1.Kappus, KD, et al. Intestinal parasitism in the United States: update on a continuing problem. American Journal of Tropical Medicine and Hygiene 1994; 50: 705–713.
2.Centers for Disease Control and Prevention. Giardiasis surveillance – United States, 2003–2005. Morbidity and Mortality Weekly Report 2007; 56: 11–18.
3.Birkhead, G, Vogt, RL. Epidemiologic surveillance for endemic Giardia lamblia infection in Vermont: the roles of waterborne and person-to-person transmission. American Journal of Epidemiology 1989; 129: 762–768.
4.Isaac-Renton, JL, Philion, JJ. Factors associated with acquiring giardiasis in British Columbia residents. Canadian Journal of Public Health 1992; 83: 155–158.
5.Gagnon, F, et al. Risk of giardiasis associated with water supply in an endemic context. International Journal of Environmental Health Research 2006; 16: 349–359.
6.Chute, CG, Smith, RP, Baron, JA. Risk factors for endemic giardiasis. American Journal of Public Health 1987; 77: 585–587.
7.Hoque, ME, et al. Children at risk of giardiasis in Auckland: a case-control analysis. Epidemiology and Infection 2003; 131: 655–662.
8.Stuart, JM, et al. Risk factors for sporadic giardiasis: a case-control study in southwestern England. Emerging Infectious Diseases 2003; 9: 229–233.
9.Centers for Disease Control and Prevention. Surveillance for waterborne-disease outbreaks – United States, 1997–1998. Morbidity and Mortality Weekly Report 2000; 49: 1–45.
10.Centers for Disease Control and Prevention. Surveillance for waterborne-disease outbreaks- United States, 1999–2000. Morbidity and Mortality Weekly Report 2002; 51: 1–28.
11.Centers for Disease Control and Prevention. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking – United States, 2001–2002. Morbidity and Mortality Weekly Report 2004; 53: 23–45.
12.Centers for Disease Control and Prevention. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking – United States, 2003–2004. Morbidity and Mortality Weekly Report 2006; 55: 31–58.
13.Centers for Disease Control and Prevention. 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 2008; 57: 39–62.
14.Sulaiman, IM, et al. Triosephosphate isomerase gene characterization and potential zoonotic transmission of multispecies Giardia duodenalis. Emerging Infectious Diseases 2003; 9: 1444–1452.
15.Environmental Protection Agency. Method 1623: Cryptosporidium and Giardia in water by filtration/IMS/FA. Washington, DC, USA: Office of Water, 2005; EPA 815-R-05-002.
16.Environmental Protection Agency. Consensus method for determining ground water is under the direct influence of surface water using microscopic particulate analysis (MPA). Washington, DC, USA: Office of Water, 1992; EPA Report Number 910/9-92-029.
17.Hill, VR, et al. Multi-state evaluation of an ultrafiltration-based procedure for simultaneous recovery of enteric microbes in 100-L tap water samples. Applied and Environmental Microbiology 2007; 73: 4218–4225.
19.Navin, TR, et al. Case-control study of waterborne giardiasis in Reno, Nevada. American Journal of Epidemiology 1985; 122: 269–275.
20.Sulaiman, IM, et al. Distribution of Giardia duodenalis genotypes and subgenotypes in raw urban wastewater in Milwaukee, Wisconsin. Applied and Environmental Microbiology 2004; 70: 3776–3780.
21.Robertson, LJ, et al. Application of genotyping during an extensive outbreak of waterborne giardiasis in Bergen, Norway, during autumn and winter 2004. Applied Environmental Microbiology 2006; 72: 2212–2217.
22.Thompson, RCA, Palmer, CS, O'Handley, R. The public health and clinical significance of Giardia and Cryptosporidium in domestic animals. Veterinary Journal 2008; 177: 18–25.
23.Fayer, R, et al. Prevalence of Microsporidia, Cryptosporida spp., and Giardia spp. in beavers (Castor canadensis) in Massachusetts. Journal of Zoo and Wildlife Medicine 2006; 37: 492–497.
24.Dykes, AC, et al. Municipal waterborne giardiasis: an epidemiologic investigation. Beavers implicated as a possible reservoir. Annals of Internal Medicine 1980; 92: 165–170.
25.Lopez, CE, et al. Waterborne giardiasis: a community wide outbreak of disease and a high rate of asymptomatic infection. American Journal of Epidemiology 1980; 112: 495–507.
26.Teodorovic, S, Braverman, JM, Elmendorf, HG. Unusually low levels of genetic variation among Giardia lamblia isolates. Eukaryotic Cell 2007; 6: 1421–1430.
27.Dixon, BR, et al. Giardia duodenalis and Cryptosporidium spp. in the intestinal contents of ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus) in Nunavik, Quebec, Canada. Journal of Parasitology 2008; 94: 1161–1163.
28.Foronda, P, et al. Identification of genotypes of Giardia intestinalis of human isolates in Egypt. Parasitology Research 2008; 103: 1177–1181.
29.Caccio, SM, Ryan, U. Molecular epidemiology of giardiasis. Molecular and Biochemical Parasitology 2008; 160: 75–80.
30.Keeley, A, Faulkner, BR. Influence of land use and watershed characteristics on protozoa contamination in a potential drinking water resources reservoir. Water Research 2008; 42: 2803–2813.
31.LeChevallier, MW, Norton, WD, Lee, RG. Occurrence of Giardia and Cryptosporidium spp. in surface water supplies [published erratum appears in Applied and Environmental Microbiology 1992; 58: 780]. Applied and Environmental Microbiology 1991; 57: 2610–2616.
32.Ryu, H, Abbaszadegan, M. Long-term study of Cryptosporidium and Giardia occurrence and quantitative microbial risk assessment in surface waters of Arizona in the USA. Journal of Water Health 2008; 6: 263–273.
33.Wallis, PM, et al. Prevalence of Giardia cysts and Cryptosporidium oocysts and characterization of Giardia spp. isolated from drinking water in Canada. Applied and Environmental Microbiology 1996; 62: 2789–2797.
34.Dunlap, BG, Thies, ML. Giardia in beaver (Castor canadensis) and nutria (Myocastor coypus) from east Texas. Journal of Parasitology 2002; 88: 1254–1258.