Snapshot A 35-year-old man presents to the emergency department with cough and progressively worsening shortness of breath. He recently returned from a medical mission in East Asia approximately 10 days ago, where he was managing multiple patients with respiratory symptoms. His temperature is 101°F (38.3°C), blood pressure is 135/85 mmHg, pulse is 100/min, and respirations are 20/min with an oxygen saturation of 92%. A CT of the chest demonstrates ground glass opacities, fine reticular opacities, and vascular thickening. SUMMARY Condition is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) a novel betacoronavirus positive sense single-stranded RNA virus Diagnosed by a positive nasal swab Treatment is observation and isolation for mild cases, while severe cases require hospitalization and pulmonary support Epidemiology Incidence United States cases worldwide cases Risk factors close contact with suspected or confirmed cases of COVID-19 residence or travel to areas with high incidence of COVID-19 Etiology Incubation enters cells via the angiotensin-converting enzyme 2 receptors, especially on epithelium that line the respiratory tract TMPRSS2 primes spike protein on SARS-CoV-2 for entry The incubation period is thought to be 2-14 days post-exposure Illness severity of this infection ranges from mild to critical mild (~81% of cases) no dyspnea severe (~14%) dyspnea respiratory rate ≥ 30/min hypoxia critical (~5%) respiratory failure shock multiorgan dysfunction Transmission person-to-person tramission thought to mainly occur via respiratory droplets the virus can be released into the air when the infected person coughs or sneezes the virus reaching the host's mucous membrane can result in infection can also be transmitted longer distances via airborne route studies suggest that droplets may get aerosolized and be carried > 6 ft (2 meters) with speaking, coughing, or sneezing fomite transmission touching an infected surface and subsequently touching one's eyes, nose, or mouth can result in infection therefore, disinfectant is recommended fecal-oral transmission the SARS-CoV-2 RNA has been detected in stool, so fecal-oral transmission is possible Classification SARS-CoV-2 is in the same subgenus as severe acute respiratory syndrome corona virus (SARS-CoV) Presentation Symptoms often asymptomatic common symptoms fever (~99% of cases) fatigue (~70%) dry cough (~60%) rare symptoms myalgias (~35%) dyspnea (~30%) sputum (~27%) anosmia (10-50%) gastrointestinal symptoms nausea (~12%) diarrhea (~19%) Physical exam fever tachycardia tachypnea Imaging Radiographs CXR often normal CT chest CT findings ground-glass opacification (GGO) consolidative abnormalities may or may not be present more likely to affect both lungs, particularly in the lower lobes, and in a peripheral distribution Studies Diagnostic tests Reverse-transcription PCR (RT-PCR) for SARS-CoV-2 procedure nasopharyngeal swab sputum collection in patients with a productive cough positive test indicates detection of viral genome regions specific to SARS-CoV-2 Antigen test procedure nasal swab positive result indicates detection of SARS-CoV-2 antigens Serum labs WBC count variable (leukopenia, leukocytosis, and lymphopenia) lymphopenia is more common lactate dehydrogenase and ferritin level are commonly elevated IL-6 may be elevated Differential COVID-19 Differential Diagnosis Virus Fever Cough Fatigue Myalgia Headache Rhinitis Sore Throat COVID-19 ↑↑↑ ↑↑↑ ↑↑↑ ↑↑ Rare ↑ ↑ Influenza ↑↑↑ ↑↑↑ ↑↑↑ ↑↑↑ ↑↑↑ ↑ ↑ Common cold Rare ↑↑ ↑ ↑ ↑↑ ↑↑↑ ↑↑↑ Treatment Medical supportive care and isolation indications for mild cases, patients are isolated to their homes and symptomatically managed adults with mild-to-moderate COVID-19 infection typically remain infectious for up to ~10 days after symptom onset pharmacologic indications remains controversial without clear evidence supporting medications lopinavir-ritonavir a combined protease inhibitor remdesivir a novel nucleotide analog that impairs RNA-dependent polymerases IL-6 pathway inhibitors tocilizumab siltuximab sarilumab hospitalization with potential oxygen supplementation or mechanical ventilation indications for severe disease, characterized by hypoxia (O2 saturation ≤ 94% on room air), an oxygen requirement, or ventilatory support hospitalized patients with severe disease but not yet on oxygen supplementation remdesivir only hospitalized patients with severe disease who are receiving supplemental oxygen (including high-flow oxygen and non-invasive ventilation) low-dose dexamethasone AND remdesivir hospitalized patients with severe disease who require mechanical ventilation low-dose dexamethasone only Operative indications rarely plays a role in treatment Prevention Hand hygiene should be washed with water and soap or virucidal hand disinfectant avoid face touching Respiratory hygiene maintain 6 feet of distance from others masks (N95 respirators) and face shields or goggles for health care personnel or persons taking care of infected individuals in a health care facility or home Face coverings the CDC and WHO recommend wearing masks when in public spaces and when in the presence of individuals outside of one's household Social and physical distancing Avoidance of crowds and non-essential travel Screening in high-risk settings (e.g. nursing facilities, college campuses, hospital employees) testing-based screening is advantageous compared to symptom-based screening in that it allows identification of asymptomatic infections Vaccines primary antigenic target: surface spike protein multiple vaccine candidates have shown efficacy without major adverse effects in early-phase human clinical trials two mRNA vaccines have over 95% vaccine efficacy in preventing symptomatic COVID-19 BNT162b2 (Pfizer-BioNTech) COVID-19 mRNA vaccine two intramuscular injections administered 3 weeks apart mRNA-1273 (Moderna) COVID-19 mRNA vaccine two intramuscular injections administered 4 weeks apart Janssen Biotech viral vector vaccine one intramuscular injection Complications Acute respiratory distress syndrome has been associated with older age (≥ 65 years of age) diabetes mellitus hypertension Pneumonia Septic shock Cardiac arrhythmia Cardiac injury Prognosis Poor Prognostic Predictors older age (≥ 65 years of age) more likely to develop severe disease chronic medical conditions diabetes cardiovascular disease hypertension chronic lung disease chronic kidney disease cancer body mass index ≥ 30 immunocompromising conditions transplant patients on immunosuppressant drugs certain laboratory derrangements ↑ D-dimer ↑ ferritin and C-reactive protein ↑ creatine phosphokinase ↑ troponin ↑ lactate dehydrogenase ↑ prothrombin time acute kidney injury severe lymphopenia