Measles is a highly contagious, serious disease caused by a virus in the paramyxovirus family. The measles virus normally grows in the cells that line the back of the throat and the lungs.
It is a human disease not known to occur in animals.
The first sign of measles is usually a high fever, which begins about 10 to 12 days after exposure to the virus, and lasts 4-7 days. A runny nose, a cough, red and watery eyes, and small white spots inside the cheeks can develop in the initial stage. After several days, a rash erupts, usually on the face and upper neck. Over about three days, the rash spreads, eventually reaching the hands and feet. The rash lasts for 5-6 days and then fades. The rash occurs, on average, 14 days after exposure to the virus (within a range of 7-18 days).
Measles is often a moderately severe illness. Severe measles is more likely among poorly nourished young children, especially those with insufficient vitamin A, or whose immune systems have been weakened by HIV/AIDS or other diseases. People who recover from measles are immune for the rest of their lives.
The highly contagious virus is spread by coughing and sneezing, close personal contact or direct contact with infected nasal or throat secretions. The virus remains active and contagious in the air or on infected surfaces for up to two hours. It can be transmitted by an infected individual from 4 days prior to the onset of the rash to 4 days after the rash erupts.
Measles outbreaks can result in epidemics that cause many deaths, especially among young, malnourished children.
Healthcare workers and those who work with children, who were born during or since 1966 and are non-immune or who have only received 1 dose of measles-mumps-rubella (MMR), should be vaccinated with MMR. Healthcare workers and those who work with children should have documented evidence of 2 vaccinations or serological evidence of protection for measles, mumps and rubella.