China said Monday it had recorded 659 swine flu deaths in 2009, nearly all of them in the last two months of the year, and warned that the danger of mass outbreaks still existed in certain areas.
The health ministry said in a statement that the total number of A(H1N1) infections recorded since the virus was first detected last year stood at 120,940.
At the end of October, the reported death toll stood at just six. The number of recorded deaths then spiked, reaching about 180 at the start of December and 659 by the end of the month.
In November, renowned medical whistle-blower Zhong Nanshan, who helped expose the scale of the 2003 Severe Acute Respiratory Syndrome outbreak, said the true A(H1N1) death count was being covered up.
The government responded by ordering more accurate case reporting by officials.
"The danger of an explosion of outbreaks in some places exists, and the number of fatalities and serious cases will remain at a rather high level," the ministry said.
It noted that serious difficulties remained in containing the spread of the virus in rural areas and at schools.
Ministry officials had already warned of a "grim" winter flu outlook, and are urging caution ahead of the February Lunar New Year holidays, when hundreds of millions of people swamp the roads and rails to visit family.
China has so far vaccinated 49.9 million people, the ministry said, the largest campaign in the world.
Chinese laboratories were at the forefront of worldwide efforts to develop and mass-produce a swine flu vaccine, but the quick clinical trials and production cycle led to concerns that the shot was perhaps unsafe.
Officials have said that adverse reactions were only reported in a handful of cases, about one out of a million jabs.