CDC says response to bird flu outbreak is 'robust' but risk to public remains low

CNN
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Bird flu is affecting a growing number of cattle herds in the United States, and this is the second known human infection of these infections. domesticby Centers for Disease Control and Prevention.

There is no human-to-human transmission in the United States, but infections do occur. sporadic cases The CDC says it is closely monitoring the situation as more people are becoming infected with the avian influenza virus in other parts of the world. Like all viruses, H5N1 has the potential to mutate and become more of a threat to humans.

Dr. Nirav D. Shah, the agency's principal deputy director, said Wednesday that “the overall risk to the general public remains low.” “But make no mistake, the CDC has been activated as a result of these findings. We are taking this situation very seriously and are working aggressively to ensure a public health response.” We are working on it.”

When humans become infected with this version of the virus, the risk is thought to be low because it is usually people who have had close contact with sick animals. The infection usually stops there.

“So it's possible for a bird or a chicken to infect a human, and that human could actually infect their spouse, for example, but then we don't see sustained human-to-human transmission. '' says Shah. Said.

Latest Case – Individual in Texas who had contact with dairy cows seems to be infected Officials said the symptoms were mild, but humans can become seriously ill and die from the disease.

“So even though we haven't seen sustained transmission, we are taking this seriously and that's why the CDC has started taking action,” Shah said.

Shah said government agencies and local public health partners are monitoring anyone who may have come into contact with these herds and may have symptoms of bird flu. Worried about false positives, only people with underlying symptoms are tested.

The CDC said about 15 people were tested during the outbreak, and only one was found to have the virus.

The Texas patient's only symptom was red eyes, which the CDC notes are not typically associated with the flu, which often causes cough, fever and shortness of breath.

“In this regard, we want to test more people, not fewer people. That is why we have given the green light to proceed with testing of symptomatic people who have been infected. I did it,” Shah said.

Doctors treated the Texas patient with an antiviral drug commonly used for the more familiar influenza virus, and the patient was isolated.

The CDC said existing products are ready to be used to detect and protect against the virus even if it does mutate and spread among humans. The strain most recently recovered from the affected person is the same type that is prevalent in affected cattle and birds.

“We did not see any genomic changes that would suggest a reduction in the effectiveness of either vaccine. [the antiviral drug] Tamiflu or a diagnostic test,” Shah said.

Scientists discovered the first cows infected with the virus at two dairy farms in Texas in March, the first cows known to have been infected with avian influenza.more humans have been exposed to the virus since the USDA announced Monday The company announced that influenza has been detected in a dairy herd in New Mexico and five additional dairy herds in Texas. This is the first time the virus has been found in cattle in New Mexico.

A total of seven herds in Texas, two in Kansas, one in Michigan and one in New Mexico are affected by bird flu, according to the Department of Agriculture. A herd in Idaho is also suspected of being infected, but those test results are still being analyzed.

Since the avian influenza outbreak began in January 2022, more than 82 million poultry birds in 48 states have been announced to be affected. CDC. Infections were also detected in 9,253 wild birds, although the actual number is likely much higher.

Although the number of mammals in which this virus occurs is relatively small, its numbers are increasing. Baby goats, ducks, geese, deer, foxes, raccoons, opossums, skunks, pet cats and other animals have tested positive.

Dr. Thomas Inglesby, director of the Johns Hopkins Center for Health Security, said it was concerning to see the virus jump to cattle.

“Every time there's a change, it's important. This is the first time that a cow has been infected that we know of, and this is the second human case detected in the U.S. “We need to dig into it and make sure it's not more than a single isolated case from industrial exposure,” he said.

Shah said people should not be alarmed by the virus' official name, “highly pathogenic avian influenza.”

“The name itself can raise the blood pressure of many who read or see it. The 'highly pathogenic' part of the name refers to toxicity and severity in birds, not humans.” he stated. “Certainly, if you're a migratory bird, this virus is bad news.”

Ducks and geese can carry the virus without showing symptoms, but poultry We're not always so lucky.Transmitted by highly pathogenic avian influenza “Very high mortality rate” Farmers are concerned because the disease is occurring in chickens and turkeys and continues to spread despite best efforts to contain it.

The virus spreads easily and can quickly kill birds, so farmers usually have to kill uninfected birds as well to prevent the spread of infection.

on tuesday, Michigan A case was reported at a commercial poultry facility. On Wednesday, the nation's largest egg producer discovered avian influenza at its Texas facility.

Cal Maine Foods said it will need to reduce the population of 1.6 million layer hens and 337,000 baby chickens at its Texas facilities. According to the state Department of Agriculture Commissioner Sid Miller called it “absolutely devastating news for Cal Marin and the entire Panhandle region, which has already been hit hard.”

Inglesby said people who work with sick birds should take precautions, but not everyone needs to remove bird feeders. According to research, Avian influenza can also be transmitted to songbirds, but birds that normally congregate at feeding grounds, such as cardinals, sparrows, and bluebirds, and birds seen on the streets, such as pigeons and crows, are usually the threat of avian influenza. does not carry the virus. For humans, According to the CDC.

But “it's always a good idea to wash your hands when interacting with wild birds,” Inglesby says.

For cattle, it is recommended that they be kept in special cages for sick animals, where they usually recover in 7 to 10 days.

Based on current knowledge, ranchers do not need to kill sick cattle, Shah said. He said as of Wednesday, no cows in the infected herd had died from the infection.

The cows likely contracted the virus when they encountered wild migratory birds. but, USDA Animal and Plant Health Inspection Service Given the prevalence of the disease among herds in Michigan, cow-to-cow transmission cannot be ruled out, he said. The virus does not appear to be a respiratory infection of any kind, but it was likely spread through infected milk.

“That seems to be the prevailing theory at this point,” Inglesby said.

Although the virus can be found in high concentrations in the milk of sick cows, most milk in the United States is pasteurized and must be pasteurized before it can be sold across the state, so milk does not pose a threat to humans who drink alcohol or eat dairy products. line. The pasteurization process inactivates the virus before the product goes to market.

The U.S. Food and Drug Administration continues to remind people that raw milk can have negative effects. serious health risks To those who drink.

“Before this happened, the CDC and FDA position was to stay away from raw milk. What we've done now is put an asterisk on it and say, 'We really mean it. 'We are in a position to do so,''' Shah said.

The U.S. Department of Agriculture said milk production is typically high in the U.S. in the spring, and the cow infections would not negatively impact the nation's food supply. The agency said the milk lost so far from symptomatic cows was “too limited” to have a significant impact and would not affect milk prices.

USDA and CDC said they will continue to work with industry and local public health departments to monitor the situation and encourage veterinarians and farmers to promptly report sick animals to help limit the impact of the virus.