Via Nature News & Comment, a long, important article by Declan Butler: Vietnam on high alert over flu risk. Click through for the full report and links. Excerpt:
The H7N9 avian-influenza virus that has killed more than 100 people in China in the past year has for the first time been detected in a province bordering Vietnam, raising the prospect that the disease may take hold across Asia and beyond. It was found in poultry in the live-bird markets of southern China’s Guangxi province in late January, and has caused three known human cases in the region.
The news comes as a surge in human H7N9 flu cases in China since the start of the year shows signs of abating, possibly because of the reintroduction of control measures. Vietnam, which had already prepared response plans for such an H7N9 outbreak, has placed itself on high alert.
“There is a very high likelihood of H7N9 entering the poultry sector in Vietnam,” says Peter Horby, a researcher at the Oxford University Clinical Research Unit in Hanoi.
H7N9 flu was first detected in China in March last year, and almost all of the human cases were reported the following month. They subsequently dropped off sharply after the prompt, temporary closure of live-bird markets, which were quickly identified as the places where most human infections occurred. Researchers say that the surge in cases since the start of the year is probably due to the arrival of winter and the intense poultry trading at live markets in the run-up to the Chinese New Year on 31 January.
So far, more than 200 human cases of H7N9 flu have been registered in China this year, compared with around 160 recorded in 2013 (see ‘Ups and downs’). This year’s outbreak has been centred in many of the same eastern provinces as last year’s, although with a coastal and southerly shift (see ‘The flu front line’). Zhejiang and Guangdong provinces are the worst affected. Last week, the first human case of H7N9 flu was detected in Jilin province in the far north of the country, raising a further risk of spread to North Korea and Russia, which border the province.
Vietnam, at least, is well prepared. The country was hit hard by another avian-flu virus, H5N1, a decade ago, and suffered enormous economic losses and more than 60 human deaths. Learning from that experience, it has since introduced measures to prevent and mitigate avian-flu outbreaks, including boosting the number of veterinary surgeons and improving diagnostic facilities.
To specifically address the risk of H7N9 flu, Vietnam has banned the importation of poultry from China. It has also introduced twice-weekly monitoring for H7N9 in markets in the north of the country, and ordered their weekly disinfection.
In addition, the country’s health and agriculture ministries have developed contingency plans should H7N9 arrive, including closing markets and shutting down trade routes.
“Vietnam’s preparedness and response actions should be seen as a model for the region,” says Scott Newman, senior technical coordinator at the Vietnam branch of the Emergency Centre for Transboundary Animal Diseases, part of the Food and Agriculture Organization of the United Nations.
I suspect that if we could simply follow poultry shipments into and out of Shanghai since last winter, we could retrace the spread of the disease.