Representatives from the Centers for Disease Control and Prevention, the U.S. Department of Agriculture and other agencies discussed the latest news on avian flu in the United States on Wednesday.
Authorities continue to test milk, dairy products and meat to prevent the virus from spreading, and are also monitoring farm workers for human cases of bird flu.
Here are some of the questions they answered.
Does the virus spread from person to person?
Bird flu can rarely spread from person to person, but not in the U.S. Dr. Rosemary Sifford, chief veterinary officer at the U.S. Department of Agriculture, said researchers have not seen any changes in the virus that would suggest it might spread more easily from person to person.
A dairy worker who was reported to have avian flu on April 1 is the second human case of the virus reported in the U.S. The worker had conjunctivitis and a mild eye infection but has recovered.
How is the CDC responding to bird flu outbreaks?
Dr. Demeteur Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, said the center is monitoring unusual trends of influenza-like illnesses and conjunctivitis across the country, especially in areas where the H5N1 virus has been found in dairy cows and other animals. CDC’s influenza surveillance system has not found any signs of unusual influenza activity suggestive of avian influenza.
The CDC is also helping monitor infected workers, Daskalakis said. People who have come into contact with infected cattle, poultry or other animals will be monitored for 10 days and tested if they show symptoms of illness. More than 100 farm workers are being monitored so far.
The CDC also provides guidance on protecting farm workers, including a graphic guide to personal protective equipment recommendations for workers who handle farm animals, available in English and Spanish, he said.
He said the CDC also has ongoing research that includes genetic sequencing. Because viruses are constantly changing, the CDC is continually analyzing the virus to identify genetic changes that might suggest it may be more easily transmitted from person to person or from person to person, or that it may undergo changes that could make antiviral drugs or vaccines less effective.
How does the virus spread among dairy cows?
Dr. Rosemary Sifford, chief veterinary officer for the U.S. Department of Agriculture, said research suggests recent infections in dairy cows in the U.S. are the result of “spillover” from wild birds and that no further cases have been found.
The first bird-to-cattle transmission occurred in Texas, among multiple herds, she said. When infected cattle from those herds were moved to other states, the infection spread. As of Wednesday, 36 herds in nine U.S. states had confirmed cases, according to the U.S. Department of Agriculture.
Sifford said the virus spreads when cattle are moved, but can also be spread on farm equipment, and that farmers with infected cattle have reported seeing around 10% of their animals develop symptoms.
He said sick cows generally return to their previous milk production levels after recovering from the virus, but that recovery takes about two weeks and most cows have recovered, with “low to no mortality.”
Which dairy products have been tested for Avian Flu and where did you purchase them?
The FDA said last week that it had tested 96 commercially available dairy products and found genetic traces in one in five, but that initial data did not detect any live virus. Donald A. Prater, acting director of the FDA’s Center for Food Safety and Applied Nutrition, said Wednesday that the agency had tested 201 additional products, including milk, cottage cheese and sour cream, and initial data showed no “live virus” in any of the samples.
Several samples of powdered milk were also tested, but these also came back negative.
Federal agencies have raised further concerns about the dangers of drinking raw milk and reiterated their urging for people to avoid drinking raw milk and eating raw cheese.
What treatments are available?
According to the CDC, there are four over-the-counter, FDA-approved prescription antiviral treatments recommended for influenza that are effective against H5N1.
When reporters asked Daskalakis about farmworkers being given the antiviral drug Tamiflu “prophylactically” to protect them from the disease, he said the decision about which workers were given the drug was made on a case-by-case basis based on clinical considerations.
Atlanta Journal-Constitution
