A Staggering 81% Of Cruise Passengers With COVID-19 Were Asymptomatic
Since the beginning of the COVID-19 outbreak, cruises have been at the forefront of news stories concerning the spread of the virus. This largely stems from the fact that cruise ships are considered Petri dishes for viruses. In March, the Diamond Princess cruise ship had the largest cluster of COVID-19 infections outside of mainland China. Because of this, questions remain as to when it will be safe for cruise companies to return to the sea. But a new study published in Thorax demonstrates the difficulty cruise companies face in returning to business.
You may remember stories about the Greg Mortimer, which was trapped off South America with coronavirus-positive passengers and crew. Chile and Argentina denied docking to the cruise line due to border restrictions. Uruguay ended up aiding the ship and assisted in the repatriation of the passengers.
A study examined test results from the cruise, which departed in mid-March, after the World Health Organization declared COVID-19 a pandemic. Medical professionals tested all passengers on board the cruise before disembarkation. Of the 217 passengers and crew on board, 128 of them (59%) tested positive for COVID-19, which was reported in April media reports. But even more startling: 81% of the positive patients exhibited no coronavirus symptoms. This study shows one of the challenges for cruise lines will be ensuring passenger safety, as asymptomatic people can be on the cruise without even knowing they are positive.
The ship’s planned route was an Antartica cruise departing from Argentina. All 128 passengers and 95 crew members were screened for COVID-19 symptoms, including a fever check. passengers from highly impacted countries like China, Japan, and Iran were not allowed on the cruise.
On day 3 of the cruise, the decision was made to terminate the cruise after completing the Antarctic portion. The decision came after countries began implementing new border controls and travel restrictions.
On day 13, the cruise docked in Montevideo, Uruguay. Medical officials evacuated eight passengers and crew members to hospitals in Montevideo. Uruguayan officials then tested all passengers on the ship for COVID-19. All eight passengers evacuated later tested positive for the virus.
Bad News For Cruises?
Of course, this study causes some concern over cruises returning, even in a limited capacity. Obviously, the study limits testing to just that one ship with a small number of passengers in comparison to other cruise ships. However, the study provides a metric on just how prevalent the virus can be on a cruise, even when symptoms aren’t present. It’s hard to say when cruises will return, but undoubtedly science will have to look at this information and see how it drives cruise line companies’ decisions.
The study also raises questions about the effectiveness of screening passengers before boarding. In this case, officials screened all passengers and crew before boarding the ship. However, the screen is only so effective since we know people can be asymptomatic. The CDC now recommends face masks when social distancing isn’t possible. So face masks will likely be important when cruising returns. That may be why Royal Caribbean trademarked its own version of face masks shortly after the pandemic began in the U.S. But masks do have their limits on confined cruise ships with regular interaction with many different people.
A survey conducted on passengers and crew from a cruise that departed in mid-March demonstrated a significant amount of asymptomatic COVID-19 patients. Of the 217 on board, 59% tested positive for COVID-19 as they departed the ship. Of that 59%, a staggering 81% were asymptomatic. The study only includes testing from one cruise, but it raises questions about the danger of cruising returns. I booked a cruise to Hawaii last week for 2021, but did so with the understanding it may not happen.