U.S.-Ethiopian Effort Will Monitor Malaria Risk

Associate professor Michael Wimberly of South Dakota State University’s Geographic Information Science Center of Excellence said the work builds on SDSU’s experience using geospatial tools to study a different mosquito-borne illness in the United States. Wimberly and his SDSU colleagues have carried out several studies in recent years studying West Nile virus outbreaks in South Dakota and the surrounding region, where the virus that causes the disease is spread largely by a mosquito called Culex tarsalis.

Malaria is also a mosquito-borne disease. The parasite that causes the disease is spread by the bite of the female Anopheles mosquito. Malaria is found in about 109 countries in the Americas, Africa, and Asia. The World Health Organization estimated that as many as 1 million people died of malaria in 2008. Most fatalities are in children younger than 5. The vast majority of cases are in sub-Saharan Africa.

Wimberly said some of the techniques that SDSU geographers use to study West Nile virus can be deployed to also study malaria in Africa.

“Malaria is a major public health problem in Ethiopia, where outbreaks in highland regions can be affected by climatic variability, land use change, and seasonal movements of human populations,” Wimberly said. “We can apply geospatial technologies, including geographic information systems, or GIS, and satellite remote sensing to forecast the spatial and temporal patterns of malaria risk — where and when outbreaks are likely to occur.”

Wimberly said the plan depends on a multidisciplinary team that links scientists who have knowledge of geospatial data and techniques with public health practitioners who have a detailed understanding of local needs. Wimberly and his colleagues have developed such a partnership involving the Geographic Information Science Center of Excellence or GIScCE at South Dakota State University, the U.S. Geological Survey’s EROS Center in Sioux Falls, and the Anti-Malaria Association or AMA, a non-governmental organization located in Addis Ababa, Ethiopia.

“In this partnership, the role of the GIScCE is to develop models for ecological forecasting of malaria risk using satellite remote sensing, and the role of the AMA is to facilitate data collection, model validation, and implementation of the resulting products,” Wimberly said.

The partnership’s preliminary results have documented relationships between satellite-derived environmental metrics and malaria incidence in the Ethiopian highlands, confirming the feasibility of malaria risk mapping and forecasting.

“We have also developed other GIS data products related to land use, health facility accessibility, transportation, and population characteristics that may be useful for enhancing malaria prevention efforts,” Wimberly said. “A key technical challenge in Ethiopia has been implementing Internet-based mapping technologies in an environment of low connectivity and low bandwidth. Therefore, another important aspect of the partnership is developing effective, low-cost, and easy-to-use methods for providing public health practitioners with access to digital map products.”

The SDSU scientists’ latest visit to Ethiopia in summer 2010 has spawned a subproject that will focus on providing baseline geographic data to health centers in Ethiopia’s Amhara region.

“We’re going to pick 10 woreda, or districts, in the Amhara region and collaborate with a GIS consulting firm in Ethiopia to generate a number of paper map products for them,” Wimberly said. This low-tech exercise will help researchers learn what types of maps are most useful for malaria prevention and control.

The lessons learned and the tools developed through the ongoing collaboration between GIScCE and AMA can help to inform and enhance other global health partnership efforts, he added.

In addition to Wimberly, others involved in the project include Alemayehu Midekisa, Ting-Wu Chuang, and Geoffrey Henebry, all of the Geographic Information Science Center of Excellence at South Dakota State University; Gabriel Senay of the USGS Earth Resources Observation and Science Center, or EROS Center, in Sioux Falls, S.D.; and Abere Mihretie and Paulos Semunigus, both of the Anti-Malaria Association, Addis Ababa, Ethiopia.