News & Views: Have You Ever Diagnosed Measles?

In the first five months of 2014, the United States has experienced more cases of measles than in the first five months of any other year since the disease was declared eliminated in 1994. Indeed, the U.S. Centers for Disease Control and Prevention (CDC) recently announced in the MMWR that to date, during 2014, 288 cases of measles have been diagnosed in 18 states and New York City. Of the cases, almost 80 percent were from 15 separate outbreaks with the largest occurring in Ohio among unvaccinated Amish communities. As of June 16, 2014, more than 400 cases of measles have been reported.

So, what does this mean for healthcare providers?

Increasingly, someone could come into your office ill with measles. For many healthcare providers, this has never happened before. In fact, in the CDC’s recent MMWR announcement, the authors indicated misdiagnoses of measles as Kawasaki disease, dengue and scarlet fever as well as other illnesses.



Measles diagnosis can be confused with other illnesses because of its common presentation as a rash accompanied by fever. When a patient has these symptoms, the following should also be considered to help distinguish measles from other possible illnesses:

• Recent travel, particularly to measles-endemic regions
• Two to four days of cough, coryza, conjunctivitis, and aversion to light prior to onset of fever and rash
• Presence of Koplik’s spots on the back of the palate – the spots are irregular in shape and red with blue-white centers
• Rash that typically starts at the hairline and progresses from head to trunk to extremities
• Resolution of fever shortly after rash develops

Children presenting with measles typically appear to be miserable.

What if I suspect that a patient has measles?

Patient isolation and measles containment

Measles is one of the most contagious diseases spreading most commonly, but not only, via large droplets. The virus is so contagious that if a susceptible person occupies an elevator or other enclosed space up to four hours after a person infected with measles, he or she is likely to be infected. The period of highest contagion is four days before to four days after onset of rash. Because of this ease of spread, it is imperative to isolate infected patients from susceptible patients, such as those who are too young to be immunized. Methods for decreasing chance of transmission in the waiting room include the following:

• Train front office staff and post signs urging communication and observations related to presence of respiratory symptoms, rash or suspected exposure to an infectious disease.
• Immediately isolate suspected cases in an exam room, or minimally, separate well-visit and sick-visit waiting areas.
• Provide masks for patients – and any symptomatic caregivers -  who might be contagious, if possible.
• Implement special precautions so that immune-compromised patients are aware that that they should alert front office staff of their increased susceptibility upon arrival.

Current isolation precautions were published in 2007 and can be accessed online. Isolation procedures for infections transmitted via airborne routes in ambulatory settings can be found on pages 58-9 of the document.

Laboratory confirmation

Get a serum sample and throat or nasopharyngeal swab from the patient. A urine sample may also contain viral proteins. The most common tests are an IgM test and a real-time polymerase chain reaction (RT-PCR) test; either of these can typically be used for laboratory identification of measles. The CDC has a comprehensive section on its website related to measles lab tests.

Health department notification

Suspected cases of measles should be reported to local public health officials within 24 hours.

Vaccination

The MMR vaccine should be given at 12 to 15 months of age with a second dose between 4 and 6 years of age as recommended on the approved immunization schedule. The current measles outbreaks provide a compelling argument for not choosing to delay the MMR vaccine. Two studies provide additional reasons for children to be immunized as soon as they are of age:

• Delayed immunization (in the second year of life) increases the risk of febrile seizures – A recent paper in Pediatrics(PDF) by Simon J Hambidge and colleagues found that when the MMR (or MMRV) vaccine was given between 16 and 23 months of age, the risk of experiencing a fever-associated seizure following the vaccination was significantly greater than when the vaccine was given between 12 and 15 months of age.
• Risk of suffering the fatal complication of measles known as subacute sclerosing panencephalitis (SSPE) is greater following infection with measles at an earlier age – This paper from Germany by Katharina Schönberger and colleagues identified cases of SSPE in Germany and attempted to calculate the risk of developing this complication following an acute measles infection. Although the data set was small, their finding, that the risk of developing SSPE is greater in individuals who are infected with measles in the first few years of life than in those who are infected later, agrees with findings from other studies.
  
  
  
  Because maternal antibodies can interfere with the development of a protective immune response in the first year of life, the authors conclude by pointing out that the findings related to SSPE make the protection afforded by strong herd immunity in the first year of life all the more important.

Medscape recently posted a special report on measles with a wealth of information, including a two-and-a-half minute video by Dr. Offit discussing the recent cases of measles in the U.S.