Harvard School of Public Health Study Finds That Deforestation May Increase Malaria Transmission

A Harvard School of Public Health study published Oct. 21 found that ecological changes in the Brazilian Amazon have led to a significant increase in the risk of malaria transmission.

In the study, researchers examined data from 2003 to 2022 to analyze a connection between malaria transmission and deforestation. The malaria case data, sourced from the Brazilian Ministry of Health, and deforestation levels, pulled from MapBiomas, were compiled monthly to account for previously neglected seasonal components of malaria transmission.

Malaria is a life-threatening disease spread by mosquitoes infected by parasites. Although it’s been virtually eradicated in some countries, it remains a serious public health risk in Brazil. In 2022 alone, 42.5 million people in Brazil were at risk of malaria, with 129,000 reported cases.

Discussing previous literature, Maria C. de Castro, the study’s author and chair of the Department of Global Health and Population at HSPH, says there seems to be a gap in current studies.

“Unfortunately, we have a lot of garbage published,” Castro said.

She added that by analyzing the data from an annual perspective, these studies overlook the seasonality of the disease.

“It peaks during certain months of the year,” Castro said.

The researchers said they aim to use this work to affect policy on the eradication of malaria in Brazil.

“The work that we do is directly trying to impact policy and improve the efficacy of malaria elimination programs across Brazil,” said Nicholas J. Arisco, a postdoctoral fellow at HSPH.

Oladimeji E. Mudele, a postdoc at HSPH, also spoke to the ramifications this research could have on public policy.

“A very important component of doing studies like this is to ensure that there is important collaborations with government or policy agencies in the countries,” he said.

However, bringing science to policymaking poses a challenge.

“Eliminating malaria is political, and it's really going to require the political will not just to do it, but to involve other sectors of the government” Castro said.

“You want to assume that there is political buy-in and that the politics of that is easy. Many times good intentions from a scientific standpoint just doesn't cut through the whole policy landscape,” Mudele added.

Despite this, the researchers expressed hope that their research will bring visibility to these solutions.

“Awareness is the first step. That's what I always think. When you do a study like this, you bring it to public awareness, where people realize, okay, it's not a very small effect,” Mudele said.

Correction: December 14, 2024

A previous version of this article incorrectly referred to Nicholas J. Arisco as a third-year doctoral student at HSPH. In fact, Arisco is a postdoctoral fellow.