Madagascar urgently needs new anti-malarial drugs, as the prevalent strain of the disease there is fast growing resistant to the most affordable medication, the World Health Organisation said on Thursday.

The United Nations health agency says malaria is the biggest cause of death on the huge Indian Ocean island, although it has no firm totals because so many deaths go unreported.

“We need to switch away from chloroquine, quickly,” WHO country director Dr Andre Ndikuyeze told Reuters in an interview.

“This will be urgent within one or two years, but we don’t want to wait that long.”

Last year, 2 million cases were reported out of the 17 million people on Madagascar, where three-quarters of the population lives on less than a dollar a day.

In 2002, WHO advised a number of countries using chloroquine to switch to more effective, but more expensive, artemisinin therapies. But a lack of money in Madagascar is hampering the switch, Ndikuyeze said.

“Almost all countries in Africa are using or have on order up-to-date malaria drugs. Madagascar now needs to do the same,” he said. “We cannot keep prescribing a drug that is losing its effectiveness.”

Malaria in sub-Saharan Africa is already highly resistant to chloroquine, with around half of cases no longer treatable. In Madagascar, resistance is about 20 percent but is expected to rise steeply.

“The new drugs are expensive because the patent is still on. But with the support from (donors), we should be able to switch,” Ndikuyeze said.

Swiss pharmaceutical giant Novartis owns the patent on artemisinin-based therapies, which partly derive from a traditional Chinese herb.

It costs $1.50-2.40 a dose for adults and around $0.90 for children. The cost of a dose of generic chloroquine can be as low as $0.10.

This month the Global Fund to fight HIV/AIDS, tuberculosis and malaria agreed to give $50 million to Madagascar for 2005. The Ministry of Health said none of the money was earmarked for a switch to new malaria treatments.