Measles Virus - Rubeola

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • Suspicious rash with clinical syndrome
  • Known exposure to measles by an unvaccinated person
  • Confirmation of immunity to measles after vaccination

Criteria for Diagnosis

  • Acute febrile rash with ≥1 of the following (CDC, 2013)
    • Isolation of measles virus from clinical specimen
    • Detection of nucleic acid specific to the measles virus using polymerase chain reaction (PCR)
    • Significant rise in measles IgG antibody or IgG seroconversion
    • Positive test for measles IgM antibody
    • Established epidemiologic link to a confirmed case

Laboratory Testing

  • Measles testing recommendations (CDC)
  • Serum testing for antibodies
    • Confirm acute infection with measles using IgM and IgG serial testing – IgM is very sensitive if performed 2-3 days after onset of rash
    • Confirm seroconversion after vaccination using IgG testing
  • Viral culture
    • Nasopharyngeal and blood cultures are most sensitive if collected during prodrome up to 1-2 days after onset of rash
    • Virus can be isolated from urine culture up to 1 week or more after onset of rash
    • Difficult to isolate from cerebrospinal fluid (CSF) and brain tissue
  • Reverse transcription PCR (RT-PCR) – not widely available but more specific and may be preferred over serologic testing

Other Testing

  • Subacute sclerosis panencephalitis (SSPE) – rare complication of measles
    • Electroencephalogram (EEG) – periodic complexes
    • Magnetic resonance imaging (MRI)
      • Early – asymmetrical hyperintense lesions
      • Later – atrophy, new lesions
    • CSF IgM, IgG analysis
      • Cellular pleocytosis
      • Normal glucose
      • Normal to elevated protein
      • Elevated IgG titers
      • PCR positive

Differential Diagnosis

Measles is a highly contagious disease caused by the rubeola virus, a single-stranded RNA virus that is the only member of genus Morbillivirus in the Paramyxoviridae family. Humans are the only natural reservoirs for the rubeola virus.


  • Prevalence – minimal number of cases yearly in U.S. due to high rate of vaccination
    • >750,000 deaths worldwide
    • Occasional small outbreaks from imported cases of measles primarily infecting unvaccinated individuals
  • Transmission
    • Respiratory droplets
    • Highly contagious – >90% transmission among nonimmune individuals

Clinical Presentation

  • Highly contagious, acute, exanthematous respiratory disease
    • Incubation
      • 7-21 days (Kumar, 2016)
      • Most cases become apparent 10-12 days after exposure
    • Pathognomonic Koplik spots (bluish-gray specks on an erythematous base) on buccal mucosa
    • Maculopapular rash starts at face and neck and spreads to entire body
    • High fever, malaise, anorexia, coryza, cough, conjunctivitis
  • Diagnosis based on clinical exam may be difficult, especially in atypical cases
    • Can occur in persons vaccinated from 1963-1967 if exposed to wild measles – symptoms believed to be hypersensitivity reactions to vaccine
    • Atypical rash begins peripherally and moves centrally
    • High fever and edema
    • May occur in patients who received killed vaccines and later came in contact with wild virus strain
  • Complications – most often <5 years or >20 years, pregnant women, and immunosuppressed individuals
    • Pulmonary – primary giant cell pneumonia (Hecht pneumonia)
      • Severe, often fatal pneumonia can occur in patients with deficient cell-mediated immunity
    • Neurological – coma, seizures, encephalitis
      • Acute disseminated encephalomyelitis
      • Measles inclusion body encephalitis in immunocompromised patients
      • Subacute sclerosing panencephalitis (SSPE) – rare, progressive encephalitis that may result in dementia and death
        • Chronic encephalitis appears on average 7-10 years after measles
        • More prevalent in areas where measles vaccination rate is low
        • Disease affects neurons – can survive in latent form for years
        • Virus exposure at earlier age increases likelihood of SSPE infection due to immune system immaturity
    • Other respiratory complications – otitis media (most common complication), laryngotracheobronchitis, mastoiditis, pneumothorax, and mediastinal emphysema
    • Gastrointestinal – disease mimicking appendicitis, hepatitis, ileocolitis
    • Cardiovascular – myocarditis, pericarditis
    • Ocular – corneal ulceration and scarring
    • Gestational – increased incidence of pneumonia in pregnant women, spontaneous abortion, premature delivery, and low-birth-weight babies


Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Measles (Rubeola) Antibodies, IgG and IgM 0050375
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Chemiluminescent Immunoassay


Low IgM antibody levels occasionally persist >12 months after infection or immunization

Measles (Rubeola) Virus Culture 0065055
Method: Cell Culture/Immunofluorescence

Measles (Rubeola) Antibody, IgG 0050380
Method: Semi-Quantitative Chemiluminescent Immunoassay

Measles (Rubeola) Antibody, IgM, CSF 0054441
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay


Rubeola CSF antibody detection may indicate central nervous system infection; however, consider possible contamination by blood or transfer of serum antibodies across blood-brain barrier

Measles (Rubeola) Antibody, IgG, CSF 0054440
Method: Semi-Quantitative Chemiluminescent Immunoassay


Rubeola CSF antibody detection may indicate central nervous system infection; however, consider possible contamination by blood or transfer of serum antibodies across blood-brain barrier


Adult Immunization Schedule. Center for Disease Control and Prevention. [Last updated Feb 2017; Accessed: Aug 2017]

Centers for Disease Control and Prevention (CDC). Recommendations from an ad hoc Meeting of the WHO Measles and Rubella Laboratory Network (LabNet) on use of alternative diagnostic samples for measles and rubella surveillance. MMWR Morb Mortal Wkly Rep. 2008; 57(24): 657-60. PubMed

Manual for the Surveillance of Vaccine-Preventable Diseases. Centers for Disease Control and Prevention. Atlanta, GA [Last updated Apr 2016; Accessed: Aug 2017]

Measles / Rubeola 2013 Case Definition. Centers for Disease Control and Prevention. Atlanta, GA [Accessed: Aug 2017]

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Recommended Immunization Schedules for Persons Aged 0 Through 18 Years. United States, 2016. Centers for Disease Control and Prevention. Atlanta, GA [Last Updated Jan 2017; Accessed: Aug 2017]

General References

American Academy of Pediatrics. Measles. In Pickering LK. Red Book 2012: 2012 Report of the Committee on Infectious Diseases, 29th ed. Elk Grove Village, IL: American Academy of Pediatrics, 2012.

Gutiérrez J, Issacson RS, Koppel BS. Subacute sclerosing panencephalitis: an update. Dev Med Child Neurol. 2010; 52(10): 901-7. PubMed

Kumar D, Sabella C. Measles: Back again. Cleve Clin J Med. 2016; 83(5): 340-4. PubMed

Moss WJ, Griffin DE. Measles. Lancet. 2012; 379(9811): 153-64. PubMed

Rima BK, Duprex P. Morbilliviruses and human disease. J Pathol. 2006; 208(2): 199-214. PubMed

Sabella C. Measles: not just a childhood rash. Cleve Clin J Med. 2010; 77(3): 207-13. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Shirts BH, Welch RJ, Couturier MR. Seropositivity rates for measles, mumps, and rubella IgG and costs associated with testing and revaccination. Clin Vaccine Immunol. 2013; 20(3): 443-5. PubMed

Medical Reviewers

Last Update: September 2017