Epidemiological investigations of infectious disease are mainly dependent on indirect contact information and only occasionally assisted by characterization of pathogen sequence variation from clinical isolates. Direct sequence analysis of the pathogen, particularly at a population level, is generally thought to be too cumbersome, technically difficult, and expensive. We present here a novel application of mass spectrometry (MS)-based technology in characterizing viral sequence variations that overcomes these problems, and we apply it retrospectively to the severe acute respiratory syndrome (SARS) outbreak in Singapore.

Biological particles deposit on air handling system filters as they process air. This study reports and interprets abundance and diversity information regarding biomass accumulation on ordinarily used filters acquired from several locations in a university environment.

Human evidence for the role of continuous antigenic stimulation from persistent latent infections in frailty is limited. We conducted a nested case-control study (99 deceased and 43 survivors) of participants aged 55 and above in a longitudinal ageing cohort followed up from 2003 to 2017. Using blood samples and baseline data collected in 2003-2004, we examined the association of pathogenic load (PL) count of seropositivity to 10 microbes (viruses, bacteria and mycoplasma) with cumulated deficit-frailty index (CD-FI) and the physical frailty (PF) phenotype, and mortality. Controlling for age, sex, education, smoking and alcohol histories, high PL (7-9) versus low PL (3-6) was associated with an estimated increase of 0.035 points in the CD-FI (Cohen's D=0.035 / 0.086, or 0.41). High PL was associated with 8.5 times odds of being physically frail (p=0.001), 2.8 times odds of being weak (p=0.010), 3.4 times odds of being slow (p=0.024), and mortality hazard ratio of 1.53 (p=0.046). There were no significant associations for specific pathogens, except marginal associations for Epstein-Barr virus and Chikungunya. Conclusion: A high pathogenic load of latent infections was associated with increased risks of frailty and mortality.

Zika virus (ZIKV) is a little known flavivirus that caused a major outbreak in 2007, in the South-western Pacific Island of Yap. It causes dengue-like syndromes but with milder symptoms. In Africa, where it was first isolated, ZIKV is mainly transmitted by sylvatic Aedes mosquitoes. The virus has also been isolated from Ae. aegypti and it is considered to be the vector involved in the urban transmission of the virus. Transmission of the virus by an African strain of Ae. aegypti has also been demonstrated under laboratory conditions. The aim of the present study is to describe the oral susceptibility of a Singapore strain of Ae. aegypti to ZIKV, under conditions that simulate local climate.

The International Hapmap project serves as a valuable resource for human genome variation data, however its applicability to other populations has yet to be exhaustively investigated. In this paper, we use high density genotyping chips and resequencing strategies to compare the Singapore Chinese population with the Hapmap populations. First we compared 1028 and 114 unrelated Singapore Chinese samples genotyped using the Illumina Human Hapmap 550 k chip and Affymetrix 500 k array respectively against the 270 samples from Hapmap. Secondly, data from 20 candidate genes on 5q31-33 resequenced for an asthma candidate gene based study was also used for the analysis.

We determined the seroprevalence of chikungunya virus (CHIKV) infection in the adult resident population in Singapore following local outbreaks of chikungunya fever (CHIKF) in 2008-2009.

The promotion of commercial milk formula (CMF) negatively impacts breastfeeding outcomes. In 2019, Singapore updated its 1979 Code of Ethics of the Sale of Infant Foods Ethics Committee Singapore (SIFECS) to increase marketing restrictions on CMF for infants 0-12 months. However, little is known about industry tactics to undermine these restrictions. This qualitative study explores health workers' and mothers' experiences with CMF marketing in Singapore following the 2019 restrictions. We conducted a qualitative study, using semistructured interviews with 14 mothers of infants aged less than 5 months and 20 health workers with expertise in antenatal, maternity, or paediatric care. We analysed data thematically using inductive coding. Five themes were identified. Mothers and health workers reported digital marketing, product line extensions with toddlers' milk and milk for mothers, and CMF sponsorships in the healthcare setting. Expert endorsement, competitive price, nutritional claims, and brand reputation influenced mothers' infant formula choices, yet both mothers and health workers appeared to be unaware of the impact of CMF marketing tactics on their own perceptions. The restriction of CMF marketing and infant feeding practices varied widely between hospitals, with private hospitals and practices having less strict controls on CMF marketing. Despite the updated SIFECS restrictions, CMF companies continue to target mothers and health workers in Singapore. SIFECS restrictions should be tightened to align with international guidelines, by increasing their scope to include toddlers' milk and prohibiting cross-promotion, digital marketing, and any sponsorships of events targeting health workers that may create a conflict of interest.

Pseudomonas aeruginosa ST308 clone has been reported to carry carbapenemase genes such as blaIMP and blaVIM but has been rarely associated with blaNDM-1. A total of 199 P. aeruginosa ST308 clinical and environmental isolates obtained between April 2019 and November 2020 from a tertiary-care hospital in Singapore were characterized using whole-genome sequencing. In addition, 71 blaNDM-1-positive ST308 whole-genome sequences from two other local tertiary-care hospitals in Singapore and 83 global blaNDM-1-negative ST308 whole-genome sequences in public databases were included to assess phylogenetic relationships and perform genome analyses. Phylogenetic analysis and divergent time estimation revealed that blaNDM-1-positive P. aeruginosa ST308 was introduced into Singapore in 2005 (95 % highest posterior density: 2001 to 2008). Core genome, resistome, and analyses of all local blaNDM-1-positive ST308 isolates showed chromosomal integration of multiple antibiotic resistance genes (ARGs) [aac(3)-Id, aac(6')-Il, aadA6, aadA11, dfrB5, msr(E), floR, sul2, and qnrVC1], which was absent in global blaNDM-1-negative ST308 sequences. Most ARGs and virulence genes were conserved across isolates originating from the three different local hospitals. Close genetic relatedness of the blaNDM-1-positive ST308 clinical and environmental isolates suggests cocirculation between the hospital environment and human hosts with the hospital environment as a potential reservoir. Core genome single nucleotide polymorphism analyses revealed possible clonal transmission of blaNDM-1-positive ST308 isolates between the three hospitals over 7 years. Bloodstream isolates accounted for six of 95 (6.3%) clinical isolates. This study reports the introduction of a pathogenic blaNDM-1-positive P. aeruginosa ST308 more than a decade ago in Singapore and warrants surveillance for wider dissemination. IMPORTANCE P. aeruginosa is a Gram-negative opportunistic pathogen ubiquitously found in the environment and a major cause of nosocomial infections. While the P. aeruginosa ST308 clone has been known to bear blaIMP and blaVIM among global isolates, reports of blaNDM-1-positive P. aeruginosa ST308 are rare. The local blaNDM-1-positive P. aeruginosa ST308 isolates detected in this study appear to be unique to this region, with evidence of chromosomal acquisition of multiple ARGs compared to global blaNDM-1-negative P. aeruginosa ST308 isolates. Surveillance in Singapore and beyond for dissemination is essential to determine whether existing measures are sufficient to control the spread of this ST308 clone.

Coronavirus disease (COVID-19) and tuberculosis (TB) developed in 4 foreign workers living in dormitories in Singapore during April-May 2020. Clinical manifestations and atypical radiographic features of COVID-19 led to the diagnosis of TB through positive interferon-gamma release assay and culture results. During the COVID-19 pandemic, TB should not be overlooked.

A number of serious human adenovirus (HAdV) outbreaks have been recently reported: HAdV-B7 (Israel, Singapore, and USA), HAdV-B7d (USA and China), HAdV-D8, -D54, and -C2 (Japan), HAdV-B14p1 (USA, Europe, and China), and HAdV-B55 (China, Singapore, and France).

Singapore, a city-state with a multi-ethnic Asian population, has one of the world's largest market shares for cigarettes with added flavors, such as menthol and fruit, which increase the appeal of smoking. Little is known on the sociodemographic or smoking-related traits associated with flavored cigarette use in the Asian context.

How diet is related with cognition and health has not been systematically examined in Asians whose eating habits are very different from their counterparts in the West and the biological mechanisms underlying such links are not well known yet. The diet and healthy aging (DaHA) study is a community-based longitudinal study conducted to examine the role of diet and nutrition in promoting cognitive, emotional, and physical health among community-living elderly Singaporeans. The first wave of DaHA, conducted from 2011 to 2017, provided detailed information on diet and baseline cognitive function and health from 1010 community-living elderly in Singapore. Biomarkers of oxidative stress, systemic inflammation, and genetic information were collected. The ongoing second wave of DaHA is conducted from 2017 to 2020, which provides follow- up assessments using established cognitive tests and clinical tools. This well-characterized cohort, with its archived biological samples and high-quality data on diet and lifestyle factors will allow researchers to explore the relationships among diet, nutrition, genes, cognition, mental and physical health in an extremely cost-effective manner. Translations of the research findings into clinical and public health practices will potentially help to promote cognitive health at the population level and reduce healthcare costs related to cognitive impairment.

Influenza B viruses are classified into two main lineages: Yamagata-like and Victoria-like, which differ antigenically and phylogenetically. To understand the evolution of influenza B viruses in South East Asia as well as to determine the vaccine efficacy, we genetically characterised gene segments 4, 6 and 8 from non-tissue culture adapted influenza B viruses detected in Singapore from 2004 to 2009.

Background: Although WU polyomavirus (WU) and KI polyomavirus (KI) have been demonstrated to infect the human respiratory tract, it remains unclear if WU or KI cause human disease. We sought to further investigate the relationship between WU and KI infection and respiratory disease in a pediatric population with respiratory symptoms in Singapore. Methods: We conducted a cross-sectional study of pediatric patients with respiratory symptoms in a Singaporean pediatrics hospital. Upon consent, residual respiratory samples from pediatric inpatients, previously screened for common respiratory viruses, were collected and further screened for WU and KI using qPCR. The amplicons of positive samples were sequenced for confirmation. The severity of a patient's illness was assessed by chart review post-discharge looking for clinical markers of respiratory status such as presenting symptoms, diagnoses, and interventions. Results: From December 2016 to April 2017, 201 patients with residual respiratory samples were enrolled in the study. The average age of all participants recruited was 45 months. WU and KI were detected in 13% (26/201) and 3% (6/201) of patients, respectively. Conducting bivariate and multivariate modeling, patients with WU or KI positivity were not at increased risk of SARI, need for additional oxygen, intravenous fluids, and did not receive additional oral antibiotics or bronchodilators during admission. In contrast, patients with RSV detections were at increased risk of requiring supplemental oxygen during hospital admission. Conclusion: While limited in sample size, our pilot study data do not support the hypothesis that molecular evidence of WU or KI was associated with increased morbidity among a sample of general, pediatric patients with respiratory illness in Singapore.

Ficus elastica, otherwise known as India Rubber (although its geographical origins are unclear), was an important source of latex in the early 19th century and was widely cultivated in tropical Asia. Like all figs, F. elastica is dependent on tiny, highly specific wasps for pollination, and detailed studies based out of Singapore in the 1930s suggested that through the loss of its pollinator F. elastica was extinct in the wild. However, around 2005 wild seedlings of F. elastica began appearing in Singapore. We identified the pollinator as Platyscapa clavigera, which was originally described from F. elastica in Bogor in 1885. A visit to Bogor Botanical Gardens revealed that not only was F. elastica being pollinated by P. clavigera in the gardens, but there was clear evidence it had been reproducing naturally there over many decades. Although Singapore has a native fig flora of over 50 species, F. elastica went unpollinated for at least 70 years and probably from the time it was introduced during the 19th century. These observations illustrate the extraordinary specificity of this interaction and, through the fig's ability to wait for its pollinators, demonstrates one way in which such highly specific interactions can be evolutionarily stable.

This study examined the physical and social environment (facilities and activities) of Singapore's Recreational Centres (RCs) and female patrons' (>50 years) perception of the RC facilities and activities.

To evaluate how public perceptions and trust in government communications affected the adoption of protective behaviour in Singapore during the coronavirus disease 2019 (COVID-19) pandemic.

The dual-specificity phosphatase (DUSP) family plays an important role in response to adverse external factors. In this study, the DUSP5 from Epinephelus coioides, an important marine fish in Southeast Asia and China, was isolated and characterized. As expected, E. coioides DUSP5 contained four conserved domains: a rhodanese homology domain (RHOD); a dual-specificity phosphatase catalytic domain (DSPc); and two regions of low compositional complexity, indicating that E. coioides DUSP5 belongs to the DUSP family. E. coioides DUSP5 mRNA could be detected in all of the examined tissues, and was mainly distributed in the nucleus. Infection with Singapore grouper iridovirus (SGIV), one of the most important pathogens of marine fish, could inhibit the expression of E. coioides DUSP5. The overexpression of DUSP5 could significantly downregulate the expression of the key SGIV genes (MCP, ICP18, VP19, and LITAF), viral titers, the activity of NF-κB and AP-I, and the expression of pro-inflammatory factors (IL-6, IL-8, and TNF-α) of E. coioides, but could upregulate the expressions of caspase3 and p53, as well as SGIV-induced apoptosis. The results demonstrate that E. coioides DUSP5 could inhibit SGIV infection by regulating E. coioides immune-related factors, indicating that DUSP5 might be involved in viral infection.

Recent genome-wide association studies (GWAS) have identified 97 body-mass index (BMI) associated loci. We aimed to evaluate if dietary intake modifies BMI associations at these loci in the Singapore Chinese population.

No abstract available