Fending off Delta - Hospital measures to reduce nosocomial transmission of COVID-19.

OBJECTIVES: Following the emergence of the Delta variant of SARS-CoV-2 in Singapore, our hospital experienced a Delta-linked ward cluster. In this study, we review the enhanced strategies in preventing nosocomial transmission of COVID-19 following widespread community transmission of the Delta variant. METHODS: We conducted a cohort study on exposures to unexpected COVID-19 cases for which contact tracing was initiated from June 2021 to October 2021. Strategies evaluated included upgraded personal protective equipment (PPE) and rostered routine testing (RRT) for staff and patients, surveillance of staff with acute respiratory illness (ARI), and expanded quarantining and testing for contacts of identified cases. RESULTS: From 193 unexpected COVID-19 exposures, 2,573 staff, 542 patients, and 128 visitor contacts were traced. Four staff contacts subsequently had SARS-CoV-2 infection. Two were likely from exposure in community settings, whereas 2 had exposure to the same COVID-19 positive staff in the hospital, forming the only hospital cluster. One inpatient had a nosocomial infection, possibly from visitors. The SARS-CoV-2 detection rate among staff was 0.3% (of 11,200 staff) from biweekly RRT and 2.5% (of 3,675 staff) from ARI surveillance. CONCLUSION: Enhanced hospital measures, including upgraded PPE and RRT for staff and patients, staff sickness surveillance, and more rigorous management of contacts of COVID-19 cases, were likely to have reduced nosocomial transmission amid the Delta variant.

Intranasal octenidine for methicillin-resistant Staphylococcus aureus (MRSA) carriers and universal octenidine bathing reduced MRSA acquisition in an acute-care general ward.

In this quasi-experimental before-and-after study in a methicillin-resistant staphylococcus aureus (MRSA) high-prevalence acute-care dermatology ward from August 2016 to November 2018, patients admitted during intervention period who received additional topical intranasal octenidine were 63% less likely to acquire MRSA than those receiving universal daily octenidine bathing alone during baseline period (aOR, 0.37; 95% CI, 0.14-0.98).

Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a case-control study.

BACKGROUND: Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore. METHODS: Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015 to 2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design. RESULTS: We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1 ± 15.4 years, and 65.5% were male. Compared with controls (N = 9181), IPD patients were younger (mean age 61.5 ± 16.3 years, vs 72.2 ± 16.1 years in controls; p < 0.001) and with less co-morbidities [median Charlson's score 1 (IQR 0-4), vs 3 (1-5) in controls; p < 0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio = 0.20, 95%CI 0.06-0.69; p = 0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥ 85 years and Charlson's score > 3. CONCLUSION: Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectiveness against IPD was estimated to be about 80%, and should be encouraged among high-risk patients.

Responding to the COVID-19 Outbreak in Singapore: Staff Protection and Staff Temperature and Sickness Surveillance Systems.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by a novel coronavirus (SARS-CoV-2) and first reported in Wuhan, China, in December 2019. Since the severe acute respiratory syndrome (SARS) outbreak in 2003, Tan Tock Seng Hospital (TTSH) in Singapore has routinely fit-tested staff for high-filtration N95 respirators and established Web-based staff surveillance systems. The routine systems were enhanced in response to Singapore's first imported COVID-19 case on 23 January 2020. METHODS: We conducted a cross-sectional study from 23 January to 23 February 2020 among healthcare workers to evaluate the effectiveness of the staff protection and surveillance strategy in TTSH, a 1600-bed multidisciplinary acute-care hospital colocated with the 330-bed National Centre for Infectious Diseases (NCID). As of 23 February 2020, TTSH/NCID has managed 76% of confirmed COVID-19 cases in Singapore. The hospital adopted a multipronged approach to protect and monitor staff with potential COVID-19 exposures: (1) risk-based personal protective equipment, (2) staff fever and sickness surveillance, and (3) enhanced medical surveillance of unwell staff. RESULTS: A total of 10 583 staff were placed on hospitalwide fever and sickness surveillance, with 1524 frontline staff working in COVID-19 areas under close surveillance. Among frontline staff, a median of 8 staff illness episodes was seen per day; almost 10% (n = 29) resulted in hospitalization. None of the staff was found to be infected with COVID-19. CONCLUSIONS: A robust staff protection and health surveillance system that is routinely implemented during non-outbreak periods and enhanced during the COVID-19 outbreak is effective in protecting frontline staff from the infection.

Determinants of change in intention to receive influenza vaccination among health-care workers in Singapore.

Understanding the change in intention for influenza vaccine among health-care workers (HCWs) is important to increase influenza vaccination uptake. We aimed to investigate the psychosocial beliefs associated with a change in the intention for influenza vaccine. An anonymous cross-sectional survey was distributed to tertiary hospital HCWs in 2016. Of 3007 HCWs, 70% were compliant (vaccinated, with an intention to revaccinate), 8% were resistant (unvaccinated, without intention to vaccinate), 10% had positive change (unvaccinated, but with intention) and 12% had negative change (vaccinated, but without intention). Across HCW groups, medical staff had both the highest proportion receiving all influenza vaccinations in the last 5 years (101, 28.4%), as well as the highest proportion who had never received vaccination (41, 11.5%). With increasing age, HCWs were less likely to have a negative (p = .02) or positive change (p = .06) in intention, compared to the vaccine-resistant group. HCWs were more likely to be compliant or have a positive change in intention to receive influenza vaccine, if they perceived the vaccine as effective, safe, or had a higher frequency of influenza vaccination in the last 5 years (all with p < .05). HCWs who were medical staff, who believed that side effects of the vaccine were common, or had worked for 6 to 10 years (vs 5 years or less) were less likely to be compliant (all with p < .05). In conclusion, older HCWs were more likely to maintain the status quo in their behavior toward influenza vaccination. Influenza vaccination strategies should place emphasis on vaccine effectiveness and safety.

Factors influencing seasonal influenza vaccination uptake among health care workers in an adult tertiary care hospital in Singapore: A cross-sectional survey.

BACKGROUND: This study aimed to evaluate the factors influencing seasonal influenza vaccination uptake among different health care professional groups. METHODS: A single-center, cross-sectional survey using a standardized anonymous, self-administered questionnaire to assess knowledge, attitudes, and uptake of seasonal influenza vaccination was used. Associations between respective health care groups and vaccination acceptance were then assessed. RESULTS: In total, 3,873 health care workers completed the questionnaire. Of these, 7% were administrative staff, 17% were allied health staff, 7% were ancillary staff, 11% were medical staff, and 58% were nursing staff. The overall vaccination rate for the Southern Hemisphere 2015 influenza season was 82%. In a multivariate logistic regression model, after controlling for gender and presence of chronic disease, associated factors for accepting influenza vaccination were age, education level of bachelor degree or higher, preference for vaccination provided by mobile teams, having 1-50 patient contacts per week, and belief in the potential severity of influenza and vaccine safety (P < .05). In contrast, factors negatively associated with vaccination acceptance included being a medical staff member or allied health staff member, living with family members under the age of 16, fear of adverse reactions, and disbelief in vaccination effectiveness (P < .05). CONCLUSIONS: Although vaccine coverage in Singapore has been high, our findings provide guidance for the development of strategies to further improve vaccine coverage among different groups of health care workers.

Correlation of clinical illness with viremia in Zika virus disease during an outbreak in Singapore.

BACKGROUND: The first autochthonous Zika virus (ZIKV) outbreak in Singapore was detected in August 2016. We report an analysis of the correlation of clinical illness with viremia and laboratory parameters in this Asian cohort. METHODS: We conducted a prospective longitudinal cohort study of patients with a positive blood ZIKV polymerase chain reaction (PCR) result who were admitted to Tan Tock Seng Hospital, Singapore, for isolation and management. RESULTS: We included 40 patients in our study. Rash was present in all patients, while 80% (32/40) had fever, 62.5% (25/40) myalgia, 60% (24/40) conjunctivitis and 38% (15/40) arthralgia. The median duration of viremia was 3.5 days (IQR: 3-5 days). Patients with viremia of ≥4 days were more likely to have prolonged fever compared to those with viremia of less than 4 days (95% versus 63%, p = 0.01), but had no significant correlation with other clinical signs and symptoms, or laboratory investigations. However, 21 patients (53%) had hypokalemia despite the absence of gastrointestinal symptoms. CONCLUSION: Although fever correlated with duration of viremia, 30% of patients remained viremic despite defervescence. Laboratory abnormalities such as leukopenia or thrombocytopenia were not prominent in this cohort but about half the patients were noted to have hypokalemia.

Characterisation of bone and joint infections due to Group B Streptococcus serotype III sequence type 283.

In 2015, an epidemic of Group B Streptococcus (GBS) serotype III sequence type 283 (ST283) disease was reported in Singapore, associated with consumption of raw freshwater fish. In this study, we further characterise the characteristics of bone and joint infections associated with ST283 GBS in adults and the differences between ST283 and non-ST283 manifestations. A retrospective study of 54 inpatients with invasive GBS disease involving bones and/or joints from 2010 to 2015 was performed. Archived isolates were identified as GBS serotype III and ST283 positive using PCR methods. Clinical data were collected from a review of clinical charts. Twenty-three cases were ST283 and 31 were non-ST283. ST283 GBS patients were more likely to be of Chinese ethnicity, have lower Charlson comorbidity scores, and have fewer overall comorbidities, including diabetes mellitus with end-organ damage, peripheral vascular disease, and previous stroke, compared to non-ST283 GBS patients. ST283 patients had more oligoarthritis, with greater involvement of the knee, shoulder, and vertebrae, compared to monoarticular joint involvement in non-ST283 patients. Six patients had a unique combination of knee and shoulder joint involvement. All ST283 cases were mono-microbial, compared to a significant proportion of polymicrobial cultures in non-ST283 patients. Non-ST283 patients had a significantly longer length of stay and were more likely to undergo amputation or wound debridement. This study adds to growing evidence of a distinct clinical presentation associated with ST283 GBS, involving predominantly healthier patients without significant comorbidities, and with distinct clinical manifestations with regard to bone and joint disease.

Psychosocial determinants of influenza vaccination intention: A cross-sectional study on inpatient nurses in Singapore.

Nurses have the closest interaction with inpatients and could transmit influenza to patients. From a self-administered questionnaire survey among inpatient nurses at a tertiary hospital, we observed that the strongest factors associated with intention for future vaccination were perceived benefits of and motivations for vaccination (adjusted odds ratio [aOR], 3.30; 95% confidence interval [CI], 2.55-4.27), and perceived nonsusceptibility to influenza and preference for vaccination alternatives (aOR, 0.26; 95% CI, 0.20-0.34). These factors need to be addressed to increase vaccination uptake and prevent nosocomial transmission.

Prevalence of and risk factors for MRSA colonization in HIV-positive outpatients in Singapore.

BACKGROUND: Whilst there have been studies on the risks and outcomes of MRSA colonization and infections in HIV-positive patients, local data is limited on the risk factors for MRSA colonization among these patients. We undertook this study in a tertiary HIV care centre to document the risk factors for colonization and to determine the prevalence of MRSA colonization among HIV-positive outpatients in Singapore. METHODS: This was a cross-sectional study in which factors associated with MRSA positivity among patients with HIV infection were evaluated. A set of standardized questionnaire and data collection forms were available to interview all recruited patients. Following the interview, trained nurses collected swabs from the anterior nares/axilla/groin (NAG), throat and peri-anal regions. Information on demographics, clinical history, laboratory results and hospitalization history were retrieved from medical records. RESULTS: MRSA was detected in swab cultures from at least 1 site in 15 patients (5.1%). Inclusion of throat and/or peri-anal swabs increased the sensitivity of NAG screening by 20%. Predictors for MRSA colonization among HIV-positive patients were age, history of pneumonia, lymphoma, presence of a percutaneous device within the past 12 months, history of household members hospitalized more than two times within the past 12 months, and a most recent CD4 count less than 200. CONCLUSIONS: This study highlights that a proportion of MRSA carriers would have been undetected without multiple-site screening cultures. This study could shed insight into identifying patients at risk of MRSA colonization upon hospital visit and this may suggest that a risk factor-based approach for MRSA surveillance focusing on high risk populations could be considered.