Corona viruses: reaching far beyond the common cold

BACKGROUND: Human coronaviruses (HCoVs) are one of the most common causes of the “common cold”. Some HCoV strains, however, can cause fatal respiratory disease. Some examples of these diseases are severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Coronavirus Disease 19 (COVID-19). This article will review the etiology, clinical features, diagnosis, and management of HCoVs. METHODS: A systematic literature review was performed using the terms “human coronaviruses”, “MERS-CoV”, “SARSCoV”, “SARS-CoV2”, “COVID-19”, and “common cold” in OVID MEDLINE, PubMed, and Cochrane Library. FINDINGS: Most HCoVs cause mild upper respiratory infections which resolve with supportive care and no sequelae. In recent decades, however, there have been outbreaks of novel HCoVs that cause more severe disease. This is largely due to HCoVs having large genomes which undergo frequent recombination events, leading to the emergence of novel and more virulent strains of the virus. These severe respiratory illnesses can lead to acute respiratory distress requiring invasive intervention, such as mechanical ventilation. These severe infections can lead to long-lasting sequelae in patients. Scientists continue to investigate potential treatments for these viruses, though supportive care remains the gold standard. Scientists have succeeded in developing numerous vaccines for the SARS-CoV-2 virus, and ongoing data collection and analysis will shed even more light on the next steps in fighting the COVID-19 pandemic. CONCLUSION: Due to the frequency of recombination events and the subsequent emergence of novel strains, HCoVs are becoming more prevalent, making them a global health concern as they can lead to epidemics and pandemics. Understanding the epidemiology, etiology, clinical features, diagnosis, and management of HCoVs is important, especially during this worldwide pandemic.