Risk factors for SARS-CoV-2 infection among health workers in India: a case control study.

Background: COVID-19 was declared as a Public Health Emergency of International Concern on 30th January 2020. Compared to the general population, healthcare workers and their families have been identified to be at a higher risk of getting infected with COVID-19. Therefore, it is crucial to understand the risk factors responsible for the transmission of SARS-CoV-2 infection among health workers in different hospital settings and to describe the range of clinical presentations of SARS-CoV-2 infection among them. Methodology: A nested case-control study was conducted among healthcare workers who were involved in the care of COVID-19 cases for assessing the risk factors associated with it. To get a holistic perspective, the study was conducted in 19 different hospitals from across 7 states (Kerala, Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra, Gujarat, and Rajasthan) of India covering the major government and private hospitals that were actively involved in COVID-19 patient care. The study participants who were not vaccinated were enrolled using the incidence density sampling technique from December 2020 to December 2021. Results: A total of 973 health workers consisting of 345 cases and 628 controls were recruited for the study. The mean age of the participants was observed to be 31.17 ± 8.5 years, with 56.3% of them being females. On multivariate analysis, the factors that were found to be significantly associated with SARS-CoV-2 were age of more than 31 years (adjusted odds ratio [aOR] 1.407 [95% CI 1.53-1.880]; p = 0.021), male gender (aOR 1.342 [95% CI 1.019-1.768]; p = 0.036), practical mode of IPC training on personal protective equipment (aOR 1. 1.935 [95% CI 1.148-3.260]; p = 0.013), direct exposure to COVID-19 patient (aOR 1.413 [95% CI 1.006-1.985]; p = 0.046), presence of diabetes mellitus (aOR 2.895 [95% CI 1.079-7.770]; p = 0.035) and those received prophylactic treatment for COVID-19 in the last 14 days (aOR 1.866 [95% CI 0.201-2.901]; p = 0.006). Conclusion: The study was able to highlight the need for having a separate hospital infection control department that implements IPC programs regularly. The study also emphasizes the need for developing policies that address the occupational hazards faced by health workers.

A Multicenter Clinical Diagnostic Accuracy Study of SureStatus, an Affordable, WHO Emergency Use-Listed, Rapid, Point-Of-Care Antigen-Detecting Diagnostic Test for SARS-CoV-2.

Access to reverse transcription-PCR (RT-PCR) testing, the gold standard for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection, is limited throughout the world, due to restricted resources, available infrastructure, and high costs. Antigen-detecting rapid diagnostic tests (Ag-RDTs) overcome some of these barriers, but independent clinical validations in settings of intended use are scarce. To inform the World Health Organization's (WHO) emergency use listing (EUL) procedure and ensure affordable, high-quality Ag-RDTs, we assessed the performance and ease of use of the SureStatus for SARS-CoV-2. For this prospective, multicenter diagnostic accuracy study, we recruited unvaccinated participants with presumed SARS-CoV-2 infection in India and Germany from December 2020 to March 2021, when the Alpha (B.1.1.7) variant was predominantly circulating. Paired swabs were performed for (i) routine clinical RT-PCR testing (sampling was either nasopharyngeal [NP] or combined NP and oropharyngeal [NP/OP]) and (ii) Ag-RDT (sampling was NP). Performance of the Ag-RDT was compared to RT-PCR overall and by predefined subgroups, e.g., cycle threshold (CT) value, symptoms, and days from symptom onset. To understand the usability, a system usability scale (SUS) questionnaire and ease-of-use (EoU) assessment were performed. A total of 1,119 participants were included in the analysis, of whom 205 (18.3%) were RT-PCR positive. SureStatus detected 169 out of 205 RT-PCR-positive participants, reporting a sensitivity of 82.4% (95% confidence interval [CI]: 76.6% to 87.1%) and a specificity of 98.5% (95% CI: 97.4% to 99.1%). In the first 7 days post-symptom onset, the sensitivity was 90.7% (95% CI: 83.5% to 94.9%), when CT values were low and viral loads were high. The test was characterized as easy to use (SUS, 85/100) and considered suitable for point-of-care settings, although quality concerns were raised due to visibly contaminated packaging of swabs included in the test kits. The SureStatus diagnostic test can be considered a reliable test during the first week of SARS-CoV-2 infection, with high sensitivity in combination with excellent usability. IMPORTANCE Our manufacturer-independent, prospective diagnostic accuracy study assessed clinical performance in participants presumed to have a SARS-CoV-2 infection at three study sites in two countries. We assessed the accuracy overall and in predefined subgroups (CT values and symptom duration). SureStatus performed with high sensitivity. Its sensitivity was particularly high in the first 3 days after symptom onset and when CT values were low (i.e., the viral load was high). The system usability and ease-of-use assessment complements the accuracy assessment of the test and highlights critical factors to facilitate the widespread use of SureStatus in point-of-care settings. The high sensitivity demonstrated by the evaluated Ag-RDT within the first days of symptoms, when most transmission occurs, supports the role of Ag-RDTs for public health-relevant screening. Evidence from this study was used to inform the World Health Organization Emergency Use Listing procedure.

Evaluation of the Parasight Platform for Malaria Diagnosis.

The World Health Organization estimates that nearly 500 million malaria tests are performed annually. While microscopy and rapid diagnostic tests (RDTs) are the main diagnostic approaches, no single method is inexpensive, rapid, and highly accurate. Two recent studies from our group have demonstrated a prototype computer vision platform that meets those needs. Here we present the results from two clinical studies on the commercially available version of this technology, the Sight Diagnostics Parasight platform, which provides malaria diagnosis, species identification, and parasite quantification. We conducted a multisite trial in Chennai, India (Apollo Hospital [n = 205]), and Nairobi, Kenya (Aga Khan University Hospital [n = 263]), in which we compared the device to microscopy, RDTs, and PCR. For identification of malaria, the device performed similarly well in both contexts (sensitivity of 99% and specificity of 100% at the Indian site and sensitivity of 99.3% and specificity of 98.9% at the Kenyan site, compared to PCR). For species identification, the device correctly identified 100% of samples with Plasmodium vivax and 100% of samples with Plasmodium falciparum in India and 100% of samples with P. vivax and 96.1% of samples with P. falciparum in Kenya, compared to PCR. Lastly, comparisons of the device parasite counts with those of trained microscopists produced average Pearson correlation coefficients of 0.84 at the Indian site and 0.85 at the Kenyan site.