Influenza Virus A & B Antigen, Throat Swab
This rapid test detects influenza A and B antigens from a throat swab specimen. It offers quick results to support clinical decision-making during respiratory illness outbreaks.
- DHA-licensed lab
- Includes Doctor Consultation
- Physician-reviewed
- Same Day Collection
24 hours
Turnaround
Swab
Sample
What the Influenza Virus A & B Antigen, Throat Swab test tells you
Influenza A and B antigen testing on a throat swab looks for proteins that sit on the surface of the influenza virus. A swab is passed over the back of the throat and the tonsil area, and the material collected is exposed to antibodies that bind only to influenza proteins. Nothing is grown and no genetic material is copied, which is why this format is chosen when an answer during the same visit is more useful than the most sensitive method available.
The throat is a compromise sampling site. The nasopharynx, high up behind the nose, usually holds more influenza virus, so a nasal specimen tends to detect infection more reliably. A throat swab is easier to tolerate, which matters for children, for people with nosebleeds or recent nasal surgery, and for anyone who cannot stay still for deeper sampling. Because the test depends on there being enough viral protein on the swab, timing matters a great deal: shedding is at its heaviest in the first days of illness and falls away afterwards, so a specimen taken late can read negative even when influenza was the cause.
A positive result is meaningful and is usually accepted at face value during the influenza season, since the test rarely reacts to anything else. A negative result is weaker evidence and has to be read alongside your symptoms, the time of year and what is circulating locally. Your doctor may treat the illness as influenza regardless, or send a molecular test that copies viral genetic material and so detects far smaller amounts of virus. Knowing whether influenza A or influenza B is present also helps with sensible precautions at home, at work and around vulnerable relatives.
Used when influenza is suspected and a throat specimen is preferred, particularly during flu outbreaks or when nasal collection is not feasible.
- A same-visit answer
Antigen detection needs no culture step, so the result can inform decisions while the illness is still in its early phase.
- Separating flu from lookalikes
Fever, aches and cough have many causes. Identifying influenza narrows the list and reduces guesswork about whether antibiotics are needed.
- Timing antiviral decisions
Antiviral medicines work best when started early. A confirmed influenza result helps your doctor decide quickly whether they are appropriate for you.
- Protecting people around you
Confirmed influenza is a reason to keep distance from infants, pregnant women, older relatives and anyone with weakened immunity.
Reasons your doctor may request the Influenza Virus A & B Antigen, Throat Swab test
Your doctor may order this test for any of the reasons below. Some are routine checks, others follow specific symptoms or an earlier result.
Sudden flu-like illness
- Sudden fever, muscle aches, headache and dry cough during the influenza season.
- Sore throat with fever where nasal sampling is not tolerated or not possible.
Higher-risk groups
- Respiratory symptoms in someone with asthma, chronic lung disease, heart disease or diabetes.
- Illness in a person who lives with or cares for an infant, an elderly relative or an immunocompromised patient.
Outbreaks & clusters
- A cluster of similar respiratory illness in a household, school or workplace.
Detected means influenza protein was found on your throat swab, and the report separates influenza A from influenza B. In the influenza season a positive result is usually taken at face value, since the test rarely reacts to anything else; it does not identify the strain or say anything about antiviral resistance. Not Detected is less conclusive. The throat usually holds less virus than the nasopharynx, and shedding is heaviest in the first days of illness, so a swab taken late (or taken soon after mouthwash, a gargle, a medicated lozenge or a meal) can read negative when influenza is the cause. A recent live nasal influenza vaccine, or an antiviral already started, changes how the result should be read. Your doctor weighs the answer against your symptoms, the time of year and local illness patterns, and may add a molecular test that detects far smaller amounts of virus.
Medically reviewed by Dr Nirupama Sabhapathy
This test is reported descriptively rather than on a numeric scale: each finding below explains what your report may say.
No influenza A or B antigen found on the throat swab; this does not rule influenza out.
Influenza A or B antigen found on the throat swab: strong evidence of flu at the time of sampling.
Ranges are a guide: your physician interprets your result alongside your symptoms and history.
What a higher result can point to
- Active influenza A infection while the virus is still being shed from the throat.
- Active influenza B infection, which is seen often in children and younger adults.
- Recent influenza that is settling but is still shedding detectable viral protein.
- Recent vaccination with a live attenuated influenza vaccine given into the nose, which can leave detectable viral antigen for a short period.
- Influenza occurring alongside another respiratory infection, so the result is true but is not necessarily the whole story.
These are possibilities, not diagnoses. A single value outside the reference range is interpreted alongside your symptoms, history and other tests: your doctor decides what it means for you.
What this test cannot tell you
- A negative result does not rule out influenza, particularly when the swab is taken very early or several days into the illness.
- Throat specimens usually recover less virus than nasopharyngeal specimens, so this format detects fewer true infections than a molecular test.
- The test reports the influenza type but not the strain, and says nothing about whether the virus will respond to antiviral medicines.
- Other respiratory viruses and bacteria are invisible to this test, so a broader panel is needed when the cause remains unclear.
Collecting your sample safely
- The swab can feel uncomfortable for a few seconds and may make your eyes water or make you cough or gag briefly.
- Slight soreness or a small nosebleed can follow and settles quickly; tell the nurse beforehand if you have a bleeding disorder or recent nose or throat surgery.
- Every swab is sterile and used once.
- 1A positive result is strong evidence of influenza infection at the moment of sampling.
- 2A negative result is not proof that you do not have influenza and is read together with your symptoms.
- 3Sampling within the first few days of symptoms gives the best chance of detection.
- 4The result separates influenza A from influenza B but not the specific circulating strain.
- 5Treatment decisions rest with your doctor, who weighs the result against the whole clinical picture.
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Frequently Asked Questions
Everything you need to know about the Influenza Virus A & B Antigen, Throat Swab test. Can't find what you're looking for?
Talk to our team→A Detected result means influenza protein was found on your throat swab, and the report shows whether it is influenza A or B. During the flu season it is strong evidence of infection at the time of sampling, because the test rarely reacts to anything else. It does not identify the strain or show whether the virus will respond to antiviral medicines.
Within the first few days of symptoms, when the amount of virus in the throat is at its highest. A swab taken very early in the illness, or several days in once shedding has faded, is more likely to read Not Detected even when influenza is the cause, so tell your doctor when your symptoms started.
This antigen test looks for influenza protein and needs a certain amount of it on the swab before it reacts. A molecular test such as PCR detects the virus's genetic material and picks up far smaller amounts, so it finds more true infections. When an antigen result is negative but influenza still seems likely, your doctor may add a molecular test.
Not quite. The throat usually holds less virus than the nasopharynx, the area at the back of the nose, so a throat swab detects fewer true infections. It is used when a throat specimen is preferred or nasal collection is not feasible. A positive throat result is still reliable; it is a negative one that needs reading with your symptoms.
No. It detects only influenza A and B, and other respiratory viruses and bacteria are invisible to it. A positive result can also sit alongside another respiratory infection, so it is true but not necessarily the whole story. If the cause of your illness remains unclear, your doctor may arrange a broader respiratory panel.
Yes. The test needs a certain amount of viral protein on the swab before it will react, and that amount is not always present, especially in the first hours of illness or once shedding has faded. Your doctor may still treat the illness as influenza on clinical grounds, or arrange a molecular test that picks up much smaller quantities of virus.
Both cause the same broad illness and are managed in much the same way, so the distinction rarely changes your treatment. It does matter for tracking what is circulating in the community, and it can be useful when several people in one household or workplace fall ill at the same time.
Not directly. The test confirms that influenza protein was present on the swab, not how much virus you are shedding or how long you will remain contagious. In general people are most infectious around the onset of symptoms and in the days that follow, and your doctor can advise when returning to work or school is reasonable.
An injected influenza vaccine contains no live virus and will not cause a positive result. A live attenuated vaccine sprayed into the nose can leave detectable viral protein in the upper airway for a short time afterwards, so mention any recent vaccination when the sample is taken.
No fasting is needed. Avoid mouthwash, gargles, antiseptic throat sprays and medicated lozenges in the hour or so before the swab, and do not eat or drink immediately beforehand, since these can wash away the material being collected.
The flu A and B antigen test is AED 55, including a physician-reviewed report, with results usually within 24 hours. Home collection anywhere in Dubai is free when your order reaches AED 300 or includes a package; below that, a AED 100 home collection fee applies (AED 50 for a lab walk-in).