ABSTRACT
Objective: To evaluate the accuracy of the COVID-19 Ag Rapid test device for detection of SARS-CoV-2 with Reverse Transcriptase Polymerase Chain Reaction as the gold standard. Study Design: Cross-sectional study. Place and Duration of Study: Department of Virology, Armed Forces Institute of Pathology, Rawalpindi, in the month of Sept 2020. Methodology: A total of 106 patients suspected of COVID-19 were tested, including 63 patients admitted to the COVID-19 ward of Pak Emirates Military Hospital and 43 from the emergency department of Combined Military Hospital, Rawalpindi Pakistan respectively. The samples were transported to the Virology department and subjected to Polymerase Chain Reaction and Antigen testing. In addition, the diagnostic accuracy of the COVID-19 Ag Rapid test device was compared to Reverse Transcriptase Polymerase Chain Reaction for detection of SARS-CoV-2 infection. Results: Out of 106 nasopharyngeal swab samples tested, 48 (45.2%) samples were positive by Rapid test device and Reversed Transcriptase Polymerase Chain Reaction, and 52 (49.0%) samples tested negative by both methods. Inconsistent results (False Negative) were obtained in 6 (5.6%) samples. COVID-19 Ag Rapid test device has detected the maximum number of cases, 41 (85.4%), during the first week of illness. Its sensitivity decreases as the duration of infection progress. Conclusion: The overall sensitivity of the Rapid test device is much less than the Polymerase chain reaction due to potential false negative results. However, it can be helpful in the early isolation of cases in an outbreak in a closed community and for case management in peripheral setups, where Polymerase chain reaction facilities are unavailable. © 2022, Army Medical College. All rights reserved.
ABSTRACT
Objective: To evaluate the Saliva specimen as a non-invasive sample for molecular detection of SARS-CoV-2 compared with Nasopharyngeal Swab. Study Design: Cross-sectional study. Place and Duration of Study: Department of Virology Armed Forces Institute of Pathology (AFIP), Rawalpindi, in Oct 2020. Methodology: Forty-eight patients were included in this study from SARS-CoV-2 Outdoor Clinic in Pak Emirates Military (PEMH), Rawalpindi. Out of 48 patients, 28 known SARS-CoV-2 positives by Real-Time Polymerase Chain Reaction (RT-PCR) and 20 known SARS-CoV-2 RT-PCR negative patients were included in this study. Paired samples of Nasopharyngeal swabs and Saliva samples were collected from forty-eight patients. Samples were transported to Virology Department AFIP in Viral Transport Medium (VTM) and subjected to SARS-CoV-2 RT-PCR simultaneously. The sensitivity and specificity of the Saliva specimen for SARS-COV-2 RT-PCR were compared with Nasopharyngeal Swab. Results: A total of 48 patients were included in this study, of which 28 (58%) patients were positive for SARS-CoV-2 on NPS by RT-PCR. Among the 28 positive cases, 18 (64.3%) were positive by RT-PCR using saliva specimens. The sensitivity and specificity of saliva specimens compared with NPS were 64.3% and 95%, respectively. Conclusion: Saliva specimen has much lower sensitivity as compared to NPS in our study. Therefore, it cannot be implemented for the diagnosis of COVID-19 as it can compromise the results of a highly sensitive test like RT-PCR. © 2022, Army Medical College. All rights reserved.
ABSTRACT
Objective: To share our large scale SARS CoV-2 PCR test experience in Northern Pakistan. Study Design: Prospective observational study. Place and Duration of Study: Virology Department, Armed Forces Institute of Pathology, Rawalpindi, from Feb to Dec 2020. Methodology: All the patients reporting to COVID-19 desk both indoor and outdoor were included in study. Nasopharyngeal swab specimen was taken from the patients arriving at reception. For hospitalized patient’s samples were received at reception placed in viral transport medium maintaining cold chain. Results: Among 193656 samples tested for SARS CoV-2 RNA by RT-PCR, 24338 (12.6%) were found positive and 169318 (87.4%) were negative. Mean age of patients was 38.25 ± 16.73 (1-110 years). 138781 (71.7%) were males and 54875 (28.3%) were females. 109765 (56.7%) samples were received from in patient department and 83891 (43.3%) samples were received from outpatient department. Highest number of cases (n=6224) seen during month of June followed by 5813 cases during May and 4786 cases during November (p-value <0.001). Most of the positive cases were in age group 21-40 years;11122 (6%), followed by age group 41-60 years;8133 (4.2%). More positive samples 14890 (7.7%) were received from in patient department and males 17928 (9.3%) were affected more than females. Conclusion: The two peaks of COVID-19 pandemic in Pakistan were observed during the months of May to July and again during October to December. Most positive patients in our setup were males in age group 21-40 years as this age group is more exposed to external environment. © 2021, Army Medical College. All rights reserved.
ABSTRACT
Given the known presence of SARS-Cov-2 in wastewater, stemming disease spread in global regions where untreated effluent in the environment is common will experience additional pressure. Though development and preliminary trials of a vaccine against SARS-CoV-2 have been launched in several countries, rapid and effective alternative tools for the timely detection and remediation of SARS-CoV-2 in wastewater, especially in the developing countries, is of paramount importance. Here, we propose a promising, non-invasive technique for early prediction and targeted detection of SARS-CoV-2 to prevent current and future outbreaks. Thus, a combination of nanotechnology with wastewater-based epidemiology and artificial intelligence could be deployed for community-level wastewater virus detection and remediation.