[Human diseases transmitted by Culicidae in southwest Indian Ocean islands]. / Maladies humaines transmises par les culicidés dans les îles du sud-ouest de l'Océan Indien.

South-West Indian Ocean islands were inhabited at the beginning and free from all kind of vector. In Madagascar, Mayotte, Moheli and Anjouan, malaria vectors were carried by the first settlements. According to epidemics, the anopheles arrived in 1867 in Mauritius, 1869 in La Reunion and 1920 in Grande Comore. Rodrigues, Saint-Brandon and the Seychelles are still free from malaria vectors in the coastal part of Madagascarcar and in Comores archipelago, malaria is stable with a permanent transmission. Unstable malaria is seasonaly transmitted in the high territories of Madagascar; it was the same in Mauritius and Reunion island before the eradication campaign. Lymphatic filariasis is quoted in Madagascar, but Comores archipelago is an area with high transmission. The incidence of the disease is moderate in La Reunion and Mauritius and very low in Chagos and Seychelles archipelagos. There is no transmission in Rodrigues and St Brandon. Epidemics of dengue were described during the second part of the XIXth century in Mauritius and La Reunion, then in 1943 in Mayotte. But the disease was controlled in the fifties by the antimalaria campaign. A new epidemy appeared in Seychelles by the end of 1976 and then in Reunion and Mauritius next year. An isolated outbreak was described in Grande Comore only in 1994.

[Historical epidemiology of malaria in the archipelago of the Mascarenes (Indian Ocean)]. / Epidémiologie historique du paludisme dans l'archipel des Mascareignes (Océan Indien).

The Mascarenes Islands (Mauritius, Rodrigues and Reunion) have been for the last few centuries a place of rest and convalescence for sailors, soldiers and inhabitants of the other regions of the Indian Ocean affected by "intermittent fevers". In the middle of the nineteenth century a severe and deadly malaria epidemic occurred first in Mauritius and then in Reunion Island. It took a century to bring the disease under control, but this has in no way diminished the risk of its re-introduction. Comparative study of the way the disease appeared and got established in these two islands and not in the adjoining ones (Rodrigues, Chagos, Seychelles) leads us to formulate the hypothesis that massive deforestation for sugar cane cultivation created a favourable environment for the implantation of the malaria vector, the african origin of which is beyond doubt. The evolution of the environment, subjected to natural catastrophe (cyclones) and to human activities (often as a consequence of economic development) has exerted pressure on the vector which in a way gives an answer of the development of the disease over time. This study highlights the importance of epidemiological analysis of the history of major communicable diseases not only in the cognitive context but also in predicting probable public health problem arising from environmental modifications.