Overview/Definition

Definition:
-• Measles is highly contagious viral infection caused by measles virus (family Paramyxoviridae) characterized by fever, cough, conjunctivitis, and pathognomonic Koplik spots followed by maculopapular rash
-Despite effective vaccination, global resurgence occurred in 2018-2019 with declining vaccination coverage and vaccine hesitancy.
Epidemiology:
-• India reported 58,179 measles cases in 2019, significant increase from previous years
-Resurgence attributed to suboptimal vaccination coverage (85-90%), vaccine hesitancy, and migration patterns
-Case fatality rate 1-3% in children, higher in malnourished and immunocompromised
-Endemic in many states with seasonal peaks during winter-spring.
Age Distribution:
-• Infants (<9 months): Protected by maternal antibodies, vaccination not routinely recommended
-Children (9 months-15 years): Primary target group for vaccination and outbreaks
-Adolescents (15-18 years): Susceptible if inadequately vaccinated, important for herd immunity
-Adults: Secondary cases from infected children.
Clinical Significance:
-• Critical topic for DNB Pediatrics and NEET SS examinations focusing on outbreak management, vaccination strategies, and complication prevention
-Understanding measles elimination goals, catch-up vaccination programs, and public health response essential
-Knowledge of modified measles in partially immune individuals important.

Age-Specific Considerations

Newborn:
-• Neonates (0-8 months): Usually protected by maternal antibodies if mother immune
-Maternal antibody wanes by 6-9 months depending on maternal antibody levels
-Vaccination not recommended <9 months except during outbreaks (6-8 months)
-Severe disease possible in infants born to non-immune mothers.
Infant:
-• Infants (9-24 months): MR vaccine at 9-12 months, MMR at 16-24 months as per UIP schedule
-Higher risk for severe disease and complications
-Vitamin A supplementation crucial for complication prevention
-Outbreak settings may require vaccination at 6-8 months with revaccination later.
Child:
-• Children (2-15 years): Most common age group affected during outbreaks
-Two-dose MMR schedule provides 95-98% immunity
-Catch-up vaccination important for incompletely vaccinated children
-School-based surveillance and vaccination programs effective for outbreak control.
Adolescent:
-• Adolescents (15-18 years): Often missed in routine vaccination programs
-Higher risk for complications including pneumonia, encephalitis
-Important reservoir for transmission to vulnerable populations
-College outbreaks common requiring mass vaccination campaigns.

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Clinical Presentation

Symptoms:
-• Prodromal phase (2-4 days): High fever (39-40°C), malaise, anorexia, conjunctivitis with photophobia
-Respiratory symptoms: Harsh barking cough, coryza, hoarse voice
-Koplik spots: Pathognomonic bluish-white spots on buccal mucosa appearing 1-2 days before rash.
Physical Signs:
-• Exanthem phase: Erythematous maculopapular rash appearing on face, spreading centrifugally to trunk and extremities over 3-4 days
-Rash becomes confluent, gives characteristic measles appearance
-Lymphadenopathy: Generalized, especially posterior cervical and occipital
-Conjunctival injection and photophobia prominent.
Severity Assessment:
-• Uncomplicated measles: Typical presentation with fever, rash, respiratory symptoms resolving in 7-10 days
-Complicated measles: Secondary bacterial infections (pneumonia, otitis media), encephalitis, severe diarrhea
-Modified measles: Atypical presentation in partially immune individuals.
Differential Diagnosis:
-• Rubella: Milder symptoms, posterior cervical lymphadenopathy, no Koplik spots
-Roseola infantum: Younger age, rash appears after fever subsides
-Drug rash: History of medication use, no systemic symptoms
-Kawasaki disease: Prolonged fever, specific diagnostic criteria.

Diagnostic Approach

History Taking:
-• Vaccination history: Number of MMR doses received, timing of last dose
-Contact history: Exposure to measles cases in preceding 7-21 days
-Travel history to measles-endemic areas
-Household and school contacts assessment
-Previous measles illness history.
Investigations:
-• Measles IgM antibody: Positive 3 days to 4 weeks after rash onset
-RT-PCR: Throat swab or urine sample for viral RNA detection
-Measles IgG: Paired sera showing four-fold rise in convalescent sample
-Viral culture: Throat swab, urine, or blood for virus isolation (rarely done).
Normal Values:
-• Measles IgM: Negative in immune individuals
-Measles IgG: >200 mIU/ml indicates immunity, <150 mIU/ml suggests susceptibility
-RT-PCR: Negative in non-infected individuals
-White blood cell count: Often low during acute phase (leucopenia common).
Interpretation:
-• IgM positive: Recent measles infection (appears day 3-4 of rash)
-IgG seroconversion: Four-fold rise confirms recent infection
-RT-PCR: Most sensitive in early illness, useful for outbreak investigation
-Clinical diagnosis sufficient during confirmed outbreaks with typical presentation.

Management/Treatment

Acute Management:
-• Supportive care: Adequate hydration, fever management with paracetamol, rest in darkened room for photophobia
-Vitamin A supplementation: 200,000 IU for children >12 months, 100,000 IU for 6-12 months, reduces complications and mortality
-Isolation precautions for 4 days after rash onset.
Chronic Management:
-• Complication management: Antibiotic therapy for secondary bacterial infections (pneumonia, otitis media)
-Respiratory support for severe pneumonia
-Anticonvulsants for febrile seizures
-Nutritional rehabilitation post-illness
-Ophthalmological assessment for vitamin A deficiency complications.
Lifestyle Modifications:
-• Isolation at home for 4 days after rash onset to prevent transmission
-Adequate nutrition and hydration during illness
-Avoid aspirin due to Reye syndrome risk
-Eye protection from bright light during conjunctival involvement
-Gradual return to normal activities post-recovery.
Follow Up:
-• Daily monitoring during acute phase for complications
-Weekly follow-up for 2-3 weeks post-illness
-Growth monitoring especially in malnourished children
-Hearing assessment if otitis media occurred
-Vaccination status review and catch-up if needed.

Age-Specific Dosing

Medications:
-• Vitamin A supplementation: Children >12 months: 200,000 IU orally on days 1 and 2, repeat at 4 weeks if deficiency signs
-Infants 6-12 months: 100,000 IU orally on days 1 and 2
-Infants <6 months: 50,000 IU orally
-Paracetamol: 10-15 mg/kg every 6 hours for fever.
Formulations:
-• Vitamin A: Capsules 200,000 IU, 100,000 IU, liquid formulation 50,000 IU/ml
-Paracetamol: Suspension 120 mg/5 ml, 250 mg/5 ml, tablets, dispersible tablets
-MMR vaccine: Live attenuated vaccine, 0.5 ml subcutaneous injection.
Safety Considerations:
-• Vitamin A toxicity rare with recommended doses but monitor for hypervitaminosis signs
-Avoid aspirin in children due to Reye syndrome risk
-MMR vaccine contraindicated in immunocompromised children, pregnancy, severe illness
-Live vaccine interaction considerations.
Monitoring:
-• Clinical improvement: Fever resolution, appetite return, activity increase
-Complication monitoring: Respiratory distress, altered consciousness, secondary bacterial infections
-Nutritional status assessment especially in malnourished children
-Hearing and vision assessment post-recovery.

Prevention & Follow-up

Prevention Strategies:
-• Routine immunization: MR vaccine at 9-12 months, MMR at 16-24 months
-Catch-up vaccination for incompletely vaccinated children
-Outbreak response: Ring vaccination around cases, mass vaccination campaigns
-Herd immunity threshold 95% to prevent outbreaks.
Vaccination Considerations:
-• MMR vaccine schedule: First dose 12-15 months, second dose 4-6 years
-Catch-up: Two doses separated by minimum 4 weeks
-Outbreak settings: Vaccination from 6 months with revaccination at appropriate age
-Post-exposure prophylaxis within 72 hours of exposure.
Follow Up Schedule:
-• Post-vaccination: No routine follow-up needed unless adverse events
-Outbreak investigation: Contact tracing, secondary case surveillance for 21 days
-Community surveillance: Enhanced surveillance during outbreaks
-Annual vaccination coverage assessment.
Monitoring Parameters:
-• Vaccination coverage monitoring at community level
-Outbreak surveillance: Case-based surveillance with laboratory confirmation
-Adverse events following immunization (AEFI) monitoring
-Population immunity assessment through serosurveys.

Complications

Acute Complications:
-• Secondary bacterial infections: Pneumonia (most common cause of death), otitis media, sinusitis requiring antibiotic therapy
-Laryngotracheobronchitis (croup): Respiratory compromise requiring close monitoring
-Febrile seizures: Usually brief and self-limiting
-Encephalitis: Rare but serious, 1:1000 cases.
Chronic Complications:
-• Subacute sclerosing panencephalitis (SSPE): Rare chronic degenerative CNS disease, 7-10 years after measles
-Vitamin A deficiency complications: Blindness, keratomalacia
-Secondary immunosuppression: Increased susceptibility to other infections for weeks to months.
Warning Signs:
-• Respiratory distress indicating pneumonia or croup
-Altered consciousness, seizures suggesting encephalitis
-High fever persisting >5 days after rash onset
-Signs of dehydration: Decreased urine output, dry mucous membranes
-Secondary bacterial infection signs.
Emergency Referral:
-• Immediate referral for respiratory distress, altered consciousness, signs of encephalitis
-ICU consultation for severe pneumonia, respiratory failure
-Ophthalmology referral for eye complications
-Neurology consultation for seizures, encephalitis
-Intensive monitoring for high-risk groups.

Parent Education Points

Counseling Points:
-• Measles is serious but preventable disease through vaccination
-Two doses of MMR vaccine provide lifelong immunity in 95-98% children
-Importance of completing vaccination schedule and catch-up vaccination
-Understanding of outbreak risks and community protection through herd immunity.
Home Care:
-• Isolation for 4 days after rash onset to prevent transmission to others
-Adequate fluid intake to prevent dehydration
-Dim lighting to reduce discomfort from photophobia
-Paracetamol for fever, avoid aspirin
-Nutritious diet as tolerated, vitamin A supplementation important.
Medication Administration:
-• Vitamin A capsules can be opened and contents given with food if child cannot swallow
-Paracetamol dosing based on weight, not age
-Complete vitamin A course as prescribed
-Monitor for side effects and report if concerned
-Store medications safely away from children.
When To Seek Help:
-• Immediate medical attention for difficulty breathing, persistent high fever >5 days
-Altered consciousness, seizures, severe headache
-Signs of dehydration: No urination for >8 hours, dry mouth, lethargy
-Eye problems: Pain, discharge, vision changes
-Any worsening symptoms or parental concerns.