It is seen in every country of the world. Before the use of vaccines, epidemics of measles occurred every two to five years. Cough, cold, fever and a skin rash that begins several days before the initial symptoms characterise the illness. Recovery from measles is usual, but serious complications of the respiratory and central nervous system may occur. Cause and Pathogenesis Measles virus belongs to the Morbillivirus group of the Paramyxovirus family.
Humans are the only natural host for wild measles virus.
The virus is easily destroyed but remains in the droplet form in air for several hours, especially under conditions of low relative humidity. It is spread by direct contact with droplets from respiratory secretions of infected persons. It is one of the most communicable of infectious diseases and is most infectious when cough and cold is at its peak. The virus invades the respiratory lining membrane and then enters the blood stream. It causes inflammation of the respiratory tract and may predispose to secondary bacterial pneumonia.