Infectious diseases don’t recognize borders and despite international health care efforts, the mosquito-borne parasite Plasmodium falciparum remains a lethal scourge as it spreads malaria across the globe.
This concerns Dr. Gillian Stresman, associate professor in the Department of Epidemiology at USF’s College of Public Health (COPH). She recently published a scholarly article on ways to strengthen existing surveillance systems that could help lower the mortality rate in countries most affected by malaria.
Gillian Stresman, PhD, MHS. (Photo courtesy of Stresman)
“Despite more than 100 years of research, it’s still one of the top global burden of diseases and kills more than 600,000 people per year, mostly children in sub-Saharan Africa,’’ she said. “We’ve made a lot of progress with new tools but the more we learn the more the parasite and mosquito vectors adapt to evade our efforts.’’
Stresman’s paper, “Evidence-based decision making for malaria elimination applying the Freedom From Infection statistical framework in five malaria eliminating countries: An observational study,” appeared in The Lancet Global Health, a leading science journal presenting peer-reviewed research to influence policy and best practices.
The paper addresses the application of Freedom From Infection (FFI), a novel method for determining whether the evidence available from a routine surveillance system and other data is consistent with claims of ending malaria. This tool provides a quantitative approach that accounts for both the strength of a surveillance system as well as other data that may be available.
The research addresses a major challenge in malaria elimination: knowing whether routine health data truly reflects the real malaria situation. The FFI tool measures how effective surveillance systems are and whether a region can be considered malaria-free.
Stronger surveillance systems are essential in preventing malaria from spreading, which reduces illness and saves lives. Ultimately, this supports global efforts to eradicate malaria and protect vulnerable populations, which encourages researchers to be tenacious.
“If we don’t keep our foot on the gas pedal, the progress we’ve made as a global community will be undone,’’ she said. “So, it keeps me motivated to try and stay one step ahead.’’
The paper describes how strong malaria surveillance systems − those that ensure easy access to testing, proper training for health workers and quick access to health facilities − are essential for ending the disease. The research found that only about half of the health facilities studied had systems strong enough to confidently do this.
“By improving surveillance and adding community-based and active case detection, countries can better track and stop malaria transmission, which is critical for protecting communities and preventing the disease from coming back,’’ she said. “For the public, this means better health security.’’
Transmitted by the bite of an infected female Anopheles mosquito, the single-celled, protozoan parasite P. falciparum is the most lethal of the five major malaria strains, particularly in sub-Saharan Africa, according to the National Institutes of Health. The less harmful forms are P. vivax, P. malariae, P. ovale, and P. knowlesi.
The malaria parasite’s exceptional ability to adapt to its environment is a challenge for elimination. Its complex evolutionary history predates the origins of primates and their many other host species. The variety of Plasmodium have highly conserved gene content despite vast biological differences and their metabolic processes rely on and adapt to nutrients available from their hosts.
Malaria’s burden is highest in parts of Africa, where strained health care systems struggle with prevention techniques and treatment. But Stresman’s research focused on Cabo Verde, Dominican Republic, Peru, the Philippines and Vietnam, in part because these countries are close to eliminating malaria and make good case studies for the FFI work.
Should people in Florida be concerned about malaria? While the disease isn’t endemic to the state, its long summers and mild winters allow the mosquitoes to mature faster and survive.
“Because of our tropical climate and abundance of Anopheles mosquitoes, we remain highly vulnerable to re-establishment of transmission if the parasite is introduced into the area and any onward transmission not quickly dealt with,’’ Stresman said. “This happened as recently as the 2022 outbreak in Sarasota that was only contained due to the state’s prompt and effective response.’’