What is being tested?
Measles (rubeola) and mumps are viruses that are members of the Paramyxoviridae family. They both cause infections that usually resolve within several days but can sometimes cause serious complications in certain cases. Both are preventable through vaccination.
Measles and mumps testing may include:
- Testing for antibodies in the blood that develop in response to measles or mumps infection
- Testing for viral genetic material (RNA) in a sample using a molecular method such as polymerase chain reaction (PCR). This method may be used for a variety of samples.
The number of cases of measles and mumps infections in the U.S. has decreased because most people have received the MMR vaccine that protects against measles, mumps, and rubella. In recent years, the majority of new cases in the U.S. have occurred in occasional outbreaks (epidemics), primarily in people who have not been vaccinated, especially those who have traveled to areas of the world where measles or mumps are more prevalent.
Measles, also called rubeola, is a virus that infects cells in the lungs and the back of the throat. It is an extremely contagious viral infection that is easily spread through coughing and sneezing or touching a surface contaminated with the virus and then touching your mouth, nose or eyes. According to the Centers for disease control and Prevention (CDC), the measles virus can live for up to two hours in the air where an infected person coughed or sneezed. Infected individuals are contagious for a couple of days before the symptoms appear.
About 1 to 2 weeks after infection, measles causes symptoms such as:
- A high fever
- Dry cough
- Red eyes
- Light sensitivity
- Runny nose
- Sore throat
- Tiny white spots inside the mouth
- A typical rash that starts on the face and spreads down the body to the trunk and legs
Most people recover within a couple of weeks, but up to 20% develop complications that may include an ear infection, bronchitis, pneumonia, diarrhea, or more rarely encephalitis or blindness. Although it is rare, one to two people, usually babies or young children, out of every thousand people infected, will die from a measles infection. People who are malnourished, have a vitamin A deficiency, or have weakened immune systems have increased risk of severe infections. Women who are pregnant when they are infected with measles are at a greater risk of miscarriage or of premature labor.
Vaccination has drastically reduced the number of people affected by measles in the United States and in many parts of the world, but the World Health Organization (WHO) still lists measles as a leading cause of death in young children. According to their estimates, measles causes about 450 deaths each day worldwide.
In 2000, endemic measles (measles continuously present in the population) was declared to be eliminated in the U.S. However, outbreaks continue to occur on an annual basis. Most cases are occurring in those people who are unvaccinated or have an unknown vaccination status, and most outbreaks are tied to travel to areas of the world where measles outbreaks are occurring.
According to the Centers for Disease Control and Prevention (CDC), in 2014, the U.S. had the highest number of measles cases reported in 20 years, with more than 600 cases. Many were linked to travelers who had visited the Philippines, where an exceptionally large outbreak of more than 50,000 cases occurred. Current CDC estimates for 2018 are 372 cases from 17 outbreaks, and for January to mid-March 2019 are 268 cases from six outbreaks. According to WHO, in 2018 there were 41,000 children and adults in Europe infected with measles in the first six months of that year. This estimate was much higher than any of the 12-month totals reported in Europe from 2000-2017.
The CDC and the U.S. and global medical communities remain concerned and vigilant. Measles is still common in many areas of the world, there is always the risk of travelers spreading measles, and there continue to be some unvaccinated individuals (including children too young for vaccination).
Mumps is a contagious viral infection that is easily spread through coughing, sneezing, talking, or by sharing items or touching surfaces with respiratory droplets or saliva on them (e.g. cups, utensils). About 2 to 3 weeks after infection you typically develop flu-like symptoms such as:
- Headache
- Muscle aches
- Fever
- Followed by typical parotitis – swelling of the salivary (parotid) glands below one or both ears
For most people, mumps is a mild, self-limited illness, but some may develop complications such as temporary or permanent deafness, inflammation of the testicles (orchitis) or ovaries (oophoritis), pancreatitis, meningitis, or encephalitis.
Mumps, a milder illness than measles, is much less widespread than it used to be but is still common in many parts of the world. According to the CDC, mumps cases in the U.S. range from about 200 to 2,000 a year. In the first two months of 2019, for instance, there were 151 cases of mumps reported to the CDC from 30 states and the District of Columbia.Outbreaks can occur in environments where people come in close contact, such as classrooms, sports teams, or in college dormitories. During 2011-2013, for example, several small outbreaks occurred on college campuses in California, Maryland, and Virginia, but their spread was very limited.
How is the sample collected for testing?
Antibody testing requires a blood sample, obtained by inserting a needle into a vein. Viral molecular testing may be performed on a variety of samples, including nasopharyngeal (nasal) aspirate/washing, throat swab or a swab of the inside of the cheek (buccal swab).
A nasopharyngeal swab is collected by having a person tip their head back and then a Dacron swab (like a long Q-tip with a small head) is gently inserted into one of their nostrils until resistance is met. It is left in place for several seconds, then rotated several times to collect cells, and withdrawn. This is not painful, but it may tickle a bit and cause your eyes to tear. For a nasal aspirate, a syringe is used to push a small amount of sterile saline into the nose and then gentle suction is applied to collect the resulting fluid.
In order to fully evaluate a suspected measles case, the CDC recommends the collection of blood as well as samples for RT-PCR testing. For mumps, the CDC recommends the collection of blood and a buccal swab.
Is any test preparation needed to ensure the quality of the sample?
Prior to collection of a buccal swab for mumps, the salivary gland located in front of and below the ear (parotid gland) is massaged. For other specimens, no test preparation is needed.
