Experts are stumped and very nervous about the current swine flu outbreak, the Wall Street Journal reports. The previously unknown flu strain, which has killed up to 68 in Mexico and infected eight Americans, is doing two new things: passing from person to person, and mixing viruses in a new way. The World Health Organization has asked an expert panel to determine whether a global pandemic is at hand.
Called A/H1N1, the new strain combines North American swine- and bird-flu viruses, a human-flu virus, and parts of pig-flu viruses seen in Asia and Europe. Its symptoms—nausea, vomiting, fever, among others—resemble those of a common human flu. It is also sensitive to medications like Tamiflu and Relenza. But experts say the novel bug resembles bird-flu viruses that caused pandemics in Asia in 1957 and Hong Kong in 1968.