Aviremic organ transplant dengue virus transmission - A case report.

Dengue virus (DENV), a mosquito-borne pathogen, causes systemic infections. There are no clear guidelines regarding the screening of donor blood is used in endemic countries to prevent blood transfusion or transplant-associated dengue. DENV has been shown to be detected in urine samples even when DENV viremia is undetectable. We describe an incident of transplant-associated dengue where the donor tested negative for DENV viremia but positive for DENV viuria resulting in the transmission of DENV to our two kidney recipients. Both recipients resolved DENV infection uneventfully, with no adverse impact on the renal graft. Our findings raise the consideration for revised screening recommendations in endemic countries to include DENV RT-PCR in the urine.

Rapid measurement of SARS-CoV-2 spike T cells in whole blood from vaccinated and naturally infected individuals.

Defining the correlates of protection necessary to manage the COVID-19 pandemic requires the analysis of both antibody and T cell parameters, but the complexity of traditional tests limits virus-specific T cell measurements. We tested the sensitivity and performance of a simple and rapid SARS-CoV-2 spike protein-specific T cell test based on the stimulation of whole blood with peptides covering the SARS-CoV-2 spike protein, followed by cytokine (IFN-γ, IL-2) measurement in different cohorts including BNT162b2-vaccinated individuals (n = 112), convalescent asymptomatic and symptomatic COVID-19 patients (n = 130), and SARS-CoV-1-convalescent individuals (n = 12). The sensitivity of this rapid test is comparable to that of traditional methods of T cell analysis (ELISPOT, activation-induced marker). Using this test, we observed a similar mean magnitude of T cell responses between the vaccinees and SARS-CoV-2 convalescents 3 months after vaccination or virus priming. However, a wide heterogeneity of the magnitude of spike-specific T cell responses characterized the individual responses, irrespective of the time of analysis. The magnitude of these spike-specific T cell responses cannot be predicted from the neutralizing antibody levels. Hence, both humoral and cellular spike-specific immunity should be tested after vaccination to define the correlates of protection necessary to evaluate current vaccine strategies.

Survey of Respiratory Virus in Patients Hospitalised for Acute Exacerbations of Heart Failure - A Prospective Observational Study.

INTRODUCTION: Respiratory virus (RV) infections have been implicated in acute exacerbation cardiopulmunary conditions. This study aimed to determine the prevalence of RV infections in patients admitted to the cardiology unit with acute decompensated heart failure (ADHF) in a tertiary hospitals in Singapore. MATERIALS AND METHODS: This was a single-centre, prospective observational study. A total of 194 adults (aged >21) admitted to the Singapore General Hospital with ADHF were recruited. A nasopharyngeal swab was taken for multiplex polymerase chain reaction (PCR) detection of influenza virus, rhinovirus, parainfluenza virus (HPIV), human coronavirus (HcoV), adenoviurs, human bocavirus (HboV), human metapneumovirus (hMPV), and respiratory syncytial virus (RSV). RESULTS: Twenty-five (13%) had RVs detected by RV multiplex PCR. There comprised 9 rhinoviruses (36%), 4 influenza A viruses (16%), 3 HPIV (12%), 3 HCoV (12%), 2 adenoviruses (8%), 1 human HBoV (4%), 1 hMPV (4%), and 1 RSV (4%). Symptoms-wise, cough was significantly more common in the PCR-positive group (48% vs 24%, P = 0.02). There were no statistically significant differences in laboratory investigations (haemoglobin, leukocytes, platelets, creatine kinase, creatine kinase-muscle/brain, troponin T), and radiology findings between RV PCR-positive and -negative groups. The PCR-positive group did not have increased mortality or length of hospital stay. CONCLUSION: This study identified a considerable burden of RVs in our ADHF cohort, and highlights the need for prevention of RVs in this group of patients. We also recognised the difficulty with clinical diagnosis of RVs in ADHF patients.

18F-FDG as an inflammation biomarker for imaging dengue virus infection and treatment response.

Development of antiviral therapy against acute viral diseases, such as dengue virus (DENV), suffers from the narrow window of viral load detection in serum during onset and clearance of infection and fever. We explored a biomarker approach using 18F-fluorodeoxyglucose (18F-FDG) PET in established mouse models for primary and antibody-dependent enhancement infection with DENV. 18F-FDG uptake was most prominent in the intestines and correlated with increased virus load and proinflammatory cytokines. Furthermore, a significant temporal trend in 18F-FDG uptake was seen in intestines and selected tissues over the time course of infection. Notably, 18F-FDG uptake and visualization by PET robustly differentiated treatment-naive groups from drug-treated groups as well as nonlethal from lethal infections with a clinical strain of DENV2. Thus, 18F-FDG may serve as a novel DENV infection-associated inflammation biomarker for assessing treatment response during therapeutic intervention trials.

Differentiating early adult dengue from acute viral respiratory infections – A comparative analysis.

The clinical presentations of dengue disease in adults are not fully described. Differentiating dengue from other acute viral respiratory infections (ARIs) is important. We conducted a prospective study from January 2008 to March 2010, recruiting subjects with early febrile illness presenting within the first 72 hours of illness at primary care outpatient clinics. This study evaluates cases enrolled to identify distinguishing clinical features of early dengue infection from ARIs. Acute and convalescent venous blood and nasal swab specimens were collected. Dengue was confirmed by RT-PCR, virus isolation, IgM/IgG seroconversion or fourfold IgG titre increase in paired blood samples. Non-dengue cases were tested for respiratory viruses from nasal swabs by RT-PCR. Dengue was confirmed in 49 patients along with 151 cases of influenza, 10 of parainfluenza and 29 patients of other viruses. The demographics between dengue (n=49) and PCR-positive viral ARI cases (n=190) did not differ significantly except by age (mean 39.1 years vs 33.7 years respectively; P