Malaria in the Americas: No Time to Ease Up

Washington, D.C., November 6, 2008 (PAHO)—Cases of malaria have declined 32 percent in Latin American and the Caribbean since 2000, and deaths have dropped nearly 40 percent. Yet more than 140 million people in the Region (16 percent of the population) remain at risk of the disease, experts said today in a panel discussion marking Malaria Day in the Americas at the Pan American Health Organization (PAHO).

The progress so far is largely due to improved treatment of the most deadly form of the disease, along with more effective mosquito control, said the experts. Continued funding for both treatment and control is essential to consolidate these achievements and to spur further progress toward elimination of transmission of the disease throughout the hemisphere, they said.

"Malaria is a problem not only for health, but also for social and economic development," said Jarbas Barbosa, PAHO Area Manager for Health Surveillance and Disease Management. "We have the infrastructure, commitment, tools, and strategies to eliminate malaria."

"Sustaining commitment to high levels of funding even in the face of lower prevalence is essential to get to elimination," said Matthew Lynch, Director of the Global Program on Malaria at Johns Hopkins Bloomberg School of Public Health.

Malaria is caused by Plasmodium parasites, which are carried by mosquitoes and transmitted to people through their bites. In Latin America and the Caribbean, 75 percent of malaria infections are caused by P. vivax and are rarely fatal, while 25 percent are caused by the more lethal P. falciparum, the dominant malaria parasite in Africa. Out of a total 775,500 malaria cases in 2007 in Latin America and the Caribbean, 212 deaths were reported.

Past efforts to eliminate malaria from the Americas have yielded mixed results. Mosquito control efforts in the mid—20th century succeeded in eradicating the disease from North America and most of the Caribbean, and dramatically reduced it in Central and South America.

However, cutbacks in public health funding—largely as a result of the decline in cases—led to a major malaria resurgence in a number of countries. Later control efforts succeeded in reducing the disease, but not in eliminating it.

The most recent efforts were launched in 2000, when a group of South American countries joined together—with PAHO support—in the Amazon Malaria Initiative (AMI). In response to World Health Organization (WHO) findings that malaria parasites in other regions had developed resistance to traditional drugs, AMI set out to assess the emergence of resistance in the Amazon Region. The group documented the growth of resistance to older single-drug treatments and then collectively introduced more effective artemisinin-based combination drug therapies to replace them.

"This is a good example of how cross-border collaboration and consensus-building can be used to achieve a public health impact," said Trenton Ruebush, an expert on malaria and other tropical diseases at the U.S. Agency for International Development (USAID). The AMI network formed to study drug resistance is now serving to improve laboratory diagnosis in the countries as well as to strengthen country capacity in entomology and for pharmaceutical testing, Ruebush noted.

Current AMI efforts focus on the widespread use of insecticide-treated bed nets, indoor residual spraying, and treatment of malaria cases with artemisinin-based combination drug therapies.

Keith Carter, PAHO's top malaria expert, said that while it was important to ensure sustained funding of malaria control and treatment efforts, it was equally important to increase support for general health systems strengthening in affected countries.

"We cannot just be content to say, here are the drugs that work," said Carter. "Health workers and service providers have to be clear when talking to patients about how they should take these drugs. And it's not just a question of getting the drugs to the ministry of health in the capital city, when patients are getting sick out in rural areas. We need to train people in the use of these tools and we need to ensure good coverage."

PAHO is also supporting malaria-control efforts in other member countries, including countries in Central America.

PAHO, founded in 1902, works with all the countries of the Americas to improve the health and quality of life of their peoples. It also serves as the Regional Office for the Americas of the World Health Organization (WHO).