The Test Sample
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 involve the detection of antibodies in the blood that develop in response to infection. Additionally, the virus or its genetic material (RNA) may be directly detected in a sample using culture or a molecular method such as polymerase chain reaction (PCR). These methods may be used for a variety of samples. (Read the "How is it used?" section for more testing details.)
The number of cases of measles and mumps infections has decreased from several hundred thousand a year in the U.S. to several hundred. The decreases are due to comprehensive measles and mumps vaccination programs. While vaccines are available for each virus, combination vaccines, such as MMR that protects simultaneously against measles, mumps, and rubella, are frequently utilized. 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 an extremely contagious viral infection that is transmitted through respiratory secretions. The virus infects cells in the lungs and at the back of the throat and, after a 1 to 2 week incubation, causes symptoms such as a high fever, dry cough, red eyes, light sensitivity, a runny nose, sore throat, tiny white spots inside the mouth, and a characteristic rash that typically 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. People who are malnourished, have a vitamin A deficiency, or have compromised immune systems are frequently more severely affected. 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 killed about 145,700 people globally in 2013, most of them children under the age of five.
The result of the vaccination efforts In the U.S. was the declaration in 2000 that endemic measles (measles continuously present in the population) had been eliminated. However, small outbreaks continue to occur on an annual basis. Most cases are occurring in those people who are either 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), during 2001-2011, 911 measles cases from 63 outbreaks were reported. 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.
The CDC and the U.S. and global medical communities remain concerned and vigilant. Measles is still endemic in many areas of the world, there is always the risk of travelers spreading measles, and there continue to be small percentages of unvaccinated individuals (including children too young for vaccination).
Mumps is a viral infection that is transmitted through respiratory secretions or saliva. After a 2 to 3 week incubation period, an infected person typically develops flu-like symptoms such as a headache, muscle aches, and fever that are followed by characteristic 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 common than it used to be but is still endemic 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. 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 in the arm. Viral culturing or molecular testing may be performed on a variety of samples, including blood, urine, nasopharyngeal (nasal) aspirate/washing, throat swab, a swab of the inside of the cheek (buccal swab), cerebrospinal fluid, or other body tissue.
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 the person's 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 culture and RT-PCR testing. For mumps, the CDC recommends the collection of blood and a buccal swab.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
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.