Mouchet J, Laventure S, Blanchy S, Fioramonti R, Rakotonjanabelo A, Rabarison P, Sircoulon J, Roux J
ORSTOM, Paris.
Bull Soc Pathol Exot. 1997;90(3):162-8.
A strong malaria epidemic with a high mortality rate occurred on the Madagascar Highlands in 1986-88. 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 1878 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 1949. In 1949 a malaria eradication programme based on DDT spraying and drug chemoprophylaxis and chemotherapy was launched. By 1960 malaria was eliminated and DDT spraying cancelled. Only 3 foci were kept under surveillance with irregular spraying until 1975. The prophylaxis and treatment centres ("centres de nivaquinisation") were kept open up to 1979. The catholic dispensary of Analaroa, 100 km N.E. of Tananarive, opened in 1971 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 1971 but at a low prevalence; in 1980 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 1986 to 1988 which was the peak of the epidemic; malaria remained at a high level until the end of 1993; yearly DDT spraying since 1993 have decreased the number of malaria cases among the dispensary attendants by 90%. The epidemic peak of 1988 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 1988 was a reconquest by malaria of the land from which it had been eliminated in the years 1950. 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 30 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. These findings should be taken in account in drawing the strategy planning for the next years.
1986 - 1988年，马达加斯加高地爆发了一场死亡率很高的严重疟疾疫情。通过病媒控制和免费提供抗疟疾药物，疫情得到了控制。作者们探寻了此次疫情的成因，以提出避免此类事件发生的策略。马达加斯加高地以前被认为没有疟疾。1878年，一场极其严重的疫情席卷了整个国家。灌溉稻田的开发为阿拉伯按蚊和有害按蚊提供了栖息之所，从而创造了一个新的人类环境。此外，从疟疾流行的沿海地区引进劳动力用于水稻种植以及建造大型寺庙，可能带来了恶性疟原虫。经过几次疫情爆发后，这种疾病在1949年之前一直呈地方性流行。1949年，一项基于滴滴涕喷洒以及药物化学预防和化疗的疟疾根除计划启动。到1960年，疟疾被消除，滴滴涕喷洒也取消了。直到1975年，仅对3个疫点进行不定期喷洒监测。预防和治疗中心（“氯喹治疗中心”）一直运营到1979年。位于塔那那利佛东北100公里处的阿纳拉罗阿天主教诊疗所于1971年开业，至今一直不间断地运营。疟疾诊断一直通过显微镜检查来控制。其记录可能是该地区关于疟疾最可靠的信息来源。这些记录显示，1971年高地就已经存在疟疾，但患病率较低；1980年“氯喹治疗中心”关闭时，病例数增加了两倍，从1986年到1988年病例数呈指数级增长，这是疫情的高峰期；疟疾在1993年底之前一直处于高发水平；自1993年起每年进行滴滴涕喷洒，使得诊疗所就诊者中的疟疾病例数减少了90%。1988年的疫情高峰在塔那那利佛附近的马达加斯加巴斯德研究所得到了充分记录。在疫情开始之前，人们观察到有害按蚊再度出现，这种蚊子此前已通过滴滴涕喷洒在大多数村庄被消灭。1988年疟疾的增加不仅仅是一场疫情，更是疟疾对其在20世纪50年代被消灭的地区的重新“占领”。由于当地人口缺乏免疫力以及药品短缺，这一事件变得十分严峻。有人提出全球变暖来解释此次疫情，但这并无关联，因为在过去30年里马达加斯加高地的温度并未变化。同样，气旋似乎也未起到任何作用。很可能是控制措施的逐渐减少，先是滴滴涕喷洒，后来是药物分发，在高地这场灾难中起了主要作用。在寄生虫宿主重建的时期，有害按蚊在各地都达到了很高的数量。它们相互协同作用。在制定未来几年的策略规划时应考虑到这些发现。
