Fear that the outbreak of swine flu will claim more victims is driving Mexico’s worried population to don masks and stay at home.All the reported deaths – which have risen to more than one hundred – have been in the Central American country. But the stringent measures designed to contain the spread of infection are beginning to hit the country’s economy. However, at least 900 of the suspected 1300 infected cases are now thought to be clear. That has not stopped the US from declaring a public health emergency although officials say it is just a procedural measure to free up funds for agencies to buy more antivirals. So far confirmed cases of swine flu are in the US, Canada and Mexico, but Europe has several suspected infections. Dr. Keiji Fukuda of the WHO told reporters: “We are in a period in which we have to be very careful to collect the best possible information. We really need to understand a bit more about the epidemiology, we want to understand a bit more about the behaviour of these viruses – we want to understand to the extent that these viruses cause mild infection and the extent to which these viruses can cause serious infection.” In London at one of the WHO’s four flu research centres, scientists are isolating the virus. The work is designed to stay one step ahead in case the strain mutates into something more dangerous. But UN health officials are stressing, the international community is better prepared than ever to deal with a possible pandemic, with world wide stocks of antivirals available.