Background: Self-collection of nasal swabs for the detection of SARS-CoV-2 RNA by reverse transcription-polymerase chain reaction (RT-PCR) would considerably increase the testing capability and decrease the risk of transmission among healthcare workers (HCW) and the use of personal protective equipment (PPE). Objectives: This study aimed to evaluate the performance of self-collected nasal swabs compared with professionally collected nasopharyngeal (NP) swabs for detection of SARS-CoV-2 RNA by RT-PCR. Materials and methods: We performed a cross-sectional study where the suspected cases of coronavirus disease 2019 (COVID-19) were instructed about the self-collection of nasal swabs from their mid-turbinate. The results were compared to a nasopharyngeal swab collected by a trained healthcare worker in the same patient at the same sitting. Results: We enrolled 100 participants, of which, 69 (69%) were male and 31 (31%) were female. The median age of the study participant was 36 years. Of the participants, 58 (58%) were symptomatic, and the commonest clinical presentation was cough, which was present in 42 (42%) participants. Out of 100 samples, 31 (31%) professionally collected nasopharyngeal swabs and 28 (28%) self-collected nasal swabs were positive for SARS-CoV-2 by RT-PCR. Out of 31 professionally collected positive samples, three samples were negative in self-collection. Out of 28 self-collected positive samples, no sample was negative in the professional collection. The sensitivity and specificity of self-collected nasal swabs compared to professionally collected nasopharyngeal swabs were 90.32% and 100.00%, respectively. The sensitivity of self-collected nasal was 100% when the cycle threshold (Ct) value of the professionally collected NP swab was less than 30. Conclusion: Our study showed that self-collected nasal swabs' sensitivities were similar to professionally collected NP swabs with a high viral load (low Ct value). Hence, this method could be used when the patient is symptomatic and come to the health providers in the early stage of COVID-19 illness.

The coronavirus disease 2019 (COVID-19) pandemic has manifested into an unprecedented public health crisis. The rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has facilitated reagent developers to customize and receive authorization for nucleic acid testing kits in a short period, which would have resulted in some shortcomings in the quality parameters of the kits. Consequently, in-house clinical validations of innovative real-time quantitative polymerase chain reaction (RT-qPCR) kits are required. This research aims to determine the sensitivity, specificity, and accuracy of various RT-qPCR kits available in Bangladesh. A total of 150 samples were obtained from patients with suspected COVID-19 infection when the delta variant was predominant, followed by RNA extraction performed using a nucleic acid isolation kit. Subsequently, three commercially available PCR kits named Sansure (China), STAT-NAT^Ⓑ (Sentinel Diagnostics, Italy), and Roche Biochem (Switzerland) were applied to detect SARS-CoV-2. The results showed that the STAT-NAT^Ⓑ kit is more sensitive than the other two, as indicated by the cycle threshold (Ct) values of respective genes. STAT-NAT^Ⓑ RT-qPCR can detect the ORF1ab gene sensitively (p < 0.001) compared to Sansure. STAT-NAT^Ⓑ was also capable of detecting E and RdRp genes more sensitively (p < 0.001) compared to Roche. Regarding specificity, STAT-NAT^Ⓑ (95% confidence interval [Cl] = 92.29-99.73%). RT-qPCR showed more accuracy than Sansure (95% Cl = 90.77-99.32%) and Roche (95% Cl = 81.17-94.38%). The area under the curve for E, ORF1ab, and RdRp genes of the STAT NAT^Ⓑ PCR kit was 0.952, 0.959, and 0.981, respectively. This study concluded that STAT-NAT^Ⓑ is a better diagnostic RT-qPCR kit compared to Sansure and Roche for detecting SARS-CoV-2.

Background: Healthcare workers (HCWs) at the frontline are confronting a substantial risk of infection during the COVID-19 pandemic. This emerging virus created specific hazards to researchers and laboratory staff in a clinical setting, underlined by rapid and extensive worldwide transmission. Objectives: This study aimed to investigate the prevalence of SARS-CoV-2 infection among COVID-19 reverse transcription-polymerase chain reaction (RT-PCR) laboratory health workers in Bangladesh. Materials and methods: This retrospective study was conducted between October 2 to December 2, 2020. A total of 508 participants, including doctors, scientific officers, medical technologists, and cleaners working in several COVID-19 RT-PCR laboratories, were included in this study. Data were collected from each participant using a semi-structured questionnaire prepared in the format of an anonymous Google form. All statistical analyses were performed using SPSS, version 25.0 (SPSS Inc., Chicago, IL, USA). Results: Out of the 508 participants, 295 tested positive for SARS-CoV-2 RT-PCR. Among the positive cases, 202 were men, and 93 were women, with a median age of 30 years. The most positive cases were medical technologists (53.22%) followed by doctors (28.8%). Out of the 271 symptomatic positive cases, the most typical symptoms were fever (78.5%), fatigue (70%), loss of smell and taste (65%), and cough (64%). Hypertension, obesity, and diabetes were found in 8.8%, 8.8%, and 7.1% positive cases. A + blood group was present in 37% of the positive cases, followed by the B+ blood group (27%) and O+ blood group (25%). Inadequate supply of personal protective equipment (PPE), absence of negative pressure ventilation, laboratory contamination, and no training on molecular test methods were found in 13.8%, 67.8%, 44.7%, and 40.6% of positive cases, respectively. Conclusion: Evaluating the infection status of laboratory HCWs is crucial for drawing attention from the public, providing practical suggestions for government agencies, and increasing protective measures for laboratory HCWs.

Background: Chronic obstructive pulmonary disease (COPD) is the most prevalent long-term respiratory condition. Patients with COPD experience detrimental effects of COVID-19 infection. Objective: To figure out whether COPD is a risk factor influencing the progression of COVID-19 and to explore the clinical value of laboratory biomarkers to assess the severity of COVID-19 in patients with COPD comorbidity. Methods: In total, 1572 participants aged 35 to 70 years were enrolled to a tertiary hospital in Bangladesh between March 2022 and October 2022. Participants were categorized into four groups: (1) control, (2) COPD, (3) COVID-19, and (4) COVID-19 with COPD, and blood levels of clinical laboratory markers were assessed to analyze how these markers differ among the study groups. Results: COVID-19 patients with COPD had a significantly lower level of sodium (131.81 ± 2.8 mmol/L) and calcium (1.91 ± 0.28 mmol/L), and a significantly higher level of NT-proBNP (568.45 ± 207.40 pg/mL), bilirubin (1.34 ± 0.54 mg/dL), fibrinogen (577.27 ± 145.24 mg/dL), D-dimer (2.97 ± 2.25 μg/mL), C-reactive protein (71.08 ± 62.42 mg/L), interleukin-6 (166.47 ± 174.39 pg/mL), and procalcitonin (0.25 ± 0.30 ng/mL) compared to other study groups patients (p < 0.0001). In addition, the GOLD 4 group demonstrated significantly altered clinical parameters among COVID-19 patients with COPD. Furthermore, NT-proBNP, interleukin 6, D-dimer, C-reactive protein, and fibrinogen demonstrated excellent diagnostic performance in predicting disease severity among the COVID-19 patients with COPD, with a cut-off value of 511.2 pg/mL, 51.375 pg/mL, 1.645 μg/mL, 40.2 mg/L, and 510 mg/dL, respectively. Our results also indicate that inflammatory markers had significant positive correlations with the biochemical and coagulation markers in the COVID-19 patients suffering with COPD (p < 0.0001). Conclusions: NT-proBNP, interleukin 6, D-dimer, C-reactive protein, and fibrinogen are the most potential parameters for differentiating severe cases of COVID-19.