Skip to main content

A comparison of exposure to risk factors for giardiasis in non-travellers, domestic travellers and international travellers in a Canadian community, 2006–2012

  • A. L. SWIRSKI (a1), D. L. PEARL (a1), A. S. PEREGRINE (a2) and K. PINTAR (a3)

The purpose of this study is to determine how demographic and exposure factors related to giardiasis vary between travel and endemic cases. Exposure and demographic data were gathered by public health inspectors from giardiasis cases reported from the Region of Waterloo from 2006 to 2012. Logistic regression models were fit to assess differences in exposure to risk factors for giardiasis between international travel-related cases and Canadian acquired cases while controlling for age and sex. Multinomial regression models were also fit to assess the differences in risk profiles between international and domestic travel-related cases and endemic cases. Travel-related cases (both international and domestic) were more likely to go camping or kayaking, and consume untreated water compared to endemic cases. Domestic travel-related cases were more likely to visit a petting zoo or farm compared to endemic cases, and were more likely to swim in freshwater compared to endemic cases and international travel-related cases. International travellers were more likely to swim in an ocean compared to both domestic travel-related and endemic cases. These findings demonstrate that travel-related and endemic cases have different risk exposure profiles which should be considered for appropriately targeting health promotion campaigns.

Corresponding author
*Author for correspondence: Dr K. Pintar, Centre for Food-Borne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada, Ottawa, Ontario, Canada. (Email:
Hide All
1. United Nations World Tourism Organization (UNWTO). UNWTO tourism highlights: 2014 edition. Geneva, 2014 ( Accessed 14 September 2014.
2. Greenwood, Z, et al. Gastrointestinal infection among international travelers globally. Journal of Travel Medicine 2008; 15: 221228.
3. Swaminathan, A, et al. A global study of pathogens and host risk factors associated with infectious gastrointestinal disease in returned international travelers. Journal of Infection 2009; 59: 1927.
4. Ravel, A, et al. Description and burden of travel-related cases caused by enteropathogens reported in a Canadian community. Journal of Travel Medicine 2011; 18: 819.
5. Harvey, K, et al. Surveillance for travel-related disease – GeoSentinel Surveillance System, United States, 1997–2011. Morbidity and Mortality Weekly Report. Surveillance Summaries 2013; 62: 123.
6. Leder, K, et al. GeoSentinel surveillance of illness in returned travelers, 2007–2011. Annals of Internal Medicine 2013; 158: 456468.
7. Bogglid, AK, et al. Travel-acquired infections and illnesses in Canadians: surveillance report from CanTravNet surveillance data, 2009–2011. Open Medicine 2014; 8: e2032.
8. Cotton, JA. Host parasite interactions and pathophysiology in Giardia infections. International Journal of Parasitology 2011; 41: 925933.
9. Carmena, D. Waterborne transmission of Cryptosporidium and Giardia: detection, surveillance and implications for public health. In: Mendez-Vilas, ed. Current Research, Technology and Education Topics in Applied Microbiology and Microbial Biotechnology, 2nd edn. Badajoz: Formatex, 2010.
10. Baldursson, S, Karanis, P. Waterborne transmission of protozoan parasites: review of worldwide outbreaks- an update 2004–2010. Water Research 2011; 45: 66036614.
11. Smith, HV, et al. Cryptosporidium and Giardia as foodborne zoonoses. Veterinary Parasitology 2007; 149: 2940.
12. Pozio, E. Epidemiology and control prospects of foodborne parasitic zoonoses in the European Union. Parassitologia 2008; 50: 1724.
13. Younas, M, Shah, S, Talaat, A. Frequency of Giardia lamblia infection in children with recurrent abdominal pain. Journal of Pakistan Medical Association 2008; 58: 171174.
14. Ang, LH. Outbreak of giardiasis in a daycare nursery. Communicable Disease and Public Health 2000; 3: 212213.
15. Hlavasa, MC, et al. Surveillance for waterborne disease outbreaks and other health events associated with recreational water – United States, 2007–2008. Morbidity and Mortality Weekly Report. Surveillance Summaries 2011; 60: 132.
16. Public Health Agency of Canada (PHAC). 2014 ( Accessed 27 April 2014.
17. Region of Waterloo (ROW). Infectious diseases in Waterloo Region: 2013 edition ( Accessed 9 June 2015.
18. Ravel, A, et al. Epidemiological and clinical description of the top three reportable parasitic diseases in a Canadian community. Epidemiology and Infection 2013; 141: 431442.
19. Vrbova, L, et al. A descriptive study of reportable gastrointestinal illnesses in Ontario, Canada, from 2007 to 2009. BMC Public Health 2012; 12: 970.
20. Gormley, FJ, Rawal, N, Little, CL. Choose your menu wisely: cuisine-associated food-poisoning risks in restaurants in England and Wales. Epi and Infect 2012; 140: 9971007.
21. Dohoo, I, Martin, W, Stryhn, H (eds). Veterinary Epidemiologic Research, 2nd edn. Charlottetown: VER Inc., 2010.
22. Van Herck, K, et al. Knowledge, attitudes and practices in travel-related infectious diseases: the European airport survey. Journal of Travel Medicine 2004; 11: 38.
23. Baer, A, et al. Risk factors for infections in international travelers: an analysis of travel-related notifiable communicable diseases. Travel Medicine and Infectious Disease 2014; 12: 525533.
24. Kendall, ME, et al. Travel-associated enteric infections diagnosed after return to the United States, Foodborne Disease Active Surveillance Network (FoodNet), 2004–2009. Clinical Infectious Disease 2012; 54 (Suppl. 5): S480487.
25. Hoque, ME, et al. Risk of giardiasis in Aucklanders: a case-control study. International Journal of Infectious Disease 2002; 6: 191197.
26. Espelage, W, et al. Characteristics and risk factors for symptomatic Giardia lamblia infections in Germany. BMC Public Health 2010; 10: 41.
27. Boggild, AK, et al. Prospective analysis of parasitic infections in Canadian travelers and immigrants. Journal of Travel Medicine 2006; 13: 138144.
28. Bradford, SA, Schijven, J. Release of Cryptosporidium and Giardia from diary calf manure: impact of solution salinity. Environmental Science and Technology 2002; 36: 39163923.
29. Langkjaer, RB, et al. Molecular and phylogenetic characterization of Cryptosporidium and Giardia from pigs and cattle in Denmark. Parasitology 2007; 134: 339350.
30. Bajer, A. Cryptosporidium and Giardia spp. infections in humans, animals and the environment in Poland. Parasitology Research 2008; 104: 117.
31. Plutzer, J, Tomor, B. The role of aquatic birds in the environmental dissemination of human pathogenic Giardia duodenalis cysts and Cryptosporidium oocysts in Hungary. Parasitology International 2009; 58: 227231.
32. Sprong, H, et al. Identification of zoonotic genotypes of Giardia duodenalis . PLoS Neglected Tropical Diseases 2009; 3: e558.
33. Thompson, RC, et al. The molecular epidemiology of Cryptosporidium and Giardia infections in coyotes from Alberta, Canada, and observations on some cohabiting parasites. Veterinary Parasitology 2009; 159: 167170.
34. Stuart, JM, et al. Risk factors for sporadic giardiasis: a case-control study in southwestern England. Emerging Infectious Diseases 2003; 9: 229233.
35. Snel, SJ, et al. A tale of two parasites: the comparative epidemiology of cryptosporidiosis and giardiasis. Epidemiology and Infection 2009; 137: 16411650.
36. Boulware, DR. Influence of hygiene on gastrointestinal illness among wilderness backpackers. Journal of Travel Medicine 2004; 11: 2733.
37. Yoder, J, et al. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking – United States, 2005–2006. Morbidity and Mortality Weekly Report. Surveillance Summaries 2008; 57: 3962.
38. Pardhan-Ali, A, et al. A descriptive analysis of notifiable gastrointestinal illness in the Northwest Territories, Canada, 1991–2008. BMJ Open 2012; 2: e000732.
39. Vollaard, AM, et al. Risk factors for transmission of foodborne illness in restaurants and street vendors in Jakarta, Indonesia. Epidemiology and Infection 2004; 132: 863872.
40. Gould, LH, et al. Contributing factors in restaurant-associated foodborne disease outbreaks, FoodNet sites, 2006 and 2007. Journal of Food Protection 2013; 76: 18241828.
41. Rendtorff, RC. The experimental transmission of intestinal protozoan parasites. II Giardia lamblia cysts given in capsules. American Journal of Hygiene 1954; 59: 209220.
42. Ankarklev, J et al. Common coinfections of Giardia intestinalis and Helicobacter pylori in non-symptomatic Ugandan children. PLoS Neglected Tropical Diseases 2012; 6: e1780.
43. Bhavnani, D, et al. Synergistic effects between Rotavirus and coinfecting pathogens on diarrheal disease: evidence from a community-based study in Northwestern Ecuador. American Journal of Epidemiology 2012; 176: 387395.
44. Mukherjee, AK, et al. Association between Giardia duodenalis and coinfection with other diarrhea-causing pathogens in India. Biomedical Research International 2014; 2014: 786480.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
  • URL: /core/journals/epidemiology-and-infection
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 5
Total number of PDF views: 74 *
Loading metrics...

Abstract views

Total abstract views: 387 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 18th September 2018. This data will be updated every 24 hours.