<prompt> Measles is infective for: March 2009One day before and 4 days after rashFour days before and five days after rashEntire incubation periodOnly during scabs falling  <response>: Ans. B: Four days before and five days after rash MeaslesEnglish Measles is spread through respiration contact with fluids from an infected persons nose and mouth, either directly or through aerosol transmission, and is highly contagious -- 90 of people without immunity sharing a house with an infected person will catch it. The infection has an average incubation period of 14 days range 6-19 days and Period of communicability in measles is approximately 4 days before and 5 days after the appearance of the rash. Measles is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, single-stranded, negative-sense RNA viruses. Symptoms include fever, cough, runny nose, red eyes and a generalized, maculopapular, erythematous rash. 