Malaria nearly eliminated in Sri Lanka despite decades of conflict

According to a paper published August 29 in the online, open-access journal PLoS ONE, researchers from Sri Lanka's Anti-Malaria Campaign and the UCSF Global Health Group examined national malaria data and interviewed staff of the country's malaria program to determine the factors behind Sri Lanka's success in controlling malaria, despite a 26-year civil war that ended in 2009.

Typically, countries with conflict experience a weakening of their malaria control programs and an increased risk of outbreaks and epidemics, the researchers said.

Chief among its keys to success was the program's ability to be flexible and adapt to changing conditions, the study found. For instance, to protect hard-to-reach, displaced populations, public health workers deployed mobile clinics equipped with malaria diagnostics and antimalarial drugs, whenever it was safe to do so. Likewise, when it was impossible to routinely spray insecticides in homes in conflict zones, the malaria program distributed long-lasting insecticide-treated nets, engaging non-governmental partner organizations familiar with the areas to help with distribution.

The program was able to sustain key prevention and surveillance activities in conflict areas through support from partner organizations and support from the Global Fund to Fight AIDS, Tuberculosis and Malaria.

Otherwise, researchers found that the keys to Sri Lanka's success were the same as those deployed in non-conflict areas: rigorously and consistently providing interventions to prevent malaria among high-risk populations; proper and prompt diagnosis and treatment of all confirmed malaria cases; and maintenance of an effective surveillance system to quickly detect and respond to spikes in cases. Still, challenges remain.

"Sustaining the gains of elimination efforts and preventing resurgence is even more challenging today, especially in tropical settings such as Sri Lanka," said Rabindra Abeyasinghe, MD, the paper's first author, who led the research at the Sri Lankan Anti-Malaria Campaign. "In this era, sustaining the interest of partners and local decision makers, and ensuring continued funding, are becoming increasingly difficult. To avoid the tragic mistakes of the past, we must resolve to continue to devote the necessary resources and energy to the fight against malaria in Sri Lanka."

Sri Lanka has an extensive history of battling malaria, and nearly eliminated it once before. In 1963, during the era of global eradication efforts, the country achieved a low of only 17 cases, down from 92,000 cases in 1953. With funding declines and reduced spraying and surveillance, the country saw a massive resurgence to 1.5 million cases in 1967-1968.

Since 1970, Sri Lanka has worked to bring malaria back under control, with compelling success, the authors said. In 2011, the country recorded just 124 locally acquired cases -- about six cases per million people. This reduction is particularly noteworthy, the researchers noted, given that much of the progress was made during the civil war.

"It is very exciting to document Sri Lanka's current progress toward malaria elimination, to add another chapter to our country's ongoing fight against the disease," said Gawrie Galappaththy, MD, a study coauthor at the Anti-Malaria Campaign at Sri Lanka's Ministry of Health. However, she said, achieving zero malaria will require continued investments and hard work.

"There is no silver bullet for malaria elimination," Galappaththy said. "Instead, it's a daily commitment to finding the cases, treating the patients and preventing transmission."

Today, even with the country's great progress, Sri Lanka continues to face hurdles in its goal of driving malaria transmission to zero. Total malaria cases have dramatically dropped, but the proportion of Plasmodium vivax malaria infections -- the more difficult to diagnose and treat form of malaria most common in Sri Lanka -- is on the rise.

Another challenge is the shift in the population group at highest risk for malaria. In most of the world, children and pregnant women are most at risk; however following the success of Sri Lanka's control program in protecting and treating these populations, the researchers found that the group most at risk today in Sri Lanka is adult men, particularly those exposed to malaria-carrying mosquitoes through their work, such as gem mining, military service and farming. Sri Lanka is developing new strategies to target these groups.

"Sri Lanka is showing the world how to eliminate malaria," said Sir Richard Feachem, KBE, FREng, DSc(Med), PhD, director of the Global Health Group and senior author of the paper. "The country has made extraordinary progress, reducing malaria by 99.9 percent in the past decade. And all this achieved during a particularly nasty civil war. With continued commitment from the country's Government and supporters, we are confident that Sri Lanka will finish the fight and become a malaria-free country."