To detect and diagnose a Bordetella pertussis infection, commonly known as whooping cough
Pertussis Tests
Pertussis Tests
Also Known As
Whooping Cough Tests
Formal Name
Bordetella pertussis Culture, PCR, Antibodies (IgA, IgG, IgM)
This article was last reviewed
on
This article waslast modified
on January 11, 2018.
At a Glance
Why Get Tested?
When To Get Tested?
When you have persistent spasms or fits of coughing (paroxysms) that the healthcare practitioner suspects is due to pertussis (whooping cough); when you have symptoms of a cold and have been exposed to someone with pertussis
Sample Required?
A nasopharyngeal (NP) swab or a nasal aspirate; occasionally, a blood sample drawn from a vein in your arm
Test Preparation Needed?
None
Accordion Title
Common Questions
-
How is it used?
Pertussis tests are used to detect and diagnose a Bordetella pertussis infection, commonly known as whooping cough, a highly contagious infection of the respiratory tract. Early diagnosis and treatment may lessen the severity of symptoms and help limit spread of the disease.
There are a few test methods that may be used to detect a pertussis infection:
- Polymerase chain reaction (PCR) – this test amplifies the genetic material of the bacteria when present in a sample so that it can be detected. Results are available within a couple of days. False-positive results may occur when PCR is used. Therefore, the Centers for Disease Control and Prevention (CDC) recommend that during a suspected outbreak, at least one case be confirmed using culture.
- Culture – this test was the "gold standard" for identifying pertussis before the advent of the PCR assay and it may be used to diagnose pertussis early in the infection. The sample is put into nutrient media and the bacteria are grown and identified. Results are reported in one to two weeks. A pertussis culture will allow the recovery of the bacteria in order to investigate potential outbreaks. Susceptibility testing can also be performed to determine which antibiotic to use for treatment. Typically, a pertussis culture and PCR test will both be ordered, as early in the illness as possible. Cultures are less likely to grow the bacteria two to three weeks into the illness and will be affected by some antibiotics if the person has been treated.
- Blood test for pertussis antibodies, IgA, IgG, IgM – these blood tests detect antibodies produced by the body's immune response to a pertussis infection. Antibody testing is not useful to determine if a person has had a recent pertussis infection. Pertussis IgG antibodies will be present in anyone who has been vaccinated. Pertussis IgM and IgA antibodies will usually only be present a short time after vaccination or infection. These tests may be performed in a research setting to evaluate and study the spread of pertussis in the community. Rarely, an antibody test may be performed to evaluate the adequacy of a person's immune response to a pertussis vaccine.
-
When is it ordered?
Pertussis tests are ordered when someone has signs and symptoms suggestive of pertussis, and as early in the illness as possible (generally within the first two weeks for culture and the first three weeks for PCR).
Symptoms during the first stage of the infection, called the catarrhal stage, may include typical cold symptoms such as a runny nose, sneezing, mild cough, and/or a low-grade fever. After about two weeks, the paroxysmal stage begins and may include symptoms such as:
- Frequent severe bouts of coughing, sometimes followed by vomiting
- Several rapid coughs followed by a whooping sound as the person inhales; affected adults may cough but not whoop, and infants may have trouble breathing and may choke more than whoop.
These symptoms may last for one or two weeks or persist for a couple of months. During the convalescent stage, the severity of symptoms lessens, with the frequency of coughing gradually decreasing over the next several weeks.
-
What does the test result mean?
A positive PCR test means that it is likely that the person has pertussis. However, the PCR test may also be positive with other Bordetella species. A negative PCR test means that it is less likely that the person has pertussis but does not rule it out. If there are an insufficient number of bacteria in the sample, then they may not be detected.
A positive culture is diagnostic for a B. pertussis infection, but a negative culture does not rule it out. Culture results are dependent on proper specimen collection and transport, duration of symptoms, when the sample is collected, and prior antimicrobial therapy administered before the culture is taken.
Both culture and PCR tests are less likely to be positive as the illness progresses.
-
Is there anything else I should know?
The pertussis vaccination is given to infants as a series of shots. Those children who have not completed the series of pertussis vaccinations are at a higher risk of becoming infected. Even some people who have been vaccinated may be infected by Bordetella pertussis, but they will tend to have a less severe illness.
Pertussis is treated with antibiotics, which will help to resolve the infection and help stop spread of the disease.
International travelers should be aware that many less developed countries do not have widespread vaccination for pertussis. Infants who have not completed their series of vaccinations and people who have not had a booster vaccination in many years may be at an increased risk of contracting pertussis.
Pregnant women are advised to be re-vaccinated to prevent transmission of pertussis to the newborn. Grandparents and other caretakers who will be spending time with a newborn are also advised to be re-vaccinated.
Direct fluorescent antibody (DFA) is a test method that is no longer recommended to detect pertussis infections since it is less specific and sensitive than either the pertussis culture or PCR.
-
Can a throat culture be used instead of a nasopharyngeal sample from my nose?
A throat culture is not acceptable. During a pertussis infection, the bacteria are found in the tissues in the back of the nose, not in the throat or the front portion of the nose.
-
Can pertussis testing be done in my healthcare practitioner's office?
No. There is no simple, rapid diagnostic test for pertussis. It requires specialized equipment and is typically performed in laboratories. Not every laboratory performs this testing and samples may need to be sent to a public health laboratory.
-
Why did my doctor report my child's pertussis infection?
Healthcare practitioners are required to report pertussis to state health departments. Outbreaks are tracked and interventions, such as vaccination and appropriate antibiotic treatment, are used to stop the outbreak.
-
My doctor said I have Bordetella parapertussis. Is this the same as whooping cough?
B. parapertussis are bacteria that can infect humans in the same manner as B. pertussis, but the infection usually causes a milder respiratory illness. Culture methods and PCR tests can detect and distinguish B. parapertussis from B. pertussis, and both are commonly tested for since the signs and symptoms may be similar in people with either infection. There is no vaccine to prevent B. parapertussis infections.
