Early detection and monitoring malaria from space

Malaria is the major vector-born disease in the world. It occurs in 107 countries with a ½ of world population. Every year 300-500 million clinical cases of malaria occur with 1.5-3 million fatalities. Children, old people and pregnant women are the most vulnerable to malaria. Africa is the most affected continent, which contributes 60 % of global malaria cases and 80% of death. Malaria is strongly affected by the environment. Climate and ecosystems determines distribution of malaria and weather affects timing, duration, area and intensity of outbreaks. In general warm and wet weather stimulated mosquitoes hatching, activity and the rate of malaria transmission to people. Such weather parameters as precipitation, temperature and relative humidity serves as the indicators of malaria and its development. However, weather station network is not dense enough especially in Africa to provide a decent tool for malaria monitoring. Therefore, satellite data have been used in recent years to monitor malaria. New theory provided a good background for development of Vegetation health (VH), techniques that have been developed applied successfully for early detect and monitor malaria from the operational environmental satellite. VH was developed from reflectance/emission measured by the Advanced Very High Resolution Radiometer (AVHRR) flown on NOAA polar-orbiting satellites since 1981. The calibrated measurements were converted to the Normalized Difference Vegetation Index (NDVI) and brightness temperature (BT), which were expressed as a deviation from 30-yeqr climatology. Three indices characterizing moisture (VCI), thermal (TCI) and vegetation health (VHI) conditions were produced and calibrated against in situ data. They were applied to identify malaria early enough to mitigate its consequences. These results covering several countries in Africa, Asia and South America are presented in this paper.