Measles is a viral infection that many NPs have studied but few have actually diagnosed because of the effectiveness of the measles, mumps, and rubella (MMR) vaccine. The US achieved elimination status with the World Health Organization (WHO) in 2000 after no continuous transmission of measles occurred for 12 straight months. In early 2019, the WHO declared vaccine hesitancy one of the top 10 threats to global health.1 By the fall of 2019, the US reached a record-high number of measles cases—over 1,200 in at least 31 states—jeopardizing the nation's elimination status.2
Complications of measles occur in more than 30% of infected patients. Acute encephalitis occurs in 2 of every 1,000 measles cases with a case fatality rate of 15% and permanent residual neurologic impairment in 25% of encephalitis cases. Death occurs in 2 per every 1,000 measles cases, with 60% of measles deaths caused by pneumonia.3 In the US, MMR vaccine coverage rates, or the amount of people vaccinated, are at 91%, but a minimum of 95% coverage is needed to prevent transmission. State MMR coverage rates range from a low of 85.8% in Missouri to a high of 98.3% coverage in Massachusetts according to the 2017 National Immunization Survey of states' 19- to 35-month olds.4 However, certain counties have been identified as being at higher risk for measles based on state vaccine exemptions laws, international travel, population, and measles cases.5
Although the recent rise in measles cases in the US is cause for concern, there are actions NPs can take to help prevent the spread of this virus. This article covers epidemiology, risk factors, pathophysiology, clinical presentation, diagnosis, management, and prevention of measles. Patient resources and a measles preparedness checklist for clinicians are provided.
The US reported only 37 measles cases in 2004, the nation's record low. Before the record high in 2019, the US saw a spike in 2014 with 667 cases.6 Major measles outbreaks are also occurring in Israel, Venezuela, Ukraine, and the Philippines. As of April 29, 2019, the US had recorded 44 cases of Americans importing the measles back to the US after traveling internationally; once in America, the virus then spreads mostly to children too young to receive the MMR vaccine.7 The 2019 US outbreak has the highest concentration of infection in New York's ultra-Orthodox Jewish community, contributing to over half of all US cases. A combination of factors are currently contributing to measles outbreaks, including increased cases of measles around the globe because of public health challenges in some countries, international travel to measles-endemic areas, and an increase in MMR vaccine refusal caused by misinformation spread by the organized antivaccination movement.7
Those without immunity have the highest risk of contracting measles. Some of the most vulnerable patient populations include infants younger than 1 year who are not yet vaccinated and pregnant women and their fetuses.8 Immunocompromised people are also at risk; these include patients who have received a heart transplant and adults on immune-modulating medications who are unable to receive live vaccines such as the MMR vaccine.
However, because of misinformation about the MMR vaccine spread via social media, more people are at risk because of delayed or refused MMR vaccination. This is why NPs must advocate strongly in their clinics, at their state legislatures, and on social media that the MMR vaccine is one of the most well-studied, safest, and effective medical interventions available.9 Delaying or refusing the MMR vaccine puts that person, as well as others in the community, at risk. Like following traffic laws, vaccination is a civic responsibility in a society with shared social contracts that include not spreading preventable infectious diseases.
When inhaled, measles virus targets immune cells in the nose, throat, lungs, and corneas, focusing on CD150 stem cells that allow the virus to invade, rapidly replicate, and spread to immune cells of the bone marrow, tonsils, lymph nodes, and spleen with newly made viral particles moving to the respiratory tract and out, spreading the contagion to others. Science suggests an immune amnesia occurs as the virus attacks and destroys memory T and B lymphocytes from previous infections, which can make the patient susceptible to other infections for months to years after recovering from measles.10,11
One of the great challenges of measles is that it presents typically in late winter into spring and appears like other common upper respiratory tract infections (URTIs).12 Presenting symptoms typically include high fever (104° F or higher [40° C or higher]), cough, coryza, and conjunctivitis. This typical URTI prodrome lasts just 2 to 4 days and is followed by 1 day of Koplik spots (bluish, pearly lesions the size of a grain of sand appearing on the buccal mucosa and posterior pharynx, which is usually quite erythematous). (See Koplik spots.) Koplik spots are fleeting just prior to rash onset and are pathognomonic for measles. Cough, while present in all measles cases, is not diagnostic alone, such as with the classic whoop of pertussis. Conjunctivitis severity varies, developing early in the infection, often before rash onset, and can be accompanied by photophobia and increased lacrimation.13
The tell-tale sign of measles is the characteristic rash. It appears as a maculopapular erythematous rash starting around the hairline or face and moving down the trunk and limbs until it becomes nearly a confluent erythematous rash, clearing in the order it presented. (See The measles rash.) The day and time of the first sign of rash is a critical piece of history to gather and document. This marks the infectious period, which is 4 days before and 4 days after the rash onset day. Infection preventionists and local public health teams require this information from clinicians to determine potential exposures.
One key difference of measles from other common viral rash illnesses is that children with measles are toxic-appearing and look quite miserable. They often have photophobia, are not drinking or eating, cannot get comfortable, and look sick compared with a happier child with a URTI and viral exanthum. Likewise, a child with a post-MMR vaccine-associated measles rash (5% of vaccinations) will have a low-grade fever and not appear toxic.14 Hospitalized children with acute measles typically are admitted with dehydration, keratitis, otitis media, and pneumonia and need I.V. fluids and respiratory support. Uncommonly, intensive care is required.15,16
The final phase of measles is the resolution and complication phase. For most, this may be a similar recovery phase after other viral illnesses. However, impact on the immune system is a critically important detail for NPs to explain to parents who are refusing the MMR vaccine for their child, as it not only will prevent measles, but it may prevent other infections that occur in the immune recovery phase. The most significant complication of measles is subacute sclerosing pan-encephalitis (SSPE), a devastating and always fatal consequence of measles that can occur 1 to 10 years after infection; it involves slow loss of neurologic functions until death. Although most children will have a rash illness they recover from, clinicians vaccinate against measles to prevent death from pneumonia, encephalitis, and SSPE.12
In addition to the clinical picture described earlier, measles is best diagnosed with a polymerase chain reaction (PCR) from nasal, throat, or nasopharyngeal swab. This allows the quick turnaround needed when working in a measles emergency. These swabs are usually sent to the state public health labs and can be resulted within 24 hours. Few state health labs also have a PCR that can distinguish between wild-type measles infection versus vaccine-associated measles. State labs may send this type of testing to the CDC, who can verify and help prevent unnecessary exposure workup because vaccine-associated measles is not contagious to others. Serology is not recommended for measles diagnosis, as the result is usually returned several days later, which is not timely enough for a measles emergency and is often equivocal.12
There is no antiviral treatment available for measles. Most interventions are supportive care, such as I.V. fluids for dehydration, antibiotics for secondary otitis media, and ventilatory support for pneumonia or severe respiratory failure. Children with low vitamin A concentrations have more-severe measles. The WHO currently recommends vitamin A for all hospitalized children with acute measles, regardless of their country of residence. Vitamin A for treatment of measles is administered once daily for 2 days, at the following doses:17
- 200,000 international units for children 12 months or older
- 100,000 international units for infants 6 through 11 months
- 50,000 international units for infants younger than 6 months.
An additional age-specific dose of vitamin A should be given 2 to 4 weeks later to children with clinical signs and symptoms of vitamin A deficiency.18 In a study, Hester and colleagues noted only 39% of US children hospitalized with measles received the vitamin A needed.15 Postexposure prophylaxis for susceptible people exposed to measles is to administer the MMR vaccine within 72 hours of exposure, or a single dose of I.M. immune globulin (IMIG 0.50 mL/kg to maximum dose of 15 mL) within 6 days, or I.V. immune globulin (IVIG 400 mg/kg) for immune-compromised pregnant women.18
One dose of MMR vaccine given at 12 to 15 months confers 93% coverage to prevent measles. A second dose typically given at the prekindergarten visit around the patient's fourth or fifth birthday raises the coverage to 97%. This is not a booster dose; it is a second dose to cover the 5% of patients who are nonresponsive to the first dose. If traveling to locations where the measles virus is present, babies ages 6 to 12 months may have an early MMR vaccine for protection that will need repeating after their first birthday, followed by a second dose that for any age can be given at a minimum interval of 28 days later. For members of the military, international travelers, and healthcare professionals, two doses of the MMR vaccine documented with a minimum of 28 days apart is all that is needed for proof of immunity. Drawing serology is not recommended. Adults born before 1957 are considered immune because measles was endemic in that era. A third MMR vaccine is not typically recommended in a measles outbreak.2
NPs' confident science-based support of vaccination has never been needed more than now. More disease and eventual death will be the result of the negative influence of social media and the spread of misinformation.19 Healthcare clinicians are a trusted source on vaccination, and studies show this is where most parents still place their trust.20 Educate with the presumption the family is at that visit to follow clinical recommendations. Listen first, then determine what is motivating a parent or patient's fears and hesitations. Finally, talk over the parent or patient's concerns while providing reliable resources. (See Vaccination resources.)
Implications for clinical practice
When measles is in a community, there are two primary interventions that will help stop the outbreak. One is to increase community immunity by vaccinating all eligible members of that community. The other is to reduce transmission in healthcare settings like clinics and EDs, as well as in schools, day cares, and other public places. NPs can use good phone triage to detect possible measles and safely direct patients for care without exposing others. Many clinics do not have negative airflow or Airborne Infectious Isolation (AII) rooms. When AII rooms are not available, patients must be masked and enter the least publicly accessed door. Patients with suspected measles cases should be roomed farthest away from other patients with a portable air filtration system placed outside the room. For children going to an ED, clinicians or parents should call ahead and make sure ED staff are ready with an available AII room and the staff know to wear N95 masks even if they have been vaccinated.
NPs are in a significant position to turn back the incidence of measles by vaccinating patients on schedule with confidence. Communicate clearly that the MMR vaccine is safe in combination, does not cause autism, protects against a deadly disease, and is the best protection against severe adverse reactions, such as blindness, deafness, or other neurologic or immunologic impairments.21 In addition to vaccinating, clinicians can prepare for the worst and hope for the best using the measles preparedness checklist for managing outbreaks.22 (See Measles preparedness checklist.)
NPs can help educate parents by offering easily accessible websites such as:
- Centers for Disease Control and Preventionwww.cdc.gov/vaccines
- Children's Hospital of Philadelphia Vaccine Education Centerwww.chop.edu/centers-programs/vaccine-education-center
- National Foundation for Infectious Diseaseswww.nfid.org
- Immunization Action Coalitionwww.immunize.org.
Measles preparedness checklist
Use the following checklist with response teams as a discussion guide and self-assessment. Highlight the areas that need more planning, develop an action plan, and then simulate readiness.
- Do we have a strong relationship with local/state public health officials?
- Do we work closely with individuals in public health to quickly consult?
- Can our ED/clinics recognize measles rash to promptly isolate?
- Do our teams know internal and external experts to call if they suspect measles?
- Does our lab and/or state health department have lab capability to quickly perform measles PCR tests?
- Is the measles PCR lab order an easily accessible order set?
- Are we proficient in the Hospital Incident Command System (HICS) for an infectious disease outbreak situation?
- Are internal communications systems easily accessible for measles updates? Are those updates user-friendly?
- Can our communications department make signage and internal FAQs as well as manage translations and external media responses?
- Do we have AII isolation rooms? If not, are facilities ready to create an AII room? Do we have enough AII rooms? What is our backup plan in the event of a surge of measles patients?
- Can we run a report to identify potentially exposed patients who shared air space with someone with measles in the ED waiting rooms/patient rooms/inpatient rooms?
- Are potential infectious disease exposure questions part of the ED triage screening process? Do we have a question that would capture measles exposure?
- Does our facility carry a supply of IMIG? If not, do we know how and where to get it quickly or where to send patients to get it? Who would lead that postexposure prophylaxis process?
- Do we have a standing order for IMIG post measles exposure in EHR?
- Are our healthcare professionals vaccinated with two doses of the MMR vaccine or do they have other proof of immunity on file?
- Who would our resources be to call exposed patients? Can we access an interpreter as needed after hours?
- Who will work with public health in determining criteria of a suspect case and when testing is needed?
- Do we have a clear procedure for transport of a patient with measles prior to arrival and safe rooming of measles and other highly infectious diseases? Have we drilled to prevent spread in our waiting areas?
- Is the organization clear that one case of measles is an infectious disease emergency?
- Are clinicians aware of the need for vitamin A therapy in the first 2 days after diagnosis?
- Can clinicians articulate to families the potential immune suppression and at risk for future infections in the months to years following measles?
- Do we have a staff education plan for the above?
3. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases
. 13th ed. Chapter 13: Measles
5. Sarkar S, Zlojutro A, Khan K, Gardner L. Measles
resurgence in the USA: how international travel compounds vaccine resistance. Lancet Infect Dis
8. Robinson DP, Klein SL. Pregnancy and pregnancy-associated hormones alter immune responses and disease pathogenesis. Horm Behav
9. Greenwood B. The contribution of vaccination to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci
11. Mina MJ, Metcalf CJ, de Swart RL, Osterhaus AD, Grenfell BT. Long-term measles
-induced immunomodulation increases overall childhood infectious disease mortality. Science
12. Bester JC. Measles
vaccination: a review. JAMA Pediatr
13. Cherry JD. Measles
virus. In: Cherry J, Demmler-Harrison GJ, Kaplan SL, Steinbach WJ, Hotez P, eds. Feigin and Cherry's Textbook of Pediatric Infectious Diseases
. 8th ed. Philadelphia, PA: Saunders; 2019.
14. Sood SB, Suthar K, Martin K, Mather K. Vaccine-associated measles
in an immunocompetent child. Clin Case Rep
15. Hester G, et al Demographics, complications, and resource utilization for patients hospitalized for measles
across United States Children's Hospitals. Pediatr Infect Dis J
16. Hester G, Nickel A, LeBlanc J, et al Measles
hospitalizations at a United States children's hospital 2011-2017. Pediatr Infect Dis J
17. D'Souza RM, D'Souza R. Vitamin A for treating measles
in children. Cochrane Database Syst Rev
20. Freed GL, Clark SJ, Butchart AT, Singer DC, Davis MM. Sources and perceived credibility of vaccine-safety information for parents. Pediatrics
. 2011;127(suppl 1):S107–S112.
22. Stinchfield PA. Are You Ready for a Measles
Outbreak? Association of Professionals in Infection Control (APIC) national conference presentation. Orlando, 2013. Minneapolis, 2018.