[A contribution to the history of understanding the epidemiology of plague in Madagascar].

Plague appeared in Madagascar in 1898, the pandemic coinciding with the French conquest. Until 1921, harbor epidemics occurred in Tamatave, Majunga, Diégo-Suarez, Fort-Dauphin, Vatomandry. In 1921, probably favored by the building of roads and railways, plague takes root on the High Lands where it becomes endemic above 800 meters. The vaccine achievement by Girard and Robic with the EV strain, and its mass application from 1935 by Estrade, Milliau, Brault, Seyberlich and Jan Keguistel, allowed to control the disease. The D.D.T. and sulfamids discovery makes the urban epidemics almost disappear, allowing it to subsist as only rural sporadic or familial cases with a low mortality. The mass vaccination can be stopped in 1959. Since 1988 the diseases incidence has been increasing, probably in relation with the quasi disappearance of deinsectisation and antibiotics. Nevertheless, urban epidemics are still rare and limited in a parallel direction to the substitution, in the city, of Rattus rattus, main reservoir and victim of the disease, by Rattus norvegicus, less sensitive to the infection.