The news shared by the World Health Organization (WHO) in its annual World Malaria Report is at once heartening and concerning. While fewer people died from malaria in 2015 than in years past, the rate of progress against the disease has slowed.
We have seen before that when progress slows, malaria regains its foothold. Though elimination in more countries over the next decades is possible, it will require concerted effort and the right tools to achieve and maintain gains.
In 2015, according to the report, malaria caused 429,000 deaths, most of them children in sub-Saharan Africa, and 212 million cases of the disease were reported. Although the populations most affected now have greater access to malaria-fighting tools in Africa—with a 77 percent increase in diagnostic testing in children and an 80 percent increase in the use of treated bed nets over the last five years—the malaria community is behind on many of the targets outlined in the Global Technical Strategy for Malaria, and funding has flatlined since 2010. Malaria is an ancient disease, caused by a very adaptable parasite, which is why it has been so difficult to tackle. Getting rid of it completely is the only way to ensure it won’t come back, and new tools, along with increased funding, will be needed to ensure that happens.
Sri Lanka stands as a reason for hope. Earlier this year, the country was certified malaria-free by WHO, more than 50 years after coming close to eliminating the disease in 1963. In the 1940s, with more than one million cases diagnosed, the government embarked on a massive spraying campaign and treatment initiative that drove the incidence rate down. In 1963, there were only 17 cases of malaria diagnosed in the country.
But then, vigilance faltered, investment ceased, and prevention efforts were stymied. By 1969, the annual number of cases exceeded 500,000. Eventually, the government redoubled its efforts, and with new tools and significant, sustained investment, Sri Lanka was able to fight its way back to finally achieve elimination in 2016.
In contrast is the case of Venezuela, which was the first country in the world to eliminate malaria, certified by WHO in 1961. The government scaled up proven malaria interventions and made elimination a priority, by going door to door to drain standing pools of water, fumigate houses, and distribute quinine—the primary medicine at the time—to people infected with the disease.
Over the last few years, however, malaria has made a dramatic resurgence in Venezuela, demonstrating how difficult it is to maintain elimination status without constant vigilance, funding, and robust government programs. In the midst of an economic collapse, Venezuela is now experiencing the disease at rates not seen in 75 years.
Economic and political challenges in Venezuela have crippled its health system, allowing malaria back in, but there are scientific concerns as well. The parasite that causes malaria and the mosquitoes that transmit it continue to evolve. Resistance developed to quinine—the medicine used to eliminate malaria in Venezuela in 1961—and resistance has now emerged in parts of Asia to artemisinin, a key ingredient in the drug regimen most used against malaria. We have also seen increasing resistance to insecticides used in bed nets and in sprays to control mosquitoes; since 2010, 60 countries have reported mosquito resistance to at least one insecticide class. The need for increased investment in research and development is clear, if we are to stay ahead of this disease.
New tools are on the horizon. Once such tool is the RTS,S malaria vaccine candidate. This partially-effective vaccine will be piloted in three countries in sub-Saharan Africa beginning in 2018, and will be assessed as a complement to currently available interventions. The pilots are being funded in large part by Gavi, the Vaccine Alliance, The Global Fund to Fight AIDS, Tuberculosis and Malaria, and UNITAID—organizations that represent countries worldwide, making the pilots a truly international effort.
It is possible for more countries to join Sri Lanka by eliminating malaria from their borders. The WHO report notes that 10 countries are well on their way, having seen fewer than 150 locally-acquired cases in 2015. However, the only way to ensure malaria won’t come back, as has happened in Venezuela, is to wipe it out completely. To do that, we will need not only the will of governments to make malaria a priority, but increased investment and new tools, including vaccines, to address growing resistance to currently-used interventions. The 2016 World Malaria Report offers hope that a deadly disease can be vanquished, but only if we remain vigilant.