new UT Arlington study about the elimination of malaria in the 1930s American
South may have significant implications for solving modern day malaria
outbreaks in parts of Africa, Central and Latin America and Asia.
Daniel Sledge's research, published in the American Journal of Public Health, has implications
for those who work to eradicate malaria.
challenged a leading argument that movement of Southern tenant farmers away from
mosquito breeding grounds was the dominant factor in the decline of malaria in
U.S. during the 1930s.
targeted public health interventions and the
development of local-level public health infrastructure helped eradicate the
disease, according to Daniel Sledge, assistant
professor of political science
at UT Arlington and lead
author of “Eliminating Malaria
in the American South: An Analysis of the Decline of Malaria in 1930s Alabama,” a paper recently published by the American
Journal of Public Health.
found that targeted
public health interventions, supported by the federally backed development of
state and local public health infrastructure, led to the decline of malaria despite
widespread and deep-seated poverty,” Sledge said.
dean of the College of Liberal Arts at UT Arlington, said Sledge’s research
benefits the public, health professionals and policy makers globally.
Sledge’s work has far-reaching implications for those who work to eradicate
malaria and similar diseases,” Wright said. “Huge challenges remain, but such
research brings about better understanding of potential solutions and could
ultimately help save lives.”
is an infectious disease caused by a parasite called plasmodium and
transmitted through the
bites of infected mosquitoes. The disease causes fever, headache and
vomiting. Untreated, it can become life threatening.
Malaria killed an estimated 1.24 million people worldwide in 2010 and
has decimated economies in the heavily populated, warm climate regions of the
Global South, according to recent studies.
played a similarly devastating role in the American South until the 1930s, researchers
detailed, by lowering the productivity of workers, deterring migration into the
region and severely limiting economic growth.
Sledge's research showed that targeted
public health interventions led to the decline of mosquito-borne malaria in the 1930s.
Margaret Humphreys argued in her landmark 2001 book, “Malaria: Race, Poverty,
and Public Health in the United States,” that it was the removal of the malaria
carrier and victim from the vicinity of the anopheles mosquito that likely had
the largest effect on the decline of the disease.
Sledge and co-author George Mohler, assistant professor of mathematics and
computer science at Santa Clara University in California, found otherwise.
assessed this argument using Census data on the number of farms operated by
tenants during the 1930s. We found that highly malarial areas actually gained
population during the period that malaria declined,” Sledge said. “Changes in
the type of farms, meanwhile, didn’t lead to a decline in malaria.”
added: “Put another way, population movement didn’t lead to the end of malaria
in the United States – public health work did.”
the 1930s, the federal Works Progress Administration put unemployed Southerners
to work draining millions of acres of wetlands. Along with the federally
sponsored creation of local health departments, these drainage projects led to
the decline of malaria, the authors said.
federal government further ramped up its efforts during World War II, creating
the agency that became the Centers for Disease Control and Prevention
specifically to fight southern malaria. After the war, the CDC used the
insecticide DDT to eradicate the few remaining pockets of the disease.
their study, Sledge and Mohler used a mathematical model to analyze the decline
of malaria in each of the 67 counties in Alabama, an archetypical Deep South
cotton state that experienced high levels of malaria incidence well into the
the model, we categorized counties into three risk levels and then estimated
the dependence of mortality rates on variables related to weather, WPA projects
and population movement,” Mohler said. “After drought, the most important
variable for predicting a decline in mortality rates was the amount of drainage
in a county, rather than movement out of high risk counties or a reduction in
addition to drainage work, researchers point to the importance of measures such
as screening and public health infrastructure as well as the training of public
health workers in the elimination of the disease.
the team concedes that there are considerable distinctions between the current
Global South and the American South of the 1930s, they argue that malaria can be
controlled in the face of poverty and economic dislocation without major social change.
disease surveillance, drainage measures and screening work to ensure that, on
those occasions when malaria is reintroduced from outside of the U.S., the
chain of transmission does not begin again,” Sledge said.
work is representative of the world-class research under way at The University
of Texas at Arlington, a comprehensive research institution of more than 33,000
students and more than 2,200 faculty members in the heart of North Texas. Visit
www.uta.edu to learn more.