Fighting Malaria

Zohdy, Several Auburn Departments Collaborate in International Battle Against Mosquito-Borne Disease

Dr. Sarah Zohdy has spent much of her adult life on the front lines of a war she may never see won.

It is a war against an implacable foe, fought in steaming jungles and fetid swamps, or—more recently—in the hidden alleys and byways of sprawling cities ripe with urban slums and poor sanitation. It is the cruelest of conflicts, one in which many of the casualties could be prevented and a disturbing majority of the victims are children.

But Zohdy is not a soldier in a traditional war. Instead, she and her colleagues, fellow disease ecologists, biologists, entomologists, doctors, laboratory technicians and other researchers, are in a crusade against one of mankind’s oldest and deadliest enemies—the malaria mosquito.

Zohdy, who holds a joint appointment as associate professor in the Auburn University College of Forestry, Wildlife and Environment and the College of Veterinary Medicine and also serves as a disease ecologist for the President’s Malaria Initiative, or PMI, at the U. S. Centers for Disease Control, is currently fighting her war in Madagascar. The island nation, like many others in sub-Saharan Africa, is a place where malaria kills thousands of people each year, most of them children. It is also the place where more than a decade ago, as a young researcher studying wildlife conservation, Zohdy first saw the human suffering from malaria and other environmentally related illnesses that inspired her to shift her research focus to disease ecology.

“I was working in the rain forest, studying the effects of habitat loss and destruction on lemurs,” she recalled recently from a laboratory in Madagascar, where she is supporting malaria control efforts through her role at the CDC while on professional development leave from Auburn. “But it was difficult to focus on threats to wildlife when children in nearby villages were dying from preventable diseases like malaria. It didn’t take long to see the two things were interconnected.”

While tremendous progress has been made, malaria is still a killer of epic proportions in much of the world, particularly in Africa. “More than 95% of the world’s malaria cases and 96% of its malaria deaths are in sub-Saharan Africa,” Zohdy explained, “and 85% of the deaths from those cases occur among children under age five. Steady progress had resulted in significant decreases in malaria between 2005 and 2015, but insecticide resistance, changes in mosquito behavior and the spread of invasive malarial mosquitoes to new habitats have led to a recent upswing.”

Zohdy and her colleagues are particularly concerned about the current spread of one of the most persistent of malaria-carrying mosquitoes, Anopheles stephensi, to cities in Djibouti and Ethiopia—another country Zohdy supports through PMI—as well as other parts of Africa where it has not been found before. Malaria has historically been a predominantly rural disease associated with rainfall; however, alarming predictions suggest that if this invasive species continues to spread, it may lead to an additional 126 million people per year at risk of malaria in Africa, particularly in urban areas, as well as malaria outbreaks during dry seasons.

“Dry season malaria in Ethiopia is not something that happens,” Zohdy recently told an interviewer from National Public Radio. Yet it is happening now. And the culprit is Anopheles stephensi. “It’s not a new mosquito to science at all,” Zohdy said. “It’s actually one of the most well-studied malaria mosquitoes in the world.”

But previously, it had been largely studied elsewhere—in South Asia and the Arabian Peninsula. Now it has shown up not only in Djibouti and Ethiopia, but in Somalia, the Sudan and Nigeria, as well. And it could easily erase decades of hard-won progress in Africa’s war on malaria. “This is a mosquito that has the potential to change malaria as we know it,” warned Zohdy.

Why? Most malaria mosquitoes tend to be seasonal, with population sizes swelling following rainfall, but Anopheles stephensi is active year-round. It thrives in urban environments, readily breeding in the many small pools of water found in human-made water catchments, whether intentional, such as cisterns and wells, or incidental, such as discarded containers in trash. In addition, most city dwellers have had minimal exposure to malaria, making them more susceptible. And, due to their long history of interaction with humans and insecticide-based control tools, Anopheles stephensi is largely resistant to insecticides used in malaria control.

It is this threat that is the greatest battle currently facing Zohdy and her CDC and PMI colleagues in their never-ending war. Fortunately, it’s also an area where she has been able to leverage her role at Auburn. “The best way to see where infective malaria parasites (sporozoites) are found in mosquitoes is by using a ‘gold standard’ laboratory test called csELISA,” Zohdy noted. “This test also provides a key indicator used by malaria programs to see what the risk of malaria infection is in an area and whether their interventions are working.

“Some may even argue that it is one of the most important tools in the fight against global malaria,” she continued. “Through the CDC’s Malaria Research and Reference Reagent Resource Center, anyone around the world can obtain for free the protocols and the tools and reagents needed for the test. But until now, there has not been an interactive video training tool to help increase laboratory expertise and the capabilities to conduct it. Auburn and the CDC collaborated to put one together.”

Working with the College of Forestry, Wildlife and Environment and Auburn’s media studies program, as well as the Entomology Branch at CDC, Zohdy and a team led by associate professors Hollie Lavenstein and Kevin Smith of the AU School of Communication and Journalism filmed a video designed to increase familiarity with csELISA testing. The pair are the founders of Auburn Films, a production company specializing in creating branded and non-commercial video content, short films and education videos for nonprofit partners.

Using a script provided by Zhody and several of her colleagues at the CDC, Lavenstein and Smith also enlisted one of their undergraduate students, Sarah Kirk, to do some of the filming along with Haley Stephens, one of Zohdy’s graduate students, to serve as the lab technician demonstrating the csELISA protocol. Dr. Mary Sandage, an associate professor in the Auburn Department of Speech, Language and Hearing, handled the voice-over for the video.

“Speaking for myself,” said Lavenstein of the film, “working on the production was really great. We made it during the pandemic, so it was not always easy. But everyone was just terrific to work with and so dedicated to the project. It was wonderful to work on a video that has the potential to do so much good.”

Since the video was posted online, it has been widely used by the National Malaria Control Program in Madagascar, as well as with national malaria programs in other nations. In fact, a series of additional videos directed at further building global lab expertise and capacity has been requested. The Auburn-produced video has been a victory in a war where progress is often painfully slow.

“In the fight against Anopheles stephensi,” Zohdy concluded, “the csELISA test could be vital because it is one of—if not the only—ways to determine whether this invasive mosquito is responsible for outbreaks of urban malaria. If countries find this mosquito in their cities, they can use the test to determine if it is playing a role in malaria transmission. This film also provides a futuristic opportunity to provide laboratory training and technical support in times when travel or in-person training may not be possible. So, increasing familiarity with the test and increasing the capacity to conduct it by such means as this video is absolutely critical to our future success.”