10. Measles (Rubella)

OTHER NAMES
nine day measles; measles; hard measles; red measles
DEFINITION
A highly contagious viral illness characterized by a fever, cough, and spreading rash.
CAUSES, INCIDENCE, AND RISK FACTORS
Rubella, or measles, is caused by the paramyxovims. The infection is spread by droplets from the nose, mouth or throat of an infected person. The incubation period is 7 to 14 days before symptoms generally appear. An immunity to the disease occurs after vaccination, after active infection, and passive immunity of an infant whose mother is immune lasts most of the first year of life. Before widespread immunization, measles was very common during childhood so that 90% of the population had been infected by age 20. Susceptible individuals are young infants as the maternal antibody decreases, and those who refuse immunization. Teenagers and young adults who have not received a second immunization are also susceptible.
PREVENTION
The routine immunization of children at 15 months old with MMR (live mumps, measles, and rubella) vaccine prevents infection. A second MMR immunization (vaccine) is now given between 4 and 6 years of age.
SYMPTOMS
- a sore throat
- a runny nose
- a barking cough
- muscle pain
- fever
- bloodshot eyes
- tiny white spots inside the mouth (called Koplik’s spots) appearing 3 to 4 days after the onset of symptoms
- photophobia (light sensitivity)
- rash
- appears around the fifth day of the disease
- may last 4 to 7 days
- usually starts on the head and spreads to other areas, progressing downward
- maculopapular rash—appears as both maculae (flat discolored areas) and papules (solid, red, elevated areas) that later merge together (confluent); occasionally may bleed very slightly
- itching of the rash
Note: The period between the appearance of the earliest symptoms and the appearance of a rash or fever is usually 3 to 5 days.
SIGNS AND TESTS
- a Donath-Landsteiner test
- a blood differential
- a viral culture (rarely done)
- a measles serology

Differential Diagnosis

 _... Rubella (German measles) _... Roseola infantum _... Erythema infectiosum (fifth disease) _... Infectious mononucleosis _... Kawasaki disease _... Scarlet fever _... Toxoplasmosis _... Drug eruption _... Differential for atypical measles-includes Rocky Mountain spotted fever, Henoch-Schönlein purpura, and meningococcemia

Diagnosis

Physical Examination

 The classic presentation is a severe upper respiratory infection, after which Koplik's spots, which are pathognomonic, appear on the oral mucosa. The classic measles rash appears several days after the Koplik's spots disappear.

Laboratory Tests

 _... Neutropenia, particularly lymphopenia, are common secondary to invasion of virus into leukocytes with subsequent cell death _... Leukocytosis may be a sign of bacterial superinfection _... Immunofluorescent staining of nasopharyngeal or respiratory secretions-to detect measles antibodies and/or multinucleated giant cells _... Enzyme immunoassay (EIA)-to detect IgM (present within 1 to 2 days of rash) or IgG antibodies (rises after 10 days); atypical measles is associated with very high antibody titers _... Hemagglutination inhibition test-to detect IgM or IgG antibodies; older test; not as sensitive as EIA _... In the case of CNS symptoms, lumbar puncture is performed; in the case of measles encephalitis, CSF reveals elevated protein and lymphocytosis Pathology/Pathophysiology

 Measles virus first attacks the respiratory system and spreads to the reticuloendothelial system via the bloodstream. When it infects the leukocytes, it results in primary viremia, with systemic spread to many organs and tissues. T-cell invasion may account for the depressed cellular immunity of measles. Cellular immunity (including cytotoxic T cells and natural killer cells) plays a prominent role in the host's defense against measles.

Other Diagnostic Procedures

 _... Electroencephalogram-to determine extent of CNS involvement _... Polymerase chain reaction-to detect measles virus RNA

Treatment Options

Treatment Strategy Treatment for measles is symptomatic and supportive; however, complications may indicate specific treatment and hospitalization which is common in certain parts of the world. If encephalitis ensues, the patient must be observed because of the risk of increased intracranial pressure.

Drug Therapies

 _... Antipyretics for the management of high fevers _... Antibiotics for the management of bacterial complications such as pneumonia and otitis media _... High-dose vitamin A, 50,000 IU for infants 1 to 6 months; 100,000 IU for infants 7 to 12 months; and 200,000 IU for children over 1 year; given for 2 days particularly for severe measles in malnourished children. May see transient vomiting and headache with high doses of vitamin A. See section entitled

Nutrition for more information regarding use of vitamin A in the case of measles. _... Ribavirin has demonstrated antiviral activity in vitro and may be considered for immunocompromised host, although not FDA-approved for measles. _... Postexposure prophylaxis: immune globulin, 0.25 ml/kg (0.5 ml/kg for immunocompromised patients) IM within 6 days of exposure followed by immunization in 5 to 6 months. (Caution: immune globulin should not be given at the same time as the vaccine.) The vaccine may also be used for post-exposure prophylaxis within 72 hours; the vaccine is not as effective for these purposes as immunoglobulin; also, vaccine should not be used in immunocompromised individuals.

Complementary and Alternative Therapies

 Studies have demonstrated the importance of nutrient supplementation in the treatment of measles, specifically supplementation with vitamin A (sometimes called the "anti- infective" vitamin). Herbs have been used worldwide to treat measles and there is mounting evidence of their benefit. Some folk remedies, such as the Cherokee use of spicebush (Lindera benzoin), have been used traditionally for measles but have yet to be scientifically investigated. Constituents include benzoin, aromatic hydrocarbons, and aporphines, which possess cytotoxic properties.

Nutrition

 Vitamin A Vitamin A deficiency is a critical problem among populations commonly lacking adequate dietary intake. This nutrient deficiency is associated with greater frequency, severity, and mortality of infectious diseases, including measles. In areas of the world where vitamin A deficiency is endemic or where fatality from measles occurs at a rate of 1% or higher, the WHO recommends routine vitamin A supplementation for children with the infection (Hussey and Klein 1990). This recommendation is based upon and supported by randomized, controlled clinical trials demonstrating a benefit of vitamin A supplementation including the following outcomes (Coutsoudis et al. 1991; Hussey and Klein 1990): _... Reduction in mortality rate by > 50% _... Decreased duration of pneumonia and diarrhea by > 30% _... Shorter length of hospital stay by > 30%

EXPECTATIONS (PROGNOSIS)
The probable outcome is excellent in uncomplicated cases. The probable outcome is worse with complicating encephalitis.
COMPLICATIONS
A bacterial infection may cause otitis media, bronchitis, or pneumonia. Encephalitis occurs in approximately 1 out of 3,000 measles cases. Hemorrhagic measles is a rare complication and causes generalized bleeding.

Courtesy:

Compiled and Shared By: Habib Anwar 

habib.anwar@hotmail.com