Comparative analysis of the diagnostic performance of five commercial COVID-19 qRT PCR kits used in India.

To meet the unprecedented requirement of diagnostic testing for SARS-CoV-2, a large number of diagnostic kits were authorized by concerned authorities for diagnostic use within a short period of time during the initial phases of the ongoing pandemic. We undertook this study to evaluate the inter-test agreement and other key operational features of 5 such commercial kits that have been extensively used in India for routine diagnostic testing for COVID-19. The five commercial kits were evaluated, using a panel of positive and negative respiratory samples, considering the kit provided by National Institute of Virology, Indian Council of Medical Research (2019-nCoV Kit) as the reference. The positive panel comprised of individuals who fulfilled the 3 criteria of being clinically symptomatic, having history of contact with diagnosed cases and testing positive in the reference kit. The negative panel included both healthy and disease controls, the latter being drawn from individuals diagnosed with other respiratory viral infections. The same protocol of sample collection, same RNA extraction kit and same RT-PCR instrument were used for all the kits. Clinical samples were collected from a panel of 92 cases and 60 control patients, who fulfilled our inclusion criteria. The control group included equal number of healthy individuals and patients infected with other respiratory viruses (n = 30, in each group). We observed varying sensitivity and specificity among the evaluated kits, with LabGun COVID-19 RT-PCR kit showing the highest sensitivity and specificity (94% and 100% respectively), followed by TaqPath COVID-19 Combo and Allplex 2019-nCoV assays. The extent of inter-test agreement was not associated with viral loads of the samples. Poor correlation was observed between Ct values of the same genes amplified using different kits. Our findings reveal the presence of wide heterogeneity and sub-optimal inter-test agreement in the diagnostic performance of the evaluated kits and hint at the need of adopting stringent standards for fulfilling the quality assurance requirements of the COVID-19 diagnostic process.

Laboratory diagnosis of covid-19: Current status and challenges

The magnitude and pace of global affliction caused by Coronavirus Disease-19 (COVID-19) is unprecedented in the recent past. From starting in a busy seafood market in the Chinese city of Wuhan, the virus has spread across the globe in less than a year, infecting over 76 million people and causing death of close to 1.7 million individuals worldwide. As no specific anti-viral treatment is currently available, the major strategy in containing the pandemic is focused on early diagnosis and prompt isolation of the infected individuals. Several diagnostic modalities have emerged within a relatively short period, which can be broadly classified into molecular and immunological assays. While the former category is centered around real-time PCR, which is currently considered the gold standard of diagnosis, the latter aims to detect viral antigens or antibodies specific to the viral antigens and is yet to be recommended as a stand-alone diagnostic tool. This review aims to provide an update on the different diagnostic modalities that are currently being used in diagnostic laboratories across the world as well as the up-coming methods and challenges associated with each of them. In a rapidly evolving diagnostic landscape with several testing platforms going through various phases of development and/or regulatory clearance, it is prudent that the clinical community familiarizes itself with the nuances of different testing modalities currently being employed for this condition.

Nlr as a prognostic marker in covid19

Aims & Objectives: To analyze NLR as a surrogate prognostic marker for COVID 19. Patients/Materials & Methods: This is a prospective study done in Department of Pathology, Index Medical College, Indore from 07 may 2020 to 05 August 2020.In the present study, a total number of 517 patients are included. Out of which 299 are male and 218 are female. NLR is computed by Absolute Neutrophil count divided by absolute lymphocyte count. Results: Majority of the patients are Asymptomatic (89.7%),which is followed by Low risk (5.4%),High risk (3.5) and Moderate risk (1.4%). We have observed that 5 patients died due the covid-19 and these patients falls into severe or high risk group i.e. The Neutrophil lymphocyte ratio(NLR) of all these 5 patients was more than 7.The minimum neutrophil lymphocyte ratio was 7.71 whereas the maximum neutrophil lymphocyte ration was 47.50. In those patients who died because of COVID 19.,minimum absolute lymphocyte count is 278 whereas maximum absolute lymphocyte count is 2040 having standard deviation of 643.245 In our study we had observed NLR>7 & Absolute lymphocyte count(ALC)<600 indicates severe COVID19. Discussion & Conclusion: Complete Blood Count (CBC) is easily assessible hematological investigation at primary Health Care level in our country and NLR can be assesed for severity of COVID 19 and it will be surrogate prognostic marker and will be helpful in timely referral of critical patients to Dedicated Covid Hospitals.

Neutrophil to lymphocyte ratio (NLR): A predictor of outcome in Indian covid-19 patients

Aims & Objectives: Aims: To study the significance of NLR in outcome of COVID-19 patients. Objectives: To set the exact value of NLR of defining the severity of COVID-19 patients. To use NLR value for defining management protocol of COVID-19 patients. To use NLR value as prognostic marker in COVID-19 patients. Patients/Materials & Methods: 52COVID-19 patients admitted in our institute since May 2020, diagnosed by RT-PCR technique from naso-pharyngeal swab were included in study. Clinical, demographic and laboratory data collected retrospectively. NLR was calculated by using absolute counts of each patient. NLR = Absolute Neutrophils count/Absolute Lymphocytes count. Results: Out of 52 patient analyzed 32 (65%) were male, median age of infection was 51 year (12-78 years). 10 out of 52(19.2%) patient had hypertension and 5 out of 52(9.6%) patient had diabetes and one patient had bothasapre-existingco-morbidities. The median NLR was 4.15. 9 out of 52 (17.3%) patient required ICU admission. Death of 4 (7.6%) patient registered and 48 discharged after recovery. 8 out of 9 (88.9%) who required ICU admission had NLR>4 and all 4 patient expired had NLR>4. Discussion & Conclusion: In our study NLR predicting the severity of infection as 8 out of 9 patient who admitted in ICU had NLR>4 and four patient who expired had NLR>4. So high NLR predicting the severity of infection and ICU admission retrospectively. NLR<3 predicting the less severity and improvement of COVID-19 infection. Although further studies with a larger sample size will be needed to properly assess this matter, in our study shows that NLR may be a rapid, less expensive, useful prognostic factor for categorizing severity and outcome of COVID-19 patients.