Tan Tock Seng Hospital

Importance: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2019 and has spread globally with sustained human-to-human transmission outside China. Objective: To report the initial experience in Singapore with the epidemiologic investigation of this outbreak, clinical features, and management. Design, Setting, and Participants: Descriptive case series of the first 18 patients diagnosed with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection at 4 hospitals in Singapore from January 23 to February 3, 2020; final follow-up date was February 25, 2020. Exposures: Confirmed SARS-CoV-2 infection. Main Outcomes and Measures: Clinical, laboratory, and radiologic data were collected, including PCR cycle threshold values from nasopharyngeal swabs and viral shedding in blood, urine, and stool. Clinical course was summarized, including requirement for supplemental oxygen and intensive care and use of empirical treatment with lopinavir-ritonavir. Results: Among the 18 hospitalized patients with PCR-confirmed SARS-CoV-2 infection (median age, 47 years; 9 [50%] women), clinical presentation was an upper respiratory tract infection in 12 (67%), and viral shedding from the nasopharynx was prolonged for 7 days or longer among 15 (83%). Six individuals (33%) required supplemental oxygen; of these, 2 required intensive care. There were no deaths. Virus was detectable in the stool (4/8 [50%]) and blood (1/12 [8%]) by PCR but not in urine. Five individuals requiring supplemental oxygen were treated with lopinavir-ritonavir. For 3 of the 5 patients, fever resolved and supplemental oxygen requirement was reduced within 3 days, whereas 2 deteriorated with progressive respiratory failure. Four of the 5 patients treated with lopinavir-ritonavir developed nausea, vomiting, and/or diarrhea, and 3 developed abnormal liver function test results. Conclusions and Relevance: Among the first 18 patients diagnosed with SARS-CoV-2 infection in Singapore, clinical presentation was frequently a mild respiratory tract infection. Some patients required supplemental oxygen and had variable clinical outcomes following treatment with an antiretroviral agent.

Neutralizing antibodies have become an important tool in treating infectious diseases. Recently, two separate approaches yielded successful antibody treatments for Ebola-one from genetically humanized mice and the other from a human survivor. Here, we describe parallel efforts using both humanized mice and convalescent patients to generate antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, which yielded a large collection of fully human antibodies that were characterized for binding, neutralization, and three-dimensional structure. On the basis of these criteria, we selected pairs of highly potent individual antibodies that simultaneously bind the receptor binding domain of the spike protein, thereby providing ideal partners for a therapeutic antibody cocktail that aims to decrease the potential for virus escape mutants that might arise in response to selective pressure from a single-antibody treatment.

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions. The occurrence of anaphylaxis has increased in recent years, and subsequently, there is a need to continue disseminating knowledge on the diagnosis and management, so every healthcare professional is prepared to deal with such emergencies. The rationale of this updated position document is the need to keep guidance aligned with the current state of the art of knowledge in anaphylaxis management. The World Allergy Organization (WAO) anaphylaxis guidelines were published in 2011, and the current guidance adopts their major indications, incorporating some novel changes. Intramuscular epinephrine (adrenaline) continues to be the first-line treatment for anaphylaxis. Nevertheless, its use remains suboptimal. After an anaphylaxis occurrence, patients should be referred to a specialist to assess the potential cause and to be educated on prevention of recurrences and self-management. The limited availability of epinephrine auto-injectors remains a major problem in many countries, as well as their affordability for some patients.

The illustrated World Allergy Organization (WAO) Anaphylaxis Guidelines were created in response to absence of global guidelines for anaphylaxis. Uniquely, before they were developed, lack of worldwide availability of essentials for the diagnosis and treatment of anaphylaxis was documented. They incorporate contributions from more than 100 allergy/immunology specialists on 6 continents. Recommendations are based on the best evidence available, supported by references published to the end of December 2010. The Guidelines review patient risk factors for severe or fatal anaphylaxis, co-factors that amplify anaphylaxis, and anaphylaxis in vulnerable patients, including pregnant women, infants, the elderly, and those with cardiovascular disease. They focus on the supreme importance of making a prompt clinical diagnosis and on the basic initial treatment that is urgently needed and should be possible even in a low resource environment. This involves having a written emergency protocol and rehearsing it regularly; then, as soon as anaphylaxis is diagnosed, promptly and simultaneously calling for help, injecting epinephrine (adrenaline) intramuscularly, and placing the patient on the back or in a position of comfort with the lower extremities elevated. When indicated, additional critically important steps include administering supplemental oxygen and maintaining the airway, establishing intravenous access and giving fluid resuscitation, and initiating cardiopulmonary resuscitation with continuous chest compressions. Vital signs and cardiorespiratory status should be monitored frequently and regularly (preferably, continuously). The Guidelines briefly review management of anaphylaxis refractory to basic initial treatment. They also emphasize preparation of the patient for self-treatment of anaphylaxis recurrences in the community, confirmation of anaphylaxis triggers, and prevention of recurrences through trigger avoidance and immunomodulation. Novel strategies for dissemination and implementation are summarized. A global agenda for anaphylaxis research is proposed.

Primary aldosteronism (PA) is a common form of endocrine hypertension previously believed to account for less than 1% of hypertensive patients. Hypokalemia was considered a prerequisite for pursuing diagnostic tests for PA. Recent studies applying the plasma aldosterone/plasma renin activity ratio (ARR) as a screening test have reported a higher prevalence. This study is a retrospective evaluation of the diagnosis of PA from clinical centers in five continents before and after the widespread use of the ARR as a screening test. The application of this strategy to a greater number of hypertensives led to a 5- to 15-fold increase in the identification of patients affected by PA. Only a small proportion of patients (between 9 and 37%) were hypokalemic. The annual detection rate of aldosterone-producing adenoma (APA) increased in all centers (by 1.3-6.3 times) after the wide application of ARR. Aldosterone-producing adenomas constituted a much higher proportion of patients with PA in the four centers that employed adrenal venous sampling (28-50%) than in the center that did not (9%). In conclusion, the wide use of the ARR as a screening test in hypertensive patients led to a marked increase in the detection rate of PA.

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 samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface samples 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 sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 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.

When drug reactions resembling allergy occur, they are called drug hypersensitivity reactions (DHRs) before showing the evidence of either drug-specific antibodies or T cells. DHRs may be allergic or nonallergic in nature, with drug allergies being immunologically mediated DHRs. These reactions are typically unpredictable. They can be life-threatening, may require or prolong hospitalization, and may necessitate changes in subsequent therapy. Both underdiagnosis (due to under-reporting) and overdiagnosis (due to an overuse of the term ‘allergy’) are common. A definitive diagnosis of such reactions is required in order to institute adequate treatment options and proper preventive measures. Misclassification based solely on the DHR history without further testing may affect treatment options, result in adverse consequences, and lead to the use of more-expensive or less-effective drugs, in contrast to patients who had undergone a complete drug allergy workup. Several guidelines and/or consensus documents on general or specific drug class-induced DHRs are available to support the medical decision process. The use of standardized systematic approaches for the diagnosis and management of DHRs carries the potential to improve outcomes and should thus be disseminated and implemented. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), formed by the European Academy of Allergy and Clinical Immunology (EAACI), the American Academy of Allergy, Asthma and Immunology (AAAAI), the American College of Allergy, Asthma and Immunology (ACAAI), and the World Allergy Organization (WAO), has decided to issue an International CONsensus (ICON) on drug allergy. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences and deficiencies of evidence, thus providing a comprehensive reference document for the diagnosis and management of DHRs.

This collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it predispose to more aggressive biological behaviour in patients with advanced colorectal cancer.

Virus-specific humoral and cellular immunity act synergistically to protect the host from viral infection. We interrogate the dynamic changes of virological and immunological parameters in 12 patients with symptomatic acute SARS-CoV-2 infection from disease onset to convalescence or death. We quantify SARS-CoV-2 viral RNA in the respiratory tract in parallel with antibodies and circulating T cells specific for various structural (nucleoprotein [NP], membrane [M], ORF3a, and spike) and non-structural (ORF7/8, NSP7, and NSP13) proteins. Although rapid induction and quantity of humoral responses associate with an increase in disease severity, early induction of interferon (IFN)-γ-secreting SARS-CoV-2-specific T cells is present in patients with mild disease and accelerated viral clearance. These findings provide support for the prognostic value of early functional SARS-CoV-2-specific T cells with important implications in vaccine design and immune monitoring.

To the Editor: A cluster of unexplained pneumonia cases was reported by the Peopleʼs Republic of China to the World Health Organization (WHO) on 31 December, 2019. The etiology for this outbreak was a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was responsible for the Corona Virus Disease 2019 (COVID-19).1 Singapore confirmed its first imported case on 23 January 2020 and local transmission was detected on 4 February, 2020. As of 28 February, 2020, Singapore had 96 confirmed cases of COVID-19 infection. SARS-CoV-2 was confirmed by real time reverse transcriptase-polymerase chain reaction (RT-PCR), performed on respiratory samples of these patients. A majority of 69 out of these 96 patients were treated at the National Centre for Infectious Diseases (NCID). We herein present a detailed analysis of the hematological parameters of the COVID-19 patients at the NCID (see Table 1). Of the 69 patients that had been admitted to the NCID, 26 patients were still hospitalized, and 43 patients had been discharged as of 28 February 2020. Also, 67 patients had at least one complete blood count (CBC) performed during inpatient stay; 65 patients had CBC performed on day of admission. We analyzed the hematological indices of all COVID-19 infected patients from day 1 of admission until 28 February 2020. We obtained data from the Laboratory Information System (LIS) exclusively which provided information on the age, gender, ethnicity and location of each patient. We divided the patients into two groups; ICU and non-ICU patients. Additionally, flow cytometry on lymphocyte subsets was performed from 24 to 28 February 2020, on a subgroup of nine COVID-19 patients; five ICU patients and four non-ICU patients (with six normal individual blood samples as controls). Immunophenotyping was performed using a Becton Dickinson FACSCanto II Flow analyzer. Most patients were of Chinese ethnicity (89.5%), while the minority were of Malay (4.5%), Indian (1.5%) and other ethnicities (4.5%). Just 9 out of the 67 (13.4%) patients required ICU care. Notably, ICU patients were about a decade older than the non-ICU patients; the median age of ICU patients was 54 years old while the median age of non-ICU patients was 42 years old (P = .02). On admission, leukopenia was observed in 19 patients (29.2%) with only one patient presenting with severe leukopenia (WBC < 2 × 109/L). Lymphopenia featured in 24 patients (36.9%) with 19 having moderate lymphopenia (absolute lymphocyte count [ALC] 0.5-1 × 109/L), and five with severe lymphopenia (ALC < 0.5 × 109/L). Most patients had normal platelet counts, with 13 patients (20.0%) having mild thrombocytopenia (platelet count 100-150 × 109/L). Peripheral blood film review showed that a higher number of patients (69%) who were lymphopenic had the presence of a few reactive lymphocytes, of which a subset appeared lymphoplasmacytoid. This contrasts with the severe acute respiratory syndrome (SARS) outbreak in 2003 where reactive lymphocytes were not observed in a study on Haematologic parameters in SARS in Singapore2 and only in 15.2% of cases in a similar Hong Kong study.3 Our analysis revealed that on admission, most patients had a normal CBC (normal Hb, WBC and platelet count) and lactate dehydrogenase (LDH). And, no patient presented with moderate or severe thrombocytopenia that is frequently observed in other viral illnesses such as dengue fever which is endemic in our region. However, 28% of all patients presented with lymphopenia (ALC < 1 × 109/L). This number is significantly smaller compared to 63% of patients in Wuhan, China, and 42% of patients outside of Wuhan who presented with lymphopenia.4, 5 This disparity in numbers may in part be reflective of the extent of epidemiological data available within the surveillance pyramid in those regions. Those requiring ICU care had a lower ALC and higher LDH. These were findings also reported by Huang et al on the characteristics of COVID-19 patients in Wuhan, China.4 Lymphopenia has been well described in retrospective analysis of patients in Hong Kong and Singapore afflicted with SARS-CoV in 2003, and was associated with adverse outcomes and ICU stay.2, 3, 6 Lymphopenia featured prominently in our COVID-19 ICU group with a median nadir ALC of 0.4 × 109/L, compared to 1.2 × 109/L in the non-ICU group. Monitoring of such hematologic parameters may help to identify patients who may need ICU care. An ALC approaching severe lymphopenia of <0.6 × 109/L may possibly be considered as one of the indicators for early admission for supportive care in the ICU. Between the ICU (n = 9) and non-ICU (n = 58) patients, using Fisherʼs exact tests, we found that admission ALC and LDH stood out as discriminating laboratory indices with a P value of <.001 and .005 respectively. The ICU patients in general presented with more profound lymphopenia with seven out of nine being lymphopenic; four of whom had severe lymphopenia. Note, LDH was performed for 4 out of the 9 ICU patients on admission, and all four cases had a raised LDH with a median value of 1684 U/L (reference range 270-550 U/L). Comparatively non-ICU patients tend to present with a normal LDH, median value 401 U/L; with only five out of 26 non-ICU patients presenting with a raised LDH above 550 U/L. During their stay in ICU, those patients developed more profound, statistically significant decrements in their hemoglobin levels, with ALC and absolute monocyte count (AMC) levels compared to the non-ICU group. The median nadir ALC was 0.4 × 109/L in the ICU group compared to 1.2 × 109/L in the non-ICU group (P value <.001), while the median nadir AMC was 0.2 × 109/L in the ICU group, compared to 0.4 × 109/L in the non-ICU group (P value <.001). Notably, ICU patients tend to develop neutrophilia during the hospitalization with a median peak Absolute Neutrophil Count (ANC) of 11.6 × 109/L, compared to 3.5 × 109/L in the non-ICU group (P value < .001). The ICU group also had a peak LDH which was significantly higher than the non-ICU group. The median nadir platelet count remained in the normal range (above 150 × 109/L) for both groups and was not a discriminating test on admission or during the hospitalization. To date, three out of the nine ICU patients have been discharged from ICU care. We noted increasing values in their WBC, ALC, AMC, and down trending LDH as their clinical condition improved. Flow cytometry performed on peripheral blood lymphocytes demonstrate prominent lymphopenia in the ICU patients as compared to the non-ICU patients and normal controls. The ICU patients have significantly lower CD45+, CD3+, CD4+, CD8+, CD19+ and CD16/56+ counts. The CD4/CD8 ratio was not inverted in all groups of patients, unlike other viral infections such as human immunodeficiency virus (HIV) and cytomegalovirus (CMV) infections where the CD4/8 ratio is usually inverted. The limitation of our study is missing data as laboratory investigations were not performed daily on all patients especially those who were minimally symptomatic in the general isolation ward. We also recognize that correlating onset of symptoms (days of illness) with hematological parameters is important and would require a case note review which was not done in this study. However, this review is a reflection of real-life clinical setting wherein a proportion of asymptomatic patients (admitted from positive RT-PCR results during contact tracing) may not have significant anomalies on their CBC at presentation. Lastly, admission laboratory results for ICU patients transferred from other institutions were not reflected in our data set. This may result in lower hematological indices on admission as those patients were already in critical condition. Further studies should be conducted comparing patientsʼ onset of symptoms and correlating their clinical condition to laboratory findings. In conclusion, our study showed that on admission, older age, lymphopenia and raised LDH were associated with ICU admissions. Patients who were transferred to the ICU had a deeper nadir ALC, nadir AMC and nadir hemoglobin, and higher peak ANC and peak LDH levels as compared to patients who did not require ICU stay. We thank the Department of Haematology and the Department of Laboratory Medicine, Tan Tock Seng Hospital for the full support in the laboratory investigations. We also greatly appreciate the efforts of healthcare workers and the support of their families during this outbreak. Special thanks to Lim Shu Ping and Wong Lai Har for their assistance with specimen collection and processing; and Lin Yihao Clement for his assistance with the DSRB application. All authors declare no competing interests. This study was approved by the National Healthcare Group Domain Specific Review Board (DSRB). No patient identifiers were collected and approval of exemption for informed consent was obtained.

PURPOSE: To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the intervisit reproducibility of diurnal patterns. METHODS: A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on two separate days at five fixed, 2-hour time intervals. Spectral domain optical coherence tomography (OCT) with enhanced depth imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by two masked graders. CT diurnal variation was assessed using repeated-measures ANOVA. RESULTS: A significant diurnal variation in CT was observed, with mean maximum CT of 372.2 μm, minimum of 340.6 μm (P < 0.001), and mean diurnal amplitude of 33.7 μm. Retinal thickness (mean, 235.0 μm) did not exhibit significant diurnal variation (P = 0.621). The amplitude of CT variation was significantly greater for subjects with thicker morning baseline CT compared with those with thin choroids (43.1 vs. 10.5 μm, P < 0.001). There were significant correlations between amplitude of CT and age (P = 0.032), axial length (P < 0.001), and spherical equivalent (P < 0.001). The change in CT also correlated with change in systolic blood pressure (P = 0.031). Comparing CT on two different days, a similar diurnal pattern was observed, with no significant difference between corresponding measurements at the same time points (P = 0.180). CONCLUSIONS: There is significant diurnal variation of CT, with good intervisit reproducibility of diurnal patterns on two different days. The amplitude of variation varies with morning baseline CT, and is correlated with age, axial length, refractive error, and change in systolic blood pressure.

Importance: Extended-spectrum β-lactamases mediate resistance to third-generation cephalosporins (eg, ceftriaxone) in Escherichia coli and Klebsiella pneumoniae. Significant infections caused by these strains are usually treated with carbapenems, potentially selecting for carbapenem resistance. Piperacillin-tazobactam may be an effective "carbapenem-sparing" option to treat extended-spectrum β-lactamase producers. Objectives: To determine whether definitive therapy with piperacillin-tazobactam is noninferior to meropenem (a carbapenem) in patients with bloodstream infection caused by ceftriaxone-nonsusceptible E coli or K pneumoniae. Design, Setting, and Participants: Noninferiority, parallel group, randomized clinical trial included hospitalized patients enrolled from 26 sites in 9 countries from February 2014 to July 2017. Adult patients were eligible if they had at least 1 positive blood culture with E coli or Klebsiella spp testing nonsusceptible to ceftriaxone but susceptible to piperacillin-tazobactam. Of 1646 patients screened, 391 were included in the study. Interventions: Patients were randomly assigned 1:1 to intravenous piperacillin-tazobactam, 4.5 g, every 6 hours (n = 188 participants) or meropenem, 1 g, every 8 hours (n = 191 participants) for a minimum of 4 days, up to a maximum of 14 days, with the total duration determined by the treating clinician. Main Outcomes and Measures: The primary outcome was all-cause mortality at 30 days after randomization. A noninferiority margin of 5% was used. Results: Among 379 patients (mean age, 66.5 years; 47.8% women) who were randomized appropriately, received at least 1 dose of study drug, and were included in the primary analysis population, 378 (99.7%) completed the trial and were assessed for the primary outcome. A total of 23 of 187 patients (12.3%) randomized to piperacillin-tazobactam met the primary outcome of mortality at 30 days compared with 7 of 191 (3.7%) randomized to meropenem (risk difference, 8.6% [1-sided 97.5% CI, -∞ to 14.5%]; P = .90 for noninferiority). Effects were consistent in an analysis of the per-protocol population. Nonfatal serious adverse events occurred in 5 of 188 patients (2.7%) in the piperacillin-tazobactam group and 3 of 191 (1.6%) in the meropenem group. Conclusions and relevance: Among patients with E coli or K pneumoniae bloodstream infection and ceftriaxone resistance, definitive treatment with piperacillin-tazobactam compared with meropenem did not result in a noninferior 30-day mortality. These findings do not support use of piperacillin-tazobactam in this setting. Trial Registration: anzctr.org.au Identifiers: ACTRN12613000532707 and ACTRN12615000403538 and ClinicalTrials.gov Identifier: NCT02176122.

BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI), the use of percutaneous coronary intervention (PCI) to restore blood flow in an infarct-related coronary artery improves outcomes. The use of PCI in non-infarct-related coronary arteries remains controversial. METHODS: We randomly assigned 885 patients with STEMI and multivessel disease who had undergone primary PCI of an infarct-related coronary artery in a 1:2 ratio to undergo complete revascularization of non-infarct-related coronary arteries guided by fractional flow reserve (FFR) (295 patients) or to undergo no revascularization of non-infarct-related coronary arteries (590 patients). The FFR procedure was performed in both groups, but in the latter group, both the patients and their cardiologist were unaware of the findings on FFR. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, revascularization, and cerebrovascular events at 12 months. Clinically indicated elective revascularizations performed within 45 days after primary PCI were not counted as events in the group receiving PCI for an infarct-related coronary artery only. RESULTS: The primary outcome occurred in 23 patients in the complete-revascularization group and in 121 patients in the infarct-artery-only group that did not receive complete revascularization, a finding that translates to 8 and 21 events per 100 patients, respectively (hazard ratio, 0.35; 95% confidence interval [CI], 0.22 to 0.55; P<0.001). Death occurred in 4 patients in the complete-revascularization group and in 10 patients in the infarct-artery-only group (1.4% vs. 1.7%) (hazard ratio, 0.80; 95% CI, 0.25 to 2.56), myocardial infarction in 7 and 28 patients, respectively (2.4% vs. 4.7%) (hazard ratio, 0.50; 95% CI, 0.22 to 1.13), revascularization in 18 and 103 patients (6.1% vs. 17.5%) (hazard ratio, 0.32; 95% CI, 0.20 to 0.54), and cerebrovascular events in 0 and 4 patients (0 vs. 0.7%). An FFR-related serious adverse event occurred in 2 patients (both in the group receiving infarct-related treatment only). CONCLUSIONS: In patients with STEMI and multivessel disease who underwent primary PCI of an infarct-related artery, the addition of FFR-guided complete revascularization of non-infarct-related arteries in the acute setting resulted in a risk of a composite cardiovascular outcome that was lower than the risk among those who were treated for the infarct-related artery only. This finding was mainly supported by a reduction in subsequent revascularizations. (Funded by Maasstad Cardiovascular Research and others; Compare-Acute ClinicalTrials.gov number, NCT01399736 .).

The vascularity of the choroid has been implicated in the pathogenesis of various eye diseases. To date, no established quantifiable parameters to estimate vascular status of the choroid exists. Choroidal vascularity index (CVI) may potentially be used to assess vascular status of the choroid. We aimed to establish normative database for CVI and identify factors associated with CVI in healthy eyes. In this population-based study on 345 healthy eyes, choroidal enhanced depth imaging optical coherence tomography scans were segmented by modified image binarization technique. Total subfoveal choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area. CVI was calculated as the proportion of LA to TCA. Linear regression was used to identify ocular and systemic factors associated with CVI and subfoveal choroidal thickness (SFCT). Subfoveal CVI ranged from 60.07 to 71.27% with a mean value of 65.61 ± 2.33%. CVI was less variable than SFCT (coefficient of variation for CVI was 3.55 vs 40.30 for SFCT). Higher CVI was associated with thicker SFCT, but not associated with most physiological variables. CVI was elucidated as a significant determinant of SFCT. While SFCT was affected by many factors, CVI remained unaffected suggesting CVI to be a more robust marker of choroidal diseases.

In December 2019, a novel coronavirus (CoV) epidemic, caused by the severe acute respiratory syndrome coronavirus – 2 (SARS-CoV-2) emerged from China. This virus causes the coronavirus disease 2019 (COVID-19). Since then, there have been anecdotal reports of ocular infection. The ocular implications of human CoV infections have not been widely studied. However, CoVs have been known to cause various ocular infections in animals. Clinical entities such as conjunctivitis, anterior uveitis, retinitis, and optic neuritis have been documented in feline and murine models. In this article, the current evidence suggesting possible human CoV infection of ocular tissue is reviewed. The review article will also highlight animal CoVs and their associated ocular infections. We hope that this article will serve as a start for further research into the ocular implications of human CoV infections.

COVID-19 ARDS is a predictable serious complication of COVID-19 that requires early recognition and comprehensive management “This disease is still too strange to us, and there are too many doubts”, says Dr Ling Qin (LQ), after reviewing more than 400 patients with coronavirus disease 2019 (COVID-19) pneumonia in Wuhan Union Hospital, China. COVID-19 is a novel disease. We are familiar with acute respiratory distress syndrome (ARDS); however, when it occurs as part of COVID-19, it has different features and there remain unanswered questions. So if someone has COVID-19 ARDS, how does it compare and contrast with ARDS from other causes? To answer this question we provide a summary of the published literature (based on a PubMed search using the terms “COVID-19” and “ARDS”, 17 April 2020) and current clinical experience from managing patients with COVID-19 ARDS in Singapore (SHP) and Wuhan (LQ). Severe COVID-19 represents viral pneumonia from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to ARDS. Its manifestations can be viewed as a combination of the two processes, namely viral pneumonia and ARDS. COVID-19 is a novel disease recognised initially in Wuhan, China, in December 2019, and is now pandemic. It is likely caused by zoonotic spillover of a β-coronavirus type 2b that is now transmitted between humans. Along with the other serious coronavirus infections of severe acute respiratory syndrome and Middle East respiratory syndrome, which also cause ARDS, COVID-19 represents an ongoing global threat as this virus family has the potential to mutate and infect non-immune populations. Australia's living guidelines provide the latest recommendations and evidence.1 SARS-CoV-2 infection can be confirmed by positive detection of viral RNA in nasopharyngeal secretions using a specific PCR test. COVID-19 illness can be confirmed by a consistent clinical history, epidemiological contact, and a positive SARS-CoV-2 test. COVID-19 ARDS is diagnosed when someone with confirmed COVID-19 infection meets the Berlin 2012 ARDS diagnostic criteria2 of (i) acute hypoxaemic respiratory failure; (ii) presentation within 1 week of worsening respiratory symptoms; (iii) bilateral airspace disease on chest x-ray, computed tomography (CT) or ultrasound that is not fully explained by effusions, lobar or lung collapse, or nodules; and (iv) cardiac failure is not the primary cause of acute hypoxaemic respiratory failure. ARDS is underdiagnosed in intensive care settings.3 ARDS develops in 42% of patients presenting with COVID-19 pneumonia, and 61–81% of those requiring intensive care.4 COVID-19 ARDS follows a predictable time course over days, with median time to intubation of 8.5 days after symptom onset in Singaporean patients.5 This is similar to previous reports where ARDS developed at day 8 or 9 after symptom onset. It is therefore important to monitor patients for the development of ARDS as their COVID-19 infection progresses. Respiratory rate and SpO2 are two important parameters for judging patients’ clinical condition and allowing early recognition of ARDS. A patient who fits any one of the following conditions may have severe disease and require further evaluation: respiratory rate ≥ 30 breaths/min; SpO2 ≤ 92%; and PaO2/FiO2 ≤ 300 mmHg. Blood tests can also be helpful. In Singapore, it was noted that raised C-reactive protein levels and blood neutrophil counts along with lymphopenia were more common in patients requiring invasive mechanical ventilation for COVID-19 ARDS.5 ARDS causes diffuse alveolar damage in the lung. There is hyaline membrane formation in the alveoli in the acute stage, and this is followed by interstitial widening and by oedema and then fibroblast proliferation in the organising stage. COVID-19 ARDS causes the typical ARDS pathological changes of diffuse alveolar damage in the lung.6, 7 As patients move through the course of their illness, the longer term outcomes of ARDS are being reported, with lung fibrosis appearing as part of COVID-19 ARDS.8, 9 A study reported that 17% of patients had fibrous stripes in chest CT scans,9 and considered that the fibrous lesions may form during the healing of pulmonary chronic inflammation or proliferative diseases, with gradual replacement of cellular components by scar tissues. Pulmonary thrombosis is common in sepsis-induced ARDS. Coagulation dysfunction appears to be common in COVID-19, and is detected by elevated D-dimer levels. In fatal cases there is diffuse microvascular thrombosis, suggesting a thrombotic microangiopathy, and most deaths from COVID-19 ARDS have evidence of thrombotic disseminated intravascular coagulation.10 This may explain some of the atypical or unexpected manifestations seen in the lung, such as dilated pulmonary vessels on chest CT, and episodes of pleuritic pain. Vascular enlargement is rarely reported in typical ARDS, yet was seen in most cases of COVID-19 ARDS.9 COVID-19 ARDS appears to have worse outcomes than ARDS from other causes. The intensive care unit and hospital mortality from typical ARDS are 35.3% (95% CI, 33.3–37.2%) and 40.0% (95% CI, 38.1–42.1%), respectively.3 For COVID-19 ARDS, mortality ranged between 26% and 61.5% if ever admitted into a critical care setting, and in patients who received mechanical ventilation, the mortality can range between 65.7% to 94%.4 Risk factors for poor outcomes include older age; presence of comorbidities such as hypertension, cardiovascular disease and diabetes mellitus; lower lymphocyte counts; kidney injury; and raised D-dimer levels. Death from COVID-19 ARDS is due to respiratory failure (53%), respiratory failure combined with cardiac failure (33%), myocardial damage and circulatory failure (7%), or death from an unknown cause.4 The radiology of ARDS is distinctive, yet COVID-19 pneumonia appears to have unique features. This likely results from the co-occurrence of viral pneumonia and ARDS, and allows radiologists to be fairly specific in diagnosing COVID-19 pneumonia. The most discriminating features for COVID-19 pneumonia in China compared with viral pneumonia in the United States included a peripheral distribution of opacification (80% v 57%; P < 0.001), frosted glass opacities (91% v 68%; P < 0.001), and vascular thickening or enlargement (58% v 22%; P < 0.001).11 These imaging features appear to be typical for COVID-19 pneumonia and can be helpful in early screening of highly suspected cases and in evaluation of the severity and extent of disease. As COVID-19 lung disease progresses, the lesions are more likely to be bilateral, lower lung predominant and multifocal. They often have the appearance of rounded opacities, termed “COVID balls”. With the development of ARDS, the extent of lung involvement increases, and there is a consolidative component.12 The opacities resolve with recovery from COVID-19;13 however, with ARDS, the lesions increase in their extent and density, and evolve to fibrotic bands. The strategy of breathing support is very important in treating COVID-19 ARDS, as is the case with typical ARDS caused by other pathogens.14 The key elements are: Because of concerns about viral transmission to other patients and health care workers,15 the use of high flow nasal oxygen and non-invasive ventilation (such as bi-level positive pressure ventilation) for COVID-19 ARDS is highly dependent on the health care setting. Australian COVID-19 guidelines1 strongly recommend against the use of high flow nasal oxygen in emergency departments, but provide a strong recommendation for its use in negative pressure single rooms. Non-invasive ventilation may be used in negative pressure rooms with appropriate viral transmission precautions.1 Clinical experience has found inconsistent benefit from non-invasive ventilation and there is concern about aerosol generation and increased risk of viral transmission. Prone ventilation appears to be beneficial for COVID-19 ARDS.1 Placing a person in prone position promotes more homogenous aeration of the lung in ARDS and can improve oxygenation. While prone ventilation is used in only about 16% of patients with typical ARDS,3, 16 in COVID-19 it is being used successfully earlier in the course of ARDS, and suggested use is for > 12 hours per day.16 Venovenous extracorporeal membrane oxygenation can be used as rescue for mechanically ventilated adults with COVID-19 and hypoxaemia that persists despite optimised ventilation, use of rescue therapies and prone ventilation. Among critically ill patients treated in Wuhan, prone ventilation and extracorporeal membrane oxygenation treatment were not found to be as effective as for ARDS caused by other pathogens. Possible reasons include: Anecdotal observations in Singapore (SHP) and investigations in the Netherlands17 suggested that patients ventilated for COVID-19 ARDS tended to have plateau pressures < 30 cmH20 and driving pressures < 15 cmH20 despite high oxygen requirements. The lung protective ventilation strategy used in typical ARDS involves a low tidal volume (6 mL/kg) and higher positive end expiratory pressure targets. For COVID-19 ARDS, a change to more generous tidal volume targets allowing up to 8 mL/kg and lower positive end expiratory pressure levels is suggested to prevent patient self-inflicted lung injury. In typical ARDS, continuous neuromuscular blocking agents, high dose corticosteroids and recruitment manoeuvers were the most frequently used adjunctive therapies. In COVID-19 ARDS, the evidence for systemic steroids is still scarce and they are only recommended in patients with concomitant shock which has been unresponsive to vasopressors. There are concerns that steroids may increase viral shedding and possibly lead to a higher mortality rate. Many patients with COVID-19 receive antiviral or immunosuppressive therapy. In Australia, the National COVID-19 Clinical Evidence Taskforce1 recommends administering antiviral medications or other disease-modifying treatments in the context of clinical trials. Singapore was using empiric lopinavir–ritonavir plus subcutaneous interferon-β 1b initially, but is now randomising patients to receive remdesivir. In Wuhan, a broad range of antiviral and immune therapies are being used. All patients also received treatment with Chinese medicine. COVID-19 ARDS is a predictable serious complication of COVID-19 that requires early recognition and comprehensive management. Research programs such as the Medical Research Future Fund 2020 Respiratory Medicine Clinical Trials Research on COVID-19 grant opportunity are required to answer the important questions that remain about therapies for COVID-19 ARDS. No relevant disclosures. Commissioned; externally peer reviewed.

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis provide a unique global perspective on this increasingly common, potentially life-threatening disease. Recommendations made in the original WAO Anaphylaxis Guidelines remain clinically valid and relevant, and are a widely accessed and frequently cited resource. In this 2015 update of the evidence supporting recommendations in the Guidelines, new information based on anaphylaxis publications from January 2014 through mid- 2015 is summarized. Advances in epidemiology, diagnosis, and management in healthcare and community settings are highlighted. Additionally, new information about patient factors that increase the risk of severe and/or fatal anaphylaxis and patient co-factors that amplify anaphylactic episodes is presented and new information about anaphylaxis triggers and confirmation of triggers to facilitate specific trigger avoidance and immunomodulation is reviewed. The update includes tables summarizing important advances in anaphylaxis research.

Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone.

Relapse to anti-HER2 monoclonal antibody (mAb) therapies, such as trastuzumab in HER2 + breast cancer (BC), is associated with residual disease progression due to resistance to therapy. Here, we identify interferon-γ inducible protein 16 (IFI16)-dependent STING signaling as a significant determinant of trastuzumab responses in HER2 + BC. We show that down-regulation of immune-regulated genes (IRG) is specifically associated with poor survival of HER2 + , but not other BC subtypes. Among IRG, IFI16 is identified as a direct target of EZH2, the underexpression of which leads to deficient STING activation and downstream CXCL10/11 expression in response to trastuzumab treatment. Dual inhibition of EZH2 and histone deacetylase (HDAC) significantly activates IFI16-dependent immune responses to trastuzumab. Notably, a combination of a novel histone methylation inhibitor with an HDAC inhibitor induces complete tumor eradication and long-term T cell memory in a HER2 + BC mouse model. Our findings demonstrate an epigenetic regulatory mechanism suppressing the expression of the IFI16-CXCL10/11 signaling pathway that provides a survival advantage to HER2 + BC to confer resistance to trastuzumab treatment.

BACKGROUND: The value of rapid, panel-based molecular diagnostics for positive blood culture bottles (BCBs) has not been rigorously assessed. We performed a prospective randomized controlled trial evaluating outcomes associated with rapid multiplex PCR (rmPCR) detection of bacteria, fungi, and resistance genes directly from positive BCBs. METHODS: A total of 617 patients with positive BCBs underwent stratified randomization into 3 arms: standard BCB processing (control, n = 207), rmPCR reported with templated comments (rmPCR, n = 198), or rmPCR reported with templated comments and real-time audit and feedback of antimicrobial orders by an antimicrobial stewardship team (rmPCR/AS, n = 212). The primary outcome was antimicrobial therapy duration. Secondary outcomes were time to antimicrobial de-escalation or escalation, length of stay (LOS), mortality, and cost. RESULTS: Time from BCB Gram stain to microorganism identification was shorter in the intervention group (1.3 hours) vs control (22.3 hours) (P < .001). Compared to the control group, both intervention groups had decreased broad-spectrum piperacillin-tazobactam (control 56 hours, rmPCR 44 hours, rmPCR/AS 45 hours; P = .01) and increased narrow-spectrum β-lactam (control 42 hours, rmPCR 71 hours, rmPCR/AS 85 hours; P = .04) use, and less treatment of contaminants (control 25%, rmPCR 11%, rmPCR/AS 8%; P = .015). Time from Gram stain to appropriate antimicrobial de-escalation or escalation was shortest in the rmPCR/AS group (de-escalation: rmPCR/AS 21 hours, control 34 hours, rmPCR 38 hours, P < .001; escalation: rmPCR/AS 5 hours, control 24 hours, rmPCR 6 hours, P = .04). Groups did not differ in mortality, LOS, or cost. CONCLUSIONS: rmPCR reported with templated comments reduced treatment of contaminants and use of broad-spectrum antimicrobials. Addition of antimicrobial stewardship enhanced antimicrobial de-escalation. CLINICAL TRIALS REGISTRATION: NCT01898208.