Five more people in mainland China have tested positive for the H5N6 bird flu, leaving two dead and three others critically ill, officials said. It adds to a growing number of human cases which has led to urgent calls for increased surveillance.
Hong Kong’s health department said in a statement it was informed of five new human cases in Sichuan province, Zhejiang province and Guangxi autonomous region. The cases occurred in recent weeks and were not immediately made public by local authorities.
The first case, a 75-year-old man from Luzhou in Sichuan province, fell ill on Dec. 1 after being exposed to domestic poultry. He was hospitalized four days later and died on December 12, according to the Hong Kong health department.
The second case, a 54-year-old man from Leshan in Sichuan province, fell ill on Dec. 8 and was hospitalized nearly a week later. He died on December 24. He was reportedly exposed to live domestic fowl.
The third case, a 51-year-old woman from Hangzhou in Zhejiang province, fell ill on Dec. 15 after being exposed to live domestic poultry. She was taken to hospital on December 18 and was last reported in critical condition.
The other two cases occurred in Liuzhou, a city in Guangxi Autonomous Region. The Hong Kong health department said a 53-year-old man with a history of exposure to dead poultry fell ill on December 19 before being admitted to hospital in serious condition. A 28-year-old man from the same city fell ill on December 23 and is believed to be in critical condition.
It was not immediately clear how the second man became infected.
Only 65 people have been infected with the H5N6 bird flu since the first confirmed case in 2014, but more than half of them have been reported in the past half year. The most recent case was announced Jan. 7, when Guangdong provincial health officials said a 43-year-old woman had been hospitalized with H5N6 avian flu.
Click here for a list of all human cases to date.
Chinese officials only provide limited information on human cases of H5N6 avian flu and it often takes weeks before cases are publicly reported to the WHO. Most cases are first reported by the Hong Kong Department of Health, which closely monitors human cases.
The H5N6 bird flu is known to cause serious illness in humans of all ages and has killed nearly half of those infected, according to the WHO. There are no confirmed cases of human-to-human transmission, but a woman who tested positive in July 2021 denied having contact with live poultry.
“The increasing trend of human infection with avian influenza virus has become an important public health issue that cannot be ignored,” researchers said in a study published by the Chinese Center for Disease Control in September 2021. The study found multiple mutations in two recent cases of H5N6 Avian Influenza.
Thijs Kuiken, professor of comparative pathology at the Erasmus University Medical Center in Rotterdam, expressed concern about the growing number of cases. “It may be that this variant is a bit more infectious (for people)…or there may be more of this virus in poultry right now and that’s why more people are getting infected,” Kuiken said. to Reuters in October 2021.
Earlier that month, a WHO spokesperson said the risk of human-to-human transmission remains low because H5N6 has not acquired the capacity for sustained transmission between humans, but they added that surveillance increased was “urgently required” to better understand the growing number of human cases.