Government Medical College Srinagar today said that the report of a sample that its virology lab reported as COVID19 positive recently has been validated by NIV Pune.
Recently a journalist had been sampled for COVID19 after a team member of his tested positive. The sample was reported as positive by Chest Diseases Hospital virology lab on 8 June. However, another sample of the journalist taken by SKIMS Soura a day later and tested at its Viral Research and Diagnostic Lab had been reported as negative. The disparity in the two reports had given rise to concerns about the accuracy of COVID19 tests, especially those reported positive by CD Hospital lab.
However, the medical college, in order to get a final verdict on the reliability and accuracy of the tests it carries out sent the sample to National Institute of Virology Pune. “Regarding the said controversial sample, the run of the same was rechecked initially by the senior faculty members of the department and later on this run file was sent to the National Institute of Virology Pune for rechecking,” said a press statement issued by GMC Srinagar today.
The statement said that NIV “rechecked the run file and has given a positive confirmation of our already reported result.”
GMC has said that those patients who test positive initially and later test negative on retesting after 24hrs or more are actually in later part of the disease during the initial test itself and on subsequent tests they are in a stage where RNA is undetectable. “The same applies to samples from Kashmir nursing home, Kulgam and Pulwama where the gap between the initial positive tests and negative retests was more than 24 hrs,” it said.
Reports have been published about the results coming negative on first retest and positive on second retest of a confirmed positive case, the statement said. “Test positive by RT-PCR holds more weight than the test negative by RT-PCR because this test has higher specificity (more than 95%) but moderate sensitivity (71-98%).”
Regarding the very high number of positives reported around the time of the controversy, GMC has said, “Initially we used to test samples from all the districts of south Kashmir and Srinagar district, besides and SMHS associated hospitals (GB Panth hospital, LD hospital, Super Specialty Hospital, Psychiatry Hospital and Bone and Joint hospital), but when the travel ban was lifted our sample load increased tremendously as the districts which were initially sending their samples to SKIMS were also directed to our lab that is the districts of north Kashmir and Budgam.”
“In the beginning of this month we were almost catering to whole of Kashmir and in addition receiving samples of the returnees and from Jammu also. It is only from 3rd June that we are receiving samples from three districts (Ganderbal, Kulgam and Pulwama) only besides SMHS and all associated hospitals,” said the press statement. “Regarding the increase in positivity at a particular time, we were reporting just under 2000 tests in 24 hrs so naturally the total number of positives reported were higher. At present we are receiving around 500 samples each day so the number of positive cases being reported has come down proportionately,” it said.
“Till now our lab has tested around 37,000 samples and reported around 2000 positive cases (5.4 percent),” the statement said.