 Vector control and free access to antimalaria drugs controlled the disease . The authors have searched for the causes of the epidemic to propose a strategy avoiding such events . The Highlands on Madagascar were known as malaria free . In 0000 a very severe epidemic flooded all the country . Development of irrigated ricefields which house both An . arabiensis and An . funestus had created a new anthropic environment . Moreover manpower imported from malarious coastal areas for rice cultivation and also for building large temples , could have brought P falciparum . After several outbreaks the disease became endemic up to 0000 . In 0000 a malaria eradication programme based on DDT spraying and drug chemoprophylaxis and chemotherapy was launched . By 0000 malaria was eliminated and DDT spraying cancelled . Only 0 foci were kept under surveillance with irregular spraying until 0000 . The prophylaxis and treatment centres ( "centres de nivaquinisation" ) were kept open up to 0000 . The catholic dispensary of Analaroa , 000 km NE of Tananarive , opened in 0000 and worked without interruption up to now . The malaria diagnosis has always been controlled by microscopy . Its registers are probably the more reliable source of information on malaria in the area . They show that malaria was already present on the Highlands in 0000 but at a low prevalence ; in 0000 when the "centres de nivaquinisation" were closed the number of cases increased by three times the progressive increase of the number of cases became exponential from 0000 to 0000 which was the peak of the epidemic ; malaria remained at a high level until the end of 0000 ; yearly DDT spraying since 0000 have decreased the number of malaria cases among the dispensary attendants by 00% . The epidemic peak of 0000 was well documented by the Pasteur Institute of Madagascar around Tananarive . Before the epidemic started it was observed a come back of An . funestus which had been previously eliminated of most of the villages by DDT spraying . More than an epidemic the malaria increase in 0000 was a reconquest by malaria of the land from which it had been eliminated in the years 0000 . This episode became dramatic because the lack of immunity of the population and the shortage of medicaments . [ Sen. 00, subscore: 0.00 ]: Moreover manpower imported from malarious coastal areas for rice cultivation and also for building large temples , could have brought P falciparum . After several outbreaks the disease became endemic up to 0000 . In 0000 a malaria eradication programme based on DDT spraying and drug chemoprophylaxis and chemotherapy was launched . By 0000 malaria was eliminated and DDT spraying cancelled . Only 0 foci were kept under surveillance with irregular spraying until 0000 . The prophylaxis and treatment centres ( "centres de nivaquinisation" ) were kept open up to 0000 . The catholic dispensary of Analaroa , 000 km NE of Tananarive , opened in 0000 and worked without interruption up to now . The malaria diagnosis has always been controlled by microscopy . Its registers are probably the more reliable source of information on malaria in the area . They show that malaria was already present on the Highlands in 0000 but at a low prevalence ; in 0000 when the "centres de nivaquinisation" were closed the number of cases increased by three times the progressive increase of the number of cases became exponential from 0000 to 0000 which was the peak of the epidemic ; malaria remained at a high level until the end of 0000 ; yearly DDT spraying since 0000 have decreased the number of malaria cases among the dispensary attendants by 00% . The epidemic peak of 0000 was well documented by the Pasteur Institute of Madagascar around Tananarive . Before the epidemic started it was observed a come back of An . funestus which had been previously eliminated of most of the villages by DDT spraying . More than an epidemic the malaria increase in 0000 was a reconquest by malaria of the land from which it had been eliminated in the years 0000 . This episode became dramatic because the lack of immunity of the population and the shortage of medicaments . The global warming which was advocated to explain the epidemic has no responsibility because the temperature on the Madagascar Highlands has not changed during the last 00 years . Also the cyclones do not seem to have played any role . It is very likely that the gradual decline of control measures , first DDT spraying , later drug distributions , had the main responsibility in the Highlands drama . Everywhere An . funestus reached a high level during the time where the parasite reservoir was rebuilding . They synergised each other . 