Complications can include otitis media, pneumonia and encephalitis. Persons who have been previously immunised may present with non-classical features. Cough or coryza or conjunctivitis or Koplik's spots. It was once a common, acute highly communicable disease with potentially serious sequelae. It is much rarer since the introduction of widespread immunisation, but epidemics are still occurring, especially in school-aged children.
Death is rare but does occur.
Method of Diagnosis See Case Denition . Its transmission is airborne by droplet spread, or it is transmitted by direct contact with infected nasal or throat secretions. Incubation Period Incubation period is approximately 10 days, but varies from seven to 10 days from exposure to the onset of fever. It is usually 14 days until the rash appears. Period of Communicability From slightly before the beginning of the prodromal period to four days after the appearance of the rash.