Diagnostic testing for Covid-19 checks active infection in patients: Dr Anjum Farhana

0
228

Proper sampling along with good lab practices will give accuracy of results

Combination of RTPCR, clinical features along with CT findings help in management of patients

SRINAGAR: Microbiology Department of Government Medical College, Srinagar runs a Covid-19 testing Lab which started functioning from March 14, 2020 and is conducting 1500 tests per day, Dr Anjum Farhana, HoD,  Microbiology said the lab is a state of the art negative pressure lab BSL level (3) which was initially sanctioned and made functional in late 2017 as a molecular lab for influenza.

Proper sampling along with good lab practices will give accuracy of results, she said while adding that these labs are designed to work on organisms causing serious disease via inhalation and prevent infection to health care workers. ‘Our lab is  functional 24/7 and  with capacity to do nearly 1500 tests per day.  We have till date tested nearly 3 lakh samples’, Dr  Anjum stated.

There are 2 types of tests for covid 19,diagnostic and antibody tests.

Diagnostic tests include RT-PCR tests and Rapid Antigen Tests.

Diagnostic tests tell us whether or not person has active infection. ‘Our lab primarily does RT -PCR tests only’, she said.

‘We intend to increase our capacity by more than 2000 tests per day, once the fully automated analyser cobas 6800 is received. The  cobas 6800 is  a sophisticated machine which minimises contamination and risk of infection to HCW and tests 1200 samples in 24hrs’, informed  Dr Anjum.

‘We are also catering to associated hospitals including SMHS, Lalla Ded, Bone & Joint, Super Speciality, Kashmir Nursing Home, GB Panth, other hospitals of district Srinagar and District Bandipora’, Dr Anjum informed and added that samples received are 3 to 4 times more than previously received by the lab which increases work pressure but the department is enhancing the capacity with additional staff in the Covid Testing Lab.

Samples received by our lab are mainly nasopharyngeal swab in a Viral Transport Medium. Samples are transported from collection sites in cool boxes containing dry ice and transported as soon as possible to our lab. ‘In case of delay of more than  72 hr they may  be kept at -70 Degree Centigrade’, she advised.

Apart from taking the sample properly, timing is also important and chances of detection of virus being high within first four days of being symptomatic. In case of close contact, sample is to be taken between 5th  to 10th day of exposure.

“Combination of RTPCR, clinical features along with CT findings help in management of patients,” said Dr Anjum, Microbiologist.

‘Remember if you test positive it means you are infected now and can transmit infection to others’, she said and further added that ‘If you test negative you can still get infected and have to take precautions to prevent  from getting infected’.

‘Negative result does not exclude the possibility of being infected with covid-19 particularly if you are symptomatic and test negative, one can get again tested subsequently’, as per advice of the clinician..

While explaining the difference, she said ‘RT PCR test will not tell you if you have been previously infected. This can be known by Antibody tests’.

Regarding delay in results, Dr Anjum gave a number of reasons including excessive samples received more than capacity of the lab, sudden failure of machines due to excessive work load and  due to lock down in other states,  reagents and other consumables coming from outside states may get delayed.

Besides she said that Microbiology department is not only responsible for providing individual covid results but also involved in data uploading and sending  it to all concerned every 24 hours.

Moreover, ICMR data is also being uploaded onto ICMR portal 24/7.

This, she said, is done by closely coordinated team of consultants, senior residents and DEO. ‘Our lab is an ICMR VDRL lab. Its quality of testing is closely regulated through EQAS. Five percent samples are also being sent via SKIMS  to NCDC for genomic sequencing’.

Dr Anjum said that she got training in March 2020, under DHR ICMR National Level Training programme  which was conducted regarding SAR COV 2  sampling and transportation. Then, she  imparted training to staff  to train health care workers at district level besides  HCW of various associated hospitals.

While advising people to follow Covid SOPs she reiterated the precautions to be taken by people: to maintain distance, wear mask, avoid crowds, clean hands often and get vaccinated.