1. Measles (Rubeola)

2. Definition
Measles is a communicable disease manifesting with fever , cough , coryza , lacrimation and koplik spots in the pre – eruptive phase and a maculopapular rash starting at 4th or 5th day of the illness.
Coryza : profuse discharge from the mucous membrane of the nose
koplik spot : small, white spots (often on a reddened background) that occur on the inside of the cheeks early in the course of measles.
Koplik spots
Coryza

3. Ecological triad Agent: Measles( paramyxovirus ,RNA virus)
Age: children (6months -3 years)
Measles tend to be very serious in malnourished children, mortality is 400 times higher.
Both sexes are affected
Immunity : -
one attack of measles gives immunity for life.
Infants acquire immunity transplacentally from mothers who have had measles or measles immunization. This immunity is usually completed for the first 4–6 months of life.
Reservoir : - Man is only the reservoir of infection.

4. Environment Incidence is higher in spring and winter
Incidence is higher in densely populated urban areas
Natural history
Reservoir is a case of measles
Source of infection: nasopharyngeal secretions, lacrimal secretion, urine
Infectious period: 4 days before, and 5 days after the onset of rash

5. Mode of transmission
Directly from person to person by droplet infection, droplet nuclei
Other modes –fomites, airborne
Incubation period: 8 – 12 days

6. Pathogenesis Two types of gaint cell are seen : -
Virus infects by invasive of respiratory tract .
After entering the viral particles infects the respiratory epithelium and local multiplication leads to primary viremia ( day 2 – 3 ) and subsequently spread to the reticuloendothelial system.
Cells of reticuloendothelial system necrose , causing secondary viremia ( day 5 – 7 ) which is responsible for systemic symptoms.
Multinucleated gaint cells can be demonstrated in both epidermis and oral epithelium by 7 – 11 days
Two types of gaint cell are seen : -
Warthin – Finkeledy cells of reticuloendothelial system
Epithelium gaint cells of respiratory tract
During infection , CD4T and CD8 cells are activated and participate in clearance of virus and development of rash. During recovery,level of interleukin 4 is elevated
IL-4: protein that stimulates the immune system to develop mast cells, resting T-cells, and activated B-cells.

7. Clinical features Prodromal :
- onset is acute with moderate elevation of temperature , cough , running of nose , sneezing , redness of eyes and excessive lacrimation
- on second or third day : koplik spots appear on the inner side of the cheek, opposite to the second molars .
- Koplik spots increase in number for 2 to 3 days and disappear by the end of second day of the rash

8. Koplik’s spot:

9. Eruptive phase :
With the appearance of rash on the 4th day the fever tends to rise again
Early rash is erythematous and blanches on pressure ( blotchy )
First appears behind the ears , near the hair line on the forehead , face and neck and spread to trunk , extremities , palms and soles within 3 days.
The rash now appears brownish , and does not fade on pressure.
Rash start disappearing after 4 to 5 days in the same order in which it appeared
Fever and rash lasts for about a week in uncomplicated cases
May complain anorexia , malasie , generalised lymphadenopathy

10. Maculo-papular rash:

11. Diagnosis Clinical diagnosis: Laboratory diagnosis:
Blood count – leucocytosis in early stages followed by increased lymphocytes
Sputum or urine culture
Serological tests
Complement fixation test
Haemagglutination test
Enzyme-linked immunosorbent assay (ELISA)

12. Differential diagnosis
Rubella : rash is pink , maculopapular and discrete
Infectious mononucleosis : rash is associated with generalised lymphadenopathy and hepatosplenomegaly
Meningococcemia : rash appears within 24 hours. Fever , vomiting , irritability and possibly stiff neck are present
Drug rash : H / o drugs administration
Sunburn
Roseola infantum : - faint pink maculopapular rash.

13. Treatment : It is a self limiting disease unless it is complicated
Symptomatic and supportive
Body and oral hygiene are attended to
Parents are encouraged to give bath to the child and mouth is washed and teeth are brushed daily
Adequate amount of fluids orally
Fever (paracetamol and hydrotherapy )
Severe cough ( saline nebulization )
Vitamin A decrease the severity , complication rate and mortality. Dose : 2 lac units , orally children older than one year of age for 2 consecutive days.

14. Prevention and control
Control measures
Isolation
Bed rest
Supportive Tx- vit. A ,
Immunization of contacts within 2 days of exposure
Preventive measures
Active immunization(9 months, 0.5cc,IM/SC,deltoid)
Passive immunization (Human gamma globuline0.25ml/kg IM within 5 days of exposure)

15. Vaccines Dose and schedule: 0.5ml – S/C – 9months Adverse reactions:
Measles like illness, febrile convulsion, toxic shock syndrome, transient thrombocytopenia
Contraindications: acute illness, untreated malignant diseases, immunodeficiency, pregnancy, received any live vaccine within 3 weeks

16. complications Respiratory tract : Encephalitis Digestive system :
otitis media , cervical lymphadenopathy , laryngitis , laryngotracheitis , interstitial pneumonia ,bronchopneumonia
Encephalitis
Digestive system :
Persistent diarrhea , appendicitis ( lymphoid tissue blocking the lumen of appendix ) , hepatitis , ileocolitis
Malnutrition : PEM
Others : acute glomerulonephritis , disseminated intravascular coagulation .