Cruise ship norovirus outbreak highlights how infections spread

March 23, 2011, Infectious Diseases Society of America

Norovirus is the leading cause of acute gastroenteritis in the United States and is estimated to cause nearly 21 million cases annually. It is highly transmissible through person-to-person contact and contaminated food, water, and environmental surfaces. The results of an investigation of a 2009 outbreak on a cruise ship shed light on how the infections can spread and the steps both passengers and crew can take to prevent them. The findings are published in a new study in Clinical Infectious Diseases and available online.

Questionnaires about when people did or did not seek medical care, hygiene practices, and possible norovirus exposure were placed in every cabin after the outbreak began. The ship had 1,842 passengers on board, and 83 percent returned the questionnaires. Of the 15 percent of respondents who met the case definition for acute gastroenteritis, only 60 percent had sought medical care on the ship. Infected passengers were significantly more likely to have an ill cabin mate and to have resided or dined on the deck level where a vomiting incident had occurred during boarding. The most common symptom reported was diarrhea, followed by vomiting. Stool samples from several ill passengers tested positive for norovirus.

Less than 1 percent of the crew reported illness, and their low attack rate may have been due to the few crew members who had direct contact with passengers. This included separate sleeping and dining areas and alternate passages for boarding and exiting the ship. Another factor may have been an acquired short-term immunity from previous outbreaks.

"Cruise line personnel should discourage ill passengers from boarding their ships," according to study author Mary Wikswo, MPH, of the . "Once on board, passengers and crew who become ill should report to the ship's medical center as soon as possible. These quick actions are crucial in preventing the introduction and spread of on cruise ships and allow ship personnel to take immediate steps to prevent the spread of illness."

More information: http://www.oxfordjournals.org/our_journals/cid/cir144.pdf

Related Stories

Recommended for you

Ambitious global virome project could mark end of pandemic era

February 23, 2018
Rather than wait for viruses like Ebola, SARS and Zika to become outbreaks that force the world to react, a new global initiative seeks to proactively identify, prepare for and stop viral threats before they become pandemics.

Forecasting antibiotic resistance with a 'weather map' of local data

February 23, 2018
The resistance that infectious microbes have to antibiotics makes it difficult for physicians to confidently select the right drug to treat an infection. And that resistance is dynamic: It changes from year to year and varies ...

Study reveals how kidney disease happens

February 22, 2018
Monash researchers have solved a mystery, revealing how certain immune cells work together to instigate autoimmune kidney disease.

Scientists gain new insight on how antibodies interact with widespread respiratory virus

February 22, 2018
Scientists have found and characterized the activity of four antibodies produced by the human immune system that target an important protein found in respiratory syncytial virus (RSV), according to new research published ...

Past encounters with the flu shape vaccine response

February 20, 2018
New research on why the influenza vaccine was only modestly effective in recent years shows that immune history with the flu influences a person's response to the vaccine.

Building better tiny kidneys to test drugs and help people avoid dialysis

February 16, 2018
A free online kidney atlas built by USC researchers empowers stem cell scientists everywhere to generate more human-like tiny kidneys for testing new drugs and creating renal replacement therapies.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

FancyScrubs
not rated yet Mar 23, 2011
It is amazing how fast this virus can spread. Are the crew more aware of washing hands frequently or is it because of their immunities?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.