Get to know the measles virus better!
Date: 2 سال قبل
Measles sets in abruptly with coryza, conjunctivitis, fever, and rash. The typical maculopapular rash appears 1 to 3 days later. Complications include otitis, pneumonia, and encephalitis. Subacute sclerosing panencephalitis is a rare late sequela.
Classification and Antigenic Type
There is only a single antigenic type.
The virus causes viremia with wide dissemination and multiplies in cells of the lymphatic, respiratory, intestinal and urinary system, the skin, and sometimes the brain.
Interferon and other initial defenses are followed by specific cellular and humoral immune responses, which confer long-lasting immunity.
Prior to the vaccine era measles occurred worldwide in an endemic or epidemic pattern and disease was inevitable. In temperate climates, the incidence peaks in the late winter and early summer.
In typical cases, the clinical picture is diagnostic. Atypical cases or cases following previous vaccination are diagnosed by isolating the virus in cell culture by direct smear of cell-containing specimen, by detection of RNA with the polymerase chain reaction (Rt-PCR) or detecting specific IgM in the first serum at the time of rash with a rising titer of IgG antibodies in the second serum.
Active vaccination with a live attenuated virus vaccine gives long-lasting protection. Passive prophylaxis with measles immunoglobulin is used to prevent disease in susceptible, exposed individuals.