The discovery of the vector of Robles disease.

The origin and transmission of African filariasis has long remained enigmatic. Between 1915 and 1917, the pathogenic role of Onchocerca volvulus and its transmission by insects of the genus Simulium, had been established in Guatemala by Rodolfo Robles who took opportunity of a series of discoveries to formulate his hypothesis on the origin of Latin Americna Onchocerchiasis. The present paper gives an historical account of the steps and the context having led to the formulation of the aetiological hypothesis and the relevant vector identification.