China has reported the world's third case of human infection with the A(H3N8) avian influenza virus. This was reported by the World Health Organization (WHO) on Tuesday evening. This is not the H5N1 development line 2.3.3.4b, which is currently rampant among wild birds and poultry worldwide, and which has also been detected in various mammals.
In the latest H3N8 case, a 56-year-old woman from the Chinese province of Guangdong became infected. She came to the hospital on March 3 with severe pneumonia and died there on March 16. The woman with pre-existing conditions had contact with poultry in a market where this virus was also detected. Other people with whom the woman had contact, would not have been infected. The other two H3N8 cases in humans were reported from China in April and May 2022, according to WHO. One person fell seriously ill, a second had only mild symptoms.
As a rule, humans occasionally become infected with bird flu viruses after contact with poultry or wild birds. Many do not even notice the infection or have only mild symptoms, others develop serious respiratory diseases. Health experts warn of the danger that the virus adapts to humans and can then be transmitted from person to person.
Low risk of transmission
To the now reported from China H3N8 case, the WHO writes that this bird flu virus is often detected worldwide in dogs, horses, pigs, and other animals. Unlike H5N1, it causes little or no mild symptoms in poultry and wild birds. "According to the available information, the virus does not appear to have the ability to transmit easily from person to person," the WHO said. "The risk of spreading the virus among humans at national, regional and international levels is estimated to be low."
A more detailed risk analysis from May 2022 is still valid, said a WHO spokeswoman. It said: "While further infections in humans with A(H3N8) viruses cannot be ruled out, the risk is low. The likelihood of sustained human-to-human transmission is also low, based on the limited information available so far."
To the H5N1 development line 2.3.3.4b, which is rampant in birds worldwide. On Wednesday, the WHO named seven cases registered in humans: two in China, two in Spain and one each in Ecuador, Great Britain and the United States. In China, one case was fatal, a second person fell seriously ill. The person in Ecuador also fell seriously ill. The other cases were with no or mild symptoms. It is known that this line also infects and kills mammals such as minks, seals, foxes, raccoons, martens and bears.
Infections of humans and also deaths with other H5N1 lines of bird flu have been known for many years. A total of 5 cases of H1N2003 have been reported to WHO in people from 873 countries since 22. More than half were fatal. Since 2020, the WHO registered only a few cases, last year there were six, this year three (as of 3 March 2023).