Monday, June 25, 2012

Norovirus Sequelae



# 6404



Last month I wrote a blog called Norovirus: The Gift That Keeps On Giving, about an outbreak of this nasty gastrointestinal malady among a group of teenage girls at a soccer tournament in 2010.  


It now appears that the above title may have been more appropriate than I imagined, as a new study appearing in Clinical Infectious Diseases finds a link between norovirus infection and ongoing gastrointestinal complaints.


According to the CDC norovirus sickens more than 20 million Americans every year, hospitalizes up to 70,000, and contribute to 800 deaths.  The CDC maintains an extensive Norovirus webpage where they describe the illness, how it is spread, and how to avoid infection.




As if enduring 24 to 48 hours of vomiting and diarrhea wasn’t enough, today’s study suggests that those who experience a norovirus infection are at substantially greater risk of developing chronic dyspepsia, constipation and GERD (Gastroesophageal reflux disease).


In the following study researchers looked at the records of more than 1700 military personnel who were treated for AGE (acute gastroenteritis) during three known norovirus outbreaks. 


By comparing them to controls, they determined that those with a history of AGE were at increased risk of developing chronic gastrointestinal disorders.


Since this was a fairly small study, and some variability was detected in outcomes across the three outbreaks studied, more research will be needed to confirm their findings and to determine how long these after effects may persist.




Post-infectious gastrointestinal disorders following norovirus outbreaks

Chad K. Porter1, Dennis J. Faix, Danny Shiau, Jennifer Espiritu, Benjamin J. Espinosa, and Mark S. Riddle

Results. We identified 1,718 subjects from three outbreaks. After controlling for important demographic covariates, the incidence of constipation, dyspepsia and GERD was approximately 1.5 fold higher (p<0.01) in AGE exposed subjects than matched subjects. We also noted variability in outcome incidence across outbreaks.

Conclusions. It appears that the risk of dyspepsia, constipation and GERD are higher among those who have AGE during a confirmed norovirus outbreak. While these findings need confirmation, they suggest that dysmotility may result subsequent to these infections. If confirmed, the costs and morbidity associated with the chronic consequences of norovirus should be considered.

Dysmotility is a generic medical term to describe diseases of the GI tract (esophagus, stomach, small and large intestines) where the muscles do not function properly.


The primary route of infection is the fecal-oral route (although there is evidence it can also be airborne), and the best intervention is . . . you guessed it . . .  washing your hands.


Unfortunately, unlike with many other bacteria and viruses, alcohol gel doesn’t do a particularly good job of killing the virus, as we discussed last year in  CMAJ: Hand Sanitizers May Be `Suboptimal’ For Preventing Norovirus.


For more information, the CDC’s hand hygiene website provides many useful resources, including a link to a new iPad/iPhone application called iScrub.



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