The World Health Organisation (WHO) has issued a step-by-step plan, including the rapid mass use of the antiviral Tamiflu, for containing a birdflu outbreak if the virus starts to spread rapidly among humans.
The "rapid response and containment strategy" has a chance of quashing the deadly H5N1 virus only if people in the zone at risk receive massive doses of the drug within three weeks of a confirmed outbreak, it said.
WHO statement
"The success of a strategy for containing an emerging pandemic virus is strictly time dependent," the WHO said in its latest containment report, based on recommendations by 70 international experts who held closed-door talks in March.
"Mathematical models have indicated that a containment strategy, based on the mass administration of antiviral drugs, has a chance of success only when drugs are administered within 21 days following the timely detection of the first case representing improved human-to-human transmission of the virus."
Under the detailed timeline laid down, a country should notify WHO of a cluster of suspicious cases suggesting sustained human-to-human spread of the virus within 24 hours of detection.
A WHO-approved laboratory has another 24 hours to confirm that the H5N1 bird flu virus has changed, either through mutation or through reassortment with human influenza.
The strategy relies on WHO's global stockpile for rapid containment, three million treatment courses of Tamiflu, donated by Swiss drugmaker Roche. Quarantine, infection control measures and contact tracing must also be carried out.
Once the WHO officially asks Roche for Tamiflu doses to be sent, they should arrive at the international airport nearest the outbreak within 24 hours, the Geneva-based agency said.
The WHO said on Saturday that it had for the first time asked Roche to be prepared to ship Tamiflu to Sumatra, Indonesia, where a family of seven was infected, with possibly some limited human-to-human transmission.
In the end, the WHO did not ask for the drugs to be sent.
The WHO considers Tamiflu the frontline drug against the H5N1 bird flu strain, but says more clinical studies are needed.
"If we needed to mount a containment effort, we needed to be sure that Roche would be ready," WHO spokeswoman Maria Cheng told a briefing on Tuesday.
The WHO also said it was refining its guidelines for a global influenza pandemic alert to make them clearer.