Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, and COVID-19, beyond the lungs: a review article

Background In the past 20 years four major viral infectious diseases outbreaks caused hundreds of thousands of deaths worldwide: SARS, Influenza H1N1, MERS, and COVID-19. They all present clinically initially as upper and lower respiratory tract infections and may progress to multi-organ failure. Methods This study was a systematic review of literature conducted in September 2020 to study extra-pulmonary complications of SARS, FLU, MERS, and current COVID-19. We carried out a systematic search using the keywords in online databases of PubMed, EMBASE, and Google Scholar until June 2020. Objective This article aims to review the most common extra-pulmonary manifestations of SARS, Influenza, MERS, and COVID-19. Discussion Several studies have reported extra-pulmonary conditions in patients diagnosed with SARS, Influenza, MERS, and COVID-19, either by direct viral injury or from the systemic response to the initial infection. Conclusion SARS, Influenza, MERS, and COVID-19 have all been associated with dysfunction of kidneys, endocrine system, neuromuscular symptoms, perinatal complications, and myocardial injury. Progression from pulmonary disease to a systemic condition has a poor outcome and can result in multi-organ failure.