title: Elite athletes travelling to international destinations >5 time zone differences from their home country have a 2-3-fold increased risk of illness.
abstract: BACKGROUND
  Illness accounts for a significant proportion of consultations with a team physician travelling with elite athletes.
  
  
  OBJECTIVE
  To determine if international travel increases the incidence of illness in rugby union players participating in a 16-week tournament.
  
  
  METHODS
  2010 Super 14 Rugby Union tournament.
  
  
  METHODS
  259 elite rugby players from eight teams were followed daily over the 16-week competition period (22 676 player-days).
  
  
  RESULTS
  Team physicians completed a logbook detailing the daily squad size and illness in any player (system affected, final diagnosis, type and onset of symptoms, training/match days lost and suspected cause) with 100% compliance. Time periods during the tournament were divided as follows: located and playing in the home country before travelling (baseline), located and playing abroad in countries >5 h time zone difference (travel) and located back in the home country following international travel (return).
  
  
  METHODS
  Incidence of illness (illness per 1000 player-days) during baseline, travel and return.
  
  
  RESULTS
  The overall incidence of illness in the cohort was 20.7 (95% CI 18.5 to 23.1). For all teams, the incidence of illness according to location and travelling was significantly higher in the time period following international travel (32.6; 95% CI 19.6 to 53.5) compared with the baseline (15.4; 95% CI 8.7 to 27.0) or after returning to their home country (10.6; 95% CI 6.1 to 18.2).
  
  
  CONCLUSIONS
  There is a higher incidence of illness in athletes following international travel to a foreign country that is >5 h time difference and this returns to baseline on return to the home country.
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, UCT/MRC Research Unit for Exercise Science and Sports Medicine, University of Cape Town, Newlands, South Africa. martin.schwellnus@uct.ac.za
authors.forename: Martin P
authors.initials: MP
authors.lastname: Schwellnus
authors.forename: Wayne Elton
authors.initials: WE
authors.lastname: Derman
authors.forename: Esme
authors.initials: E
authors.lastname: Jordaan
authors.forename: Tony
authors.initials: T
authors.lastname: Page
authors.forename: Mike Ian
authors.initials: MI
authors.lastname: Lambert
authors.forename: Clint
authors.initials: C
authors.lastname: Readhead
authors.forename: Craig
authors.initials: C
authors.lastname: Roberts
authors.forename: Ryan
authors.initials: R
authors.lastname: Kohler
authors.forename: Robert
authors.initials: R
authors.lastname: Collins
authors.forename: Stephen
authors.initials: S
authors.lastname: Kara
authors.forename: Michael Ian
authors.initials: MI
authors.lastname: Morris
authors.forename: Org
authors.initials: O
authors.lastname: Strauss
authors.forename: Sandra
authors.initials: S
authors.lastname: Webb
mesh_terms: D000208:Acute Disease / Q000453:epidemiology*; D001315:Australia / Q000453:epidemiology; D005538:Football / Q000502:physiology*; D006801:Humans; D015994:Incidence; D009520:New Zealand / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D013019:South Africa / Q000453:epidemiology; D013997:Time Factors; D014195:Travel