World Malaria Day 2025: Persistent Barriers and Emerging Threats in Malaria Control

For World Malaria Day, we spoke with Andrew Lover, PhD, MPH, MS, associate professor of epidemiology at the University of Massachusetts Amherst and deputy director of the CDC-sponsored New England Center of Excellence for Vector-Borne Disease.

Reflecting on his fieldwork in countries such as Cambodia, Vietnam, Laos, and Myanmar, Lover described some of the most persistent barriers to malaria elimination in these regions.

"I certainly interviewed and talked to a lot of people with malaria in a lot of different places. Cambodia, Laos, Vietnam, Myanmar. And the biggest challenges tend to be that malaria is concentrated in the most rural, isolated areas of all those countries," he explained. "So it's at the very end of the health systems, the smallest health centers and the smallest villages and the least capacity to do, you know, kind of basic parts of what's needed for public health."

He added that geography and political dynamics further complicate efforts in these settings.

"At least in Southeast Asia, there's a lot of border malaria. So malaria is usually in forested areas, which occur on the borders between countries. And there's a lot of potentially illegal activity in terms of forestry or hunting or even military activity in those areas, which make... you know, routine health surveillance even harder. So all that together makes it quite a challenging problem."

As countries approach elimination targets, Lover emphasized the difficulty of maintaining investment in detection and control—especially in hard-to-reach populations.

"There's this complicated challenge when you get toward elimination that you need to keep spending a lot of money from a health systems perspective to detect a fewer and fewer number of cases," he said. "And so if you're the Secretary of Health or Minister of Health, it becomes a bit challenging to justify spending those kinds of funds to detect a handful of cases a year."

Targeting resources more strategically may help address this gap.

"This is where trying to target the highest risk populations makes sense, because then you have kind of a hook to be able to say this group is probably the highest risk," he said. "And then you can use the limited capacities you have to use them in the best possible way. So it's just a matter of efficiency and trying to maximize what you can do with a limited budget."

Although malaria is often framed as a global health issue, Lover pointed out that it has had—and could again have—a domestic presence in the United States.

"Certainly there was malaria throughout the U.S. until the 1920s and 30s. And, you know, historically it was as far north as Massachusetts and Vermont in the summertime. So the mosquito vectors are here. It's just the parasites aren't. And so we're really quite lucky that it's a historical problem right now," he said.

"But as you mentioned, there were cases two years ago in Florida, as well as one in Texas, that were locally acquired malaria infections. And that really made a lot of public health practitioners think carefully about, you know, even their level of suspicion. If they see someone come into the hospital, you know, the usual question is, have you traveled internationally? But if someone clearly has malaria and hasn't traveled, yeah, that raises a lot of interesting questions."

He noted that the affected individuals in Florida included people experiencing homelessness—an often-overlooked population in disease control efforts.

"That is a very challenging population to do any kind of health-centered interventions on just because they lack an address and are resistant to interventions. And so that's a really important gap in terms of a lot of the general guidance in terms of malaria control."

Lover also spoke about ongoing and future threats to malaria control worldwide. Conflict and migration are contributing to case surges in some regions.

"Internationally, there's certainly some conflict areas. So in Myanmar right now, there's a civil war. And so that has really decimated the health system there," he said. "Thailand, with a very long land border, is experiencing a huge uptick in malaria cases, who are people traveling back and forth across the border. That's a really challenging problem because you have to have two national governments coordinate. And the Myanmar Burmese government is currently, you know, quite fractured."

In addition to human and political factors, the ecology of malaria vectors is also changing. Lover described the global spread of a new species that could alter control strategies.

"There's a mosquito vector called Anopheles stephensi, which is mostly from Pakistan and India, which is now moving from the Horn of Africa. So the very Eastern side, all the way across the continent," he explained. "It's a vector that does really well in cities. So most malaria vectors like very clean streams in, in forest areas. But this one does really well in discarded water containers and air conditioning units and all kinds of places in cities. And so that's a really major situation that the WHO is watching carefully because that has a potential to really shift a lot of things in terms of how malaria control is organized and that kind of thing."