Journal of medical virology
-
Observational Study
Follow-up of SARS-CoV-2 positive subgroup from the Asymptomatic novel CORonavirus iNFection study.
A nested longitudinal study within theAsymptomatic novel CORonavirus iNFfection study followed participants with positive nasopharyngeal swab to query for development of symptoms and assess duration of positive reverse transcription-polymerase chain reaction (RT-PCR) test results. Of the 91 participants initially testing positive, 86 participated in follow-up approximately 14 days after study enrollment; of those 86 participants, 19 (22.1%) developed at least one symptom at any time after the initial positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result. The median number of days to symptom development after their initial positive test result was 6 (range 1-29 days). ⋯ Of the 78 participants who submitted a nasopharyngeal swab for repeat RT-PCR testing, 17 (21.8%) remained positive at Day 14, 4 of which continued to test positive at Day 28. These findings reinforce the probable role of silent SARS-CoV-2 infections in community transmission, and that reliance on symptom development will miss a large proportion of infections. Broad testing programs not limited to individuals presenting with symptoms are critical for identifying persons with SARS-CoV-2 infection and ultimately slowing transmission.
-
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a major public health issue worldwide. Developing and evaluating rapid and easy-to-perform diagnostic tests is a high priority. The current study was designed to assess the diagnostic performance of an antigen-based rapid detection test (COVID-VIRO®) in a real-life setting. Two nasopharyngeal specimens of symptomatic or asymptomatic adult patients hospitalized in the Infectious Diseases Department or voluntarily accessing the COVID-19 Screening Department of the Regional Hospital of Orléans, France, were concurrently collected. ⋯ In asymptomatic patients, symptomatic patients having symptoms for more than 4 days and those with an RT-qPCR cycle threshold value ≥ 32, the sensitivities were 100%, 95.8%, and 91.9%, respectively. The concordance between RT-qPCR and COVID VIRO® rapid test results was 100% for the 127 patients with no SARS-CoV-2 infection. The COVID-VIRO® test had 100% specificity and sensitivity greater than 95%, which are better than the recommendations set forth by the WHO (specificity ≥ 97%-100%, sensitivity ≥ 80%). These rapid tests may be particularly useful for large-scale screening in emergency departments, low-resource settings, and airports.
-
The ongoing coronavirus disease 2019 (Covid-19) pandemic has been rapidly spreading throughout the world with confirmed case numbers already exceeding 75 million. Although nasopharyngeal swabs are the most commonly utilized samples for based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection, collecting these specimens requires healthcare workers and necessitates the use of personal protective equipment as it presents a nosocomial transmission risk. We aimed to assess the diagnostic value of saliva samples in mildly symptomatic and asymptomatic patients with confirmed Covid-19. ⋯ Saliva specimens can be considered as a reliable and less resource-intensive alternative to nasopharyngeal specimens for screening asymptomatic SARS-CoV-2 infections.
-
During the coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), reliable diagnostics are absolutely indispensable. Molecular SARS-CoV-2 diagnostics based on nucleic acids (NA) derived from oro- or nasopharyngeal swabs constitute the current gold standard. Given the importance of test results, it is crucial to assess the quality of the underlying swab samples and NA extraction procedures. ⋯ Interestingly, samples taken from females had significantly higher NA concentrations than those from males. Among eight longitudinal patient sample sets with intermitting negative quantitative reverse transcription polymerase chain reaction results, two showed reduced NA concentrations in negative specimens. The herein described fluorescence-based NA quantification approach is immediately applicable to evaluate swab qualities, optimize sampling strategies, identify patient-specific differences, and explain some peculiar test results including intermittent negative samples with low NA concentrations.
-
We primarily quantified exposure patterns, transmission characteristics, and the clinical spectrum of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among household contacts of individuals with severe coronavirus disease-2019 (COVID-19). We conducted a retrospective cohort study of 20 index patients hospitalized with severe COVID-19 and 79 of their household contacts. We determined the transmission frequency, range of manifestations of SARS-CoV-2 infection, and factors associated with infection in household settings. ⋯ Handwashing ≥ 5 times/day was associated with reduced infection risk (52.8% vs. 76.9%, p = .04). SARS-CoV-2 has a high frequency of transmission among household contacts. Nonhospitalized individuals with SARS-CoV-2 infection should be quarantined in patient care facilities rather than at home to minimize spread, if possible, and frequent handwashing should be practiced to prevent transmission.