2013 on Track to Becoming Worst Measles Year Since 1996
According to the CDC's latest Morbidity and Mortality Weekly Report (MMWR), a total of 159 measles cases were reported to the CDC from 16 states and New York City during January 1–August 24, 2013.
Among the 159 reported cases:
- 58 patients (36%) were aged 5–19 years old
- 17 required hospitalization, including four patients diagnosed with pneumonia
- 157 (99%) were import-associated; 42 importations from 18 countries reported
- Majority of genotypes identified are D8 (47 cases)
Most cases were identified in patients who were unvaccinated (n=131) or had unknown vaccination status (n=15). Thirteen (8%) of the patients had been vaccinated, of whom three had received 2 doses of measles, mumps, and rubella (MMR) vaccine.
Eight outbreaks have accounted for 77% of the cases, with the largest outbreak having occurred in New York City since 1996. None of these patients had documentation of vaccination at the time of exposure.
The second largest outbreak was in North Carolina that occurred mostly among patients not vaccinated because of personal belief exemptions. As of August 24th, an ongoing outbreak in Texas has confirmed 20 cases among members of a church community.
Measles is a highly contagious, acute viral illness that can lead to complications and death. By the standard case definition, a measles case is confirmed in a person with febrile rash illness and laboratory confirmation or a direct epidemiologic link to a confirmed case.
Measles elimination was declared in the U.S. in 2000 but importation of measles cases continued to occur. Cases are considered imported if exposure to measles virus occurred outside the U.S. 7–21 days before rash onset and rash occurred within 21 days of entry into the U.S., with no known exposure to measles in the U.S. during that period.
During 2001–2012, the median annual number of measles cases reported in the U.S. was 60 (range 37–220) with four reported outbreaks.
Since elimination, the highest numbers of U.S. cases were in 2008 with 140 cases and 220 cases in 2011. If measles cases continue to grow at the current rate, the number of cases will most likely surpass that of 1996.
These outbreaks show that unvaccinated patients place themselves and their communities at risk for measles and that high vaccination coverage is important to prevent the spread of measles after importation.
For more information call (888) 232-4636 or visit the Morbidity and Mortality Weekly Report page.