Flu is a common respiratory disease caused by the influenza virus. The flu virus attacks mostly during the winter and spring season, and this is known as flu season. It is a highly contagious infection and the virus spreads from person to person via coughs, sneezes, and droplets of sputum released in the air, that if inhaled by a healthy person can cause infection. Also, a person with a compromised immune response is highly susceptible to developing a flu attack. The outbreak of flu can result in serious illness and can spread readily in the surrounding regions.
Most individuals show symptoms such as muscle aches, fever, nausea and fatigue. The recovery is usually one to two weeks. For a few people like children below 5 years, an adult aged 65 and over, and people with comorbid health conditions the flu attack can be very severe and even cause death. Early diagnosis of flu is critical for rapid initiation of treatment to lessen influenza related severity.
Different Types Of Flu Tests:
The presence of any infections can be detected by routine blood work like complete blood count routine, where high white blood cell count indicates infection. To confirm the diagnosis of flu the below tests may help:
Rapid Flu /Influenza Test
Rapid flu test can identify the influenza virus in a throat swab and offer results within less than 20 minutes. But test results are highly sensitive and not as precise as other flu tests.
Antigen Detection Test
The rapid influenza antigen test supports the identification of viral antigens in the nasal secretions. However, these test results are also not very accurate and can detect around 50-70% of influenza cases. A negative antigen test is followed by a molecular test or viral culture.
Molecular Test (RT-PCR)
Reverse transcription polymerase chain reaction (RT-PCR) and other molecular tests can detect viral genetic material (RNA) in the sputum or throat swab samples. This test is very specific and precise than rapid antigen detection tests.
A viral culture test is quite expensive and needs at least 3-10 days to get the test results. The sputum sample or throat swab of the patient is cultured to detect the specific strain of influenza virus which is causing the infection. However, viral cultures are not very beneficial in offering specific treatment plans for flu.
Purpose Of Flu Test
A flu profile test helps the health care provider to find out if a person has the flu. Flu tests are also used to look out for flu outbreaks in the community and for detecting the type of virus that is causing the infection. Once a person is diagnosed with flu, the doctor may prescribe medications to combat the virus. This medicine works well when given within two days after a person first feels sick.
Why Do I Need A Flu Test?
Generally, most of the flu symptoms are similar to a common cold. A person with flu infection may start showing the following symptoms:
- Body aches
- Runny nose
- Sore throat
- Nasal congestion
- Muscle and joint pains
- Extreme fatigue
- Watering of eyes
When a person exhibits these symptoms, the healthcare provider can decide if the patient need a flu test or not. On the other hand, if flu is widespread in your region, then the doctor may be able to diagnose without a test. Also, the doctor may order a flu test if a person is at a high risk of developing serious illnesses from flu such as pneumonia. Your risk may be higher if you:
- Have a compromised immune system
- Age above 65
- Under the age of 5
- Have or had cancer
- Chronic health conditions such as asthma or diabetes
Preparation For the Test
You don't need any special preparations for a flu test.
Risk Of The Test
When the throat or nose is swabbed, the person may feel a stifling sensation. A nasal aspirate or wash may also make a person uncomfortable, however, these effects are temporary.
What Does The Results Mean?
A positive test result means a person is having the flu, Also it’s possible to get a false positive result, which means you really don’t have it. Depending on the health status, the doctor may prescribe medication to help avert the flu from becoming a more severe illness.
A negative result indicates that a person may not have the flu. A different bacteria or virus may be causing symptoms. Still, flu cannot be ruled out, as a false negative is possible. This means even if your test says you don’t have the flu, but you really do.
Rapid tests tend to have more false negatives than tests that are usually analysed in the lab. False negatives may also occur if your test was done after a load of flu virus in the system began to decrease.