A woman glances through a book about A(H1N1) flu at a bookstore in Weifang, Shandong Province, on Wednesday. [China Daily]

The country's top health official Chen Zhu has denied that China overreacted to the A (H1N1) virus, which has infected 58 people on the mainland.

"There was no overreaction at all," the health minister told a press conference on Tuesday.

"The government and the Chinese people were trying their best to block the virus from entering the country, and buy time for vaccine production, technology, and material stockpiling."

Chen's comments follow criticism from the Mexican government that the Chinese response to H1N1 was "unjustified".

China has been accused of singling out Mexican citizens for quarantine last month, despite the fact they showed no symptoms of the virus.

Hundreds of Chinese and foreigners have been placed in quarantine as the country fights to contain the virus.

Chen insisted quarantine was necessary because the virus was likely to transform, although it was currently in a mild form with a relatively low death rate.

He said it could lead to serious illnesses if combined with the seasonal flu or H5N1 bird flu virus, which kills up to 60 percent of those infected.

"We have to avert possible outbreak by early intervention," he said

Margaret Chan, director-general of the World Health Organization (WHO), said China's response had been robust.

"China is highly capable of tracking down their cases. My advice now is to adjust policies in line with the changing pattern of the virus," she said.

The mainland reported its first domestic transmission on May 29 and the government was now trying to curb further spreading of the virus, Chan said.

"We are trying to make vaccines ready for high-risk groups like medical workers by October. The stockpiling of Tamiflu is also under way," she said.

Meanwhile, health organizations will pay special attention to the national college entrance examination from June 7-9, in which more than 10 million students will take part.

Internationally, the WHO is considering increasing the alert level to the highest phase 6. As of yesterday, 25,000 virus cases had been reported.

"We are moving possibly very soon into a pandemic situation," Chan said. "But current evidence shows it might be a mild pandemic."

Questioned about the appropriateness of the current level 6 global alert, Chan said: "I don't think the WHO is overreacting in alerting the world to the A (H1N1) virus which is mild now. It's our duty to act in accordance with the criteria set by the world's scientists."

"We have to warn the world of the situation in countries hit hard by the epidemic like Mexico and the US. Because of this early warning mechanism, other countries can mount preventive measures to contain the spread of the virus," she said.

(China Daily June 4, 2009)