COVID-19 pathophysiology, transmission, diagnosis, treatment

Editor's Note

In this review article, researchers from the US, UK, Netherlands, and Australia discuss current evidence on the pathophysiology, transmission, diagnosis, and management of COVID-19.

Among their findings:

• COVID-19 is spread primarily via respiratory droplets during close face-to-face contact.
• Infection can be spread by asymptomatic, presymptomatic and symptomatic carriers.
• The average time from exposure to symptom onset is 5 days, and 97.5% of people who develop symptoms do so within 11.5 days
• The most common symptoms are fever, dry cough, and shortness of breath.
• Diagnosis is made by detection of the virus via reverse transcription polymerase chain reaction testing, though false-negative test results occur in 20% to 67% of patients.
• About 5% of patients with COVID-19 and 20% of those hospitalized have severe symptoms necessitating intensive care.
• More than 75% of COVID-19 patients who are hospitalized require supplemental oxygen.
• Dexamethasone reduces 28-day mortality in patients requiring oxygen compared with usual care (21.6% vs 24.6%).
• Remdesivir improves time to recovery from 15 to 11 days.
• Convalescent plasma did not shorten time to recovery.
• Mortality varies by age, ranging from 0.3 deaths/1,000 cases for patients aged 5 to 17 years to 304.9 deaths/1,000 cases for patients aged 85 years or older.

As of July 1, 2020, many aspect of transmission, infection, and treatment of COVID-19 remains unclear, the researchers say. Nearly 120 human vaccines are currently under development, and more than a dozen are being tested in phase 1-3 trials.