How to sample for nCoV?
To get pharyngeal or oropharyngeal fluid, technician put sampling rod deep in throat, hold for 5 seconds, gently rotate. If the sample is taken incorrectly, the test result is wrong.
Master Le Hoang Anh, Virus Laboratory, Paster Institute of Ho Chi Minh City, said that according to the process, medical staff will take the pharyngeal fluid first. To increase the effectiveness of the test, health workers can combine fluid collection in both positions.
For hydrocephalus, the sampling staff inserted the stick deep into the oropharynx, and stopped until an obstruction was felt. Hold the stick there for about 5 seconds and rotate gently to ensure that the solution sticks to the tip of the probe.
For the throat, the sampling stick is inserted deep into the throat until the tonsils are visible on both sides, gently squeeze 3-4 times to get the fluid from the back throat.
“These are the positions that make the sampler uncomfortable, so the medical staff should consult before doing so for the patient to cooperate”, Dr. Hoang Anh emphasized.
Samples of specimens after being collected will be sealed, ensuring absolute safety from the outside environment and then brought to the confirmatory laboratory.
Dr. Le Van Duyet, Head of molecular biology lab, Central Hospital for Tropical Diseases, said that the test results depend a lot on the quality of the sample. Sampling staff should ensure sweeping of the lower tonsils in the throat area and ensure that a cotton swab is long enough to sweep fluid from the pharyngeal area. If the sample is taken incorrectly, the test will give negative results, falsifying the results.
According to experts, there are many other factors that affect the test results, but the cause of the error is usually not in the sampling procedure because the staff are carefully trained. Therefore, health-care workers should compare independent test results between different laboratories or compare between clinical and laboratory results. In the event that there are inconsistencies between the test results and the clinical reality of the patient, re-conduct the test to verify.
Sampling procedure for standard nCoV assay. Video: Provided by the Ministry of Health
Nearly a month now, the testing system of the health sector has tested more than 390,000 samples, accounting for 47.8% of the total number of samples since the beginning of the translation.
The country has 123 laboratories capable of testing using RT-PCR method, with a maximum capacity of more than 46,000 samples per day. Among the above, there are 71 confirmed laboratories, with a capacity of more than 36,000 samples a day. The Ministry of Health has established a testing support system in 3 areas to help localities increase testing capacity in case of need.