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.

Early molecular correlates of adverse events following yellow fever vaccination.

The innate immune response shapes the development of adaptive immunity following infections and vaccination. However, it can also induce symptoms such as fever and myalgia, leading to the possibility that the molecular basis of immunogenicity and reactogenicity of vaccination are inseparably linked. To test this possibility, we used the yellow fever live-attenuated vaccine (YFLAV) as a model to study the molecular correlates of reactogenicity or adverse events (AEs). We analyzed the outcome of 68 adults who completed a YFLAV clinical trial, of which 43 (63.2%) reported systemic AEs. Through whole-genome profiling of blood collected before and after YFLAV dosing, we observed that activation of innate immune genes at day 1, but not day 3 after vaccination, was directly correlated with AEs. These findings contrast with the gene expression profile at day 3 that we and others have previously shown to be correlated with immunogenicity. We conclude that although the innate immune response is a double-edged sword, its expression that induces AEs is temporally distinct from that which engenders robust immunity. The use of genomic profiling thus provides molecular insights into the biology of AEs that potentially forms a basis for the development of safer vaccines.