The Missouri Department of Agriculture announced Friday that a person with no history of contact with animals has tested positive for H5 avian influenza.
This is the first time in the U.S. outbreak that a patient has not had contact with a sick animal, and it is also the first time that someone has been hospitalized with avian flu, although it is not yet clear whether the reason for the hospitalization was influenza or something incidental.
The patient, who had underlying health conditions, was hospitalized on August 22 and tested positive for influenza A. Doctors sent a sample to the Missouri State Public Health Laboratory, which determined it was the H5 subtype, also known as highly pathogenic avian influenza (bird flu).
The US Centers for Disease Control and Prevention (CDC) confirmed it was H5 and said the sample was under further investigation.
In previous cases, officials have been trying to determine whether human infections are due to a strain that has been circulating among wild birds and mammals in the U.S. since 2022, or whether it is more closely related to a variant in dairy cows. Authorities will also likely investigate whether mutations have emerged that make the virus more infectious or virulent in humans.
In an exclusive interview with The Guardian in July, CDC principal deputy director Nirav Shah said there were several areas of concern the agency was watching with the current outbreak.
“One is that it increases the severity of the disease, including hospitalization and death from avian flu,” he said.
“So far, cases in the United States have been mild, but have occurred among agricultural workers, who tend to be healthy and hardy. In the general population, especially among those with other health conditions, bird flu may prove more dangerous. Globally, the mortality rate among confirmed cases is about 50%, but there are likely some mild cases that go undetected.”
“The second thing is the nature of the transmission,” Shah said. “Is person-to-person transmission occurring?”
In the 20 years since H5N1 was identified in humans, further transmission between humans has been extremely rare, he said.
Another big concern about infection is who will get sick.
“If we see people who have absolutely no connection to farms or contact with chickens developing signs and symptoms, that's very worrying,” Shah said. “Even if no other routes of transmission have been identified, that would be a sign that something else is going on.”
Authorities will continue to trace the patient's potential exposure and contact with others to determine how the virus may have spread.
Avian influenza usually affects poultry and wild birds, but in recent years its range has expanded significantly to become widespread in mammals, including dairy cows and other livestock.
Two indoor cats in Colorado recently Positive reaction Mice also tested positive for the virus.
Avian flu has not been detected in cattle in Missouri, but it has been found in poultry and wild birds.
The virus “can also be transmitted to humans through close contact with infected animals or contaminated environments,” according to a Missouri state press release.
This is 15Number This is the 14th confirmed case of bird flu in the United States since 2022.Number This is the first confirmed case of human infection with avian flu in Missouri this year.
The patient has recovered and been released from the hospital, according to a statement from the state of Missouri.
