Medical | Vito Iacoviello, MD & Heather D. Marshall, PhD | March 19, 2020
Read about the clinical progression of COVID-19 and the recovery rate and process.
While the focus in the media remains on social distancing and respiratory hygiene to limit the spread of COVID-19, it is also important to discuss the clinical progression once someone is infected. For healthcare providers, this can facilitate prompt triage and initiation of isolation protocols. For the general public, it may help determine when to request care from a healthcare provider.
Unfortunately, COVID-19 starts off like most other respiratory infections including influenza, making it a difficult clinical diagnosis. Patients typically report fever and cough. Dry cough appears more common than cough with expectoration. Other symptoms include fatigue, myalgia, diarrhea and headache. About five days after symptom onset, some patients develop shortness of breath and dyspnea (trouble breathing) prompting medical attention. Rapid deterioration to acute respiratory distress syndrome (ARDS) requiring mechanical ventilation occurs in about 10 percent of patients who develop shortness of breath.
Hospitalized patients have some common laboratory features. For example, computed tomography (CT) of the chest often shows pneumonia with bilateral ground glass opacities. Lymphopenia is a common blood test finding. The decision to test for COVID-19 is based on clinical judgement considering local epidemiology and clinical course. Physicians are strongly encouraged to test for other respiratory illnesses including influenza in these patients.
There is no specific antiviral therapy for COVID-19, though there are a few ongoing trials. Supportive care may help to relieve symptoms and should include support of vital organ functions in severe cases.
The true mortality rate of COVID-19 is unknown. In China, the first 40,000 hospitalized cases had a mortality rate of about two percent. Based on case counts reported by the World Health Organization on March 18 among countries with more than 1,000 cases, mortality ranged from nearly eight percent in Italy to 0.2 percent in Germany. During a pandemic, calculating mortality rate is only an estimation because case counts are informed by local and regional testing capacity and reporting policies. It will only be after the pandemic is over, when serological assays can be used to screen for exposure, that we will be able to calculate a definitive case fatality rate.
Despite this uncertainty, we should not forget that most patients with COVID-19 survive. According to the Johns Hopkins Center for Systems Science and Engineering (CSSE) Coronavirus Dashboard, as of March 19th, nearly 85,000 patients have recovered. Patients who recuperate from COVID-19 are more likely to be younger and healthier (without significant comorbidities). In a small study of 21 patients who recovered, severity of pulmonary lesions on chest CT peaked about 10 days after symptom onset and gradually improved after about two weeks. Another cohort study showed that patients discharged from the hospital had lower levels of C-reactive protein, interleukin-6, cardiac troponin, and myoglobin compared to patients who died, suggesting that less inflammation and absence of cardiac injury may be associated with survival.
Whether patients who recover from COVID-19 have any long-term consequences is unknown, as is whether they develop long-lasting immunity to SARS-CoV-2. Continue to check DynaMed for updates on COVID-19.
For additional resources and the most recent epidemiology see the EBSCO COVID-19 Resource Center.
Vito Iacoviello, MD, is Deputy Editor for Infectious Disease, Allergy, and Immunology at DynaMed.
Heather D. Marshall, PhD, is a Senior Medical Writer and Digital Media Specialist at DynaMed.
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