Simultaneous detection of SARS-CoV-2 and pandemic (H1N1) 2009 virus with real-time isothermal platform

Digital assay for rapid electronic quantification of clinical pathogens using DNA nanoballs

Fast and accurate detection of nucleic acids is key for pathogen identification. Methods for DNA detection generally rely on fluorescent or colorimetric readout. The development of label-free assays decreases costs and test complexity. We present a novel method combining a one-pot isothermal generation of DNA nanoballs with their detection by electrical impedance. We modified loop-mediated isothermal amplification by using compaction oligonucleotides that self-assemble the amplified target into nanoballs. Next, we use capillary-driven flow to passively pass these nanoballs through a microfluidic impedance cytometer, thus enabling a fully compact system with no moving parts. The movement of individual nanoballs is detected by a change in impedance providing a quantized readout. This approach is flexible for the detection of DNA/RNA of numerous targets (severe acute respiratory syndrome coronavirus 2, HIV, β-lactamase gene, etc.), and we anticipate that its integration into a standalone device would provide an inexpensive (<$5), sensitive (10 target copies), and rapid test (<1 hour).

RT-LAMP is a potential future molecular diagnostic tool for influenza A virus

Aim: Influenza A virus (IAV) causes serious illness and is responsible for significant morbidity and mortality. To diagnose IAV infection in its early stages, a quick, sensitive, precise detection method is needed for effective clinical management. Materials & methods: In-house hydroxylnaphthol blue (HNB)-based RT-LAMP assay for early detection of IAV using the HA gene was compared with RT-PCR/multiplex-RT-PCR. Results: For the reference strains of IAV, (H1N1 (A/Texas/50/2012) and H3N2 (A/Malaysia/2089302/2009)) RT-LAMP and RT-PCR/M-RT-PCR exhibited a limit of detection (LOD) of 10 and 100 fg/ml, respectively. Conclusion: HNB-based RT-LAMP is a rapid, sensitive, cost-effective diagnostic tool, and could be a point-of-care test for IAV patients during outbreaks.

Ferrobotic swarms enable accessible and adaptable automated viral testing

Expanding our global testing capacity is critical to preventing and containing pandemics^1–9. Accordingly, accessible and adaptable automated platforms that in decentralized settings perform nucleic acid amplification tests resource-efficiently are required^10–14. Pooled testing can be extremely efficient if the pooling strategy is based on local viral prevalence^15–20; however, it requires automation, small sample volume handling and feedback not available in current bulky, capital-intensive liquid handling technologies^21–29. Here we use a swarm of millimetre-sized magnets as mobile robotic agents (‘ferrobots’) for precise and robust handling of magnetized sample droplets and high-fidelity delivery of flexible workflows based on nucleic acid amplification tests to overcome these limitations. Within a palm-sized printed circuit board-based programmable platform, we demonstrated the myriad of laboratory-equivalent operations involved in pooled testing. These operations were guided by an introduced square matrix pooled testing algorithm to identify the samples from infected patients, while maximizing the testing efficiency. We applied this automated technology for the loop-mediated isothermal amplification and detection of the SARS-CoV-2 virus in clinical samples, in which the test results completely matched those obtained off-chip. This technology is easily manufacturable and distributable, and its adoption for viral testing could lead to a 10–300-fold reduction in reagent costs (depending on the viral prevalence) and three orders of magnitude reduction in instrumentation cost. Therefore, it is a promising solution to expand our testing capacity for pandemic preparedness and to reimagine the automated clinical laboratory of the future.

A handheld printed circuit board-based programmable platform using ferrobots can perform the complex, laboratory-equivalent procedures involved in multiplexed and pooled nucleic acid amplification testing, allowing for the decentralization of viral diagnostics.

Mental health among healthcare workers during the prolonged COVID-19 pandemic: A cross-sectional survey in Jilin Province in China

Background

The prolonged COVID-19 pandemic has seriously impacted the mental health of healthcare workers. This study aimed to explore the mental health status of healthcare workers, compare the differences in mental health between physicians and nurses, and verify the impact of risk perception on mental health in the long-term COVID-19 pandemic in Jilin Province, China.

Methods

A stratified random sample was used to conduct an on-site questionnaire survey in December 2020 to measure the mental health status, risk perceptions, and demographic characteristics of healthcare workers in Jilin Province, China. A total of 3,383 participants completed the questionnaire survey, of which 3,373 were valid questionnaires.

Results

A total of 23.6% (n = 795) of participants had symptoms of depression, 27.4% (n = 923) had symptoms of anxiety, and 16.3% (n = 551) had symptoms of stress. Physicians reported significantly higher rates of depression and anxiety than nurses (p = 0.023, p = 0.013, respectively). There was no significant difference in the proportion of participants with stress between physicians and nurses (p = 0.474). Multivariate logistic regression results showed that healthcare workers who had a high level of risk perception were more likely to have symptoms of depression (AOR = 4.12, p < 0.001), anxiety (AOR = 3.68, p < 0.001), and stress (AOR = 4.45, p < 0.001) after controlling for other variables.

Conclusion

At least one in six healthcare workers experienced mental health problems, and physicians were more likely than nurses to suffer from depression during the prolonged COVID-19 epidemic. Risk perception was highly predictive of depression, anxiety, and stress symptoms in medical staff. Public health interventions are needed to mitigate the long-term psychological impact of the COVID-19 pandemic.