What Retail Clinicians Should Know About Measles

Although measles was once endemic, most health care workers today have not seen a case of this highly contagious infection in their practicing years. The measles virus does resurface sporadically, however, as seen in the United States in recent years.

It is important for health care providers to arm themselves, their community, and their travelers to protect against measles virus import and outbreaks. When a case of measles is suspected in the convenient care setting, clinicians must identify the clinical picture and know what to do.

According to textbook definitions, the incubation period for this highly contagious viral disease averages from 10 to 12 days, beginning with high fever of 103 to 105 degrees Fahrenheit; severe upper respiratory symptoms; coryza, cough, conjunctivitis (referred to as the 3 Cs); then Koplik spots followed by the measles rash in 14 days, which can range from 7 to 21 days.¹

The rash begins as an erythematous, maculopapular eruption on the upper face, extending down the body to involve the extremities including palms and soles. Koplik spots are bluish-gray specks on a red base located on buccal mucosa near the second molars and pathognomonic for measles.²

Back when inactive measles vaccine was administered between 1963 and 1967, atypical measles occurred in this vaccinated population.³With the live measles vaccine given today, however, atypical measles is now uncommon.

The atypical response is a rash beginning peripherally instead of cephalocaudally and centrifugally. This atypical rash is characterized as urticarial, vesicular, or hemorrhagic in nature.³

Although the measles rash is less popular in the clinical setting, it is certainly not one to miss.

Epidemiology of Measles

Humans are the only host of the measles virus. Transmission is most often via direct contact of infectious droplets and less commonly via airborne particles.³

Fortunately, the measles virus rapidly inactivates with a short lifespan of less than 2 hours.³Peak measles incidence is late winter and spring, often occurring in young children and adolescents.

Measles in the United States decreased by 99% after the measles vaccine was first licensed in 1963. Later, from 1989 to 1991, measles incidence spiked because of low immunization rates.¹

Upon improved uptake of the vaccine in addition to a second dose of the measles-mumps-rubella (MMR) vaccine, the incidence of measles again declined and year-round measles transmission ceased. By 2000, the measles endemic ended.¹

Measles Today

Present day is considered to be in the post-elimination era. Today, measles outbreaks are blamed primarily on the lack of global control causing importation of measles disease and spread from those imports.

According to the 2015Red Book, 514 measles cases from 16 outbreaks occurred in 20 states in the first half of 2015.¹In 2013, approximately 145,700 measles-related deaths occurred globally, primarily in developing countries.³

Therefore, it is important for retail clinicians to identify travelers and provide immunizations prior to departure in order to protect travelers and the community upon their return.

Diagnosis of Measles

Suspected measles cases must be reported to the US Centers for Disease Control and Prevention (CDC) immediately or within 24 hours. The diagnosis can be made based on serum levels of measles-specific immunoglobulin M (IgM) antibody.¹

Acceptable methods of sampling include urine, blood, or throat/nasopharyngeal secretions. A state public health laboratory or CDC Measles laboratory will process the viral specimens.

While assays are often positive on the day when the rash is present, false-negative results can occur for up to 72 hours after rash onset. In the case of a false negative, retesting after 72 hours is suggested if the rash continues.

For those immunized against measles with 1 or 2 vaccine doses, a positive IgM may be transient and difficult to detect. The measles laboratory will determine the most appropriate testing based on the circumstances.

Treating Measles

While treatment of measles in other countries includes the use of ribavirin, the drug is not approved for this indication in the United States.¹

Because children with measles have been found to have low vitamin A serum levels, a 2-day, once-daily treatment of vitamin A is recommended for all children with acute measles infection.¹There are no antiviral medications to treat measles in the United States.

Controlling Measles Outbreaks

Isolation is the best method to control measles, specifically in the form of airborne transmission precautions for a minimum of 4 days after rash onset.¹

For immunocompromised persons, isolation should continue for the duration of illness. For all susceptible patients exposed to measles, airborne precautions should be put into place from day 5 after exposure until day 21.¹

Preventing Measles Outbreaks

Live measles virus-containing immunization is the best method for protection.

Ideally, the first dose is given to children between ages 12 and 15 months, and it should be a requirement prior to entry into pre-school.¹By school entry, children should be given a second dose.

The childhood vaccine schedule recommends that the second dose be given at age 4 through 6 years. This dose is not considered a booster; instead, it is meant to protect up to 5% of the population that is not fully protected by the first dose alone.¹

When providing catch-up vaccinations, a minimum of 28 days should space both doses.³When a young child is traveling internationally and is between ages 6 and 11 months, an early dose of MMR should be considered.¹

An early dose of MMR will not count as a valid dose for the childhood vaccine schedule, but it will provide protection. It is ideal for the child to receive the vaccine 2 weeks prior to travel so that the antibodies have time to develop.

The dose of measles-containing vaccine is 0.5 mL administered subcutaneously.1 Measles vaccine is a live, attenuated strain prepared in chicken embryo cell culture.

No reaction is likely if the patient is allergic to eggs or has a non-anaphylactic allergy to neomycin.¹Immunization should only be avoided if there is a severe hypersensitivity (anaphylaxis) to neomycin or gelatin.

The measles vaccine is available in combination formulations along with mumps and rubella (MMR), as well as a combination with varicella (MMRV).³The first dose of MMRV vaccine is only indicated for children ages 12 months to 12 years. Children with HIV should not receive the MMRV vaccine due to lack of safety data.

A single-antigen measles vaccine is no longer available in the United States.

Besides receiving 2 doses of a live measles-containing vaccine such as MMR, immunity can also be evidenced by laboratory confirmation of immunity or by having the disease itself.3 Those born before 1957 are also considered immune because they would have been 6 years or older before the vaccine was developed and would likely be immune from natural infection.

Despite their date of birth, health care workers are often required to provide laboratory confirmation of measles immunity.

Measles Complications

Measles is not a minor viral illness.

Up to 30% of those with measles infection experience complications from diarrhea, otitis media, bronchopneumonia, and laryngotracheobronchitis (croup). One in every 1000 individuals with measles infection will develop encephalitis, and another 1 to 2 cases per 1000 will die from devastating respiratory and neurological complications.³

Even 7 to 10 years after a measles infection, a rare condition called subacute sclerosing panencephalitis (SSPE) can cause fatal degenerative disease of the central nervous system (CNS) characterized by behavioral and intellectual deterioration and seizures.³Vaccination does not adequately protect immunocompromised people who are most vulnerable to the more severe CNS manifestations of disease.

Measles Outbreaks

During an outbreak, exposed individuals should be offered the MMR vaccine if they lack evidence of measles immunity.

Affected infants in a community-wide outbreak should be offered the MMR vaccine between ages 6 and 11 months.¹This dose would not count as a valid dose; rather, it would need to be followed by 2 valid doses beginning after age 12 months.

Based on local epidemiology of an outbreak, a health department may decide to provide a second dose of MMR between ages 1 and 4 years, rather than ages 4 through 6 as indicated by childhood immunization schedules.¹

Measles Vaccination Pearls

Because so many immunizations are provided in the convenient care setting, it is worth mentioning possible adverse effects from the MMR vaccine. Clinicians should discuss these with patients and parents in anticipation of possible side effects.

Approximately 5% to 15% of vaccine recipients will experience a fever of up to 103 degrees Fahrenheit. Fever usually occurs between 6 and 12 days after immunization and may last 1 to 2 days or as long as 5 days.¹

Of those with a fever, up to 5% may experience a rash that is not considered contagious. Up to 1 in 3000 may experience a febrile seizure 5 to 12 days after immunization.¹

Because adverse effects tend to occur in those who are not already immune, a reaction to a subsequent dose of MMR would be much less severe.

Summary

Measles is real, so recognition of the signs and symptoms is crucial. Clinicians in convenient care settings must report suspected cases immediately and prevent further outbreak.

We can do our part to improve the statistics from 1 in 8 unimmunized to a significantly more immunized community, protecting the patients we serve from the measles virus.³This can be done through screening and making strong recommendations for immunizations such as the MMR vaccine for our local communities, as well as for our patients traveling abroad.

Amy Warner, DNP, FNP-C, ACNS-BC, is dual board-certified as a clinical nurse specialist and family nurse practitioner and has 23 years of health care experience. She is a clinical educator with the Healthcare Clinic in Walgreens and resides in Atlanta, Georgia. Amy’s background includes family practice, comprehensive preventive health screenings, and occupational health. She is most passionate about disease prevention and health strategies.

References

1. 2015 Report of the Committee on Infectious Diseases: Early Release from Red Book, 2015 American Academy of Pediatrics. February 20, 2015. Available from: http://redbook.solutions.aap.org/DocumentLibrary/2015RedBookMeasles.pdf.

2. Uphold CR, Graham MV. (2013). Clinical Guidelines in Family Practice, Fifth Edition. Gainesville: Barmarrae Books.

3. CDC. Measles. http://www.cdc.gov/vaccines/pubs/pinkbook/downloads/meas.pdf. Accessed in October 2015.

4. Kimberlin, DW. 1 in 8 U.S. Kids Not Protected Against Measles: Report.HealthDay. https://www.nlm.nih.gov/medlineplus/news/fullstory_155050.html. Accessed on October 8, 2015.