A new strain of a potent avian influenza virus has been detected in southern China, leading to the closure of poultry markets in the region in an effort to safeguard public health.
On Sunday, the National Institute for Viral Disease Control and Prevention announced that the new, highly contagious variant of the H7N9 virus was the result of a mutation, or a change in genetic material that can alter the way a cell or virus behaves. The new strain was found in two hospital patients, both of whom had been exposed to birds before contracting the disease.
According to the World Health Organization (WHO), avian influenza, more commonly known as “bird flu,” is an infectious disease that can cause severe respiratory problems in humans who handle or come in contact with infected poultry. The current outbreak of H7N9 in China began in October 2016 with a human case in eastern China’s Jiangxi province. In January alone, 192 cases and 79 deaths were reported nationwide, according to statistics from health authorities.
China reported its first case of H7N9 in humans four years ago, in 2013. The virus is apparently at its most vigorous during wintertime because of the hardening effect colder temperatures have on its outer covering. This past winter, the country has seen an unprecedented number of human infections.
The China office of the WHO, which monitors the situation closely with Chinese authorities, told Sixth Tone that there is no indication that this particular variant has acquired the ability of sustained transmission among humans. However, the new variant is proving extremely infectious among birds.
Benjamin Cowling, professor and division head of epidemiology and biostatistics at Hong Kong University’s School of Public Health, said genetic mutations of bird flu viruses have been reported in the past in different parts of China, and that it’s still too early to say whether the latest mutation should be concerning. “Regardless of the exact infectivity, H7N9 has a proven risk to human health,” Cowling told Sixth Tone. He added that probable next steps by authorities to protect the public include closing live poultry markets in the short term and improving general hygiene in the long term.
Beginning last Saturday, Guangdong authorities implemented a ban on bringing in poultry from four of China’s eastern provinces, including Zhejiang and Jiangxi, because of their relatively high incidence of H7N9 in humans. The ban will be in effect until the end of March. Before this, four provinces in China — including Guangdong, Sichuan, Hunan, and Zhejiang — had already stopped selling live poultry due to health concerns, state news agency Xinhua reported Thursday.
But Lin Zhihui, a 59-year-old resident of Zhongshan, a city in Guangdong, told Sixth Tone that live poultry was still being sold when she visited a market on Monday, and a local newspaper reported Friday that the poultry market in Dongguan, near the provincial capital of Guangzhou, had not been closed for a four-day period that was supposed to begin Wednesday.
Guangdong’s agriculture department did not immediately respond to Sixth Tone’s request for comment. As of Thursday, Guangdong had reported 33 cases of H7N9 infection so far this year.
(Header image: Doctors treat an H7N9 bird flu patient at the Wuhan Medical Treatment Center, Hubei province, Feb. 12, 2017. IC)