Lateral Flow Tests vs. PCR: Pros and Cons in Disease Diagnosis

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Getting tested is the first and most important step towards preventing the spread of covid 19. Knowing the right time to test for the virus is also important. If you have gotten exposed to covid 19, you should give yourself 5 days before testing. Doing it earlier than that can give you inaccurate results. 

Also, when you begin experiencing symptoms like fever, fatigue, cough, and shortness of breath, you can find lateral flow tests and determine if you are infected. If you are positive, you should isolate yourself immediately to avoid infecting others. While in isolation, keep monitoring your symptoms so that you can call for emergency care if you get seriously sick. There are two types of tests as far as COVID-19 is concerned: the lateral tests and the PCR test. This article discusses the pros and cons of each disease diagnosis. 

Let’s delve in. 

The Lateral Flow Tests (LFT)

Since coronavirus is still with us and more people are still getting infected, we can’t ignore the need to keep testing ourselves. Lateral flow tests are also known as rapid diagnostic tests. They detect the presence or absence of certain target substances like antigens or antibodies. While testing for covid 19 in individuals, they use chromatography to detect the presence of the SARS Co-V-2 virus.

Pros

1. The lateral flow tests do not need the users to be in a laboratory setting or use laboratory equipment. They are so easy to use that they don’t require highly trained personnel to conduct the tests. Individuals can use them in settings like schools and community testing centres.       
2. They are rapid tests, meaning they can offer results within 15 to 30 minutes. They are highly effective during mass testing due to their quick turnaround. LTFs also come in handy in terms of speed during screening efforts.
3. Compared to the PCR tests, LFTs are very cost-effective, which works well during large-scale testing campaigns. Also, being affordable encourages many people to buy them in bulk so that they can test themselves and their loved ones anytime they need to.
4. LFTs do not use specialized reagents or equipment to test for covid 19. 
5. The lateral flow tests are portable, making them the best for easy distribution to underserved or remote areas. It works well with widespread testing, even in other healthcare applications for infectious disease detection during an outbreak. 

Cons

1. Lateral flow tests may produce false negative results as they are less sensitive compared to PCR tests. That can happen in the early stages of infection, especially when someone has a low viral load. 
2. You can expect low quantitative information as the LFTs cannot give the quantity of the virus present. They can only show if an individual is positive or negative. 
3. The lateral flow tests may produce false positive results in cross-reactivity with different substances. 
4. They may not detect past infections as they are designed to detect active infections.

The Polymerase Chain Reaction Tests (PCR)

Polymerase chain reaction tests are a molecular biological technique widely used in different applications. PCR tests indicate whether a sample has genetic material (RNA) from the SARS-CoV-2 virus. These tests use samples from patients’ respiratory tracts. 

Pros

1. They are specific to the pathogen in question and are accurate, meaning they may not produce false results.
2. They can detect pathogens even in patients with a low viral load. Medics refer to them as the gold standard when it comes to infection diagnosis.
3. Unlike lateral flow tests, PCR tests provide quantitative data, allowing healthcare providers to monitor disease progress and viral load. 
4. PCR tests are effective in identifying that your body has been infected by a virus in the past. This happens even if you have already recovered. That information is important when it comes to epidemiological studies.

Cons

1. PCR tests require more in terms of money compared to lateral flow tests. They use costly equipment and reagents to test for covid 19.
2. The tests take longer as you may wait several hours to a few days to know your covid 19 status. The delay happens because of sample processing and laboratory analysis. There are rapid PRC tests; however, the problem is that they are not widely accessible. 
3. Sample Collection for PCR tests must be carried out by a trained professional, unlike with the LFTs. The tests require throat swabs or nasopharyngeal. The process makes patients very uncomfortable.
4. The tests are very complex, requiring trained technicians to operate in specialized laboratories with sophisticated equipment. That is why the PCR tests are unsuitable for remote or point-of-care testing. 

Wrap Up

Both tests are effective in different capacities. The lateral flow tests are great for their speed, cost-effectiveness and ease of use. They are the best for initial screening and mass testing. On the other hand, polymerase chain reaction tests are known for high specificity and sensitivity. 

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They are great as they can offer quantitative information during testing. That’s why medical professionals need them for monitoring disease progression, confirming diagnosis and during research. The goal of testing and the resources available are great determinants when it comes to choosing the test option to go for.