The measles virus resides in the mucus in the nose and throat of an infected person, so transmission typically occurs through coughing and sneezing. After being infected with the virus, a person does not become sick immediately; it takes several days for symptoms to appear. Transmission of measles occurs so easily that anyone who is not immunized will probably get the disease eventually.
Measles (rubeola) is a highly contagious illness that is spread by coughing and sneezing. An infected person can transmit measles any time from about four days prior to the onset of the rash to four days after the onset. If one person has it, 90 percent of his or her susceptible close contacts will also become infected with the measles virus.
How Exactly Does the Transmission of Measles Occur?
The measles virus resides in the mucus in the nose and throat of the infected person. When that person sneezes or coughs, droplets spray into the air. The infected mucus can land in other people's noses or throats through breathing or putting their fingers in their mouth or nose after touching an infected surface.
The virus remains active and contagious on infected surfaces for up to two hours. Measles transmission occurs so easily that anyone who is not immunized will probably get it eventually.
Following transmission of measles, a person does not become sick immediately. Once the virus enters the body, it travels to the back of the throat and lungs, where it begins to multiply. It can also travel to other parts of the body. After 8 to 12 days, measles symptoms can begin. This period between transmission and the beginning of symptoms is called the measles incubation period.