2.2 | Definitions of respiratory viral infections and transplant outcomes
RVIs were classified into high-risk and low-risk RVIs based on the observed likelihood of risk for complications and type of RVI in prior studies. High-risk RVIs were adenovirus, HMPV, influenza A and B, parainfluenza, and RSV. Low-risk RVIs were coronaviruses and rhinovirus.13-14, 4 Symptoms of RVI were identified as upper- or lower-respiratory symptoms. Upper-respiratory (UR) symptoms included congestion, sneezing, headaches, sore throat, and mild cough. Lower-respiratory symptoms included phlegm, wheezing, chest pain, serious cough, shortness of breath, and severe cough.
Transplant-related complications were recorded in order to evaluate the outcome of RVIs on these. These transplant-related complications were the incidence of graft versus host disease (GVHD) and its grade, transfer to the intensive care unit (ICU), need for positive pressure (PP), intubation, bronchoalveolar lavage (BAL), transplant-associated thrombotic microangiopathy (TA-TMA), adenoviremia, and mortality at day 100 post-transplant.