Apr 15, 2013 (CIDRAP News) – Three provinces in eastern China that have already reported several H7N9 avian flu infections each announced a new case today, bringing the country's total to 64 cases, according to official and media sources.
Jiangsu province also reported a death from the virus in a previously confirmed H7N9 patient, raising the number of fatalities from the disease to 14, according to Xinhua, China's state news agency.
Hong Kong's Centre for Health Protection (CHP) said patients include a 60-year-old man from Jiangsu province, a 68-year-old woman from Zhejiang province, and a 60-year-old man from Anhui province. All three are hospitalized in critical condition.
The woman from Zhejiang province got sick on Apr 3, according to a report from Xinhua, China's state news agency. Media and official reports did not list illness-onset dates for the other two patients.
The newest death is in a 77-year-old woman from Jiangsu province who died last night, according to Xinhua. The woman appears to be part of a group of cases first announced by Chinese officials 2 days ago.
The World Health Organization (WHO) today said in an update that until the source of infection has been determined, it's likely that more H7N9 cases will be reported from China. So far there is no evidence, based on monitoring of more than 1,000 close contacts, of sustained human-to-human transmission, the agency said.
Meanwhile, the European Centre for Disease Prevention and Control (ECDC) said in its epidemiologic update today that the most likely scenario is that H7N9 is spreading undetected in poultry populations and sometimes infecting humans who have close contact with poultry or their products.
"But this will have to b validated as further data become available," the group said.
The rapid geographic spread of the disease and spike in confirmed cases is probably the result of strengthened surveillance and increased testing, the ECDC said. Test kits for detecting the H7N9 virus have been distributed to more than 400 labs across China, which is expected to increase identifications and yield important epidemiologic information.
The H7N9 outbreak is likely to expand to other part of China, and possibly neighboring countries, over the coming weeks, the ECDC said. It added that Europe could see isolated imported cases and that countries should get ready to detect and diagnose the disease.
Two key developments that would prompt the ECDC to change its risk assessment would be evidence of sustained human-to-human transmission of the new virus or its detection in European bird populations.
One of the WHO's top influenza experts, Keiji Fukuda, MD, said the world is on new flu ground with the virus, given that it doesn't show signs of disease in birds, but appears to cause severe infections in people, according to a report today from the Canadian Press. Fukuda is the WHO's assistant director-general of health security and environment.
He also said the genetic characteristics that have been reported so far, with mutations that appear to allow H7N9 to infect humans and other mammals, also add to the uneasy uncertainty about the virus. "Almost everything you can imagine is possible. And then what's likely to happen are the things which you can't imagine," Fukuda said.
In other developments, the Public Health Agency of Canada (PHAC) and the Canadian Food Inspection Agency (CFIA) recently spelled out the conditions required for handling the novel H7N9 virus.
The groups said in an Apr 10 statement that work with live cultures must be conducted in biosafety level 3 (BSL-3) containment. It recommended that all work with positive human samples be conducted at the National Microbiological Laboratory and that all experiments with positive animal samples be done at the National Centre for Foreign Animal Disease.
The two groups also said studies growing the H7N9 virus should not be done in labs that culture human influenza viruses and that personnel shouldn't have contact with susceptible animals for 5 days after handling H7N9 samples, as outlined in standard foreign animal disease protocols.
Apr 15 CHP update
Apr 15 Xinhua story
Apr 15 WHO update
Apr 15 ECDC epidemiologic update
Apr 15 Canadian Press story
Apr 10 PHAC statement