Measles (Rubeola)

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

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.

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

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

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.

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

Koplik’s spot:

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

Maculo-papular rash:

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)

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.

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.

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)

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

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 .