Another person in mainland China has tested positive for H5N6 bird flu, raising the number of cases so far this year to 20, officials say. Experts have called for increased surveillance to monitor the spike in human cases.
The latest case involves a 56-year-old man from Deyang in Sichuan province who developed symptoms on March 31 after exposure to live domestic poultry. He was hospitalized on April 4 and remains in serious condition.
Other details about the cases were not released by the Chinese government, which often takes weeks or months to announce new cases.
The Chinese government disclosed last month that a 12-year-old girl and a 79-year-old man died of H5N6 bird flu in December. Both lived in Liuzhou, a city in the Guangxi region, and visited a live poultry market before falling ill.
Only 79 people have been infected with H5N6 bird flu since the first confirmed case in 2014 but most infections were diagnosed during the past year. At least 20 cases, including five deaths, have been reported so far this year.
H5N6 bird flu is known to cause severe illness in humans of all ages and has killed nearly half of those infected, including children and young adults. The outcome in most of the other cases has not been disclosed and only 8 people are known to have recovered.
There are no confirmed cases of human-to-human transmission though a woman who tested positive last year 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 China’s Center for Disease Control in September. The study highlighted several mutations in two recent cases of H5N6 bird flu.
Thijs Kuiken, a professor at Erasmus University Medical Center in Rotterdam, expressed concern about the rising number of cases. “It could be that this variant is a little more infectious (to people) … or there could be more of this virus in poultry at the moment and that’s why more people are getting infected,” Kuiken told Reuters in October.
Earlier that month, the World Health Organization said the risk of human-to-human transmission remains low because H5N6 has not acquired the ability for sustained transmission between humans. However, increased surveillance is “urgently required” to better understand the rising number of human cases, the spokesperson said.