In a Rare Success, Paraguay Conquers Malaria

In a Rare Success, Paraguay Conquers Malaria

Paraguay has eliminated malaria, the first country in the Americas to do so in almost 50 years, according to the World Health Organization.

But worldwide, momentum against the disease has stalled. Malaria cases increased by five million between 2015 and 2016, climbing to 216 million from 211 million.

Nine countries in the Americas reported at least a 20 percent increase in malaria cases during that period — greater than in any other region.

“This is one of the diseases that hangs on tight,” said Luis Alberto Moreno, the president of the Inter-American Development Bank, which finances major anti-malaria efforts in the Americas.

“If you don’t keep the pedal to the metal — stay intensely focused on the issue — malaria is going to make its return.”

[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]

Malaria, a blood disease contracted through the bite of an infected mosquito, kills about 445,000 people each year, mostly children, according to the W.H.O. Yet cost-effective prevention tools and treatments are well known.

Public health officials at the first Malaria World Congress this week attributed Paraguay’s success to the national health system’s ability to quickly detect cases and investigate whether they had been transmitted locally or imported.

W.H.O. officials also expect to certify Argentina as malaria-free later this year, according to Dr. Marcos A. Espinal, director of the communicable diseases department at the Pan American Health Organization.

But throughout the region, other countries are backsliding. Panama, Nicaragua, Peru and Venezuela each reported more malaria infections in 2016 than in 2010. Cases in Colombia doubled from 2015 to 2016.

Officials say the chief hurdle is complacency: In many countries, domestic resources have shifted from anti-malaria efforts to other priorities as case numbers have dwindled.

“Political will is the single most important aspect for eliminating malaria,” Dr. Espinal said. “We have effective tools: bed nets, vector control methods, treatments. We get to a certain point — we see the end of the tunnel — and then we risk losing the commitment.”

The situation is most dire in Venezuela, where President Nicolás Maduro has refused to accept most medical donations amid an economic crisis. Malaria infections, along with hunger and tuberculosis, have surged since 2008.

As Venezuelans cross borders into Guyana, Colombia and northern Brazil, they may bring the infection with them. Breeding conditions for mosquitoes are favorable in those regions, so transmission may increase, according to Dr. Alexandre Macedo de Oliveira, a malaria researcher at the Centers for Disease Control and Prevention.

“Until there is a government in Venezuela willing to do something about it, it’s hard to do anything but wait,” said Mr. Moreno, who serves on the End Malaria Council, a response coordination team headed by Bill Gates.

“Mosquitoes don’t respect borders,” Mr. Moreno added.

In recent years, the fight against malaria in Central America has grown more complex. Lingering cases are concentrated in rural areas, where communities lack immediate access to health care and transmission is challenging to detect and disrupt.

Extreme flooding can increase breeding sites for mosquitoes, and the two that are the region’s main sources of malaria — Anopheles darlingi and Anopheles albitarsis — have begun to show resistance to insecticide.

Earlier this year, the Bill and Melinda Gates Foundation, the Inter-American Development Bank and the Carlos Slim Foundation together announced an $83.6 million initiative to eliminate malaria from Central America and the Dominican Republic.

A top priority is controlling the insect itself. Environmental health workers minimize mosquito populations by coating the walls of vulnerable schools and homes with insecticide, a technique called indoor residual spraying.

They also drain water in which mosquitoes might breed, such as muggy ponds, hollow cinder blocks and littered bottle caps.

But as long as mosquitoes exist, even countries that eliminate malaria remain at risk for its resurgence. Paraguay, like any other mosquito-friendly country, will need to maintain a thorough surveillance system.

“It is a much better economic investment to prevent a disease than to combat it at full force,” Mr. Moreno said. “The worst thing you can do is eliminate malaria and then have it come back.”

(Original source)