For most people, mosquito bites go unnoticed, leaving behind itchy red bumps that don't warrant much attention. But for more than 282 million people around the world, a single bite from a certain type of mosquito could lead to malaria, a disease that poses a massive global health threat.
Malaria is transmitted among people by the female Anopheles mosquito, which is mostly found in tropical countries. When this mosquito bites a person, it introduces the parasite to the bloodstream and spreads malaria. That's why for the past 100 years, humans have been trying to control the tiny, whizzing mosquito.
"You can't just eliminate the mosquito," said Melissa Graboyes, associate professor of history in the College of Arts and Sciences (CAS), and the director of the Global Health Program in the Schnitzer School of Global Studies and Languages.
For decades, various foreign governments and organizations have tried to eliminate mosquitoes in the tropics. In East Africa, where Graboyes focused her research, the British Empire transformed cities in Zanzibar, draining rivers and swampland to destroy mosquito breeding sites. And contemporary global health organizations - such as the Bill and Melinda Gates Foundation and the World Health Organization (WHO) - have spent hundreds of millions of dollars annually to control malaria and reduce mosquitoes in Africa.
Yet, these various interventions - focused either on the blood-sucking mosquito or the hardy malaria parasite - have all failed to stop malaria transmission.
"People talk about a global campaign to try to eradicate malaria, and I think that's really foolhardy," Graboyes said. "When they talk about that, they pay no attention to the history."
As Graboyes and the students in her Global Health Research Group examine and interact with historical materials, they find that there is no simple "silver bullet" for malaria. Instead, the realistic approach is one that is multi-pronged with the goal of malaria control - keeping malaria rates low.
Graboyes is taking what she's learned about the history of failed malaria eradication and control efforts on the African continent and completing a book that will come out with Ohio University Press in 2028.
Spawning from puddles, undeterred by nets
Malaria is prevalent in tropical and sub-tropical regions of the world, affecting Africa, South America and southeast Asia. According to the WHO, African populations are hit hardest by malaria, which accounts for about 95% of the world's total cases and deaths. Those most vulnerable to the symptoms are pregnant women and children under 5 years old, who are also most likely to die from malaria.
The environmental conditions in sub-Saharan Africa are perfect for mosquitoes to breed. When water puddles in tropical temperatures, mosquitoes spawn within days.
"You can see the larvae with the naked eye," Graboyes said. "You don't need a microscope."
In recent decades, one of the more common approaches to protecting people from mosquito bites is to encourage them to sleep under bed nets. But as more people utilize bed nets, mosquitoes have changed their biting behaviors.
Rather than biting between 11 p.m. and 2 a.m., mosquitoes have begun biting earlier in the evening - around 5 to 7 p.m., long before people begin sleeping under their nets. During these evening hours, people are busy cooking dinner, running errands, working in the garden or tending to livestock - leaving them unprotected from mosquito bites.
"Mosquitoes are amazingly adaptable," Graboyes said. "So, our approaches to the disease also have to be highly adaptable."
The British colonial officials took on various measures to address malaria, from reconstructing cities by draining creeks and swampland to spraying the highly toxic and now banned insecticide DDT (dichlorodiphenyltrichloroethane).
Despite these measures, malaria and the mosquitoes who carry it haven't gone away.
Digging through the history of malaria in Zanzibar
Using nearly half a million dollars in award money from National Science Foundation and other funding sources from 2019 to 2025, during research trips in the US, East Africa ,and Europe, Graboyes and her team have collected and studied archival materials from the Zanzibar National Archives, the WHO's Archives, the Rockefeller Foundation and the British colonial archives. The team has also conducted field research in Zanzibar, including more than 100 interviews.
Students who participate in Graboyes' Global Health Research Group are introduced to the importance of historical methods, historical sources and historical knowledge to understand contemporary global health challenges. The group is made up of nearly 20 students, primarily CAS undergraduates.
Graboyes invests time mentoring the students in her research group. Many undergraduate students are majoring in fields within the Division of Natural Sciences, such as biology, and envision becoming future physicians. Under her mentorship, these students study why past efforts to eradicate the mosquito and malaria haven't worked.
Marlee Odell, BS '22 (biology) was part of Graboyes' team. She pored through the old documents of malaria eradication attempts made by the British colonial government in Zanzibar from 1910 to 1960.
As a researcher, Odell, who is also a Clark Honors College alum, said she noted how so many scientists in the past felt confident that they had discovered new treatments or ways to address mosquitoes and malaria. Seeing how scientific-informed policies can fall apart in practice taught Odell something important about public health policies and practices.
"It gave me pause," she said. "When we're coming up with new treatments today, what will it look like in 2050?"
Odell supported the 2024 article "Puddles, creeks, and drainage: connected histories of water and malaria in Zanzibar, 1910-2021," published in the journal Water History.
The article includes Odell's research showing that malaria resurgence is something public health professionals should consider as an issue. The risks of malaria resurgence are something that haven't been fully accepted by many global health organizations, she said. But after digging through archives and interviews, the big picture suggested that malaria resurgence has happened in the past in Africa and is likely to happen again in the future.
"This is a very significant thing that happens, and something that I think needs to be considered with future global health efforts in malaria," Odell said. "I'm hoping that it can be more influential in future policy and approaches to malaria eradication."
Alum Marlee Odell said that as part of the Global Health Research Group she spent a lot of time on a computer, reviewing academic journals, historic documents and articles about malaria in Zanzibar. Photo courtesy of Marlee Odell
How to fight malaria
For more than a decade in the early 2000s, malaria rates in Zanzibar hovered around 1%, meaning the disease had been largely controlled and was no longer a significant public health problem.
The success in lowering malaria in Zanzibar was largely the result of a multipronged approach that involved indoor residual spraying with insecticides such as DDT, widespread distribution and use of bed nets, careful tracking of cases, and ensuring that testing and effective treatment were widely available.
But Graboyes' 2024 research about malaria in Zanzibar indicated that much of that success depended on international funding from the United States and agencies like the WHO. When the U.S. Agency for International Development was disbanded in 2025, and many US grants for global health ended, it created a situation where malaria could return and resurge.
"Many people know that eradication isn't possible, but they still talk about it because it generates energy and support for a disease that disproportionately affects people in Africa," Graboyes said. "What I'm doing is talking to policymakers and sharing this historical research."
