Plagues and Peoples
Course Reader: Measles (Rubella)
November 9, 2010.
- Measles is also known as rubeola, hard measles, red measles, 9-day measles, morbilli, hasbah is a common,
acute, viral infectious disease, principally of children.
- Symptoms: Fever, typical red, blotchy rash combined with cough, coryza (common cold), or conjunctivitis
- A vaccine-preventable disease, and its vaccine is one of the vaccines included in the Expanded Programme
on Immunication (EPI) of the WHO.
Etiology and Epidemiology
- Measles is caused by a virus which is in the genus Morbillivirus of the family Paramyxoviridae.
- One of the most highly communicable diseases, transmitted by contact of susceptible individuals with the
nose and throat secretions of infected persons primarily by droplet spread.
- Infection also occurs by direct and indirect contact through freshly soiled articles and airborne
- No reservoirs of measles other than human beings.
- Period of communicability is from slightly before onset of symptoms (prodromal phase) to 4 days after the
start of the rash.
- Incubation period from time of exposure to onset of fever of about 10 days with a range from 8 to 13 days.
- The incubation period from time of exposure to rash onset is about 14 days.
- Primarily an endemic disease of children (highest for under 2 years of age).
- Epidemic measles has a winter-spring seasonality in temperate climates and a less marked hot-dry
seasonality in equatorial regions.
- No racial or gender differences.
- Measles mortality is highest in the very young and very old.
- Fatality rate of 5 – 10 % or more in malnourished children in developing countries.
Distribution and Incidence
- Measles distributed worldwide.
- Estimated 50 million cases and 1.5 million deaths caused annually by measles in developing countries.
- Infants usually have a passive immunity to measles as a result of maternal antibodies acquired
transplacentally from immune mothers. This protects the child for 6 – 9 months.
- Measles infection induces a lifelong immunity.
- Methods for confirming infection and immunity: serological tests, fluorescent antibody techniques, and
isolation of the virus from patients during the acute phase of the disease.
- A single dose of live attenuated measles virus vaccine confers long-term, probably lifelong, immunity in
over 95 percent of susceptible individuals.