The rapid test technology in flu is rapidly gaining popularity especially the rapid influenza diagnostic tests (RIDTs). Some of rapid tests can give results within as little as fifteen minutes and are ideal for use in clinical situations where early diagnosis is important. Nonetheless, similar to any other flu rapid tests, there exist some disadvantages that may affect the efficiency of the rapid test in various ways.
Flu rapid test technology has the disadvantage of having low sensitivity when compared to other diagnostic tests. Specificity on the other hand is the capacity of a test to properly detect those who are negative for the flu. Unfortunately, RIDTs are less sensitive than some of the modern diagnostic techniques such as RT-PCR. RIDTs are not highly sensitive and generally have sensitivity rates between 50% and 70% and may therefore fail to detect a large number of flu cases, especially in individuals with low viral load.
For instance, if a patient is tested early in the infection or has mild flu, the virus may not be shed in sufficient concentrations for the RIDT to detect. This may cause false negatives whereby the test points out that a patient is not infected with the flu but is. The disadvantage of false negative outcomes is that those people who tested negative are likely to remain infected during the flu season and transmit the virus to others.
Yet another effect of flu rapid test technology is that the performance of the tests differs with the brand and type of the tests in question. It is also important to know that not all rapid tests are the same and their accuracy might depend on the type of test, the virus strain, and the quality of the taken sample. There is also the possibility that some RIDTs give better results with specific influenza strains but poorly capture other strains. This can present a problem when deciding on using the rapid tests as the sole means of diagnosing flu to healthcare providers especially when one is faced with two different flu strains within a single season.
Also, it should be noted that the quality of the sample used is the key to the reliability of the test. The flu rapid tests use nasopharyngeal swabs and if the sample is not taken properly, then there will not be enough virus in the sample to detect. This brings an aspect of inconsistency in the test since the accuracy of the test depends on the ability and method of the person who is collecting the sample.
Flu rapid tests are designed to detect the presence of influenza viruses but they are not specific to the strain of the virus. This is particularly the case because flu can be caused by different types of influenza A and B, each of which may need a different approach, treatment, or even public health measures. For instance, in flu season, some of the strains may be more common or more virulent than others. When a patient is diagnosed with having the flu, a rapid test will not tell which specific type is present in the body.
This is important especially when certain flu strains are not easily combatted by certain antiviral drugs. Lack of knowledge of the specific strain may mean that healthcare practitioners are unable to offer the best treatment. More sophisticated molecular tests like RT-PCR can distinguish between different flu strains, which makes them more suitable for diagnostic purposes as treatment depends on the strain.
It is also important to note that flu rapid tests are not exempt from false results and flu rapid tests can give a false positive. A false positive is a situation where the results of the test are positive, meaning that the test has detected the flu virus in a patient when in a real sense, the patient does not have the flu. This is rarer than false negatives but can also result in unnecessary treatments or interventions such as the use of antiviral drugs which may cause side effects or contribute to the development of drug resistance.
In clinical practice, it is not rare for a patient to have acute flaccid illness that may be due to any of the viruses or bacteria. Flu rapid tests are designed to test only for influenza viruses so a negative result does not necessarily mean no other virus is causing the illness. For instance, a patient with respiratory infection due to another virus, say respiratory syncytial virus (RSV) will still have a negative result on an RIDT while the patient is symptomatic.
Thus, the use of flu rapid tests can sometimes lead to the failure to identify and subsequently treat other diseases. There are times when the healthcare provider has to order other tests to exclude another possible diagnosis of the symptoms presented by the patient, this leads to more time and costs.
Flu rapid tests have the advantage of being fast and easy to perform, however, the technology used in performing this flu rapid test has several drawbacks that make it inconclusive and inaccurate. Less sensitivity, more interoperability, and the inability to distinguish between flu strains are some of the drawbacks that may result in missing a diagnosis or administering the wrong treatment. In the same regard, the presence of false positives, absence of information on disease severity, and problematic environment also reduce the overall viability of the rapid flu test. Due to these factors, the flu rapid tests are normally followed up with more accurate testing like the RT-PCR in the treatment of the patients.
This test identifies antigens as opposed to the PCR which identifies the genetic material of the virus, therefore, necessitating larger amounts of the virus. While most of the rapid diagnostic tests detect viral antigens, PCR tests detect RNA and thus are more sensitive since they can detect even low viral loads.
Take appropriate samples, adhere to storage procedures, and perform the test during the disease’s early stages when shedding is at its peak.
No, they identify influenza A and B but cannot tell the type of strain it is. For strain identification, the RT-PCR tests are required.
ANTITECK provide uncut sheet rapid test for rapid test kit manufacturing, contact us for more information via [email protected]
Maybe you also interested: how to set up a manufacturing unit for drug test kit production?
How To Setup Lateral Flow Assay Manufacturing Factory?
