Validation of Saliva and Self-Administered Nasal Swabs for COVID-19 Testing

BackgroundActive cases of COVID-19 has primarily been diagnosed via RT-PCR of nasopharyngeal (NP) swabs. Saliva and self-administered nasal (SN) swabs can be collected safely without trained staff. We aimed to test the sensitivity of "naso-oropharyngeal" saliva and SN swabs compared to NP swabs in a large cohort of migrant workers in Singapore. MethodsWe recruited 200 male adult subjects: 45 with acute respiratory infection, 104 asymptomatic close contacts, and 51 confirmed COVID-19 cases. Each subject underwent NP swab, SN swab and saliva collection for RT-PCR testing at 1 to 3 timepoints. We additionally used a direct-from-sample amplicon-based next-generation sequencing (NGS) workflow to establish phylogeny. ResultsOf 200 subjects, 91 and 46 completed second and third rounds of testing, respectively. Of 337 sets of tests, there were 150 (44.5%) positive NP swabs, 127 (37.7%) positive SN swabs, and 209 (62.0%) positive saliva. Test concordance between different sample sites was good, with a kappa statistic of 0.616 for NP and SN swabs, and 0.537 for NP and saliva. In confirmed symptomatic COVID-19 subjects, the likelihood of a positive test from any sample fell beyond 14 days of symptom onset. NGS was conducted on 18 SN and saliva samples, with phylogenetic analyses demonstrating lineages for all samples tested were Clade O (GISAID nomenclature) and lineage B.6 (PANGOLIN nomenclature). ConclusionThis study supports saliva as a sensitive and less intrusive sample for COVID-19 diagnosis and further delineates the role of oropharyngeal secretions in increasing the sensitivity of testing. However, SN swabs were inferior as an alternate sample type. Our study also provides evidence that a straightforward next-generation sequencing workflow can provide direct-from-sample phylogenetic analysis for public health decision-making.

Factors influencing the decision to pursue emergency medicine as a career among medical students in Singapore

<p><b>INTRODUCTION</b>The introduction of the residency programme in Singapore allows medical students to apply for residency in their graduating year. Our study aimed to determine the interest levels and motivating factors for pursuing emergency medicine (EM) as a career among medical students in Singapore.</p><p><b>METHODS</b>A self-administered questionnaire was distributed to Year 1-5 medical students in 2012. Participants indicated their interest in pursuing EM as a career and the degree to which a series of variables influenced their choices. Influencing factors were analysed using multinomial logistic regression.</p><p><b>RESULTS</b>A total of 800 completed questionnaires were collected. 21.0% of the participants expressed interest in pursuing EM. Perceived personality fit and having done an elective in EM were strongly positive influencing factors. Junior medical students were more likely to cite the wide diversity of medical conditions and the lack of a long-term doctor-patient relationship to be negative factors, while senior medical students were more likely to cite personality fit and perceived prestige of EM as negative factors.</p><p><b>CONCLUSION</b>Careful selection of EM applicants is important to the future development of EM in Singapore. Our study showed that personality fit might be the most important influencing factor in choosing EM as a career. Therefore, greater effort should be made to help medical students explore their interest in and suitability for a particular specialty. These include giving medical students earlier exposure to EM, encouraging participation in student interest groups and using appropriate personality tests for career guidance.</p>