Cause
Measles is caused by the measles virus, a single-stranded, negative-sense enveloped RNA virus of the genus Morbillivirus within the family Paramyxoviridae. Humans are the natural hosts of the virus; no animal reservoirs are known to exist. This highly contagious virus is spread by coughing and sneezing via close personal contact or direct contact with secretions.
Risk factors for measles virus infection include the following:
- Children with immunodeficiency due to HIV or AIDS, leukemia, alkylating agents, or corticosteroid therapy, regardless of immunization status
- Travel to areas where measles is endemic or contact with travelers to endemic areas
Infants who lose passive antibody before the age of routine immunization
Risk factors for severe measles and its complications include the following:
- Malnutrition
- Underlying immunodeficiency
- Pregnancy
- Vitamin A deficiency
Read more about this topic: Measles