Measles or Rubeola or Morbilli
Measles or Rubeola is a highly contagious viral disease spread by droplet infection. One attack confers a high degree of immunity. Most people suffer from measles in childhood, and a mother who has had the disease confers passive immunity on her infant for the first six months of life. The infection is generalised, but the clinical evidence of it is mainly found in the respiratory tract, the skin, the mouth and the conjunctivae. Meas-les is prevalent during the first six months of the year with a peak incidence in the march.
Incubation Period :
The incubation period of measles is about 10 days to the commencement of the catarrhal stage. A quarantine period is not necessary.
Cause of Measles :
• Measles is caused by the measles virus, a single stranded; -ve sense enveloped RNA virus of the genus Morbilli virus within the family Paramyxoviridae.
• Humans are the natural hosts of the virus.
• No animal reservoirs are known to exist.
• Measles virus is highly contagious & spread by coughing and sneezing by close contact or direct contact with secretions.
Risk factors of Measles :
Risk factors for measles infection are as follows:
• Children with immune deficiency due to cortico-steroid therapy, Leukaemia, HIV or AIDS or alkylating agents, regardless of immunisation status.
• Person travel to an area where measles is in epidemic form or contact with travellers to endemic area.
• In Infants loses antibody before the age of routine immunisation.
• Vitamin A deficiency
Clinical Features of Measles :
Clinical features of measles are divided into two stages:
• Catarrhal stage
• Exanthematous stage
Catarrhal Stage :
• Measles starts in much the same way as a common cold.
• The onset of disease is acute and febrile, with nasal catarrh, sneezing, redness of the conjunctivae, some swelling of the eyelids and watering of the eyes.
• In addition a short cough, hoarseness of the voice due to laryngitis and photophobia usually appear by the second day.
• During the catarrhal stage, which usually lasts for 3 or 4 days before the appear-ance of the specific rash, a diagnosis of measles may be made from the presence of Koplik's spots on the mucous membrane of the mouth.
• Koplik's spots are very small white spots, often compared with grains of salt, surrounded by a narrow zone of inflammation. They are best seen in daylight.
• Koplik's spots are often numerous on the side of cheeks, they may be sparse and confined to the region around the opening of the parotid duct.
• The disease is highly infectious during the catarrhal stage.
Exanthematous Stage :
• After 3 or 4 days of the catarrhal stage, the diagnostic Koplik's spots disappear while the dark red macular or maculo-papular skin rash develops.
• The rash is first seen at the back of ears and at the junction of the forehead and the hairs.
• Within a few hours there is invasion of the whole skin area, and there is usual-ly some accentuation of fever.
• As the spots rapidly become more numerous they fuse to form the characteris-tic blotchy appearance of measles.
• The face is usually the most densely covered area.
• When the rash is fully erupted in two or three day, it tends to deepen in colour and then fade into a faint brown staining.
• Finally there is a fine, branny desquamation of the skin.
• The malaise and the fever subside as the rash fades.
Diagnosis of Measles :
Diagnosis of measles is done by:
• Proper history and clinical signs and symptoms
• Laboratory tests
Proper history & clinical signs and symptoms :
• Clinical diagnosis of measles is made on the basis of a history of fever of at least three days, with at least one of the 3 C's i.e. Coryza, Cough, or Conjunctivitis.
• Observation of Koplik's spots is diagnostic of measles.
• Considerable difficulty may arise in those cases of measles in which a prodromal rash indistinguishable from scarlet fever develops in the catarrhal stage.
• In measles Koplik's spots are present and the eyes have the appearance of those of a child that has recently been crying.
• It is important to remember that drug rashes are common and may simulate closely the eruptions of measles, rubella or scarlet fever.
Laboratory tests :
Laboratory diagnosis of measles can be done by Measles Serology or Viral culture i.e. confirmation of +ve measles IgM antibodies or isolation of measles virus RNA from respiratory specimens.
Complications of Measles :
• Convulsions occur in young children and are commonest as the rash is appearing.
• Otitis media
• Acute lobar pneumonia
• Corneal ulcer/ impairment of vision due to persistent untreated conjunctivitis
• Pan encephalitis ( Rare)
Treatment of Measles :
• There is no specific treatment of measles.
• Complete rest in bed and plenty of fluid intakes is advised.
• The patient should be isolated if possible.
• Humidified air may relief symptoms of measles.
• Exclude the child from school for 14 days from the appearance of the rash.
• Nursing on a verandah or a well-ventilated room reduces the chances of secondary respiratory infection.
• Most cases of measles, instead of the high temperature, remain uncomplicated.
• Antibiotics should be prescribed only in case of secondary bacterial infections.
• Contacts should be examined daily for the first sign of infection.
• Children may need vitamin A supplements which may reduce the risk of death and complications in less developed countries.
Prophylaxis of measles :
Active Immunisation :
Routine immunisation of measles is highly effective for preventing measles. Children who are not immunised, or who have not received the full immunisation are at high risk for catching the disease.
Passive Immunisation :
Human immunoglobin, given intramuscularly, is recommended for the prevention or attenuation of measles, particularly for contacts under 18 months of age and for debilitated children 6 days after being exposed to the virus.
Prognosis of disease :
Prognosis of measles is good in majority of cases.
Bronchitis, acute lobar pneumonia and pan encephalitis is potentially fatal.