Stratification épidémiologique du paludisme dans l’archipel des Comores

In the Comoros Islands, the level of malarial endemicity varies greatly from one island to the other, even though the total area (4 islands) covers less than 2 300 km2 and has a population of some 600,000 people only. The epidemiological stratification is based on the diversity of human and physical characterisation. They both determine the presence and the behaviour as well as the size of the vector's populations. Vectorial dynamics can explain varying levels of endemicity given parasitological indicators and spe cific morbidity. Analysising these criteria shows up different epidemiological features and serves as a basic guideline for malaria control. The efficiency of this control depends on the relationships bet ween the intensity and the length of the transmission, in the framework of protection mechanisms; it is of crucial importance for clinical treatment. Further elements are the age of the patient, the sea son and the geographic situation of the area. Stratification provides explanations for these relationships and helps to define antimalarial pro grammes adapting to each situation a range of therapeutic and antivectorial methods. The availability and accessibility of anti-malarial medicine is the minimum requirement for reducing mortality: domestic spray insecticides for reducing transmission are effective for several years and should be followed by the use of mosquito nets or curtains impregnated with pyrethrinoids, and in the particular case of Grande Comore, the use of larvivorous fish. As anywhere else, the economic development, which is dependent on political stability, is the essen tial basis for malaria control.