Possible Measles Cases in Northwest Arkansas

The Arkansas Department of Health (ADH) has been notified of 3 siblings (ages 10,14 and 17 years) with presumptive measles. One of the three siblings recently returned from travel to Romania, Italy and Switzerland and developed symptoms consistent with measles shortly after returning to Arkansas on August 9th. His two siblings subsequently became ill while attending the same residential (boarding) school (Ozark Adventist Academy) in Benton County. None of the three have received measles vaccine. At this time, the diagnosis is based on the signs and symptoms consistent with measles, but laboratory confirmation is pending. Students and staff who cannot document measles vaccination have been sent home. The period of risk for contacts of the symptomatic students is from August 9th and will continue until we document the absence of secondary cases.

We are notifying providers who might see contacts of these patients. If a suspected measles case is noted, please notify your local ADH health unit. In addition, please collect a nasopharyngeal specimen for viral culture and serum for measles IgM. Call after collection of specimens, and ADH will give guidance on how to submit the samples.

Students who are older than 5 years old and have had only a single MMR are considered under-immunized, since approximately 5% of those with primary immunizations do not respond. Students who are eligible for immunization should be encouraged to receive the MMR vaccine as soon as possible. Those who cannot be immunized due to medical conditions and have had contact with a probable or proven case should consult their physicians regarding  passive immunotherapy (IVIG).

Update on Measles Worldwide and in the US:
Reported cases of measles in the US rose significantly in 2011 to 222 cases, many associated with international travel or immigration. As of August 18th, there have been 44 cases in 2012.  Worldwide case reporting lags somewhat, but there has been a downward trend over the last several years correlating with increased vaccination coverage (see table below). Nevertheless, pockets of disease persist, and travelers are particularly at risk if unimmunized.

Potential Case Identification and Testing:
Health care providers, please consider measles in the differential of a person who presents with fever ≥101o Fahrenheit, rash, and cough, runny nose (coryza), or conjunctivitis in the absence of an alternative explanation – especially if they have a history of recent international travel or recent contact with international travelers.  Initial workup should include measles specific IgM antibody testing.  Any positive serologic test or person meeting the clinical case definition with a travel history or link to a confirmed case should be reported immediately to the ADH to initiate contact tracing and control measures.   Thankfully, as measles is still rare in the US, positive tests are often ‘false positives.’   Any initial positive testing must be confirmed with additional testing at the CDC to be considered a case.

Measles is an exceptionally infectious respiratory virus that is transmitted by contact with an infected person through coughing and sneezing.  It has been known to cause explosive outbreaks, and in some cases,the secondary attack rate (or reproductive rate) for measles has been observed at 12-18 secondary cases per primary case.   Put another way, in a completely susceptible population, in just three generations of infection, up to 5,832 people could be involved.  Measles is one of the most severe febrile rash illnesses and can cause severe health complications, including pneumonia, encephalitis, and death.

The above cases reinforce the importance of MMR vaccination.  Unfounded concerns that MMR might cause autism and the false perception that the disease has vanished have contributed to declining immunization levels, which compromise effective community immunity.  Because of measles’ extremely high infectivity, to prevent ongoing transmission we need roughly 95% immunization coverage.

As a public health physician, I cannot emphasize more strongly that outbreaks of measles are preventable with the MMR vaccine.  We have the tool; we just need to use it.  Please do not miss opportunities to promote and provide MMR vaccination.

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J. Gary Wheeler, MD, MPS
Branch Chief, Infectious Diseases