Flu Testing And Diagnosis: How Does It Work
Influenza is a viral respiratory illness that affects millions of people each year.
Symptoms can include fever, cough, stuffy or runny nose, sore throat, headache, chills and fatigue. A flu test is not always needed to diagnose the flu. However, in some cases, your healthcare provider may need to confirm if you have the flu, so they may recommend testing.
When Should I Get An At
There are no strict guidelines or clear recommendations for when to take an at-home flu test.
In general, flu testing is only conducted when you have symptoms that could be caused by an underlying infection with an influenza virus. Testing is most often done when symptoms are significant or when you are at higher risk of flu complications because of your age, coexisting medical conditions, or pregnancy.
A flu test is often not necessary if you have only mild symptoms and flu transmission in your community is high. In these cases, testing may not be needed because it would not change the way you are treated.
If you have flu-like symptoms or are concerned about possibly having the flu, you should talk with a doctor. Since there are multiple factors involved in determining whether a flu test is appropriate, the doctor can address whether testing, including at-home testing, is recommended in your situation.
Why Is This Important
The findings suggest that routine use of rapid tests for flu improves detection of the illness compared with standard clinical care. Flu testing is not routine in most hospitals. Clinicians may order a PCR test when they suspect flu, but this misses patients who do not show the classic symptoms of the illness.
When the rapid test is routinely used to detect flu, patients are likely to receive appropriate medication faster. They can also be swiftly isolated from others, which reduces the spread to other patients and staff in the hospital. People with flu who were diagnosed with the rapid tests were less likely to become seriously unwell.
The researchers say that more hospitals should replace laboratory-based PCR tests for flu with routine point-of-care rapid testing. The study took place during the winter months. This means the findings are relevant to flu seasons, and not necessarily to other times of the year.
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Where Can You Get A Flu Tests
Flu tests are available at most doctors offices, urgent care settings, and hospitals.
Rapid flu tests are usually less costly than laboratory-based tests. According to Beckers Hospital Review, rapid tests cost about $5 to $10, while a laboratory test can cost $200 or more.
You may wish to contact a facility where youre seeking testing to ensure they have flu tests available, especially if youre in flu season, which usually takes place in the late fall to winter.
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How To Tell The Difference Between Covid
Flu season is right around the corner. Paired with the ongoing battle with COVID-19, some experts say we could have a twindemic on our hands this year an influenza epidemic unfolding in the middle of a relentless COVID-19 pandemic.
The medical community is concerned that if we have an increased number of influenza cases, it will strain the hospital system on top of whats already going on with the COVID-19 pandemic, says Dr. Ting Ting Wong, an attending physician and infectious disease specialist at NewYork-Presbyterian Brooklyn Methodist Hospital.
Last year, the influenza virus caused an estimated 35 million illnesses in the U.S. The severity of this years flu season is unpredictable, but with winter approaching a lot of people may be coughing and sneezing, so the likelihood of transmission is much higher when youre having active symptoms, adds Dr. Wong.
But what exactly are those symptoms? Just as in the spring when differentiating between seasonal allergies and COVID-19 was tricky, the challenge now will be identifying what could be signs of COVID-19 vs. flu.
Health Matters spoke with Dr. Wong to learn the similarities and differences of the coronavirus vs. flu and how to protect yourself against both.
What Kinds Of Flu Tests Are There
A number of tests are available to detect flu viruses in respiratory specimens. The most common are called rapid influenza diagnostic tests . RIDTs work by detecting the parts of the virus that stimulate an immune response. These tests can provide results within approximately 10-15 minutes but may not be as accurate as other flu tests. Therefore, you could still have flu, even though your rapid test result is negative. Other flu tests called rapid molecular assays detect genetic material of the flu virus. Rapid molecular assays produce results in 15-20 minutes and are more accurate than RIDTs.
In addition to RIDTs and rapid molecular assays, there are several more accurate flu tests available that must be performed in specialized laboratories, such as those found in hospitals or public health laboratories. These tests include reverse transcription polymerase chain reaction , viral culture, and immunofluorescence assays. All of require that a health care provider swipe the inside of your nose or the back of your throat with a swab and then send the swab for testing. Results may take one to several hours.
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How To Test For The Flu
This article was medically reviewed by Luba Lee, FNP-BC, MS and by wikiHow staff writer, Danielle Blinka, MA, MPA. Luba Lee, FNP-BC is a board certified Family Nurse Practitioner and educator in Tennessee with over a decade of clinical experience. Luba has certifications in Pediatric Advanced Life Support , Emergency Medicine, Advanced Cardiac Life Support , Team Building, and Critical Care Nursing. She received her Master of Science in Nursing from the University of Tennessee in 2006. This article has been viewed 7,498 times.
No one wants to get the influenza virus, commonly referred to as the flu. If you suspect you might be coming down with the dreaded virus, diagnosing it early is your best chance for a swift recovery, as antiviral medications are most effective within the first 48 hours. Your doctor can determine if you have the flu based on your symptoms, flu activity in your area, and possibly a rapid influenza diagnostic test. This simple, painless, in-office test will help the doctor diagnose and treat your symptoms.
Rapid Diagnostic Test Helps Stop The Spread Of Flu At Nuh
In the last week alone, over 100 cases of flu have been confirmed at Queens Medical Centre and Nottingham City Hospital.
Symptoms of flu include a fever, shortness of breath and extreme tiredness. The virus spreads easily through coughs and sneezes, so in areas with high footfall such as a hospital flu can pass easily from person to person.
Each year, over 8,000 people are killed by the flu virus in the UK, with the most vulnerable: the elderly, young children and the sick, most at risk.Over 500 patients were admitted to our hospitals with flu last year. So far this year, there has been 357 cases of Influenza A detected on our wards , however 2018 was a particularly heavy year for flu, and the flu season is yet to peak.
Diagnosing and treating flu causes difficulties for clinical staff. When patients present with symptoms, a throat swab is taken, which is sent to the microbiology lab for analysis before a diagnosis report is generated.
The total end-to-end diagnosis process can take over 36 hours for a positive or negative result, which has implications for the clinicians ability to isolate and treat patients with flu within a quick timeframe.
Patients waiting for a flu diagnosis are sometimes given unnecessary antibiotics to treat the symptoms, rather than antivirals which are effective in treating the flu virus.
In some cases, by the time a positive flu diagnosis has been confirmed, the patient has already been discharged and no further treatment is possible.
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How To Test For Flu
There are a number of tests used to diagnose the flu. The most common are rapid influenza diagnostic tests , and they may be performed in a healthcare providers office. RIDTs work by detecting antigens that stimulate an immune response. A rapid molecular assay is another flu test that works by detecting genetic material of the virus. In addition to rapid tests, there are several more accurate and sensitive flu tests that must be performed in specialized laboratories, such as those found in hospitals or state public health laboratories.
A flu test typically involves a healthcare provider collecting a sample from the inside of your nose or back of your throat using a sterile swab. The swab is then tested for the flu.
Will We Have Enough Tests
The most accurate tests for COVID-19 and the flu are both PCR tests that require some of the same reagents, or chemicals to process the tests, raising concerns that surges in both infections this winter could strain testing capacity.
I think weve done a much better job of sorting out the supply chain thats necessary to support a broader amount of testing, said Fahimi. So Im hopeful that were not going to run out of tests.
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Queenslanders Can Access A Single Test
Where required, GPs and clinicians will refer Queenslanders to undertake combined testing.
This means you will only have to have the one test, Queensland Health confirmed, although it’s preferable that vulnerable groups are the first priority for access.
When it comes to COVID-19 testing, Queensland health advises to look for a private pathology to get a COVID-19 PCR test, such as:
- 4Cyte Pathology
For anyone still in doubt, Queensland Health also provides a map to locate your closest COVID-19 testing sites.
Can You Tell If Its The Flu Or Covid

As the flu season ramps up this fall and winter, every cough and sniffle will carry an extra worry: possible COVID-19 infection.
With influenza, COVID-19, and the usual cold-weather respiratory infections in circulation, experts say its bound to be a confusing season for people to sort out what to do when they fall ill.
We talked to UC San Francisco emergency care physician Jahan Fahimi, MD, and infectious disease specialist Peter Chin-Hong, MD, about the differences between flu and COVID-19, when to get a test, and why you shouldnt try to diagnose yourself.
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Is It Worth Getting Tested For The Flu
Testing has plenty of benefits, Dr Short says.
Confirmation of an infection can determine how quickly you’re able to access treatments.
“We have seen the power of diagnostics and how important diagnostics is in outbreak management,” she says.
“This comes down to specific risks. Imagine if someone is elderly, or they have underlying conditions, they test early on in their illness, and they test positive for the flu and not COVID.
“They would then be eligible for antivirals, specifically Tamiflu, which reduces disease severity.”
It’s something many have witnessed during COVID.
“If they test positive for COVID they would be eligible for antivirals or monoclonal antibodies to reduce disease severity,” she says.
“Once you know and provided you know early enough in the course of the infection then you can have some treatment.
“These antivirals work very early in the course .”
Cost Could Be An Issue
Users of the Labcorp Seasonal Respiratory Virus RT-PCR DTC Test self-collect nasal samples at home using a swab.
They then mail the sample to Labcorp for analysis. Results are delivered through an online portal, with referrals to a healthcare professional available as needed.
Test kits cost $169 and can be purchased in retail stores or online.
A Labcorp spokesperson told Healthline that the tests are available with no upfront cost to individuals who have health insurance and who meet clinical guidelines, such as having symptoms of a respiratory infection.
But Nichols said it remains unclear whether insurers will cover the full cost of the combination test. Van Tuyl added the price of the Labcorp test makes it unlikely that it will supplant the COVID-only tests already on the market.
There is a big cost difference between the single COVID-19 test and the combination test, she explained. It may not be worth the extra cost just to know you do or do not have the other viral illnesses.
Having the test available for purchase and use without a prescription makes it possible to use without taking time off work, school, or securing child care. For some people, that will be important and helpful, MacDonald told Healthline. Nonetheless, the price of $169 makes it prohibitive for many people to purchase.
Van Tuyl said the combination tests could have utility for testing people who are high risk, have high risk family members, or in pediatric patients.
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How Well Can Rapid Tests Detect Flu
During a flu outbreak, a positive rapid flu test is likely to indicate flu virus infection. However, rapid tests vary in their ability to detect flu viruses, depending on the type of rapid test used, and on the type of flu viruses circulating. Also, rapid tests appear to be better at detecting flu in children than in adults. This variation in ability to detect viruses can result in some people who are infected with flu having a negative rapid test result. This situation is called a false negative test result. Despite a negative rapid test result, your health care provider may diagnose you with flu based on your symptoms and their clinical judgment.
Testing For Avian Influenza
The standard commercially available rapid influenza A tests do not detect H5N1 avian influenza. A rapid test from nasopharyngeal swab specific to H5N1 influenza was approved by the FDA in 2009.
A CBC may be more clinically useful in avian influenza than in seasonal influenza. Leukopenia , especially lymphopenia, is common and is observed in 50-80% of patients. In at least one study, lymphopenia at presentation was a significant predictor of the progression to acute respiratory distress syndrome. More than half of patients will have mild-to-moderate thrombocytopenia.
In addition to thrombocytopenia, some patients with severe disease will develop disseminated intravascular coagulation , as shown in coagulation studies.
Liver function tests may be useful in differentiating avian influenza from other febrile tropical diseases. Aminotransferase levels are elevated in more than half of all patients with H5N1 infection.
A basic metabolic panel is generally required in the care of all seriously or critically ill patients. Abnormalities in renal function may herald the progression to organ failure.
According to CDC recommendations, clinicians should attempt to specifically identify avian H5N1 influenza in patients with all of the following characteristics:
Testing may be considered in discussion with public health authorities in patients who have only some of these characteristics all testing should be discussed with local public health departments.
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What Happens During A Flu Test
A flu test requires a sample of fluid from your nose or throat. There are two ways to collect a sample for testing:
- Swab test. Your provider will use a special swab to take a sample from your nose or throat.
- Nasal aspirate or wash. Your provider will insert a saline solution into your nose and use gentle suction to remove it.
At-home tests are also available for flu testing. It’s very important to follow all the instructions that come with your test kit. There are two types of at-home tests:
- Rapid tests are done completely at home. To do the test, you usually swab your nose to collect the sample. Results are ready in under a half hour.
- Self-collection tests provide a kit to collect a fluid sample to send to a lab for testing. The sample is usually a nasal swab or a saliva sample. These tests tend to be more accurate than the rapid tests you do at home, but it may take days to get your results.
Some home tests look for both flu and COVID-19. If you’re considering a home flu test, your provider can help you choose the best test for your situation.
Should I Get A Flu Shot
The Centers for Disease Control and Prevention recommends that everyone 6 months old and older get a flu shot each season. In particular, people who are at high risk of complications from the flu should receive the vaccine. These include young children, the elderly, residents of nursing home and other long-term care facilities, pregnant women, and people with pre-existing conditions such as asthma, COPD, heart disease, and liver or kidney disorders.
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What Other Tests Might My Doctor Order To Diagnose My Flu
Your healthcare provider may order a strep test to check for strep throat, an RSV test to check for respiratory syncytial virus, a virus that often infects young children and the elderly, or a sputum culture to look for bacterial and/or fungal causes of a respiratory infection. Your healthcare practitioner may also order blood tests such as a comprehensive metabolic panel or complete blood count to monitor the health and function of organs such as your lungs and kidneys.