SRINAGAR, Jun 10 (Agencies): Amid buzz over possible errors in diagnosis with both RT-PCR tests and the faster antibody-based tests, president Doctors Association Kashmir (DAK), Dr Suhail Naik Wednesday said despite best efforts, no test can be 100% accurate.
Dr Naik, who is a senior paediatrician, said every test has its own rate of true positive, false positive, false negative and true negative.
“Despite best efforts, no test can be 100% accurate,” he said.
He said RT-PCR Covid- is highly specific that means if a patient tests positive, it is imperative to believe that person has the infection, as the test is based on the amplification of gene sequence very specific to the virus.
“False-positive is a very rare possibility and occur if there is the contamination of the sample, at the site of the collection which may be wild theoretical guess,” said Naik.
He said the sensitivity of test ranges from 50 to 60 per cent and it further depends on many factors like viral load, site of the specimen, the timing of specimen, technical expertise etc.
Therefore, a person testing negative doesn’t rule out infection and all persons at high risk should go for strict 14 days home quarantine irrespective of the test result.
Quoting a study published in Radiology, titled “Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 in China,” he said investigators found chest CT achieved higher sensitivity for the diagnosis of COVID-19 as compared with initial RTPCR from pharyngeal swab samples. General Secretary DAK, Dr Owais H Dar said that there have been situations where “we found pregnancy card test negative but Ultrasound documenting pregnancy.”