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Rubeola Antibodies IgG and IgM

Measles is caused by the rubeola virus, which is a single-stranded, enveloped RNA virus. Humans are the only natural hosts of measles virus. Measles virus normally grows in the cells that line the back of the throat and lungs.

In the decade before the measles vaccine was licensed in 1963, an average of 549,000 measles cases and 495 measles deaths were reported annually in the United States. Measles was declared eliminated in the U.S. in 2000 due to a high rate of measles vaccination. Declines in measles vaccination rates globally have increased the risk of measles outbreaks worldwide. Measles cases continue to be brought into the U.S., mostly by unvaccinated U.S. residents who become infected while traveling to other countries. Also, vaccination coverage among U.S. kindergartners has decreased from 95% during the 2019-2020 school year to 93% during the 2022-2023 school year, leaving an additional 250,000 kindergartners susceptible to measles each year. More than 1,200 measles cases were confirmed across31 states in 2019.

In 2021, an estimated 61 million measles vaccine doses were postponed or missed due to COVID-19 related delays in immunization campaigns in 18 countries. Consequently, there were an estimated 9 million cases and 18,000 deaths from measles worldwide.

Measles is one of the most highly contagious viral diseases that is transmitted by airborne spread when an infected person breathes, coughs, or sneezes. Ninety percent of unvaccinated individuals who are exposed to measles become infected and 20% are hospitalized. Patients are considered to be contagious from 4 days before until 4 days after the appearance of a rash. The virus remains contagious for up to 2 hours in the air and on surfaces after an infected person leaves a room.

The incubation period for measles, which is the interval between exposure to the onset of fever, ranges from 7 to 12 days. Early symptoms include high fever, cough, coryza, conjunctivitis, and Koplik spots. Koplik’s spots on the buccal mucosa are considered pathognomonic of measles. An erythematous rash usually appears 2 to 4 days later. The rash spreads from the head to the trunk to the lower extremities. Measles can cause severe health complications including pneumonia, encephalitis, and death, especially in unvaccinated persons.

Approximately one in 10 children with measles develops an ear infection, 1 in 20 pneumonia, 1 in 1,000 encephalitis, and 1 in 1,000 die. Subacute sclerosing panencephalitis is a rare fatal neurodegenerative disease that develops 7 to10 years after measles infection.

Detection of measles RNA is most successful when specimens are collected during the first 3 days following the onset of rash. Detection of measles RNA by reverse transcription polymerase chain reaction (rRT-PCR). rRT–PCR may be successful as late as 10-14 days after rash onset. Throat or nasopharyngeal swab specimens should be collected as soon as measles is suspected.

A diagnosis of measles can also be confirmed by testing for rubeola/measles-specific IgG and IgM antibodies. The sensitivity of measles IgM assays varies and may be diminished during the first 72 hours after rash onset. If the result is negative for measles IgM and the patient has a generalized rash lasting more than 72 hours, a second serum specimen should be obtained for repeat measles IgM testing. Positive IgG results with negative IgM results indicate immunity to infection. Positive IgM results with or without positive IgG indicates recent infection. Negative IgM and IgG results usually indicate non-immunity and absence of current infection.

Suspected measles patients should be isolated at home for 21 days. Cases should be reported immediately to local and/or state public health departments.

Measles is almost entirely preventable through vaccination with the measles-mumps-rubella-varicella vaccine (MMRV). CDC recommends routine childhood immunization with the measles-mumps-rubella-varicella vaccine (MMRV) vaccine starting with the first dose at 12 through 15 months of age and the second dose at 4 through 6 years of age. According to the Centers for Disease Control and Prevention (CDC), one dose of MMRV is 93% effective against measles and two doses are 97% effective. When more than 95% of people in a community are vaccinated most people are protected against infection through community immunity. Measles immunity is lifelong.


Measles (Rubeola) for Healthcare Providers,

CDC Health Advisory. Increase in Global and Domestic Measles Cases and Outbreaks:

Ensure Children in the United States and Those Traveling Internationally 6 Months and Older are Current on MMR Vaccination. CDCHAN-00504, March 18, 2024. 


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