The Centers for Disease Control and Prevention (CDC) has issued a health alert network advisory (HAN) in response to the H5N1 bird flu outbreak in at least 16 dairy herds in six states across the country. The advisory recommends that healthcare providers should consider whether a patient has a relevant exposure history, such as someone who works with dairy cows or lives with someone who works with dairy cows. The illness should be considered for mild, medium, and severe symptoms, from conjunctivitis to fever, shortness of breath, or pneumonia and/or organ failure.
Any patient suspected of having H5N1 flu should be isolated and cared for by medical professionals wearing protective equipment. Suspected cases should be started on the flu drug oseltamivir (Tamiflu) even before test results confirming the infection have come back. The CDC said that no additional cases of human infection with HPAI A(H5N1) virus associated with the current infections in dairy cattle and birds in the United States, and no human-to-human transmission of HPAI A(H5N1) virus have been identified.
In cows, the illness has been mild to date, with infected animals showing a decline in milk production and decreased feed consumption. Dairy operations have been instructed to destroy milk from infected animals, as milk from infected animals has been found to contain H5N1 viruses. Pasteurization would destroy the viruses even if contaminated milk were to make its way into the human food chain. Consumption of raw milk or raw milk cheese from infected cows could pose a health risk and should be avoided.
Infected cows have been reported from Texas, Kansas, New Mexico, Idaho, Michigan, and Ohio. It is unclear if the virus is transmitting from cow-to-cow through the respiratory route, or if some aspect of dairy operations is fueling the spread of the virus. The CDC’s advisory stated that analyses of viruses taken from the infected person, cows, and wild birds and poultry showed only small genetic changes.
