Measles: Vaccine Preventable Diseases Surveillance Standards

Overview

Measles is one of the most contagious diseases for humans. It is caused by a paramyxovirus virus, manifesting as a febrile rash illness. The incubation period for measles usually is 10–14 days (range 7–23 days) from exposure to symptom onset. Initial symptoms (prodrome) generally consist of fever, malaise, cough, conjunctivitis, and coryza. The characteristic maculopapular rash appears two to four days after onset of the prodrome. Patients are usually contagious from about four days before rash onset until four days after its appearance.

The exact source of transmission is frequently unknown because the patient is often infected by someone in the pre-rash prodrome stage. Measles complications such as pneumonia, diarrhea and encephalitis can occur in up to 30% of persons depending on age and predisposing conditions, such as young age, malnutrition and immunocompromising conditions. These complications usually occur two to three weeks after rash onset. Measles can infect anyone of any age, but most of the burden of disease globally is still among children < 5 years of age.