Case of Human Avian Influenza Reported in US

A person tested positive for avian influenza A(H5) virus (H5 bird flu) in Colorado, according to the US Centers for Disease Control and Prevention (CDC). The person reportedly had direct exposure to poultry, and was involved in the depopulating of poultry with suspected H5N1 bird flu.

The patient’s only reported symptom was fatigue, and they have since recovered after a few days. They are currently in isolation and are being treated with the antiviral influenza drug oseltamivir. It is possible that surface contamination caused H5 bird flu to be detected in this person, but the positive test result met the H5 criteria. The CDC has tracked more than 2500 people exposed to H5N1-infected birds, and this is the only known case in the US.

The CDC noted that the only other human known to contract this strain of H5N1 was asymptomatic. The first case occurred in the United Kingdom in a person who raised birds that became infected with H5N1. Worldwide, more than 880 human infections with earlier H5N1 viruses have been reported since 2003, but the H5N1 viruses circulating in birds now are different than prior strains. Earlier H5N1 viruses have very rarely spread from an infected person to a close contact, and person-to-person spread has not been sustained.

Birds infected with H5N1 shed the virus in their saliva, mucus, and feces. Though H5N1 infections in humans are rare, they can occur when enough of the virus is inhaled, or gets into the eyes, nose, or mouth. Bird flu illness in humans have ranged from mild (e.g., upper respiratory symptoms, eye infection) to severe (e.g., pneumonia), and may result in death.

The CDC emphasized that this 1 H5-positive infection does not change the low risk assessment of bird flu in humans. If there are multiple reports of H5N1 in people exposed to poultry, or if infection spreads from an exposed person to a close contact, the CDC will update the public health risk. The CDC is performing active surveillance for cases of H5N1 virus and is taking preventative measures. There is an existing vaccine candidate that can be utilized if needed.

The CDC reiterated practices to mitigate the risk of bird flu. People should avoid any contact with poultry that appear ill or dead, as well as avoid surfaces that are contaminated with feces from wild or domestic birds.

For people who must come into contact with ill or dead poultry, the CDC recommended wearing gloves and washing hands thoroughly. The health organization also suggested respiratory protection, such as face masks, and eye protection, such as goggles.

Poultry and eggs should be cooked to an internal temperature of 165 degrees F to ensure bacteria and viruses, like H1N1, are killed. The CDC promised to continue providing updates on this and other situations as they develop.