Risks of SARS-CoV-2 JN.1 infection and COVID-19 associated emergency-department (ED) visits/hospitalizations following updated boosters and prior infection: a population-based cohort study.

INTRODUCTION: Data on protection afforded by updated COVID-19 vaccines (bivalent/XBB 1.5 monovalent) against the emergent JN.1 variant remains limited. METHODS: We conducted a retrospective population-based cohort study amongst all boosted Singaporeans aged ≥18 years during a COVID-19 wave predominantly driven by JN.1, from 26th November 2023 to 13th January 2024. Multivariable Cox regression was utilised to assess risk of SARS-CoV-2 infection and COVID-19 associated emergency-department (ED) visits/hospitalizations, stratified by vaccination status/prior infection; with individuals last boosted ≥1 year utilized as the reference category. Vaccination and infection status were classified using national registries. RESULTS: 3,086,562 boosted adult Singaporeans were included in the study population, accounting for 146,863,476 person-days of observation. During the JN.1 outbreak, 28,160 SARS-CoV-2 infections were recorded, with 2,926 hospitalizations and 3,747 ED-visits. Compared with individuals last boosted ≥1 year prior with ancestral monovalent vaccines, receipt of an updated XBB.1.5 booster 8-120 days prior was associated with lower risk of JN.1 infection (adjusted-hazard-ratio, aHR = 0.59[0.52-0.66]), COVID-19 associated ED-visits (aHR = 0.50[0.34-0.73]) and hospitalizations(aHR = 0.58[0.37-0.91]), while receipt of a bivalent booster 121-365 days prior was associated with lower risk of JN.1 infection (aHR = 0.92[0.88-0.95]) and ED-visits (aHR = 0.80[0.70-0.90]). Lower risk of COVID-19 hospitalization during the JN.1 outbreak (aHR = 0.57[0.33-0.97]) was still observed following receipt of an updated XBB.1.5 booster 8-120 days prior, even when analysis was restricted to previously infected individuals. CONCLUSION: Recent receipt of updated boosters conferred protection against SARS-CoV-2 infection and ED-visits/hospitalization during a JN.1 variant wave, in both previously infected and uninfected individuals. Annual booster doses confer protection during COVID-19 endemicity.

Long-term Real-world Protection Afforded by Third mRNA Doses Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections, Coronavirus Disease 19-related Emergency Attendances and Hospitalizations Amongst Older Singaporeans During an Omicron XBB Wave.

BACKGROUND: Literature on long-term real-world vaccine effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) booster vaccines (up to and beyond 360 days) is scarce. We report estimates of protection against symptomatic infection, emergency department (ED) attendances and hospitalizations up to and beyond 360 days post-receipt of booster messenger RNA (mRNA) vaccines among Singaporeans aged ≥60 years during an Omicron XBB wave. METHODS: We conducted a population-based cohort study including all Singaporeans aged ≥60 years with no documented prior SARS-CoV-2 infection who had previously received ≥3 doses of mRNA vaccines (BNT162b2/mRNA-1273), over a 4-month period during transmission of Omicron XBB. We reported the adjusted incidence-rate-ratio (IRR) for symptomatic infections, ED attendances and hospitalizations at different time-intervals from both first and second boosters, using Poisson regression; with the reference group being those who received their first booster 90 to 179 days prior. RESULTS: In total, 506 856 boosted adults were included, contributing 55 846 165 person-days of observation. Protection against symptomatic infections among those who received a third vaccine dose (first booster) waned after 180 days with increasing adjusted IRRs; however, protection against ED attendances and hospitalizations held up, with comparable adjusted IRRs with increasing time from third vaccine doses (≥360 days from third dose: adjusted IRR [ED attendances] = 0.73, 95% confidence interval [CI] = .62-.85; adjusted IRR [hospitalization] = 0.58, 95% CI = .49-.70). CONCLUSIONS: Our results highlight the benefit of a booster dose in reducing ED attendances and hospitalizations amongst older adults aged ≥60 years with no documented prior SARS-CoV-2 infection, during an Omicron XBB wave; up to and beyond 360 days post-booster. A second booster provided further reduction.

Favorable outcomes of COVID-19 in vaccinated hematopoietic stem cell transplant recipients: A single-center experience.

INTRODUCTION: A high incidence of mortality and severe COVID-19 infection was reported in hematopoietic stem cell transplant (HSCT) recipients during the early phases of the COVID-19 pandemic; however, outcomes with subsequent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, such as the omicron variant, have yet to be reported. Additionally, rollout of COVID-19 vaccinations in subsequent pandemic waves may modify COVID-19 disease severity and mortality in this immunocompromised population. We describe COVID-19 outcomes among a highly vaccinated population of HSCT recipients at a single center during successive waves of community transmission arising from the SARS-CoV-2 delta and omicron variants. METHODS: We retrospectively reviewed medical records of all HSCT recipients at our institution who tested positive for SARS-CoV-2 from May 2021 to May 2022. Descriptive statistics were reported; the chi-square test was utilized to identify factors associated with 90-day all-cause mortality and severity of COVID-19 infection. RESULTS: Over the 1-year study period, 77 HSCT recipients at our center contracted COVID-19 (43 allogenic; 34 autologous). Twenty-six (33.8%) patients were infected with the SARS-CoV-2 delta variant, while 51 (66.2%) had the SARS-CoV-2 omicron variant. Thirty-nine (50.6%) patients required hospitalization. More than 80% had received prior COVID-19 vaccination (57.1% with two doses, 27.3% with three doses). The majority (90.9%) had mild disease; only one (1.3%) patient required mechanical ventilation. Active hematological disease at time of COVID-19 infection was associated with increased odds of mortality [odds ratio (OR) = 6.90, 95% confidence interval (CI) = 1.20-40]. The 90-day all-cause mortality was 7.8% (six patients). Infection with the omicron variant (vs. delta) was associated with less severe illness (OR = 0.05, 95% CI = 0.01-0.47) and decreased odds of mortality (OR = 0.08, 95% CI = 0.01-0.76). Being on immunosuppression (OR = 5.10, 95% CI = 1.10-23.60) and being unvaccinated at disease onset (OR = 14.76, 95% CI = 2.89-75.4) were associated with greater severity of COVID-19 infection. CONCLUSION: We observed favorable outcomes with COVID-19 infection in a cohort of vaccinated HSCT patients. The SARS-CoV-2 omicron variant was associated with both less severe illness and decreased odds of mortality. As COVID-19 moves toward endemicity, early access to treatment and encouraging vaccination uptake is crucial in mitigating the challenge of COVID-19 management among HSCT recipients. Surveillance and assessment of clinical outcomes with new SARS-CoV-2 variants also remains important in this immunocompromised population.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Setting-specific Transmission Rates: A Systematic Review and Meta-analysis.

BACKGROUND: Understanding the drivers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is crucial for control policies, but evidence of transmission rates in different settings remains limited. METHODS: We conducted a systematic review to estimate secondary attack rates (SARs) and observed reproduction numbers (Robs) in different settings exploring differences by age, symptom status, and duration of exposure. To account for additional study heterogeneity, we employed a beta-binomial model to pool SARs across studies and a negative-binomial model to estimate Robs. RESULTS: Households showed the highest transmission rates, with a pooled SAR of 21.1% (95% confidence interval [CI]:17.4-24.8). SARs were significantly higher where the duration of household exposure exceeded 5 days compared with exposure of ≤5 days. SARs related to contacts at social events with family and friends were higher than those for low-risk casual contacts (5.9% vs 1.2%). Estimates of SARs and Robs for asymptomatic index cases were approximately one-seventh, and for presymptomatic two-thirds of those for symptomatic index cases. We found some evidence for reduced transmission potential both from and to individuals younger than 20 years of age in the household context, which is more limited when examining all settings. CONCLUSIONS: Our results suggest that exposure in settings with familiar contacts increases SARS-CoV-2 transmission potential. Additionally, the differences observed in transmissibility by index case symptom status and duration of exposure have important implications for control strategies, such as contact tracing, testing, and rapid isolation of cases. There were limited data to explore transmission patterns in workplaces, schools, and care homes, highlighting the need for further research in such settings.

COVID-19 public health measures: a reduction in hospital admissions for COPD exacerbations.

Hospitalisations for acute exacerbations of COPD (AECOPD) carry significant morbidity and mortality. Respiratory viral infections (RVIs) are the most common cause of AECOPD and are associated with worse clinical outcomes. During the COVID-19 pandemic, public health measures, such as social distancing and universal masking, were originally implemented to reduce transmission of SARS-CoV-2; these public health measures were subsequently also observed to reduce transmission of other common circulating RVIs. In this study, we report a significant and sustained decrease in hospital admissions for all AECOPD as well as RVI-associated AECOPD, which coincided with the introduction of public health measures during the COVID-19 pandemic.

A comparative study on the clinical features of COVID-19 with non-SARS-CoV-2 respiratory viral infections.

During this coronavirus disease 2019 (COVID-19) pandemic, physicians have the important task of risk stratifying patients who present with acute respiratory illnesses. Clinical presentation of COVID-19, however, can be difficult to distinguish from other respiratory viral infections. Thus, identifying clinical features that are strongly associated with COVID-19 in comparison to other respiratory viruses can aid risk stratification and testing prioritization especially in situations where resources for virological testing and resources for isolation facilities are limited. In our retrospective cohort study comparing the clinical presentation of COVID-19 and other respiratory viral infections, we found that anosmia and dysgeusia were symptoms independently associated with COVID-19 and can be important differentiating symptoms in patients presenting with acute respiratory illness. On the other hand, laboratory abnormalities and radiological findings were not statistically different between the two groups. In comparing outcomes, patients with COVID-19 were more likely to need high dependency or intensive care unit care and had a longer median length of stay. With our findings, we emphasize that epidemiological risk factors and clinical symptoms are more useful than laboratory and radiological abnormalities in differentiating COVID-19 from other respiratory viral infections.

Health-related quality of life and its association with outcomes of outpatient parenteral antibiotic therapy.

While health-related quality of life (HRQoL) is an important component of patient-centred care, few studies have looked at the association between HRQoL and outcomes while on OPAT. From 2014 to 2017, we conducted a prospective cohort study of all patients referred to Singapore General Hospital's (SGH) OPAT service. At baseline, we collected sociodemographic, clinical, and treatment-related factors for OPAT recipients. We also measured baseline HRQoL using the EuroQoL EQ5D-3 L. We evaluated the association between HRQoL and the following outcomes: complications experienced while on OPAT, early termination requiring readmission during planned course of OPAT, all-cause readmission 30 days after completion of OPAT, and return to work while on OPAT. We used chi-squared test for univariate analysis and cox regression for multivariate analysis. From 2014 to 2017, 1213 patients received OPAT at our centre. Of those, 13.2% (160/1213) developed complications. About 10% (132/1213) of patients were readmitted while on OPAT and OPAT was terminated early. Amongst patients who completed OPAT (N = 1081), about 3.6% (39/1081) were readmitted within 30 days after OPAT completion. About half (50.8%, 278/547) returned to work while on OPAT. On multivariate analysis, patients with perfect health-related quality of life (HRQoL) (adjusted relative risk, aRR = 0.62, 95%CI = 0.45-0.85) were less likely to experience complications, had lower risk of OPAT termination (aRR = 0.57, 95%0.38-0.86), and were more likely to return to work while on OPAT (aRR = 1.94, 95%CI = 1.30-2.89). HRQoL at baseline was significantly associated with lower risk of complications and early OPAT termination, as well as greater likelihood of return to work while on OPAT.

Sociodemographic and clinical factors associated with acceptance of outpatient parenteral antibiotic therapy in a Singapore tertiary hospital from 2014 to 2017.

Outpatient parenteral antibiotic therapy (OPAT) can facilitate early discharge; however, not all offered OPAT can accept. We assessed factors associated with acceptance of OPAT in a large Asian tertiary hospital cohort. From 2014 to 2017, we reviewed all referrals to Singapore General Hospital's (SGH) Outpatient Parenteral Antibiotic Therapy (OPAT) service. We compared differences in sociodemographic and clinical factors between patients who opted for OPAT and those who declined, using chi-square test for univariate analysis and logistic regression for multivariate analysis. From 2014 to 2017, a total of 1406 OPAT referrals were made. Of these, 95.9% (1349/1406) were deemed suitable for OPAT. Amongst those suitable, 90.0% (1213/1349) accepted OPAT treatment. On multivariate analysis, being independently ambulant (aOR = 3.46, 95%CI = 2.21-5.37) was independently associated with higher odds of acceptance for OPAT; whereas, patients with peripheral vascular disease had lower odds of accepting OPAT (aOR = 0.32, 95%CI = 0.16-0.62). Lower socioeconomic status (SES) was closely associated with rejection of OPAT, with markers of both individual-level SES (subsidized ward class) and area-level SES (staying in a public rental flat) being independently associated with lower odds of OPAT preference. Distance and travel time were not associated with OPAT acceptance. The top reasons for rejecting OPAT were lack of caregiver (n = 35), mobility issues (n = 24), financial issues (n = 24), and difficulty caring for the line (n = 21). Comorbidities, mobility, and financial issues are important factors to consider when determining suitability for OPAT. More can be done to improve accessibility of OPAT amongst lower-income patients and those staying in lower-SES areas.

Factors associated with emergency room visits and hospitalisation amongst low-income public rental flat dwellers in Singapore.

BACKGROUND: In Singapore, a densely urbanised Asian society, more than 80% of the population stays in public housing estates and the majority (90%) own their own homes. For the needy who cannot afford home ownership, public rental flats are available. Staying in a public rental flat is associated with higher hospital readmission rates and poorer access to health services. We sought to examine sociodemographic factors associated with hospital admissions and emergency room visits amongst public rental flat residents. METHODS: We surveyed all residents aged ≥60 years in a public rental housing precinct in central Singapore in 2016. Residents self-reported their number of emergency room visits, as well as hospitalisations, in the past 6 months. We obtained information on residents' sociodemographic characteristics, medical, functional and social status via standardised questionnaires. We used chi-square to identify associations between emergency room visits/hospitalisations and sociodemographic characteristics, on univariate analysis; and logistic regression for multivariate analysis. RESULTS: Of 1324 contactable residents, 928 participated in the survey, with a response rate of 70.1%. A total of 928 residents participated in our study, of which 59.5% were male (553/928) and 51.2% (476/928) were ≥ 70 years old. Around 9% (83/928) of residents had visited the emergency room in the last 6 months; while 10.5% (100/928) had been admitted to hospital in the past 6 months. On multivariable analysis, being religious (aOR = 0.43, 95%CI = 0.24-0.76) and having seen a primary care practitioner in the last 6 months (aOR = 0.46, 95%CI = 0.27-0.80) were independently associated with lower odds of emergency room visits, whereas loneliness (aOR = 1.96, 95%CI = 1.13-3.43), poorer coping (aOR = 1.72, 95%CI = 1.01-3.03) and better adherence (aOR = 2.23, 95%CI = 1.29-3.83) were independently associated with higher odds of emergency room visits. For hospitalisations, similarly poorer coping (aOR = 1.85, 95%CI = 1.12-3.07), better adherence (aOR = 1.69, 95%CI = 1.04-2.75) and poorer functional status (aOR = 1.85, 95%CI = 1.15-2.98) were all independently associated with higher odds of hospitalisations, whereas those who were religious (aOR = 0.62, 95%CI = 0.37-0.99) and those who were currently employed (aOR = 0.46, 95%CI = 0.37-0.99) had lower odds of being hospitalised. CONCLUSION: In this public rental flat population, functional status, coping and adherence, and having a religion were independently associated with emergency room visits and hospitalisation. Residents who had seen a primary care practitioner in the last 6 months had lower odds of visiting the emergency room.

Caregivers: Do They Make a Difference to Patient Recovery in Subacute Stroke?

OBJECTIVE: To evaluate the relationship between caregiver nature and availability, and rehabilitation outcomes in subacute stroke. DESIGN: Retrospective cohort study. SETTING: Four community rehabilitation hospitals. PARTICIPANTS: Patients with subacute, first-time stroke (N=4042; 48.5% men; mean age ± SD, 70.12±10.4y; 51.5% women; mean age ± SD, 72.54 ±10.0y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Rehabilitation effectiveness, defined as the percentage of potential improvement eventually achieved with rehabilitation; and rehabilitation efficiency, defined as the rate of functional improvement during rehabilitation. RESULTS: In our cohort, 96.7% had available caregiver(s), of which 42.0% were primarily supported by foreign domestic workers (FDWs), 25.9% by spouses, 19.3% by first-degree relatives, 7.8% by other relatives, and 5.1% by other caregivers. Using quantile regression, we found that having a caregiver was independently associated with rehabilitation efficiency (ß=-3.83; 95% confidence interval [CI], -6.99 to -0.66; P=.018). The relationship between caregiver availability and rehabilitation effectiveness was modified by patient sex in that the negative association was significantly greater in men (ß=-22.81; 95% CI, -32.70 to -12.94; P<.001) than women (ß=-5.64; 95% CI, -14.72 to 3.44; P=.223). Having a FDW as a caregiver compared with a spousal caregiver was negatively associated with rehabilitation effectiveness (ß=-3.95; 95% CI, -6.94 to -0.95; P=.01) and rehabilitation efficiency (ß=-1.83; 95% CI, -3.14 to -0.53; P=.006). The number of potential caregivers was only significantly associated with rehabilitation effectiveness at the bivariate level (P=.006). CONCLUSIONS: Caregiver identity, and possibly availability, appears to negatively affect rehabilitation outcomes in subacute stroke. A better understanding of these relationships has potential implications on clinical practice and policy directions.

Primary care characteristics and their association with health screening in a low-socioeconomic status public rental-flat population in Singapore- a mixed methods study.

BACKGROUND: In Singapore, subsidized primary care is provided by centralized polyclinics; since 2000, policies have allowed lower-income Singaporeans to utilize subsidies at private general-practitioner (GP) clinics. We sought to determine whether proximity to primary care, subsidised primary care, or having regular primary care associated with health screening participation in a low socioeconomic-status public rental-flat community in Singapore. METHODS: From 2009-2014, residents in five public rental-flat enclaves (N = 936) and neighboring owner-occupied precincts (N = 1060) were assessed for participation in cardiovascular and cancer screening. We then evaluated whether proximity to primary care, subsidised primary care, or having regular primary care associated with improved adherence to health screening. We also investigated attitudes to health screening using qualitative methodology. RESULTS: In the rental flat population, for cardiovascular screening, regular primary care was independently associated with regular diabetes screening (adjusted odds ratio, aOR = 1.59, CI = 1.12-2.26, p = 0.009) and hyperlipidemia screening (aOR = 1.82, CI = 1.10-3.04, p = 0.023). In the owner-occupied flats, regular primary care was independently associated with regular hypertension screening (aOR = 9.34 (1.82-47.85, p = 0.007), while subsidized primary care was associated with regular diabetes screening (aOR = 2.94, CI = 1.04-8.31, p = 0.042). For cancer screening, in the rental flat population, proximity to primary care was associated with less participation in regular colorectal cancer screening (aOR = 0.42, CI = 0.17-0.99, p = 0.049) and breast cancer screening (aOR = 0.29, CI = 0.10-0.84, p = 0.023). In the owner-occupied flat population, for gynecological cancer screening, usage of subsidized primary care and proximity to primary care was associated with higher rates of breast cancer and cervical cancer screening; however, being on regular primary care followup was associated with lower rates of mammography (aOR = 0.10, CI = 0.01-0.75, p = 0.025). On qualitative analysis, patients were discouraged from screening by distrust in the doctor-patient relationship; for cancer screening in particular, patients were discouraged by potential embarrassment. CONCLUSIONS: Regular primary care was independently associated with regular participation in cardiovascular screening in both low-SES and higher-SES communities. However, for cancer screening, in the low-SES community, proximity to primary care was associated with less participation in regular screening, while in the higher-SES community, regular primary care was associated with lower screening participation; possibly due to embarrassment regarding screening modalities.