SARS-CoV-2 replicates in the throat, making it more contagious than other coronaviruses.
COVID-19 is highly contagious, spreading rapidly from person to person, primarily through respiratory droplets produced when an infected person coughs or sneezes. A recent study indicates that SARS-CoV-2, the virus responsible for COVID-19, replicates in the throat, increasing its transmissibility.
The authors of the study followed nine patients who presented with symptoms of COVID-19. They collected nose and throat swabs and sputum samples from the patients to test for the presence of SARS-CoV-2 throughout the course of their illness and up to four weeks after the onset of symptoms. They found that the swabs and sputum samples showed high levels of infectious viral particles – an indication that, unlike related coronaviruses, SARS-CoV-2 didn’t need to travel to the lungs to replicate. Instead, it rapidly replicated in the throat in the early days of infection, producing a high viral load. These findings suggest that people with SARS-CoV-2 infection can transmit the virus before they are aware that they are infected.
Enjoying this research? Get deeper insights like this delivered every other week.
Every other week our Premium Members receive deep dives like this alongside Rhonda's commentary and 8+ other hand-picked papers.
The authors noted that sputum samples with fewer than 100,000 copies of viral RNA didn’t contain any infectious viral particles, suggesting that patients who achieve this benchmark by day 10 of their illness can be discharged to isolation at home. This is critical information for overburdened hospitals and healthcare providers trying to determine when to discharge patients.