Monitoring Fever in Africa's Rift Valley
A 21st Century Satellite Orbiting Earth
Africa's Rift Valley stretches from Mozambique to the Red Sea.
In 1977, mosquitoes carried a virus from the Rift Valley on the eastern side of Africa across the continent to Egypt. Some 200,000 humans caught the fever while slaughtering sheep. More than 2,000 people and most of the sheep in Egypt were killed by the deadly fever.
Satellite photos of Eastern Africa by a National Oceanic and Atmospheric Administration (NOAA) polar-orbiting weather satellite captured the El Nino flooding in Kenya, which caused arid regions to bloom with vegetation.
Rift Valley fever comes froim a virus transmitted to humans through mosquitoes. The floods promoted mosquito growth in the wet savannas. The insects infected sheep and other animals that have direct fluid contact with humans, which led to the largest recorded outbreak of Rift Valley fever. While Rift Valley fever usually is not lethal to humans, it had a disastrous effect on the economies of local communities that rely on sheep for their livelihood.
A U.S. Army research lab at Maryland's Fort Detrick found a way to track the path of the disease by satellite. Researchers used space photos of land conditions across Africa to map vegetation density. That revealed clues to mosquito movements and let scientists predict the spread of the fever virus.
The 1977 outbreak was stemmed by animal vaccine from South Africa and human vaccine from the U.S. Army's Fort Detrick lab.
Today, predicting disease outbreak is an important task for NASA's Earth-monitoring program. Satellite images of vegetation in regions of the world help predict where diseases may crop up.
- CDC report on Rift Valley Fever
- CDC Report on Emerging Disease in Eastern Africa
- NASA's Earth Observatory
SatBytes index Satellites main page Search STO Space Today Online cover E-mail Copyright 2003 by Space Today Online