Third case of bird flu H3N8 in humans in China

China has reported the world’s third case of human infection with bird flu virus A(H3N8). This is reported by the World Health Organization (WHO). This is not the H5N1 lineage 2.3.3.4b, which is currently rampant among wild birds and poultry around the world and has also been detected in several mammals.

The most recent H3N8 case infected a 56-year-old from China’s Guangdong province. She came to the hospital on March 3 with severe pneumonia and died there on March 16. The woman with previous illnesses had contact with poultry at a market where this virus was also detected.

Other people with whom the woman had contact would not have been infected. The other two human H3N8 cases were reported from China in April and May 2022, according to WHO. One person became seriously ill, a second had only mild symptoms.

Individuals usually become infected with bird flu viruses after contact with poultry or wild birds. Many don’t even notice the infection or have only mild symptoms, while others develop severe respiratory illness. Health experts warn of the danger that the virus adapts to humans and is then transmitted from person to person.

With regard to the case of H3N8 now reported from China, the WHO writes that this bird flu virus is commonly found worldwide in dogs, horses, pigs and other animals. Unlike H5N1, it causes few or only mild symptoms in poultry and wild birds. “According to the available information, the virus does not appear to be able to spread easily from person to person,” the WHO said. “The risk of the virus spreading to humans at national, regional and international levels is estimated to be low.”

A more detailed risk analysis from May 2022 is still valid, a WHO spokeswoman said. 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 to date.”

Human infections and deaths with other H5N1 strains of bird flu have been known for many years. Since 2003, a total of 873 cases in people from 22 countries have been reported to WHO associated with H5N1. More than half were fatal. The WHO has recorded only a few cases since 2020, six last year and three this year (as of March 3, 2023). (saw/sda/dpa)