How satellite imagery helps in the fight against malaria

For malaria elimination officer Jerry Maambo, protecting eastern Zambia’s residents from the mosquito-borne disease starts with knowing where people live.

Maambo and his team are working to curb rising malaria cases in the Katete district, where cases surged by nearly 50% in 2020 over the previous year.

Malaria infects more than 200 million people annually and kills hundreds of thousands each year, mostly children under age 5. In September 2022, the U.S. government, partner nations and the private sector pledged a record $14.25 billion over the next three years to the Global Fund to Fight HIV/AIDS, Tuberculosis and Malaria.

Maps made with satellite imagery are helping Katete and other districts in Zambia more efficiently plan malaria prevention efforts, such as applying insecticides to residences’ walls and ceilings, and distributing insecticide-treated bed nets.

4 men standing around map (Chipema Chinyama/USAID)
Maps developed through a PMI partnership help Maambo’s team determine where immediate malaria prevention is needed. (Chipema Chinyama/USAID)

Better maps made from more accurate data are the result of the U.S. President’s Malaria Initiative (PMI) partnership with the government of Zambia. Led by the U.S. Agency for International Development (USAID) and the U.S. Centers for Disease Control and Prevention, PMI has helped Zambia’s National Malaria Elimination Program carry out more effective malaria interventions since 2008.

PMI’s VectorLink project worked with the government of Zambia and Akros, a local partner, to create maps that help malaria elimination teams determine which areas need immediate intervention. The PMI project and Akros used satellite images and field-verified data, captured with a geospatial data collection tool called Reveal, to estimate local populations. In all, 20 PMI-supported districts received the new Reveal maps.

With the new maps, Maambo’s team could identify smaller, more remote communities that may have been missed in previous malaria elimination campaigns. “With the PMI maps, we can target the structures that are eligible for the program,” Maambo said.

Better mapping helps the team maximize the number of houses sprayed and allows them to be more cost effective. The new maps show the distances between villages and let the team know how many structures they will need to address when they arrive.

2 men wearing protective equipment while speaking to woman (Chipema Chinyama/USAID)
Teams are now incorporating additional data into planning, such as community members’ questions about insecticide spraying. (Chipema Chinyama/USAID)

When Maambo’s team decides that distributing insecticide-treated nets is the appropriate intervention, improved population data helps them know how many nets to bring.

Zambian malaria prevention officials also have begun incorporating more data in their work, including community members’ questions that arise during the team’s work. “Indoor residual spraying is a community intervention and its success is dependent on the acceptance level of the community,” Maambo said.

Maambo’s team also has begun using the population data to address other challenges, such as water security, sanitation and hygiene. “We have also used the maps in identifying the areas that need sanitation facilities, for example the construction of latrines and drilling of water sources, so that we can assist these densely populated areas,” he said.

A version of this story previously appeared on USAID’s Exposure.