By Sameen Ijaz, Scientist, IMD & Molecular Biology
My husband and his old school friends are in the process of planning their annual reunion getaway, and are thinking about taking a cruise to scenic Alaska. In most cases I’m happy that my husband and his friends dedicate a chunk of time every year to catch up and stay in touch with one another, but when I heard their possible plan for this year’s reunion, I couldn’t help but feel a little uneasy.
Recent news of cruise ships cutting their journeys short due to norovirus outbreaks has me questioning my husband as to whether or not it might be wise to keep this year’s reunion on land. Ship-wide virus outbreaks are fairly common in the cruise industry, but this year is off to an unfavorable start. According to the Centers for Disease Control and Prevention, there have been three separate outbreaks of norovirus on cruise ships so far this year – Princess Cruise Line’s Caribbean Princess, Royal Caribbean Cruise Line’s Explorer of the Seas, and Norwegian Cruise Line’s Norwegian Star have each experienced norovirus outbreaks affecting a total of 945 passengers.
As I read more about these outbreaks, I can’t help but wonder who or what is responsible for the spread of norovirus, and, more importantly, how can these outbreaks be prevented?
Norovirus is a highly contiguous virus that causes gastroenteritis. Crowded and confined spaces on cruise ships can be a ripe breeding ground for norovirus infections if proper precautions are not taken by both the passengers and the crew. Outbreaks usually occur when poor sanitation is combined with large crowds of people stuck in confined spaces. One of the articles I came across posited the theory that cruise ships are like floating petri dishes.
There can be several causes of norovirus outbreaks – the infection can find its way aboard a cruise ship by someone who is already ill, and thereafter, other passengers or crew members become infected by consuming contaminated food or by touching contaminated surfaces. The virus causes nausea, severe diarrhea, vomiting, and abdominal pain. Although infection can cause a person to experience miserable symptoms, it is rarely life threatening and symptoms usually last 24 to 48 hours.
Prevention of outbreaks requires the cooperation of everyone involved, including both passengers and the crew. Many viruses, such as HIV, have a lipid envelope, and when exposed to the environment become inactivated. However, norovirus has a protein coat and can thrive in the open for several weeks. It takes as few as ten norovirus particles to infect a human host compared to other viruses, such as influenza, where thousands of viral particles are required to trigger symptoms.
The best way to prevent outbreaks is to practice basic hygiene: frequent hand-washing, hygienic cooking and dining practices, and thorough cleaning or disinfection of surfaces like door knobs, handles, handrails, elevator buttons, and shared restaurant utensils.
As the date of my husband’s reunion trip grows near, I hope to present these points as clearly as I can, and persuade him and his friends to avoid a getaway on the high seas. Or at the very least, demand that he pack a suitcase full of hand sanitizer.