Rodhain François
Professeur honoraire à l'Institut Pasteur.
SFMTSI Société francophone de médecine tropicale et santé internationale (ancienne SPE), Hôpital Pitié-Salpêtrière, Pavillon Laveran, 47-83 Boulevard de l'Hôpital, 75651 Paris cedex 13, France.
Med Trop Sante Int. 2023 Feb 13;3(1). doi: 10.48327/mtsi.v3i1.2023.312. eCollection 2023 Mar 31.
In 1880, Laveran observed the causative agent of malaria. As early as 1884, he considered that mosquitoes could be responsible for the transmission of haematozoa, a hypothesis which resulted from the observation and reflection of an informed hygienist. But, as Laveran himself said, "the opinion that I defended was considered by most observers to be highly unlikely".Nearly 15 years after the discovery of the haematozoan, the elucidation of the mechanism of transmission still proved difficult to establish. A link with the existence of swamps had been established a long time before, but the true mode of transmission remained a mystery until the end of the 19th century. The implication, by Manson in 1877, of mosquitoes in the cycle of the Bancroftian filaria, then other observations of the same order, ended up attracting the attention of malariologists. Laveran himself was quickly convinced of the role of mosquitoes in carrying out the natural cycle and propagating , but this theory had as many detractors as supporters.In 1897, Ross showed the presence of oocysts on the stomach of mosquitoes previously gorged on a malaria patient, then in 1898, of sporozoites of bird plasmodia in mosquitoes. He was convinced that, through their bite, these insects were responsible for the transmission of human malaria agents, without being able to prove it. The results obtained by Ross were immediately confirmed in Italy by Grassi and his collaborators who, in November 1898, described the stages of in man and, through various experiments carried out in collaboration with British researchers, showed the role of , a result far from being accepted by all. Skepticism persisted for a long time.An excellent protozoologist, Laveran was not an entomologist. He was however among the first defenders of the anopheline theory. He worked extensively on establishing the relationships between mosquitoes and malaria and took a close interest in the environmental conditions of the transmission. In his mind, malaria fever should henceforth be classified as a preventable disease. An era of hope thus dawned: malaria prophylaxis, based on fight against mosquitoes, could begin.
1880年，拉韦朗发现了疟疾的病原体。早在1884年，他就认为蚊子可能是血寄生虫传播的媒介，这一假设源于一位知识渊博的卫生学家的观察和思考。但是，正如拉韦朗自己所说：“我所捍卫的观点被大多数观察者认为极不可能。”在发现血寄生虫近15年后，传播机制的阐明仍然难以确立。很久以前就已确定疟疾与沼泽的存在有关，但直到19世纪末，真正的传播方式仍是个谜。1877年曼森指出蚊子在班氏丝虫传播周期中的作用，随后的其他同类观察结果最终引起了疟疾学家的注意。拉韦朗本人很快就相信蚊子在完成自然周期和传播过程中的作用，但这一理论的反对者和支持者一样多。1897年，罗斯发现先前饱食疟疾患者血液的蚊子胃上有卵囊，1898年，又在蚊子体内发现了鸟类疟原虫的子孢子。他确信，这些昆虫通过叮咬传播人类疟原虫，但无法证实这一点。罗斯的研究结果立即在意大利得到格拉西及其同事的证实，他们于1898年11月描述了疟原虫在人体中的各个阶段，并通过与英国研究人员合作进行的各种实验，证明了蚊子的作用，但这一结果并未被所有人接受。怀疑态度长期存在。拉韦朗是一位杰出的原生动物学家，但不是昆虫学家。然而，他是按蚊理论的首批捍卫者之一。他广泛致力于确立按蚊与疟疾之间的关系，并密切关注传播的环境条件。在他看来，疟疾热从今往后应被归类为可预防的疾病。于是，一个充满希望的时代来临了：基于灭蚊的疟疾预防措施可以开始实施了。
