Measles Virus
One-Sentence Definition
Measles virus is a highly contagious morbillivirus causing fever, cough, coryza, conjunctivitis, and koplik spots followed by maculopapular rash — preventable by live vaccine but dangerous in under-vaccinated populations (SSPE, pneumonia, encephalitis).
Taxonomy & Morphology
- Paramyxoviridae; (−)ssRNA; envelope; single serotype (genotypes for surveillance)
Virulence Highlights
- Transmitted via respiratory aerosols — extreme contagion (high R₀)
- Immune amnesia — erases B-cell repertoire (research/clinical significance)
- Rare late complication: SSPE (years after infection)
Clinical Syndromes
- Classic measles rash illness
- Complications: otitis, pneumonia (primary or bacterial superinfection), encephalitis
- Immunocompromised: giant cell pneumonia
Diagnosis
- Clinical in outbreak context
- Serology in Clinical Microbiology: IgM acute; IgG immunity
- PCR on urine/blood/throat — public health confirmation
Treatment / Prevention
- Supportive care; ribavirin in select severe cases (specialist)
- MMR vaccine — two-dose schedule; herd immunity needs very high coverage (Vaccination)
- Post-exposure prophylaxis: vaccine or IG in window for susceptible contacts
Related Notes
- Vaccination · Infection Prevention and Control · MOC - Virology
- Respiratory Infections · Adaptive Immunity
Active Recall
- Classic prodrome triad before rash?
- Why does measles return when coverage slips slightly?
- IgM vs IgG use?