On April 29, 2019, the Centers for Disease Control and Prevention (CDC) released an MMWR article about the increase in measles cases in the U.S. Additionally, CDC hosted a telebriefing about the topic; visit this website to find the audio recording and transcript.
Measles was eliminated in the United States in 2000, but during January 1–April 26, 2019, a total of 704 cases were reported, the highest number of cases reported since 1994. Outbreaks in close-knit communities accounted for 88% of all cases. Of 44 cases directly imported from other countries, 34 were in U.S. residents traveling internationally; most were not vaccinated.
Unvaccinated U.S. residents traveling internationally are at risk for acquiring measles. Close-knit communities with low vaccination rates are at risk for sustained measles outbreaks. High coverage with measles, mumps, rubella (MMR) vaccination is the most effective way to limit transmission and maintain elimination of measles in the United States.
Here are some key points about the MMWR:
- Based on the cases received during this time period, this is what CDC knows about the age ranges of those that were affected:
- The median age of the patients reported was 5 years.
- About 1 out of every 4 cases was a child between 16 months and 4 years old.
- 71% of the individuals with measles were unvaccinated, and another 18% had an unknown vaccination status. 11% were vaccinated.
- Overall, 66 (9%) patients were hospitalized and 24 (3%) had pneumonia. No deaths or cases of encephalitis were reported to CDC.
- There have been 13 outbreaks reported in 2019. Six outbreaks occurred in under immunized close-knit communities and account for almost 90% of all cases.
- New York and New York City have accounted for 67% of all of the reported measles cases this year so far.
- The vast majority (98%) of the cases were U.S. residents. Forty-four of the cases were the result of an international traveler (usually a U.S. resident) becoming infected in another country and returning to the United States.
- 9 out of 10 of those individuals who became infected during international travel were either unvaccinated or had an unknown vaccination status, although all were eligible to get vaccinated according to their ages.
- The top three countries where travelers became infected so far in 2019 include the Philippines, Ukraine, and Israel.