evaluated and refined,” the CDC added.
Bird Flu Spreading to Dairy Cows in the U.S.
Health officials have expressed growing concern over the recent spread of avian flu, which has jumped from birds to other animals, including cows. According to federal officials, a total of 42 cattle herds in nine states have been infected.
To contain the virus’s spread, the federal government has increased financial aid to dairy farms and provided additional testing tools for dairy workers and cattle. The additional $28,000 in funding per impacted farm will expand testing, cover costs for protective gear for workers, and compensate farms for veterinary bills and lost milk production over the next four months.
The U.S. Department of Health and Human Services will spend $101 million on testing and prevention efforts, while the CDC will allocate $93 million to expand testing and monitoring of the virus.
Risk to the General Public Remains Low
The larger concern is that the virus might evolve to become easily transmissible to humans. Bird flu is considered more dangerous than the seasonal flu because it’s a strain humans have never encountered and is likely to be highly contagious.
“There’s no current evidence of sustained human-to-human transmission,” Dr. Raj Panjabi of Harvard Medical School and the former White House senior director for global health security and biodefense on the United States National Security Council, told USA TODAY. “It’s the moment to get ready to step up investments in public health, especially around prevention, protection, and preparedness.”
Federal officials recently confirmed that the commercial milk supply is safe, as are milk-based products like cottage cheese and sour cream. However, agencies such as the CDC, FDA, and USDA are warning consumers to avoid drinking unpasteurized milk, which may harbor the virus. Testing has reaffirmed that pasteurization kills the bird flu virus.
If the bird flu begins transmitting from person to person, vaccines and antivirals should be available, officials said.
