DAKAR, Senegal — Scientists in past centuries called the sickness by the Italian phrase "mal aria" — or "bad air" — for the supposedly disease-bearing zephyrs wafting from swamps.
These days, scientists know malaria is spread by mosquitoes. And they say ill winds are buffeting their attempts to halt the spread of a disease that kills 1 million people a year.
"We need to stress that the situation is bad. The number of deaths are rising, infections are rising," said Pierre Druilhe, head of the biomedical unit at France's Pasteur Institute.
Scientists say it could take more than 10 years before a fully effective malaria vaccine is approved for use.
Hundreds of malaria experts gathered this week in Yaounde, Cameroon, for a conference on the disease. And while many scientists described solid recent advancements and reason for cautious optimism, others said the news isn't good for Africa.
While malaria has been all but eradicated in wealthy nations, scientists say they're hindered in Africa by twin hurdles: insecticide resistance in mosquitoes and drug resistance in the parasite.
Malaria is spread by mosquitoes and causes wracking pain, fever and, if left untreated, death. It kills more African children than any other disease, and is the leading cause of death of those under 5 in sub-Saharan Africa.
African poverty means few buyers for even relatively inexpensive insecticide-treated bed nets, so many companies shy away from producing them, scientists say. And anti-malarial drugs can be costly.
Malaria prevention is "in trouble," Brian Greenwood of the London School of Hygiene and Tropical Medicine said by telephone from Cameroon.
For Greenwood, the main problem is increased resistance to drugs, particularly the longtime mainstay, chloroquine, which is relatively cheap to produce in mass quantities.
Medical workers are turning to a new drug called artemisinin, derived from an herb indigenous to Asia. Drawing on lessons learned from treating HIV and AIDS, doctors are using artemisinin with other drugs. But production is slow and expensive.
"It's a plant that takes 18 months to grow. You can't just say that you need 20 million doses right now," Greenwood said.
Without chloroquine and the insecticide DDT — which helped eradicate malaria in the United States and Europe but was ultimately believed by many to cause cancer and harm the environment — anti-malaria campaigners say they've lost two key weapons.
"It's pretty straightforward," Druilhe said by telephone from Cameroon. "We have today far less means to control malaria than 50 years ago."
This means, he said, that "the next decade will be a very bad decade."
As for new insecticides, scientists say there are only pockets of resistance in the mosquitoes that carry malaria — at least so far.
"If you had in one place a high level of resistance to both drugs and insecticides, it would be a disaster," Greenwood said.
Malaria, with over a half billion infections worldwide, is a major contributor to African poverty, scientists say, cutting billions from gross domestic product while weighing on health care systems.
But not all is calamity. Scientists say they've identified a resurgence in public and political interest in malaria over the past decade, a change they ascribe to greater media coverage and increased tourism in countries where the disease is a threat.
Malaria, Greenwood said, "has dropped into the mainstream."
Plus, scientists are increasingly banding together to study the problem — as they did this week in Cameroon — while philanthropists like Microsoft founder Bill Gates have donated huge amounts of money to fight the disease.
But Druilhe said more cash is needed. "There's a need for the developing countries to put some pressure on the rich countries of the north," he said.