On June 2, China’s National Health Commission (NHC) announced that a 41-year-old man in Zhenjiang city, Jiangsu province, was infected with the H10N3 strain of avian influenza. This is the first human case of infection with this pathogen.
According to Reuters, the man was hospitalized on April 28 with symptoms of fever and general weakness. He was not diagnosed with bird flu until May 28. Fortunately, his condition was stable enough that he was discharged home. Scientists are reassuring that the chances of the H10N3 strain spreading on a larger scale are low. This means we are unlikely to face another pandemic.
What is H10N3?
According to the Centers for Disease Control and Prevention (CDC), H10N3 is a form of avian flu. These viruses usually infect wild waterfowl, as well as domestic poultry and other animal species, but do not usually transmit to humans, although infections have been reported in the past.
In these rare cases, saliva, mucus, or droppings from infected birds get into a person’s eyes, nose, or mouth. These (very rare) infections usually occur after inappropriate contact with infected birds or virus-contaminated surfaces.
The H10N3 strain has only been reported in one person and so far there is not much information about it. However, it appears that the virus has been circulating among birds for some time.
Can H10N3 transmit to other people?
Since there have been no other cases of H10N3 among the relatives of the Zhenjiang patient, we do not know if H10N3 can spread from person to person. While it is still too early to definitively state that such an infection is not possible, the fact that the people the patient came in contact with showed no signs of illness is good news. If H10N3 could transmit from person to person, we would probably already know.
One case of illness is no reason to sound the alarm. It’s still too early to start worrying about a potential epidemic, not to even mention a pandemic. The CDC has not issued any warning about the newly targeted strain.
But are there other avian flu viruses that could be dangerous to humans?
Several strains of avian flu are currently known to infect humans: H5, H7, and H9-usually in the form of H5N1 and H7N9 viruses. Although they are rare in the general population, these infections occur most often among people who work with poultry. They are often one-time infections.
According to the CDC, the first human cases of H5N1 infection were identified in Hong Kong in 1997. Although a small number of health care workers contracted the virus, it did not spread on a larger scale. Since then, smaller clusters have been found periodically in Asia, with more than 700 human infections reported worldwide to the World Health Organization (WHO) since November 2003. Although such human infections are rare, about 60 percent prove fatal.
The first cases of human infection with the H7N9 strain were reported to WHO in March 2013. Those who became ill had contact with “animals or animal environments.” According to a WHO update posted in September 2018, there were 615 deaths among 1,567 laboratory-confirmed cases of the strain.
According to the CDC, “Asian H5N1 and H7N9 viruses have not been detected in humans or birds in the United States.”
According to Filip Claes, regional laboratory coordinator for the United Nations Crisis Center for Transboundary Animal Diseases at the Regional Office for Asia and the Pacific, part of the Food and Agriculture Organization, because the strain “is not a common virus,” experts will have to analyze genetic data to see if it resembles existing pathogens or is a completely new mixture.
At this time, it is unknown whether the pathogen can transmit from person to person. There is no cause for concern, although it is important to remember that the first SARS-CoV-2 infections were similar.