The World Health Organization is reporting a sharp rise in the number of deaths and cases of influenza in the Indian Ocean island nation of Madagascar. WHO says the death toll now is close to 700, with the number of reported cases rising above 22,600.

WHO says the flu epidemic has spread to five of Madagascar's six provinces. The worst hit area is Fianarantsao in the south where the outbreak first was detected. WHO spokesman Ian Simpson says the sharp rise in the number of cases may be due to better surveillance of the disease, rather than to a worsening of the epidemic.

"The team of international health experts, which is currently working with the Madagascar government to respond and better understand this outbreak, believes that in most of the areas, particularly in the province in the south where the outbreak began, the levels of infection are dropping off and the numbers of new cases are dropping fairly sharply," said Mr. Simpson. "But the outbreak, of course, is not at an end."

Mr. Simpson says the team of international health specialists is working closely with the Madagascar government to contain the disease and prevent its spread. He says the international and government experts have set up mobile health teams to respond to reports of large numbers of new cases in new places.

"They are able to send the mobile team out to help people to understand what is happening, to also help treat people where necessary," he said. "Particularly if they have secondary infections, which are what people are actually killed by. Those who are particularly elderly, have low immunity, or the very young are at risk of death from secondary infections. And the key is to get the right drugs to them at the right time and that can now be done."

The World Health Organization says most of the flu victims in Madagascar are very poor, with little or no access to health care. It says people who are malnourished may be particularly susceptible to getting the flu.

For this reason, the World Health Organization and two other U.N. aid agencies are working to get protein-rich food to undernourished people to build up their resistance to the disease.