Measles (rubeola) is a disease caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. 'German measles' is an unrelated condition caused by the rubella virus.

Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing a house with an infected person will catch it.New York City Departrment of Health and Mental Hygiene http://www.nyc.gov/html/doh/html/imm/immmea.shtml Airborne precautions should be taken for all suspected cases of measles.

The incubation period usually lasts for 4–12 days (during which there are no symptoms). Infected people remain contagious from the appearance of the first symptoms until 3–5 days after the rash appears.

Reports of measles go as far back to at least 600 B.C.E. however, the first scientific description of the disease and its distinction from smallpox is attributed to the Persian physician Ibn Razi (Rhazes) 860-932 who published a book entitled "The Book of Smallpox and Measles" (in Arabic: Kitab fi al-jadari wa-al-hasbah). In roughly the last 150 years, measles has been estimated to have killed about 200 million people worldwide. In 1954, the virus causing the disease was isolated from an 11-year old boy from the US, David Edmonston, and adapted and propagated on chick embryo tissue culture. To date, 21 strains of the measles virus have been identified. Licensed vaccines to prevent the disease became available in 1963.

Symptoms

The classical symptoms of measles include a fever for at least three days, the three Cs—cough, coryza (runny nose) and conjunctivitis (red eyes). The fever may reach up to 40° Celsius (104° Fahrenheit). Koplik's spots seen inside the mouth are pathognomonic (diagnostic) for measles but are not often seen, even in real cases of measles, because they are transient and may disappear within a day of arising.

The characteristic measles rash is classically described as a generalized, maculopapular, erythematous rash that begins several days after the fever starts. It starts on the head before spreading to cover most of the body, often causing itching. The rash is said to "stain", changing colour from red to dark brown, before disappearing.Fact: date=February 2008

Diagnosis and treatment

Clinical diagnosis of measles requires a history of fever of at least three days together with at least one of the three Cs. Observation of Koplik's spots is also diagnostic of measles.

Alternatively, laboratory diagnosis of measles can be done with confirmation of positive measles IgM antibodies or isolation of measles virus RNA from respiratory specimens. In cases of measles infection following secondary vaccine failure IgM antibody may not be present. However, in the rare case of a secondary vaccine failure, other external symptoms may be present, including nausea, headaches, or a feeling of slight dizzyness when turning one´s head to the left. In these cases serological confirmation may be made by showing IgG antibody rises by Enzyme immunoasay or complement fixation. In children, where phlebotomy is inappropriate, saliva can be collected for salivary measles specific IgA test.Fact: date=March 2008 Adults are recommended to seek medical help right away.