The first severe human case of bird flu to occur during the nation’s current outbreak of avian influenza A (H5N1) has become the first human fatality, the Centers for Disease Control and Prevention reported on Jan. 6. The man who died was over 65 and had underlying medical conditions, according to the Louisiana Department of Health.

Following the release of news about the infected Louisiana man who was hospitalized in December, California Gov. Gavin Newsom declared a state of emergency to help expedite the state’s response to the infections spreading in its dairy industry. 

Since April, 66 human cases of bird flu have been confirmed in the United States. Avian influenza is a viral infection that primarily afflicts birds. It is a public health and economic concern because of its potential to mutate, spread among farm animals, and be passed from infected animals to people. 

The CDC continues to rate the U.S. public’s overall exposure risk as low. Avian influenza viruses do not easily infect humans, and no cases of human-to-human transmission have been detected in the U.S.  

Personal Protection  

As a precaution, personal protection measures are recommended for workers with risk of exposure to animals and animal byproducts that are or may be infected. This includes poultry and livestock farmworkers, slaughterhouse employees, wildlife workers, veterinarians, and healthcare personnel. In response to the Louisiana case, which was caused by exposure to sick and dead wild birds, hunters, backyard flock owners, and other bird enthusiasts are now also being advised to take precautions.  

“We anticipate increased occupational exposure risk to avian flu in some areas for our client employees, for example, for personnel in facilities, HVAC, building maintenance, construction, and pest control occupations who have potential contact with bird guano,” said Patrick O’Callahan, M.D., M.P.H., WorkCare’s vice president for on-site clinical operations. “If dairy farm outbreaks are associated with contaminated shared equipment and personnel, we may see sporadic cases involving transport workers and employees at product delivery sites.” If avian flu eventually spreads to commercial beef and pork industries, he added, there could be a major impact on employees at meat processing plants.

• Avoiding unprotected, direct physical contact or close contact with sick or dead animals, carcasses, feces, or litter.  

• Wearing personal protective equipment such as an N95 filtering facepiece respirator, eye protection, and gloves when contact cannot be avoided. 

• Frequent and thorough handwashing when handling raw eggs, milk, or meat, and thoroughly cooking eggs and meat. 

In healthcare settings, clinicians are advised to consider the possibility of H5N1 virus infection in patients with symptoms. Avian flu symptoms can range from fever, cough, sore throat, conjunctivitis (pink eye), and muscle aches to pneumonia, acute respiratory distress, and multiple-organ failure. Severe symptoms require emergency care and can be fatal. When treating those with confirmed infections, the CDC recommends using close contact and airborne precautions in combination with standard personal protection. 

People with symptoms who suspect they have been exposed to an infected source animal are encouraged to contact their personal provider. 

Surveillance

The U.S. Department of Agriculture Animal and Plant Health Inspection Service is facilitating national milk supply surveillance and dairy herd status programs that involve several government agencies. It has reported 311 new infected cattle herds in California, and one each in Nevada and Texas in the last 30 days, bringing the total for the current outbreak to 865 cattle herds in 16 states.   

The U.S. Food and Drug Administration (FDA) is investigating the potential for the H5N1 virus to infect bulk raw cow’s milk prior to pasteurization, a heating process that skills the virus. The FDA reports that about 99 percent of the nation’s commercial milk supply comes from farms that comply with controls that help ensure the safety of dairy products. 

Testing and Treatment Challenges 

Bird flu is caused by influenza type A viruses, which are classified into subtypes based on two proteins on the virus surface: hemagglutinin (H) and neuraminidase (N). The Center for Health Security at Johns Hopkins University notes that testing to confirm bird flu in humans is limited. Researchers believe the actual number of cases may be underreported because: 

• Commercial testing for H5N1 is unavailable. 

• When a flu test is positive for influenza A and cannot be subtyped, the CDC must retest it to confirm bird flu. 

• Commercial farms with infected animals must be receptive to health department interventions. 

• Workers may be reluctant to report symptoms to their employer. 

Bird flu viruses can develop resistance to antiviral drugs (e.g., oseltamivir), which are often used to treat human influenza infections.  

Conclusion 

While the overall risk of work-related exposure to bird flu in the U.S. is low and symptoms are usually relatively mild, individuals in affected occupations are strongly advised to adopt strict safety measures when there is an outbreak. Ongoing surveillance and biosecurity practices have been shown to significantly reduce animal-to-human transmissions.  

WorkCare’s occupational health physicians and other members of our medical monitoring team are well-prepared to assist employers in affected workplaces with the implementation of protective measures for employees with bird flu exposure risk. Visit our website to learn more about our capabilities.