1. MEASLES By Dr. sukhwantsingh

2. INTRODUCTION*Measles, an acute viralexanthematous fever caused by Morbillivirus.*It is a leading causeof childhood deaths in developing countries,* Measles is one ofthe most contagious diseases known. *Almost all non – immunechildren contract this respiratory disease if exposed to the virus. *It is a human disease not known to occur in animals

3. *Beforethe development of safe and effective vaccines, measles wasresponsible for approximately six milliondeaths of infants andchildren globally every year. *As measles vaccination has becomemore and more widespread, there has been a marked declinein measles particularly in developed countries. *The largest proportional reduction in deaths due to measles has occurred in the African Region accounting for 70% of the global reduction in measles mortality.

4. *98% of deaths due to measles occur in developing countries because it is 100-400 times more likely to cause death in pre school children with malnutrition. *Case - fatality rates in these countries are normally in the range of 1 to 5% but may reach as high as 10 to 30% in populations withhigh levels of malnutrition and poor access to health care. * Despite these advances, however, an estimated 20 million cases of measles resulted in 242,000 deaths in 2006.

5. WHO defines elimination of Measles as-Absence of endemic measles for a period of > 12 months.Indicator of Measles elimination :A sustained measles incidence < 1/10 Lac population.World Health Assembly has set a goal of achieving 90 percent reduction in global measles mortality by 2010 as compared with levels in 2000.

6. INDIABefore the introduction of measles vaccine - * Anestimated 100,000 cases of measles occurred each year in thecountry with outbreaks at an interval of about 3 years.Afterthe introduction of measles vaccination,as part of the National Immunization Schedule in 1985 * The number of caseshas decreased and the interval between outbreaks has alsoincreased to about 5 years. *The number of reported cases of measles in India has declined from 162,560 in 1989 to 51,546 in 2004.

7. AGENT*Genus Morbillivirus *Family paramyxoviridae. *The virus is a non segmented, enveloped, negative sense single stranded RNA virus. *Measlesvirus particles arepleomorphic spheres with diameter rangingfrom 100 nm to 250 nm.

8. * The virus can not survive outside the human body .* It can, however, remain viable in droplets for several hours.* It can retain the infectivity when stored at sub zero temperature.

9. *measles virus is easily destroyedby drying, exposure tosunlightand acids.*Humans are the only natural hosts forthe virus. * The virus can be grown in cell cultures. *There is only one serotype.

10. SOURCE OF INFECTION* A case of measles.* Carriers are not known to occur.INFECTIVE MATERIAL* Secretions of the nose, throat and respiratory tract of a case of measles during the prodromal period and the early stages of the rash.

11. COMMUNICABILITY* The period of communicability is approximately 4 days before and 5 days after the appearance of rash.* Isolation of the patient for a week from the onset of rash covers the period of communicability.* Measles is highly infectious during the prodromal period and at the time of eruption. ( Secondary Attack Rate – 90% )

12. HOST FACTORS AGE Susceptibility to infection isuniversal in those notexposed irrespective of age. However, most infections occur in the age group 6 months to 3 years in developing countries. And older children usually over 5 years in developed countries.

13. IMMUNITY*No age is immune if there was no previous immunity.* Infants are protected by maternal antibodies up to 6 months of age.* One attack of measles confers life long immunity, because there is only one serotype of the virus.

14. NUTRITION*Measles is verysevere in malnourished with mortality up to 400 times higher than well nourished children. *It can precipitateKwashiorkor in borderline cases. *Persons with malnutrition,especially vitamin A deficiency, or with severe immunological disorders such as advanced HIV infection are at increased riskof developing severe or even fatal measles.

15. ENVIRONMENT*In India, the peak incidence of measles is inwinter and early spring.( January to April )*In temperate countries most cases occur in winter months.*Overcrowding favors transmission.

16. TRANSMISSION * Transmission occurs directly from person to person by droplet infection and droplet nuclei.* Infection through conjunctiva is also considered likely.* Recipients of measles vaccine are not contagious to others.

17. PERIOD OF COMMUNICABILITY* Ranges from 4 days before onset of rash until 5 days thereafter.* Portal of entry is respiratory tract.

18. INCUBATION PERIOD* 10 days from exposure to fever and 14 days to appearance of rash.* When infection is artificially induced by-passing the respiratory tract ( as with administration of live vaccine ),the incubation period is shortened, averaging 7 days.

19. PRESENTATION1. PRODROMAL STAGE :* Begins 10 days after infection, and lasts until day 14.* Characterized by- - Fever, Malaise, Cough - Coryza, Nasal discharge - Redness of eyes, Lacrimation, Photophobia. - Vomiting / Diarrhea.

20. Koplik’s spots –*They are small, bluish white spots on a red base seen on the buccal mucosa opposite the first and second lower molars.* They appear one or two days before the appearance of rash.* Their presence is pathognomonic of measles.

21. 2. ERUPTIVE PHASE -*This phase is characterised by typical dusky red, maculo-papular rash, which begins behind the ears and spreads over the face and neck.* It extends down the body taking 2-3 days to progress to lower extrimities.* The rash may remain discrete, or become confluent and blotchy.* The rash fades in another 3 or 4 days in the same order of appearance leaving a brownish discoloration persisting for 2 months or more.

22. * During the prodromal phase (2-4 days ) and the first 2-5 days of rash, virus is present in tears, nasal and throat secretions, urine and blood.* Appearance of maculo-papular rash coincides with detectability of circulating antibodies.* No rash develops in patients with defective cell mediated immunity.

23. 3.POST MEASLES STAGE* The child will have lost some weight and will remain week for a number of days.* There may be failure to recover and a gradual deterioration in to chronic illness.* There may be growth retardation, diarrhea, cancrumoris, pyogenic infections, candidosis, reactivation of pulm. Tuberculosis etc.

24. COMPLICATIONS* Otitis media* Pneumonia* Blindness( Due to acute deficiency of vit-A )* SSPE( Occurs at an average of 7 years after initial infection)* Pregnancy – Spontaneous abortion - Premature delivery

25. TREATMENT

26. * Outbreaks of measles must be reported to local health authorities. * Respiratory isolation may beindicated for 6-7 days after appearance of rash.* Exclusion from school is required for one week from appearance of rash to avoid contact with susceptibles.* Inhospital strict isolation of cases is essential. *Articles soiled by secretions or fluids from vesicles to be incinerated or treated with disinfectants.

27. VITAMIN – A IN MEASLES

28. *All childrenin developing countries diagnosed with measles should receivetwo doses of vitamin A supplements given 24 hours apart. *This can help prevent eye damage and blindness. *VitaminA supplementation has been shown to reduce the number of deaths from measles by 50%. *Supplementary dosage is : - Infants 6 - 11 months - 1,00,000 IU- Children 12 months andover - 2,00,000 IU.

29. PREVENTION*A live attenuated vaccine againstmeasles has been available since 1966. * In INDIA, measles vaccine included in UIP in 1985.*A number of strains likethe Edmonston B strain, Schwarz strain and Moraten strain are used in vaccine manufacture.* The vaccine is presented as freeze dried product ( Must be stored in freezer compartment )

30. *In India,a single dose of 0.5 ml SC is given at nine months of age. (Edmonston B strain)*Indeveloped countries two doses are given, The first dose at 12 to15 months followed by asecond dose at 4 to 5 years of age.* The reconstituted vaccine should be kept on ice and used within 1 hour.

31. : REACTION :* When injected in to the body, measles virus multiplies and induces a mild measles illness (fever & rash) 5 to 10 days after immunization,but in reduced frequency and severity. * This may occur in 15-20 percent of vaccinees.* Fever may last for 1-2 days and rash for 1-3 days.

32. IMMUNITY * Immunity develops 11 to 12 days after vaccination.* Immunity is probably for life long.* One dose of measles vaccine appears to give 95 percent protection.* Susceptible contacts of 9-12 months of age may be protected by giving vaccine within 3 days of exposure.

33. CONTRAINDICATIONS* Pregnancy* Deficient cell mediated immunity* Use of immunosuppressive drugs and steroids.ADVERSE EFFECTS* Toxic Shock SyndromeWatery diarrhea, Vomiting & High feverOccurs with contaminated vaccine

34. COMBINED VACCINEMeasles vaccine can be combined with other live attenuated vaccines-Mumps and Rubella asMMRSuch combinations are also highly effective

35. MMR Vaccine Measles Vaccine

36. IMMUNOGLOBULIN*It should be given within 3 – 4 days of exposure.* Dose- 0.25 ml/kg body weight.* Persons passively immunized should be given live measles vaccine 8-12 weeks later.