Serum creatinine to absolute lymphocyte count ratio effectively risk stratifies patients who require intensive care in hospitalized patients with coronavirus disease 2019

Patients with preexisting kidney disease or acute kidney injury had poorer outcomes in coronavirus disease 2019 (COVID-19) illness. Lymphopenia was associated with more severe illness. Risk stratification with simple laboratory tests may help appropriate site patients in a cost-effective manner and ease the burden on healthcare systems. We examined a ratio of serum creatinine level to absolute lymphocyte count at presentation (creatinine-lymphocyte ratio, CLR) in predicting outcomes in hospitalized patients with COVID-19. We analyzed 553 consecutive polymerase chain reaction-positive SARS-COV-2 hospitalized patients. Patients with end-stage kidney disease were excluded. Serum creatinine and full blood count (FBC) examination were obtained within the first day of admission. We examined the utility of CLR in predicting adverse clinical outcomes (requiring intensive care, mechanical ventilation, acute kidney injury requiring renal replacement therapy or death). An optimized cutoff of CLR > 77 was derived for predicting adverse outcomes (72.2% sensitivity, and 83.9% specificity). Ninety-seven patients (17.5%) fell within this cut off. These patients were older and more likely to have chronic medical conditions. A higher proportion of these patients had adverse outcomes (13.4% vs 1.1%, P < .001). On receiver operating curve analyses, CLR predicted patients who had adverse outcomes well (area under curve [AUC] = 0.82, 95%CI 0.72-0.92), which was comparable to other laboratory tests like serum ferritin, C-reactive protein and lactate dehydrogenase. Elevated CLR on admission, which may be determined by relatively simple laboratory tests, was able to reasonably discriminate patients who had experienced adverse outcomes during their hospital stay. This may be a simple and cost-effective means of risk stratification and triage.

External validation of the PRIORITY model in predicting COVID-19 critical illness in vaccinated and unvaccinated patients

OBJECTIVES

Predictive scores are important tools for the triage of patients with coronavirus disease 2019. The PRIORITY score is advantageous because it does not require laboratory and radiologic information. However, the original development and validation cohorts studied only unvaccinated patients in early 2020. We aimed to externally validate the PRIORITY score in a cohort of patients with the novel delta and omicron variants of coronavirus disease 2019 and mixed vaccination status.

METHODS

A total of 410 patients were included in a cross-sectional sampling of all patients admitted to the National Centre of Infectious Diseases on October 27, 2021. A further 102 and 136 patients with vaccine-breakthrough Delta and Omicron variant infection from April to August and December 2021, respectively, were also included. Variables at the time of admission were collected retrospectively from medical records and used to calculate the probability of deterioration using the PRIORITY model.

RESULTS

Of the total 648 included patients, 447 (69.0%) were vaccinated. The mean age was 61.6 years (standard deviation ± 19.0 years), and 268 patients (41.4%) were female. A total of 112 patients (17.3%) met the primary outcome of developing critical illness or mortality. The performance of the score in this cohort was comparable with the original cohorts, with an area under the receiver operating characteristic curve for all patients of 0.794 (95% CI, 0.752-0.835; p < 0.001), regression coefficient of 1.069, and intercept of 0.04. Subgroup analysis of unvaccinated and vaccinated patients showed that performance was superior in vaccinated individuals, with an area under the receiver operating characteristic curve of 0.684 (95% CI, 0.608-0.760; p < 0.0001) and 0.831 (95% CI, 0.772-0.891; p < 0.0001), respectively.

DISCUSSION

Our data support the continued use of the PRIORITY score in this era of novel variants and increased vaccination uptake.

Discrepant serological findings in SARS-CoV-2 PCR negative, hospitalised patients with fever and acute respiratory symptoms during the pandemic

BACKGROUND

COVID-19 serology has an evolving role in the diagnosis of SARS-CoV-2 infection. However, its use in hospitalised patients with acute respiratory symptoms remains unclear.

METHODS

Hospitalised patients with acute respiratory illness admitted to an isolation ward were recruited. All patients had negative nasopharyngeal swab polymerase chain reaction (PCR) for SARS-CoV-2. Serological studies using 4 separate assays (cPass: surrogate neutralising ELISA; Elecsys: N-antigen based chemiluminescent assay; SFB: S protein flow-based; epitope peptide-based ELISA;) were performed on stored plasma collected from patients during the initial hospital stay, and a convalescent visit 4-12 weeks later.

RESULTS

Of the 51 patients studied (aged 54, IQR 21-84; 62.7% male), no patients tested positive on the Elecsys or cPass assays. 5/51 patients had antibodies detected on B-cell Epitope Assay, and 3/51 had antibodies detected on SFB assay. These 8 patients with positive serological test to COVID-19 were more likely to have a high-risk occupation (p=0.039), bacterial infection (p=0.028) and neutrophilia (p=0.013) during their initial hospital admission.

CONCLUSION

Discrepant COVID-19 serological findings were observed amongst those with recent hospital admissions and bacterial infections. The positive serological findings within our cohort raise important questions about the interpretation of sero-epidemiology during the current pandemic. This article is protected by copyright. All rights reserved.

Airborne SARS-CoV-2 surveillance in hospital environment using high-flowrate air samplers and its comparison to surface sampling

Reliable methods to detect the presence of SARS-CoV-2 at venues where people gather are essential for epidemiological surveillance to guide public policy. Communal screening of air in a highly crowded space has the potential to provide early warning on the presence and potential transmission of SARS-CoV-2 as suggested by studies early in the epidemic. As hospitals and public facilities apply varying degrees of restrictions and regulations, it is important to provide multiple methodological options to enable environmental SARS-CoV-2 surveillance under different conditions. This study assessed the feasibility of using high-flowrate air samplers combined with RNA extraction kit designed for environmental sample to perform airborne SARS-CoV-2 surveillance in hospital setting, tested by RT-qPCR. The success rate of the air samples in detecting SARS-CoV-2 was then compared with surface swab samples collected in the same proximity. Additionally, positive RT-qPCR samples underwent viral culture to assess the viability of the sampled SARS-CoV-2. The study was performed in inpatient ward environments of a quaternary care university teaching hospital in Singapore housing active COVID-19 patients within the period of February to May 2020. Two types of wards were tested, naturally ventilated open-cohort ward and mechanically ventilated isolation ward. Distances between the site of air sampling and the patient cluster in the investigated wards were also recorded. No successful detection of airborne SARS-CoV-2 was recorded when 50 L/min air samplers were used. Upon increasing the sampling flowrate to 150 L/min, our results showed a high success rate in detecting the presence of SARS-CoV-2 from the air samples (72%) compared to the surface swab samples (9.6%). The positive detection rate of the air samples along with the corresponding viral load could be associated with the distance between sampling site and patient. The furthest distance from patient with PCR-positive air samples was 5.5 m. The airborne SARS-CoV-2 detection was comparable between the two types of wards with 60%-87.5% success rate. High prevalence of the virus was found in toilet areas, both on surfaces and in air. Finally, no successful culture attempt was recorded from the environmental air or surface samples.

Airborne SARS-CoV-2 surveillance in hospital environment using high-flowrate air samplers and its comparison to surface sampling

Reliable methods to detect the presence of SARS-CoV-2 at venues where people gather are essential for epidemiological surveillance to guide public policy. Communal screening of air in a highly crowded space has the potential to provide early warning on the presence and potential transmission of SARS-CoV-2 as suggested by studies early in the epidemic. As hospitals and public facilities apply varying degrees of restrictions and regulations, it is important to provide multiple methodological options to enable environmental SARS-CoV-2 surveillance under different conditions. This study assessed the feasibility of using high-flowrate air samplers combined with RNA extraction kit designed for environmental sample to perform airborne SARS-CoV-2 surveillance in hospital setting, tested by RT-qPCR. The success rate of the air samples in detecting SARS-CoV-2 was then compared with surface swab samples collected in the same proximity. Additionally, positive RT-qPCR samples underwent viral culture to assess the viability of the sampled SARS-CoV-2. The study was performed in inpatient ward environments of a quaternary care university teaching hospital in Singapore housing active COVID-19 patients within the period of February to May 2020. Two types of wards were tested, naturally ventilated open-cohort ward and mechanically ventilated isolation ward. Distances between the site of air sampling and the patient cluster in the investigated wards were also recorded. No successful detection of airborne SARS-CoV-2 was recorded when 50 L/min air samplers were used. Upon increasing the sampling flowrate to 150 L/min, our results showed a high success rate in detecting the presence of SARS-CoV-2 from the air samples (72%) compared to the surface swab samples (9.6%). The positive detection rate of the air samples along with the corresponding viral load could be associated with the distance between sampling site and patient. The furthest distance from patient with PCR-positive air samples was 5.5 m. The airborne SARS-CoV-2 detection was comparable between the two types of wards with 60%-87.5% success rate. High prevalence of the virus was found in toilet areas, both on surfaces and in air. Finally, no successful culture attempt was recorded from the environmental air or surface samples.

Fever as a predictor of adverse outcomes in COVID-19

BACKGROUND/INTRODUCTION

There are little data on outcomes of COVID-19 patients with the presence of fever compared to the presence of symptoms.

AIM

We examined the associations between symptomology, presence of fever and outcomes of a COVID-19 cohort.

DESIGN AND METHODS

Between 23 January and 30 April 2020, 554 COVID-19 patients were admitted to a tertiary hospital in Singapore. They were allocated into four groups based on symptomology and fever-Group 1: asymptomatic and afebrile, Group 2: symptomatic but afebrile, Group 3: febrile but asymptomatic and Group 4: symptomatic and febrile. The primary outcomes were intensive care unit (ICU) admissions and mortality. The composite end-point included ICU admissions, mortality or any COVID-19 related end-organ involvement.

RESULTS

There were differences in ferritin (P=0.003), C-reactive protein (CRP) levels (P<0.001) and lymphopenia (P=0.033) across all groups, with the most favourable biochemical profile in Group 1, and the least in Group 4. Symptomatic groups (Groups 2 and 4) had higher ICU admissions (1.9% and 6.0%, respectively, P=0.003) than asymptomatic groups (Groups 1 and 3). Composite end-point was highest in Group 4 (24.0%), followed by Group 3 (8.6%), Group 2 (4.8%) and Group 1 (2.4%) (P<0.001). The presence of fever (OR 4.096, 95% CI 1.737-9.656, P=0.001) was associated with the composite end-point after adjusting for age, pulse rate, comorbidities, lymphocyte, ferritin and CRP. Presence of symptoms was not associated with the composite end-point.

DISCUSSION/CONCLUSION

In this COVID-19 cohort, presence of fever was a predictor of adverse outcomes. This has implications on the management of febrile but asymptomatic COVID-19 patients.

Haematological profile of COVID-19 patients from a centre in Singapore

BACKGROUND

Haematological markers such as absolute lymphopenia have been associated with severe COVID-19 infection. However, in the literature to date, the cohorts described have typically included patients who were moderate to severely unwell with pneumonia and who required intensive care stay. It is uncertain if these markers apply to a population with less severe illness. We sought to describe the haematological profile of patients with mild disease with COVID-19 admitted to a single centre in Singapore.

METHODS

We examined 554 consecutive PCR positive SARS-COV-2 patients admitted to a single tertiary healthcare institution from Feb 2020 to April 2020. In all patients a full blood count was obtained within 24 h of presentation.

RESULTS

Patients with pneumonia had higher neutrophil percentages (66.5 ± 11.6 vs 55.2 ± 12.6%, p < 0.001), lower absolute lymphocyte count (1.5 ± 1.1 vs 1.9 ± 2.1 x109/L, p < 0.011) and absolute eosinophil count (0.2 ± 0.9 vs 0.7 ± 1.8 × 109/L, p = 0.002). Platelet counts (210 ± 56 vs 230 ± 61, p = 0.020) were slightly lower in the group with pneumonia. We did not demonstrate significant differences in the neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio in patients with or without pneumonia. Sixty-eight patients (12.3%) had peripheral eosinophilia. This was more common in migrant workers living in dormitories.

CONCLUSION

Neutrophilia and lymphopenia were found to be markers associated with severe COVID-19 illness. We did not find that combined haematological parameters: neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio and platelet-lymphocyte ratio, had any association with disease severity in our cohort of patients with mild-moderate disease. Migrant workers living in dormitories had eosinophilia which may reflect concurrent chronic parasitic infection.

Utility of conventional clinical risk scores in a low-risk COVID-19 cohort

BACKGROUND

Several specific risk scores for Coronavirus disease 2019 (COVID-19) involving clinical and biochemical parameters have been developed from higher-risk patients, in addition to validating well-established pneumonia risk scores. We compared multiple risk scores in predicting more severe disease in a cohort of young patients with few comorbid illnesses. Accurately predicting the progression of COVID-19 may guide triage and therapy.

METHODS

We retrospectively examined 554 hospitalised COVID-19 patients in Singapore. The CURB-65 score, Pneumonia Severity Index (PSI), ISARIC 4C prognostic score (4C), CHA2DS2-VASc score, COVID-GRAM Critical Illness risk score (COVID-GRAM), Veterans Health Administration COVID-19 index for COVID-19 Mortality (VACO), and the "rule-of-6" score were compared for three performance characteristics: the need for supplemental oxygen, intensive care admission and mechanical ventilation.

RESULTS

A majority of patients were young (≤ 40 years, n = 372, 67.1%). 57 (10.3%) developed pneumonia, with 16 (2.9% of study population) requiring supplemental oxygen. 19 patients (3.4%) required intensive care and 2 patients (0.5%) died. The clinical risk scores predicted patients who required supplemental oxygenation and intensive care well. Adding the presence of fever to the CHA2DS2-VASc score and 4C score improved the ability to predict patients who required supplemental oxygen (c-statistic 0.81, 95% CI 0.68-0.94; and 0.84, 95% CI 0.75-0.94 respectively).

CONCLUSION

Simple scores including well established pneumonia risk scores can help predict progression of COVID-19. Adding the presence of fever as a parameter to the CHA2DS2-VASc or the 4C score improved the performance of these scores in a young population with few comorbidities.

Gauging the impact of the COVID-19 pandemic on tuberculosis services: a global study

The effects of the coronavirus disease 2019 (COVID-19) pandemic on tuberculosis (TB) disease and TB services emerged in the beginning of 2020 [1, 2]. Epidemiological and clinical studies, including mortality rates of the first cohort of patients with COVID-19 and TB co-infection were described [3, 4]. Several reports from individual countries suggested that the COVID-19 pandemic significantly affected TB services [5–9], including validation by modelling studies [10]. The Global Tuberculosis Network (GTN) reported that the COVID-19 pandemic affected TB services in 33 TB centres from 16 countries in the first 4 months of 2020 [11]. An increased use of telehealth during the COVID-19 pandemic was observed in some TB centres [11]. The major limitations of that study were the short period of observation (January to April 2020 compared to the same period in 2019) and the limited number of variables analysed [11–14].

This global study of 43 TB centres from 19 countries demonstrates the impact of COVID-19 pandemic on TB services. Newly diagnosed TB disease, drug-resistant TB, TB deaths, outpatient clinic attendances and newly diagnosed TB infection were reduced.https://bit.ly/3sdHbfk

Elevated liver enzymes in hospitalized patients with COVID-19 in Singapore

Liver dysfunction in patients with COVID-19 (coronavirus disease 2019) has been described. However, it is not clear if the presence of abnormal liver function tests at presentation was related to underlying undiagnosed liver disease, or a result of the viral infection.We retrospectively examined the first 554 consecutive polymerase chain reaction positive SARS-CoV-2 patients admitted from February 2020 to April 2020 to our academic medical centre. We reviewed their clinical data, chest radiography and laboratory studies obtained within 24 hour of admission.Despite similar hemodynamic parameters, we found significant aspartate transaminase elevation (64 ± 141 vs 35 ± 23 U/L, P < .001) in those with pneumonia compared to those without. Elevated liver enzymes were seen in 102 patients (18.4%). They presented with higher temperatures (38.5 ± 0.9 vs 37.5 ± 0.8 degC, P = .011), higher total white cell counts (6.95 ± 2.29 vs 6.39 ± 2.19 x109/L, P = .021), serum ferritin (240 ± 274 vs 165 ± 198 ng/ml, P = .002) and lactate dehydrogenase (632 ± 912 vs 389 ± 107 U/L, P < .001). These patients were more likely to require intensive care (6.9% vs 2.7% P = .036) and mechanical ventilation (5.9% vs 2.2%, P = .046). Migrant workers from dormitories had a higher rate of baseline liver function test abnormalities (88/425 vs 14/129, P = .01), which were more likely to persist at the time of discharge.Despite relatively mild COVID-19 disease, there was a significant prevalence of liver dysfunction, particularly amongst migrant workers. Elevated liver enzymes were associated with more severe disease, despite similar haemodynamic characteristics. Future studies should explore whether pre-existing liver disease may predispose to more severe COVID-19 disease.

A blood RNA transcriptome signature for COVID-19

Background

COVID-19 is a respiratory viral infection with unique features including a more chronic course and systemic disease manifestations including multiple organ involvement; and there are differences in disease severity between ethnic groups. The immunological basis for disease has not been fully characterised. Analysis of whole-blood RNA expression may provide valuable information on disease pathogenesis.

Methods

We studied 45 patients with confirmed COVID-19 infection within 10 days from onset of illness and a control group of 19 asymptomatic healthy volunteers with no known exposure to COVID-19 in the previous 14 days. Relevant demographic and clinical information was collected and a blood sample was drawn from all participants for whole-blood RNA sequencing. We evaluated differentially-expressed genes in COVID-19 patients (log2 fold change ≥ 1 versus healthy controls; false-discovery rate < 0.05) and associated protein pathways and compared these to published whole-blood signatures for respiratory syncytial virus (RSV) and influenza. We developed a disease score reflecting the overall magnitude of expression of internally-validated genes and assessed the relationship between the disease score and clinical disease parameters.

Results

We found 135 differentially-expressed genes in the patients with COVID-19 (median age 35 years; 82% male; 36% Chinese, 53% South Asian ethnicity). Of the 117 induced genes, 14 were found in datasets from RSV and 40 from influenza; 95 genes were unique to COVID-19. Protein pathways were mostly generic responses to viral infections, including apoptosis by P53-associated pathway, but also included some unique pathways such as viral carcinogenesis. There were no major qualitative differences in pathways between ethnic groups. The composite gene-expression score was correlated with the time from onset of symptoms and nasal swab qPCR CT values (both p < 0.01) but was not related to participant age, gender, ethnicity or the presence or absence of chest X-ray abnormalities (all p > 0.05).

Conclusions

The whole-blood transcriptome of COVID-19 has overall similarity with other respiratory infections but there are some unique pathways that merit further exploration to determine clinical relevance. The approach to a disease score may be of value, but needs further validation in a population with a greater range of disease severity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-01006-w.

Deranged Coagulation Profile Secondary to Cefazolin Use: Case Report

Cefazolin is a widely used first-generation cephalosporin. While generally well tolerated, several case reports have described severe coagulopathy induced by intravenous (IV) cefazolin. This was seen particularly in patients with impaired renal function, where antibiotic choice is limited and may require specific dose adjustments. Altered renal handling of antibiotics and their metabolites may potentiate toxicity and side effects. We report a case of a 72-year-old Chinese man who had been treated for methicillin-sensitive staphylococcus aureus (MSSA, coagulase-positive) infective endocarditis with cefazolin and, consequently, developed significantly elevated international normalised ratio (INR) while on therapy. This resolved within 48 h after cessation of cefazolin and administration of oral vitamin K. Malnourished patients with pre-existing or acute kidney injury may be at an increased risk of cefazolin-related coagulopathy.

Range of Varicella Zoster Co-Infections with COVID-19, Singapore

There have been recent descriptions of the novel coronavirus disease 2019 (COVID-19) presenting as 'varicella-like exanthem'. We report three cases of patients with Varicella-Zoster Virus (VZV) and COVID-19 co-infections, presenting in three varied ways. These cases highlight the need for heightened alertness to how such co-infections can present, to pick up overlapping 'dual pathologies' during this current pandemic given that infection control measures including airborne precautions are crucial for both COVID-19 and VZV.

Demographic shift in COVID-19 patients in Singapore from an aged, at-risk population to young migrant workers with reduced risk of severe disease

Objectives

The vast majority of COVID-19 cases in Singapore have occurred amongst migrant workers. This paper examined trends in the hospitalised cases and tested the assumption that the low severity of disease was related to the relatively young affected population.

Methods

All patients with PCR-positive SARS-CoV-2 admitted from February to April 2020 were divided into: (i) imported cases, (ii) locally-transmitted cases outside migrant worker dormitories and (iii) migrant worker dormitory cases. They were examined for underlying comorbidities, clinical progress and outcomes.

Results

Imported cases (n = 29) peaked in mid-March 2020, followed by local cases (n = 100) in mid-April 2020; migrant worker cases (n = 425) continued to increase in late April 2020. Migrant worker cases were younger, had few medical comorbidities and less severe disease. As the migrant worker cases increased, the proportion of patients with pneumonia decreased, whilst patients presenting earlier in their illness and asymptomatic disease became more common.

Conclusion

Singapore experienced a substantial shift in the population at risk of severe COVID-19. Successful control in the community protected an aging population. Large migrant worker dormitory outbreaks occurred, but the disease incurred was less severe, resulting in Singapore having one of the lowest case fatality rates in the world.

Four Patients with COVID-19 and Tuberculosis, Singapore, April-May 2020

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.

Nurse-Led Vital Signs Monitoring Can Safely Identify Low-Risk Hematology-Oncology Patients For De-Escalation

PURPOSE

It is routine practice for patients to be on vital signs monitoring (VSM) once every 4 hours, which is laborious and disruptive. VSM de-escalation has been demonstrated to be safe in low-risk (LR) patients, but it has not been well studied in the hematology-oncology setting.

METHODS

A quality improvement project was conducted in 3 hematology-oncology inpatient wards within a comprehensive cancer center, from March 2017 to July 2017 (pilot phase) and from October 2017 to Sept 2018 (maintenance phase). Root causes for frequent VSM identified via problem analysis include (1) perception of VSM, (2) lack of concise clinical guidelines, and (3) lack of nurse empowerment. Consensus criteria to define suitable LR patients and a nurse-led VSM de-escalation protocol were formulated.

RESULTS

Of 1,065 patients who underwent nurse-led VSM de-escalation, there was a 50% reduction in the mean number of nurse encounters (NE) per month (P < .01), with total savings of 2,731.5 NE-minutes per month. VSM re-escalation was required by 10.1% of patients; all were deemed unpreventable with more frequent VSM and none resulted in severe adverse outcomes. With additional interventions such as spot audits and retraining, recruitment for de-escalation improved from 51.7% of LR admissions in the pilot phase to 93.8% in the maintenance phase (P < .01). The time saved was used to enhance other aspects of patient care, such as patient education. One hundred thirty-nine of 169 doctors and nurses surveyed after implementation (96.5%) supported continuing this protocol.

CONCLUSION

A well-defined protocol allows safe nurse-led de-escalation of VSM for LR patients without adverse outcomes and was shown to be sustainable in this cohort of hematology-oncology patients.

Responding to COVID-19: how an academic infectious diseases division mobilized in Singapore

BACKGROUND

On January 30, COVID-19 was declared a Public Health Emergency of International Concern-a week after Singapore's first imported case and 5 days before local transmission. The National University Hospital (NUH) is Singapore's third largest hospital with 1200 beds, heavy clinical workloads, and major roles in research and teaching.

MAIN BODY

With memories of SARS still vivid, there was an urgent requirement for the NUH Division of Infectious Diseases to adapt-undergoing major reorganization to face rapidly changing priorities while ensuring usual essential services and standards. Leveraging on individual strengths, our division mobilized to meet the demands of COVID-19 while engaging in high-level coordination, strategy, and advocacy. We present our experience of the 60 days since the nation's first case. During this time, our hospital has managed 3030 suspect cases, including 1300 inpatients, 37 confirmed cases, and overseen 4384 samples tested for COVID-19.

CONCLUSION

Complex hospital adaptations were supported by an unprecedented number of workflows and coordination channels essential to safe and effective operations. The actions we describe, aligned with international recommendations and emerging evidence-based best practices, may serve as a framework for other divisions and institutions facing the spread of COVID-19 globally.