Diagnostic and prognostic study of SARS-CoV-2 infection and influenza virus

Introduction: The epidemics caused by the Influenza virus are recognized for their great impact on public health. The identification of a new coronavirus strain (SARS-CoV-2) with pandemic spread has brought new challenges for diagnosis, control and therapy. The rapid and low-cost diagnosis of SARS-CoV-2 and Influenza infections may allow the adoption of measures to control transmissibility both in the environment of Health Units and isolation from social contact in the community. The early identification of patients with a higher risk of death also allows a targeted therapeutic approach with ventilatory support measures and the use of specific antivirals against these two viruses. The understanding of pathophysiological mechanisms related to the coagulation cascade, involved in the severe forms of involvement by respiratory viruses, proposed in this project, may lead to the development of new therapeutic possibilities in order to reduce the high lethality of this serious clinical situation. Objective: 1) Development of a method for rapid and low-cost diagnosis of SARS-CoV-2 and Influenza virus infections; 2) study of early prognostic factors in patients diagnosed with SARS-CoV-2 infection and Influenza virus; 3) Study of platelet aggregation levels by Multiplate-ADP and coagulation in hospitalized patients due to respiratory distress. Method: 4 groups will be compared: SARS-CoV-2 infection patients, Influenza virus infection patients, influenza syndrome patients with negative tests for COVID-19 / Influenza virus and healthy controls. Patients with suspected flu-like symptoms (fever accompanied by one of the following symptoms: cough, sore throat, runny nose, frontal headache with onset of symptoms in the last 7 days) will be enrolled in 2 public referral hospitals. Exclusion criteria: Age below 18 years. The healthy control group will consist of 50 volunteer health care professionals paired by sex and age to the group of patients with SARS-CoV-2 infection. Peripheral blood, skin imprint and saliva samples will be collected from all individuals included in the study. Those who require hospitalization and present criteria for severe acute respiratory syndrome (SARS) will also be collected second and third samples of non-invasive specimens (skin imprint and saliva) 3 and 7 days after inclusion. Nasal flush will be collected for diagnosis of Influenza virus and SARS-CoV-2 infection by the protocol only for those who do not perform these tests through the hospital routine. All samples will be sent for storage (- 80C) at the Virology Laboratory of USP's Institute of Tropical Medicine and UNICAMP's Innovare Laboratory. Metabolites will be studied by plasma mass spectrometry, skin and saliva imprint and analyzed by artificial intelligence. The diagnosis of infection by Influenza virus or SARS-CoV-2 will be considered positive (gold standard) by positive molecular biology test in a nasal wash sample. Patients' prognosis will be assessed by the following outcomes: length of hospital stay, need for dialysis, need for orotracheal intubation or hospital death. Platelet aggregability will be studied using the Multiplate-TRAP and Multiplate-ASPI methods, reticulated platelet levels (young), mean platelet volume (MPV), P-selectin, D-dimer, PAI-1, Fibrinogen, Tromboxane, Tempo activated partial thromboplastin (PTTa), prothrombin time (TP); Type B natriuretric peptide (BNP); Ultrasensitive troponin, peak glycemia during hospitalization, lipid profile when hospitalized.