The World Health Organisation has warned of the threat of fresh outbreaks of swine flu in the southern hemisphere during winter.
A day after raising its pandemic alert level to five, the second highest, it says there is no evidence to suggest it should be raised to the maximum of six.
WHO acting assistant director-general Keiji Fukuda said the virus had been behaving like a typical influenza virus and as such it could have a bigger impact on countries that are currently heading into winter, reports the ABC.
WHO says the number of officially confirmed cases of swine flu worldwide is 331 in 11 countries, including 10 deaths.
The figures include 156 confirmed cases, with nine deaths, in Mexico and 109 confirmed cases, with one death, in the United States.
Other countries with laboratory-confirmed cases are New Zealand, Austria, Canada, Germany, Israel, Netherlands, Spain, Switzerland and Britain.
European ministers have rejected an EU-wide ban on travel to Mexico. EU Health Commissioner Androulla Vassiliou told an emergency meeting of health ministers in Luxembourg that though an international flu pandemic was "likely", it would not necessarily cause widespread deaths.