Definition
An acute, contagious and exanthematous disease that usually affects children which are susceptible to Upper Respiratory Tract Infection (URTI). This maybe one of the most common and most serious of all childhood diseases.
Etiologic Agent
Filtrable virus that belongs to genus Morbilivirus of the family paramyxoviridae is the agent of measles.
Measles virus is rapidly inactivated by heat, ultraviolet light, and extreme degrees of acidity and alkalinity.
Incubation Period
- The incubation period is from ten to twelve days (the longest is 20 days and the shortest is eight days).
- Single attack conveys a lifelong immunity.
Period of Communicability
• Measles usually lasts about nine to ten days, measured from the beginning of the prodromal symptoms to the fading of the rash.
• The disease is communicable four days before and five days after the appearance of rashes.
• The disease is most communicable during the height of rash.
Source of Infection
The virus has been found in the patient’s blood, as well as in the secretions from the eyes, nose and throat.
Mode of Transmission
o The disease is transmitted through direct contact with the droplets spread through coughing or sneezing.
o It can also be transmitted indirectly through articles or formites freshly contaminated with respiratory secretions of infected patients.
Pathognomonic Sign
Koplik’s spots are Pathognomonic of measles. These are inflammatory lesions of the buccal mucous glands with superficial necrosis.
1. They appear on the mucosa of the inner cheek opposite to the second molars, or near the junction of the gum and the inner cheek.
2. They usually appear one to two days before the measles rash.