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Public Health - Seattle & King County


Measles is one of the most highly contagious diseases, but is preventable through vaccination. The measles virus is spread through coughing and sneezing. Before widespread use of measles vaccines there was an average of half a million measles cases and hundreds of deaths each year in the United States. Measles is common in many parts of the world, including both industrialized and developing countries. Local cases of measles are often linked to travel or exposure to recent travelers. Worldwide, more than 20 million people are infected each year. Measles is the leading cause of vaccine-preventable death among children in the world.

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Measles in King County

Purpose of surveillance:

  • To facilitate prompt diagnostic testing
  • To identify cases and exposed persons at risk for transmitting measles to others
  • To identify susceptible contacts of cases for post-exposure prophylaxis or preventive treatment
  • To implement disease control measures to prevent transmission

Measles Case Data in King County

Local epidemiology:

Four measles cases were reported in 2013. Two cases were in unimmunized siblings. One sibling became ill after returning from a trip to Germany and Spain, the other sibling was a secondary case. One case was in an unimmunized child who had recently been adopted from China. Other children who were adopted at the same time from the same agency and went to other parts of the United States were also diagnosed with measles. The final case was in an infant who was too young to be vaccinated and became will after a trip to the Philippines.

In recent years, all measles cases in King County have been imported from other countries or linked to an imported case. In 2010, a child adopted from India was infected with measles before arriving in the United States.

Each year in Washington state fewer than 10 cases are reported.

Immunization levels at King County schools

Look up immunization levels at King County schools on an interactive map

Questions and answers about measles for childcares and schools