Salivary PCR is one of the methods for diagnosing COVID-19 with saliva samples. This PCR test is considered more comfortable for patients than PCR swab. However, how does salivary PCR work and how effective is it? Find out the answer in this article.
The PCR test is considered the most accurate for diagnosing COVID-19 disease. This test uses a sample of mucus taken from the nasopharynx, which is the part between the nose and throat, or from the oropharynx, which is the back of the throat. Sampling is by means of swab using dacron fiber rods.
Despite having a high level of accuracy, the swab process (swab) which is done when sampling mucus often makes many people complain of discomfort. Therefore, an alternative has emerged in the form of a salivary PCR test which is considered more convenient and easier to perform.
Know the Advantages and How Saliva PCR Works
The PCR test with saliva samples began to be developed in 2020 and has been tested by several countries, such as the United States, Germany, Japan, and South Korea.
The use of saliva samples in PCR tests has the main goal of speeding up the process tracing cases of COVID-19 and make the sampling process more comfortable, especially for children.
Not only that, the saliva sampling process is more practical and simpler than PCR swab is expected to ease the work of health workers and prevent infection to health workers.
The following is how to take a saliva PCR sample:
- The medical officer will instruct you to clear your throat by removing phlegm 3 times.
- You will be asked to collect 0-5–1 mL (about 1 teaspoon) of saliva into a dry, sterile empty tube.
- You should close the tube immediately after the saliva sample has collected.
- The medical officer will mix the saliva sample with VTM (viral transport medium), which is a liquid that serves to prevent the sample from being contaminated by bacteria.
After the collection process is complete, the saliva sample will be taken to the laboratory to be detected whether there is genetic material for the Corona virus in it.
In order for the results to be more accurate, there are several things that need to be avoided at least 30-60 minutes before carrying out a COVID-19 test with saliva PCR, namely:
- Smoking, both regular cigarettes and e-cigarettes
- Chewing gum consumption
In addition, salivary PCR tests will also be more accurate if the results are carried out in the first week since the appearance of symptoms and in the morning when the mouth has not been contaminated with food or drink residue.
Saliva PCR Effectiveness in Diagnosing COVID-19
Salivary PCR is known to be quite effective in detecting the Corona virus in COVID-19 patients, both adults and children. This is evidenced by several studies comparing the sensitivity of salivary PCR with PCR swab.
A study showed that salivary PCR has a sensitivity of up to 86 percent, not much different from PCR swab nasopharynx-oropharynx which has a sensitivity of 92 percent.
In fact, there is a study proving that the sensitivity of salivary PCR can reach 92 percent in adult patients and 84.5 percent in pediatric patients.
Although proven capable of diagnosing COVID-19, salivary PCR still has several drawbacks, such as the risk of saliva samples being contaminated by bacteria in the oral cavity and false negative results due to the inaccurate sampling process.
Therefore, further development and research to ensure the effectiveness of salivary PCR in diagnosing COVID-19 is still being carried out until now.
In Indonesia itself, salivary PCR has not been used as a tool for testing COVID-19. However, various new breakthroughs, such as PCR mouthwash and RT LAMP saliva test, continue to be developed to speed up the process tracing and break the chain of transmission of the Corona virus.
If you feel symptoms of COVID-19, there are currently three types of tests that you can choose from, namely PCR swab, rapid antigen test, and rapid antibody test. Rapid tests can indeed give faster results, but PCR swab has a higher level of accuracy and is the primary test for diagnosing COVID-19.
If the COVID-19 test is positive, you are required to self-isolate and apply health protocols, such as maintaining physical distance from other people, wearing a double mask, and washing your hands regularly.
You can also consult a doctor to get information about handling COVID-19 that you can do during self-isolation at home or using the features chat directly with the doctor in the ALODOKTER application.