A new study has revealed that more than 80 percent of passengers and crew members on a cruise ship that contracted COVID-19 were asymptomatic.
The research, published in the scientific journal Thorax, notes that 128 of 217 passengers and crew members tested positive for the disease caused by SARS-CoV-2. Of those, 81 percent did not show symptoms, leading researchers to conclude “the prevalence of COVID-19 on affected cruise ships is likely to be significantly underestimated.”
“It is difficult to find a reliable estimate of the number of COVID positive patients who have no symptoms,” Alan Smyth, the editor-in-chief of Thorax and professor at the University of Nottingham said in a statement.
Smyth added the findings have implications for easing lockdown restrictions around the globe, given the possibility more people may have been infected with COVID-19 than previously believed.
“As countries progress out of lockdown, a high proportion of infected, but asymptomatic, individuals may mean that a much higher percentage of the population than expected may have been infected with COVID,” he explained.
The cruise involved in the study was a 21-day voyage around the Antarctic, similar to the journey that explorer Ernest Shackleton went on prior to his death. The first fever was on the eighth day of the trip and isolation protocols started immediately, with all passengers confined to their cabins and everyone was issued surgical masks. Personal protective equipment was also worn by anyone who came in contact with passengers.
“Further fevers were detected in three crew on day 10, two passengers and one crew on day 11, and three passengers on day 12,” the researchers added.