title: The Prevalence of Norovirus in returning international travelers with diarrhea.
abstract: BACKGROUND
  There is a high incidence of diarrhea in traveling populations. Norovirus (NV) infection is a common cause of diarrhea and is associated with 7% of all diarrhea related deaths in the US. However, data on the overall prevalence of NV infection in traveling populations is limited. Furthermore, the prevalence of NV amongst travelers returning to Europe has not been reported. This study determined the prevalence of NV among international travelers returning to Germany from over 50 destinations in and outside Europe.
  
  
  METHODS
  Stool samples of a total of 104 patients with a recent (< 14 days) history of international travel (55 male, mean age 37 yrs.) were tested for the presence of NV genogroup (GG) I and II infection using a sensitive and well established quantitative RT PCR method. 57 patients experienced diarrhea at the time of presentation at the Department of Infectious Diseases & Tropical Medicine. The remaining 47 patients had no experience of diarrhea or other gastrointestinal symptoms for at least 14 days prior to their date of presentation at our institute.
  
  
  RESULTS
  In our cohort, NV infection was detected in 15.7% of returning travelers with diarrhea. The closer to the date of return symptoms appeared, the higher the incidence of NV, ranging as high as 21.2% within the first four days after return.
  
  
  CONCLUSIONS
  In our cohort, NV infection was shown to be frequent among returning travelers especially in those with diarrhea, with over 1/5 of diarrhea patients tested positive for NV within the first four days after their return to Germany. Due to this prevalence, routine testing for NV infection and hygienic precautions may be warranted in this group. This is especially applicable to patients at an increased risk of spreading the disease, such as healthcare workers, teachers or food-handlers.
authors.affiliation: Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians University of Munich, Georgenstr. 5, 80799 Munich, Germany. ink_2010@hotmail.com
authors.forename: Nadja
authors.initials: N
authors.lastname: Apelt
authors.forename: Christine
authors.initials: C
authors.lastname: Hartberger
authors.forename: Hartmut
authors.initials: H
authors.lastname: Campe
authors.forename: Thomas
authors.initials: T
authors.lastname: Löscher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D029322:Norovirus / Q000302:isolation & purification*; D015995:Prevalence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014195:Travel; D055815:Young Adult