A new European research project will follow from space mosquitoes, carriers of viruses that cause serious diseases such as African fever
8.7.2001
New viruses threaten the health of the earth's inhabitants and cattle herds - and are a great danger because their ways of infection are relatively easy. Shortcuts in infection can also be caused by human actions, such as the destruction of forests and the cultivation of agricultural land. Building dams to store water and expanding irrigated agricultural areas can also increase diseases, due to the breeding of mosquitoes that carry the viruses and the crowding of human populations near the water lines.
Outbreaks of the "Syrian-African depression fever" (Rift Valley Fever) in Egypt in 1977 and in Mauritania in 1987 were probably due to these two human factors. The virus that causes the disease was first identified in Kenya in 1931. A new European project of monitoring from space - may probably reduce the damage of the disease.
Several factors combine to increase the intensity of an epidemic: the general warming of the earth (half a degree in the last hundred years, and possibly two more degrees by the end of the 21st century); the projected rise in sea level; Increased evaporation rate and slower recovery-repair of the ozone layer. The changes in the amount of precipitation and the temperature may also affect the intensity of the transmission of diseases by flies, mosquitoes, etc.
The situation in East Africa is controlled by the rain. Its quantities determine the lifespan of the disease-carrying mosquitoes. The increase in temperature affects the rate of development of mosquitoes and the frequency with which they feed on the blood of their victims - which increases the chances of infection.
From a study on the outbreaks of the disease, it was clarified that there is a direct connection between a large amount of rain, and large amounts of mosquitoes that carry the disease. The most suitable place for mosquitoes to breed is in natural bodies of water, which are fed by rain but also artificial - like the catchment basin of a river closed by a dam. The connection between the disease and the artificial lakes was discovered in Egypt, after the construction of the Aswan Dam. The outbreak of the disease in Mauritania was identified as a result of many projects for irrigation and building dams.
The use of remote sensing means from space will make it possible to easily identify places prone to the outbreak of an epidemic caused by viruses carried by mosquitoes. These places are greener, on average, than their surroundings.
As a result, the European community has now begun to implement a research program in which a system will be established to monitor epidemics and identify their foci. The system will store data that may link the characteristics of the epidemics to the environmental conditions. An information database will be established on this topic - and it will be brought to the attention of the decision makers in the various countries.
The European method of sensing from space to identify breeding places for mosquito larvae may also be useful for Israel. A better recognition of the problematic places in our country may lead the decision-makers to improve the war against mosquitoes that carry West Nile fever, which many fear in the summer.
By Dr. Noah Brosh
