SARS-CoV-2 seroprevalence and transmission risk factors among high-risk close contacts: a retrospective cohort study.

Background: The proportion of asymptomatic carriers and transmission risk factors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among household and non-household contacts remains unclear. In Singapore, extensive contact tracing by the Ministry of Health for every diagnosed COVID-19 case, and legally enforced quarantine and intensive health surveillance of close contacts provided a rare opportunity to determine asymptomatic attack rates and SARS-CoV-2 transmission risk factors among community close contacts of patients with COVID-19.

Methods: This retrospective cohort study involved all close contacts of confirmed COVID-19 cases in Singapore, identified between Jan 23 and April 3, 2020.

High Prevalence of 16s rRNA Methylase Genes Among Carbapenem-Resistant Hypervirulent Isolates in a Chinese Tertiary Hospital.

Thirty-nine carbapenem-resistant hypervirulent (CR-hvKP) isolates collected from a Chinese tertiary hospital were used in the characterization of the prevalence of 16S rRNA methylase genes. In total, 66.7% (26/39) of the CR-hvKP isolates were found to carry 16S rRNA methylase genes.

Acquisition of Plasmid with Carbapenem-Resistance Gene bla in Hypervirulent Klebsiella pneumoniae, Singapore.

The convergence of carbapenem-resistance and hypervirulence genes in Klebsiella pneumoniae has led to the emergence of highly drug-resistant superbugs capable of causing invasive disease. We analyzed 556 carbapenem-resistant K. pneumoniae isolates from patients in Singapore hospitals during 2010-2015 and discovered 18 isolates from 7 patients also harbored hypervirulence features.

Klebsiella pneumoniae and Klebsiella quasipneumoniae define the population structure of blaKPC-2Klebsiella: a 5 year retrospective genomic study in Singapore.

Objectives: To describe the population structure, molecular epidemiology and genetic context of blaKPC-2-bearing Klebsiella pneumoniae.

Methods: Isolates (n = 157) were retrospective, phenotypically carbapenem-resistant blaKPC-positive K. pneumoniae, collected from public hospitals.

Airflow dynamics of coughing in healthy human volunteers by shadowgraph imaging: an aid to aerosol infection control.

Cough airflow dynamics have been previously studied using a variety of experimental methods. In this study, real-time, non-invasive shadowgraph imaging was applied to obtain additional analyses of cough airflows produced by healthy volunteers. Twenty healthy volunteers (10 women, mean age 32.