- Measles is caused by an RNA virus
- Humans are the only natural host. Carriers are not known to occur
- The virus remains in the air in droplet form for several hours, especially in humid weather
- The infection is transferred from infected secretions of the nose, throat and the respiratory tract, during the prodromal period or the early stages of rash (four days before and five days after the appearance of the rash)
- Measles affects virtually everyone in infancy or childhood between six months and three years of age in developing countries
- References to measles can be found as far back as the 7th century A.D
- Prior to 1963, almost everyone got measles; it was an expected life eve
- Each year in the United States, there were approximately three to four million cases, and an average of 450 death
- More than half the population had measles by the time they were six years old, and 90 percent had the disease by the time they were 15 years old
- However, after the measles vaccine became available, the number of measles cases dropped by 99 percent
- Between 1985 and 1988, it was discovered that many measles cases had occurred in children who had been vaccinated with the measles vaccine
- While there were far fewer measles cases among vaccinated children than among unvaccinated children, the children who received only one dose were not always protected from the disease
- This led to the recommendation of a second dose for children between 5 and 19 years of age, to ensure protection for those who had not developed immunity from the first dose
- Unfortunately measles cases have been on the rise recently. After hitting a record low number of cases in 2004 (37 cases), we seem to continue to hit new record highs every few years now
- So far, there have already been over 610 confirmed cases of measles in the U.S. in 2014 - the most since 1994.
- Infection is most commonly transmitted by inhalation of contaminated droplets.
- The incubation period is commonly 10 days from exposure to the onset of fever, and 14 days to the appearance of rash.
- After infection, virus enters lymphoid tissue of tonsils, adenoids & lymphnodes with hyperplasia of reticuloendothelial system and then enters blood.
- It starts with symptoms of common cold & photophobia which develops by the 2nd. day.
- After 3-4 days, a rash develops at the back of ears, which rapidly spreads over face and down the neck, & limbs.
- Measles vaccination has markedly reduced the incidence of measles throughout the developed world.
- However, measles cases still occur in low-incidence countries via importation by travelers.
- Therefore, maintenance of immunity is important even in countries with a low incidence of measles, since a single imported case can result in large measles outbreaks in the setting of waning immunity.
Are You Immune?
The only way to tell for sure that a person is protected (immune) is by a blood test.
The blood test shows whether the body has antibodies to fight off the virus.
Even if someone hasn't had the blood test, they are still considered immune if:
- They had measles in the past, and have medical records to prove it
- They received 2 doses of measles-containing vaccine in the past and have medical records to prove it
- They were born before 1957
*pets do not get infected with or spread the measles virus.
Steps to Prevention are:
1) isolation of the patient for 7 days after the rash appears
2) immunization of contacts within 2 days of exposure
3) prompt immunization at the beginning of epidemic.
Prevention is by measles vaccination. It is given at 9 months of age.