Health authorities in the southern Chinese province of Guangdong are battling a wave of seasonal influenza cases that are resulting in brain damage in previously healthy child patients, local media reported.
While the overall number of confirmed cases of influenza has fallen compared with last year, there has been an increase in the number of notifications of necrotizing encephalitis, a complication from viral fever sometimes found in children, reports said.
The Women and Children's Medical Center in Guangdong's provincial capital Guangzhou was overwhelmed with children suffering from the seasonal flu, with at least five confirmed cases of necrotizing encephalitis reported in the facility, Guangzhou's Southern Metropolis Daily newspaper reported.
One three-year-old is in a long-term coma after developing damage to their central nervous system after a two-week hospitalization for H1N1 flu, the paper said.
It cited local medical personnel as saying that the virus -- once known for attacking the lungs of patients and causing pneumonia -- may have mutated from previous years to a form that attacks the central nervous system.
The parent of a primary schooler in Guangzhou said many of her child's classmates were off sick with influenza, and the school had ordered sick children to remain at home to prevent further transmission of the virus.
"There have been a lot of cases of influenza at the hospital lately, and I've been teaching my kid that we don't go to as many public places when there is an outbreak of this kind," the parent said. "You can pick it up in the hospital, on the streets, and prevention is everything when it comes to the flu."
Guangzhou-based rights activist Zhang Weichu, who is also a medical doctor, said the fact that China's usually tightly controlled media is reporting the story is in itself a cause for concern.
"In the past, these things were not generally reported," Zhang told RFA. "So is the real situation actually more serious than the report says?"
She said the report may be hinting at a mutation in the H1N1 virus itself, which could constitute a public health crisis.
Improving the warning system
According to Zhang, China's health authorities improved their disease reporting and public information mechanisms after the Severe Acute Respiratory Syndrom (SARS) epidemic of 2002-2003 led to thousands of infections and more than 700 confirmed deaths worldwide, but there is still room for improvement to the system.
Wang Yuedan, deputy director of the Department of Immunology at Peking University School of Medicine, said that there has been no evidence that the virus had mutated yet, however.
"There have been no relevant warnings issued by the U.S. Centers for Disease Control and Prevention, the World Health Organization (WHO) or the CDCs in China, so it probably hasn't," Wang said.
He said a shortage of influenza vaccines is unlikely to be the culprit behind the reported complications, either.
"Many cases wouldn't have been covered by the strains in the vaccines anyway, so the current situation has very little to do with the reduction in vaccine supply," Wang said.
The Southern Metropolis Daily cited Women and Children Medical Center deputy director Xu Wei as saying that the center had confirmed 300 cases of influenza in the first week of 2019, half the number reported during the same period last year.
However, Beijing CDC said it expects the flu to remain highly active in the next few weeks.
Acute necrotizing encephalopathy is form of brain damage that usually follows an acute febrile disease, mostly those caused by viruses, according to the U.S. National Institutes of Health website.
"The symptoms of the viral infection (fever, respiratory infection, and gastroenteritis, among others) are followed by seizures, disturbance of consciousness that may rapidly progress to a coma, liver problems, and neurological deficits," the website said.
It said the disease is caused by both environmental and genetic factors, and usually develops secondary to viral infections like flu or herpes.
Sufferers have brain lesions affecting the thalami, brain stem, cerebral white matter, and cerebellum, it said.
Reported by Wong Lok-to for RFA's Cantonese Service, and by Gao Feng for the Mandarin Service. Translated and edited by Luisetta Mudie.