Improved sensitivity, safety, and rapidity of COVID-19 tests by replacing viral storage solution with lysis buffer.

Conducting numerous, rapid, and reliable PCR tests for SARS-CoV-2 is essential for our ability to monitor and control the current COVID-19 pandemic. Here, we tested the sensitivity and efficiency of SARS-CoV-2 detection in clinical samples collected directly into a mix of lysis buffer and RNA preservative, thus inactivating the virus immediately after sampling. We tested 79 COVID-19 patients and 20 healthy controls. We collected two samples (nasopharyngeal swabs) from each participant: one swab was inserted into a test tube with Viral Transport Medium (VTM), following the standard guideline used as the recommended method for sample collection; the other swab was inserted into a lysis buffer supplemented with nucleic acid stabilization mix (coined NSLB). We found that RT-qPCR tests of patients were significantly more sensitive with NSLB sampling, reaching detection threshold 2.1±0.6 (Mean±SE) PCR cycles earlier then VTM samples from the same patient. We show that this improvement is most likely since NSLB samples are not diluted in lysis buffer before RNA extraction. Re-extracting RNA from NSLB samples after 72 hours at room temperature did not affect the sensitivity of detection, demonstrating that NSLB allows for long periods of sample preservation without special cooling equipment. We also show that swirling the swab in NSLB and discarding it did not reduce sensitivity compared to retaining the swab in the tube, thus allowing improved automation of COVID-19 tests. Overall, we show that using NSLB instead of VTM can improve the sensitivity, safety, and rapidity of COVID-19 tests at a time most needed.

[ONE YEAR FOLLOW-UP OF PATIENTS AFTER CARDIAC ARREST TREATED WITH THERAPEUTIC HYPOTHERMIA: PROSPECTIVE COHORT STUDY COMPARED WITH HISTORICAL CONTROL].

BACKGROUND: Mild therapeutic hypothermia has been shown to reduce mortality and neurological morbidity in post cardiac arrest survivors. These beneficial effects had initially been reported in retrospective studies and subsequently more evidence has been gathered by two cornerstone randomized control trials. All these studies focused on the acute outcome and the clinical status at the time of hospital discharge. The main goal of this study was to describe the long term effects of therapeutic hypothermia in this population. PATIENTS AND METHODS: A prospective cohort with a historical control group was used in this study. All consecutive patients eligible for therapeutic hypothermia after cardiac arrest were enrolled. These patients were compared to an historical control group of patients who had met the same criteria of treatment with therapeutic hypothermia, but were not treated since it was not yet available. Patients' records and clinical assessment at 1 week, one, six and twelve months follow-up were collected. RESULTS: In the present study 54 consecutive patients were recruited prospectively, treated with mild hypothermia and 41 patients served as the historical control group for a similar period of time. The cooling group was significantly younger than the control group, 54 ± 16.3 versus 61.1 ± 14.5 years (p < 0.04). Peripheral arterial embolism complication was more common in the hypothermia group. 11.1% versus 0% (p < 0.035). No other clinically meaningful differences were found. In this respect, the beneficial trend towards reduced neurological outcome and mortality was observed in favor of the cooling group, which was statistically significant at six months follow-up (p < 0.044). Beyond 6 months the differences did not reach statistical significance. CONCLUSION: In the current phase of the study, a tendency in favor of mild cooling was observed in the short and medium term outcomes in patients resuscitated after out of hospital cardiac arrest due to fatal arrhythmia. The current results indicate that in spite of high survival rates after the acute stage in the cooling group, the long term mortality rate in this group is still high.