CDC Urges Testing For Bird Flu In Dairy Workers Following Asymptomatic Cases

The Centers for Disease Control and Prevention (CDC) is urging dairy workers who may have been exposed to the H5N1 bird flu virus to undergo testing—even if they are symptom-free—and recommends antiviral treatment to reduce the risk of infection. This guidance follows recent findings indicating that some workers infected with H5N1 showed no symptoms but had been exposed through contact with infected animals.

According to the CDC’s latest study, dairy workers who came into contact with H5N1-infected herds this past summer on farms in Colorado and Michigan displayed positive antibody results for the virus. Eight out of 115 workers surveyed showed signs of infection despite the absence of illness. Dr. Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, noted that none of these workers used respiratory protection, and fewer than half used eye protection.

The findings suggest that asymptomatic cases have likely gone undetected among farmworkers exposed to infected livestock. Until now, testing was primarily reserved for those who developed symptoms following known exposure. This new evidence underscores the importance of monitoring even those who don’t feel ill.

Most reported cases in the U.S. have been mild, with affected individuals experiencing symptoms such as pinkeye or mild respiratory issues. Notably, some of the dairy workers reported mild eye irritation and drainage, while four of the eight infected individuals had no recollection of any symptoms.

The CDC advises that workers with significant exposure to bird flu, such as those working with infected cattle or poultry, should receive testing and Tamiflu, an antiviral medication. This approach aims to prevent the virus from developing further or potentially spreading to close contacts.

This recommendation marks a proactive shift in the CDC’s response to H5N1 among agricultural workers. Dr. Nirav Shah, principal deputy director of the CDC, emphasized the agency’s commitment to more intensive screening practices: “We in public health need to cast a wider net in terms of who is offered a test so that we can identify, treat, and isolate those individuals.” He noted that the goal is to ensure safety on farms where known cases exist, especially since the virus is primarily transmitted from animals to humans rather than person-to-person.

The CDC is focusing on those exposed without adequate protective equipment, such as masks and goggles, who might come into close contact with infected dairy products like raw milk. The organization plans to offer comprehensive testing and preventive care without placing the financial burden on individual farms, according to a CDC spokesperson.

Health experts are endorsing the CDC’s enhanced response. Jennifer Nuzzo, director of the Pandemic Center at Brown University, pointed out that these asymptomatic cases were anticipated, and the expanded testing policy aligns with safety goals. “We’ve always suspected strongly and now have confirmation that [standard testing] was going to miss people who are infected,” Nuzzo said. “It’s essential to identify all cases to reduce any potential health risks.”

The CDC’s findings also shed light on the evolving nature of H5N1 infections. While past outbreaks of H5N1 in other regions showed a high mortality rate, cases in the U.S. have been far milder. Dr. Daskalakis suggested this might be due to different viral strains. Currently, there is no evidence to suggest any impact on commercial milk or beef supplies, according to the Food and Drug Administration (FDA).

With ongoing research and close monitoring, the CDC remains vigilant in addressing any health concerns linked to the bird flu virus among agricultural workers. This new testing and treatment strategy aims to safeguard dairy workers, maintain public health, and ensure that any asymptomatic infections are promptly managed to prevent further spread.