Potential measles transmission risk in mass gatherings: Are we safe for the Olympic games—Rio 2016?

The measles virus, genus Morbillivirus of the Paramyxoviridae family, only infects humans. Measles is transmitted by droplets when the infected individual is coughing or sneezing. It is highly infectious (R0 = 15–20 in a completely susceptible population),1 especially in closed environments such as shopping malls, schools and other confined places. Infected individuals can shed the virus up to 4 days before the appearance of their symptoms and up to 4 days after the onset of symptoms.2 Also, its RNA is still detected in biological samples for many weeks.3 Measles is characterized by its high infectivity. The initial clinical manifestations include runny nose, cough, red and watery eyes and small white spots inside the cheeks. After several days, a maculo-papular exanthema erupts.4 Measles was controlled in some regions, including Brazil. Recently, some outbreaks were reported in the country in the past few years and may represent a risk for transmission during mass gathering events, such as the Olympic Games. For that reason, the aim of this article is to discuss the potential risk for Measles transmission in the country during the Olympic Games and also preventive measures in order to avoid other outbreaks. The number of suspected and confirmed measles cases in 2015 reported by WHO5 indicates a frame, in which the African Region presents the highest number of confirmed cases, whereas Region of Americas presents the lowest: African Region (54 374 suspect/35 557 confirmed), Region of the Americas (13 083 suspect/366 confirmed), Eastern Mediterranean Region (26 178 suspect/11 610 confirmed), European Region (6642 suspect/6023 confirmed), South-East Asia Region (79 713 suspect/67 233 confirmed) and Western Pacific Region (120 319 suspect/61 493 confirmed). This represents a total of 300.309 suspect cases and 182.282 confirmed cases in the world until October 2015. WHO indicates that from June 2014 to June 2015 in the European Continent, there were more …