Measles Eradication in Morocco: Molecular Epidemiology of Measles Virus 1998–2014

The molecular characterization of measles is essential in a context of elimination. Indeed, it allows identifying the origin and transmission pathways to establish or reject the connections between cases and outbreaks, to observe the evolution of circulating strains and differentiate between indigenous strains, strains imported, or vaccine strains. Therefore, the molecular characterization of the measles virus is an essential element for the documentation of the interruption of endemic transmission. The introduction of the measles molecular surveillance in Morocco has shown significant changes over time, including the disappearance of some genotypes and the emergence of new ones. This review aims to overview this evolution, between 1998 and 2015, with regard to the measles control/elimination strategy in Morocco. This analysis reveals the direct impact of the immunization activities undertaken in Morocco on the circulating genotypes. However, a well performing surveillance system providing comprehensive epidemiological data is needed to complement the contribution of the genetic characterization.