How Long is the Incubation Period for COVID-19?

A new study from the University of Massachusetts Amherst has revealed the median incubation period for COVID-19 is around five days, with approximately 97.5% of people infected with the virus developing symptoms within 11.5 days of exposure. This is a similar timeframe to SARS, the highly contagious respiratory illness that broke out in China in 2002 and claimed more than 750 lives.

The findings were presented at a four-hour long coronavirus modelling webinar hosted by the White House Coronavirus Task Force, with coordinator Dr. Charles Vitek saying "This webinar is designed to highlight for the Task Force what modelling can tell us regarding the potential effects of mitigation measures on the coronavirus outbreak. The unprecedented speed and impact of the CoV-19 epidemic requires the best-informed public health decision-making we can produce."

Median incubation period around five days

The study was led by Stephen Lauer, a biostatistician at the University of Massachusetts Amherst. Together, Lauer and his colleagues analysed 181 patients diagnosed with COVID-19. After factoring in time of exposure and onset of symptoms, the team concluded that the median incubation period for the virus, i.e. the time it takes for the first symptoms to appear after exposure, is around five days.

The report conclusion reads, "This work provides additional evidence for a median incubation period for COVID-19 of approximately 5 days, similar to SARS. Our results support current proposals for the length of quarantine or active monitoring of persons potentially exposed to SARS-CoV-2, although longer monitoring periods might be justified in extreme cases."

Knowledge key to developing public health guidelines

While Lauer admits existing knowledge of the incubation period for COVID-19 is limited, he says the latest study is helpful for developing public health guidelines. This includes the enforcement of social distancing, as well as active monitoring which requires high risk members of the community to report their symptoms to health authorities daily.

"Understanding the length of active monitoring needed to limit the risk for missing SARS-CoV-2 infections is necessary for health departments to effectively use limited resources," reads the report.

The impact of the COVID-19 pandemic has been widespread, threatening not only public health but also the global economy. With commentary from Jacqueline Balian on behalf of Gambica Trade Association, 'Export Experts Talk Corona Virus' explores the impact the pandemic will have on international trade, and how this will affect laboratories in the UK and around the world.