Medicine & USMLE


Viruses - RNA Viruses
  1. HIV: Microbiology and Characteristics
  2. HIV: Clinical Course
  3. Reovirus
  4. Picornavirus Overview
  5. Poliovirus
  6. Echovirus
  7. Rhinovirus
  8. Coxsackievirus
  9. Hepatitis A Virus (HAV)
  10. Hepevirus (Hepatitis E Virus)
  11. Calicivirus
  12. Flavivirus
  13. Hepatitis C Virus (HCV)
  14. Yellow Fever Virus
  15. Dengue Virus
  16. St. Louis Encephalitis and West Nile Virus
  17. Zika Virus
  18. Togavirus
  19. Rubella
  20. Retrovirus
  21. Coronavirus
  22. Orthomyxovirus
  23. Paramyxovirus
  24. Respiratory Syncytial Virus (RSV)
  25. Parainfluenza Virus (Croup)
  26. Measles
  27. Mumps
  28. Rhabdovirus
  29. Filovirus
  30. Arenavirus
  31. Bunyavirus
  32. Deltavirus


Measles is a paramyxovirus that can present with a variety of symptoms. Prodromal symptoms include the 4 C’s of measles - a cough, coryza, conjunctivitis, and Koplik Spots, which are blue-grey spots visible on the oral mucosa. Measles is transmitted via respiratory droplets or contact and is highly contagious. A few days after onset, patients usually experience a downward-spreading maculopapular rash. In some rare cases, patients experience acute encephalitis. Late stage complications include the feared SSPE or Subacute Sclerosing Panencephalitis, which is usually fatal To treat a severe measles infection, vitamin A supplements are used and have been proven to reduce morbidity and mortality in malnourished children. Finally, prophylaxis for measles include the live-attenuated MMR vaccine, which is administered in children between 12-15 months of age.

Key Points

  • Measles virus
    • Transmission
      • Respiratory droplets or contact
      • Highly contagious
    • Presentation: Measles
      • Prodromal fever with cough, coryza (runny nose), conjunctivitis
        • 4 Cs of measles: cough, coryza, conjunctivitis, “Coplik” spots
      • Koplik spots
        • Bright red spots with blue white center on buccal mucosa
      • Followed 1-2 days later by maculopapular rash
        • Starts at head/neck and spreads downwards
      • Possible sequelae
        • SSPE (subacute sclerosing panencephalitis)
          • Occurs years after initial infection and apparent recovery
          • personality changes, dementia, autonomic dysfunction, death
          • High titers of measles antibodies in serum and CSF
        • Acute Encephalitis (1:1000)
          • Symptoms occur within a few days of rash
        • Acute Cerebellitis (post-viral cerebellar ataxia)
          • Occurs 2-3 weeks after infection with cerebellar symptoms (ataxia, nystagmus)
        • Giant cell pneumonia
          • rare except in immunosuppressed
        • Pneumonia
          • Most common cause of measles-associated death in kids
    • Diagnosis
      • Biopsy of lymph nodes shows Warthin-Finkeldey giant cells (fused lymphocytes) in background of paracortical hyperplasia
      • Acute rise in anti-measles IgM, IgG, or RT-PCR used to confirm diagnosis
    • Treatment
      • Vitamin A → reduces morbidity and mortality, esp. In malnourished children
    • Prophylaxis
      • MMR (Measles, Mumps, Rubella) vaccine - live attenuated
        • Administered at 12-15 months of age