The head of the World Health Organisation hit back at critics who have accused it of over-reaction to the swine flu crisis, warning it may return "with a vengeance" in the months ahead.
In her first extensive media interview since alerting the world to a potential flu pandemic nine days ago, Margaret Chan, the agency's director-general, told the Financial Times that the end of the flu season in the northern hemisphere meant an initial outbreak could be milder but then a second wave more lethal, as happened in 1918.
Fresh data from Mexico suggested the impact of the flu could be less than initially thought. José Angel Cordova, health minister said the flu virus epidemic had passed its peak and was declining. "The evolution of the epidemic is now in its phase of descent," he said.
The Mexican government, which had already scaled back its original estimate of 176 deaths, said 19 of the suspected 100 deaths from the H1N1 virus had been confirmed.
But Ms Chan warned that an apparent decline in mortality rates outside and within Mexico did not mean the pandemic was ending.
"We hope the virus fizzles out, because if it doesn't we are heading for a big outbreak." But she said: "I'm not predicting the pandemic will blow up, but if I miss it and we don't prepare, I fail. I'd rather over-prepare than not prepare."
She stressed that a likely increase to the agency's highest "level six" pandemic alert did not necessarily mean "every country and every individual will be affected" with many more deaths.
Rather "it is a signal to public health authorities to take appropriate measures" such as intensified disease surveillance.
Ms Chan acknowledged frustration with slow release of data on the threat posed by the virus. But she defended Mexico as very co-operative but overwhelmed by extending treatment and limiting the spread of infection as well as analysing cases. She added: "The information is beginning to roll in."
"These countries are so overwhelmed. Other countries may expect a lot of information now. But people need to allow time for the epidemiology, laboratory and clinical data. "
She reiterated the WHO's view based on "the evidence and science available to us" that travel restrictions were counterproductive. Although countries had the right under international health regulations to take different measures, they would need to justify them publicly.
But she defended recent decisions such as that of Hong Kong and New Zealand to quarantine travellers arriving with suspected flu.
Ms Chan called on pharmaceutical companies to increase their contributions, praising their efforts so far but calling for fresh donations and for far larger quantities of drugs and vaccines at lower prices to help treat and protect the poor.
She had released most of the WHO's stockpile of the antiviral medicine Tamiflu provided by Roche, its manufacturer, which had already agreed to provide more and to propose lower prices.
She hinted at fresh ways to encourage generic companies to produce cheap versions of Tamiflu to expand capacity.
Copyright: The Financial Times Limited 2009