ORCID Profile
0000-0002-0395-5633
Current Organisations
Tan Tock Seng Hospital
,
National Centre for Infectious Diseases, Singapore
,
National University Singapore Yong Loo Lin School of Medicine
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Related Links
Publications
MRSA Transmission Dynamics Among Interconnected Acute, Intermediate-Term, and Long-Term Healthcare Facilities in Singapore
Publisher: Oxford University Press (OUP)
Date: 29-04-2017
DOI: 10.1093/CID/CIX072
First report of emergence of OXA-48 carbapenemase-producing Enterobacteriaceae in Singapore: Proactive or reactive infection control strategy?
Publisher: Elsevier BV
Date: 05-2014
Local transmission and global dissemination of New Delhi Metallo-Beta-Lactamase (NDM): a whole genome analysis
Publisher: Springer Science and Business Media LLC
Date: 13-06-2016
Reactive Infection Control Strategy for Control of New Delhi Metallo-β-Lactamase (NDM)-Producing Enterobacteriaceae Analyzed Using Whole-Genome Sequencing: Hits and Misses
Publisher: Cambridge University Press (CUP)
Date: 04-05-2016
DOI: 10.1017/ICE.2016.92
Abstract: Genetically distinct isolates of New Delhi metallo-β-lactamase (NDM)–producing Enterobacteriaceae were identified from the clinical cultures of 6 patients. Screening of shared-ward contacts identified 2 additional NDM-positive patients. Phylogenetic analysis proved that 1 contact was a direct transmission while the other was unrelated to the index, suggesting hidden routes of transmission. Infect Control Hosp Epidemiol 2016 :987–990
Household transmission of carbapenemase-producing Enterobacteriaceae: a prospective cohort study
Publisher: Oxford University Press (OUP)
Date: 08-01-2021
DOI: 10.1093/JAC/DKAA561
Abstract: To estimate the transmission rate of carbapenemase-producing Enterobacteriaceae (CPE) in households with recently hospitalized CPE carriers. We conducted a prospective case-ascertained cohort study. We identified the presence of CPE in stool s les from index subjects, household contacts and companion animals and environmental s les at regular intervals. Linked transmissions were identified by WGS. A Markov model was constructed to estimate the household transmission potential of CPE. Ten recently hospitalized index patients and 14 household contacts were included. There were seven households with one contact, two households with two contacts, and one household with three contacts. Index patients were colonized with blaOXA-48-like (n = 4), blaKPC-2 (n = 3), blaIMP (n = 2), and blaNDM-1 (n = 1), distributed among ergent species of Enterobacteriaceae. After a cumulative follow-up time of 9.0 years, three family members (21.4%, 3/14) acquired four different types of CPE in the community (hazard rate of 0.22/year). The probability of CPE transmission from an index patient to a household contact was 10% (95% CI 4%–26%). We observed limited transmission of CPE from an index patient to household contacts. Larger studies are needed to understand the factors associated with household transmission of CPE and identify preventive strategies.
Risk factors and treatment outcome of ertapenem non-susceptible enterobacteriaceae bacteraemia
Publisher: Elsevier BV
Date: 03-2013
Draft Genome Sequence of a Multidrug-Resistant New Delhi Metallo-β-Lactamase-1 (NDM-1)-Producing Escherichia coli Isolate Obtained in Singapore
Publisher: American Society for Microbiology
Date: 26-12-2013
Abstract: We report the draft genome sequence of a New Delhi metallo-β-lactamase-1 (NDM-1)-positive Escherichia coli isolate obtained from a surgical patient. The assembled data indicate the presence of 3 multidrug resistance plasmids, 1 of which shares 100% identity with an NDM-1 plasmid isolated previously from a nearby hospital, suggesting possible local transmission.
Prevalence of Healthcare-Associated Infections and Antimicrobial Use Among Adult Inpatients in Singapore Acute-Care Hospitals: Results From the First National Point Prevalence Survey
Publisher: Oxford University Press (OUP)
Date: 29-04-2017
DOI: 10.1093/CID/CIX103
Abstract: We conducted a national point prevalence survey (PPS) to determine the prevalence of healthcare-associated infections (HAIs) and antimicrobial use (AMU) in Singapore acute-care hospitals. Trained personnel collected HAI, AMU, and baseline hospital- and patient-level data of adult inpatients from 13 private and public acute-care hospitals between July 2015 and February 2016, using the PPS methodology developed by the European Centre for Disease Prevention and Control. Factors independently associated with HAIs were determined using multivariable regression. Of the 5415 patients surveyed, there were 646 patients (11.9% 95% confidence interval [CI], 11.1%-12.8%) with 727 distinct HAIs, of which 331 (45.5%) were culture positive. The most common HAIs were unspecified clinical sepsis (25.5%) and pneumonia (24.8%). Staphylococcus aureus (12.9%) and Pseudomonas aeruginosa (11.5%) were the most common pathogens implicated in HAIs. Carbapenem nonsusceptibility rates were highest in Acinetobacter species (71.9%) and P. aeruginosa (23.6%). Male sex, increasing age, surgery during current hospitalization, and presence of central venous or urinary catheters were independently associated with HAIs. A total of 2762 (51.0% 95% CI, 49.7%-52.3%) patients were on 3611 systemic antimicrobial agents 462 (12.8%) were prescribed for surgical prophylaxis and 2997 (83.0%) were prescribed for treatment. Amoxicillin/clavulanate was the most frequently prescribed (24.6%) antimicrobial agent. This survey suggested a high prevalence of HAIs and AMU in Singapore's acute-care hospitals. While further research is necessary to understand the causes and costs of HAIs and AMU in Singapore, repeated PPSs over the next decade will be useful to gauge progress at controlling HAIs and AMU.
Detection of air and surface contamination by SARS-CoV-2 in hospital rooms of infected patients
Publisher: Springer Science and Business Media LLC
Date: 29-05-2020
DOI: 10.1038/S41467-020-16670-2
Abstract: Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air s les from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental s ling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface s les are collected. 56.7% of rooms have at least one environmental surface contaminated. High touch surface contamination is shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness ( p = 0.01, χ 2 test). Air s ling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes µm and 1–4 µm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2.
The Effect of Sample Site, Illness Duration, and the Presence of Pneumonia on the Detection of SARS-CoV-2 by Real-time Reverse Transcription PCR
Publisher: Oxford University Press (OUP)
Date: 03-08-2020
DOI: 10.1093/OFID/OFAA335
Abstract: The performance of real-time reverse transcription polymerase chain reaction (rRT-PCR) for SARS-CoV-2 varies with s ling site(s), illness stage, and infection site. Unilateral nasopharyngeal, nasal midturbinate, throat swabs, and saliva were simultaneously s led for SARS-CoV-2 rRT-PCR from suspected or confirmed cases of COVID-19. True positives were defined as patients with at least 1 SARS-CoV-2 detected by rRT-PCR from any site on the evaluation day or at any time point thereafter, until discharge. Diagnostic performance was assessed and extrapolated for site combinations. We evaluated 105 patients 73 had active SARS-CoV-2 infection. Overall, nasopharyngeal specimens had the highest clinical sensitivity at 85%, followed by throat, 80%, midturbinate, 62%, and saliva, 38%–52%. Clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 95%, 88%, 72%, and 44%–56%, respectively, if taken ≤7 days from onset of illness, and 70%, 67%, 47%, 28%–44% if & days of illness. Comparing patients with upper respiratory tract infection (URTI) vs pneumonia, clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 92% vs 70%, 88% vs 61%, 70% vs 44%, 43%–54% vs 26%–45%, respectively. A combination of nasopharyngeal plus throat or midturbinate plus throat specimen afforded overall clinical sensitivities of 89%–92% this rose to 96% for persons with URTI and 98% for persons ≤7 days from illness onset. Nasopharyngeal specimens, followed by throat specimens, offer the highest clinical sensitivity for COVID-19 diagnosis in early illness. Clinical sensitivity improves and is similar when either midturbinate or nasopharyngeal specimens are combined with throat specimens. Upper respiratory specimens perform poorly if taken after the first week of illness or if there is pneumonia.
Impact of participation in a surgical site infection surveillance network: results from a large international cohort study
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JHIN.2018.12.003
Abstract: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. To determine the time-trend of SSI rates in surveillance networks. SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.
Effect of carbapenem resistance on outcomes of bloodstream infection caused by Enterobacteriaceae in low-income and middle-income countries (PANORAMA): a multinational prospective cohort study
Publisher: Elsevier BV
Date: 06-2019
Viable Monkeypox virus in the environment of a patient room
Publisher: Cold Spring Harbor Laboratory
Date: 17-09-2022
DOI: 10.1101/2022.09.15.22280012
Abstract: We conducted a prospective environmental surveillance study to investigate the air, surface, dust and water contamination of a room occupied by a patient infected with Monkeypox virus (MPXV) at various stages of his illness. The patient tested positive for MPXV from a throat swab and skin lesions. Environmental s ling was conducted in a negative pressure room with 12 unidirectional HEPA air changes per hour and daily cleaning of the surfaces. A total of 179 environmental s les were collected on days 7, 8, 13, and 21 of his illness. Air, surface, and dust contamination was highest during the first eight days of the illness, with a gradual decline to the lowest contamination level by day 21. Viable MPXV was isolated from surfaces and dust s les and no viable virus was isolated from the air and water s les. Inadequate research prevail on the mode of transmission for monkeypox virus. This study reports the findings of viable monkeypox virus from the patient environment, highlighting its implications for human health and impact on infection and prevention control measures.
Establishing the prevalence of healthcare-associated infections in Australian hospitals
Publisher: BMJ
Date: 11-2018
DOI: 10.1136/BMJOPEN-2018-024924
Abstract: A healthcare-associated infection (HAI) data point prevalence study (PPS) conducted in 1984 in Australian hospitals estimated the prevalence of HAI to be 6.3%. Since this time, there have been no further national estimates undertaken. In the absence of a coordinated national surveillance programme or regular PPS, there is a dearth of national HAI data to inform policy and practice priorities. A national HAI PPS study will be undertaken based on the European Centres for Disease Control method. Nineteen public acute hospitals will participate. A standardised algorithm will be used to detect HAIs in a two-stage cluster design, random s le of adult inpatients in acute wards and all intensive care unit patients. Data from each hospital will be collected by two trained members of the research team. We will estimate the prevalence of HAIs, invasive device use, single room placement and deployment of transmission-based precautions. Ethics approval was obtained from the Alfred Health Human Research Ethics Committee (HREC/17/Alfred/203) via the National Mutual Assessment. A separate approval was obtained from the Tasmanian Health and Medical Human Research Committee (H0016978) for participating Tasmanian hospitals. Findings will be disseminated in in idualised participating hospital reports, peer-reviewed publications and conference presentations.
Related Organisations
National Centre For Infectious Diseases, Singapore
Location: Singapore
National University Singapore Yong Loo Lin School Of Medicine
Location: Singapore
Related Funding Activities
No related grants have been discovered for Kalisvar Marimuthu.