The opportunistic protist, <i>Giardia intestinalis</i>, occurs in gut-healthy humans in a high-income country.

"the sequences for these findings are accessible under genbank numbers or085318-or085322 and or270937-or270938. to estimate the fecal giardia load via qpcr we established a quantification curve using trophozoite cultures (further details available in supplementary data 1).; the variables considered were age (continuous; years) gender (binary; male/female) living location (binary; city/village) travelling (categorical; non-travel/europe/outside europe) and contact with animals (categorical; no contact/contact with pets/contact with pets and livestock) (for more details see supplementary data 2).; the latter two protocols exhibited low specificity and sensitivity (see supplementary data 3 for details).; this low sensitivity was determined through experiments with g intestinalis culture dilutions ranging from 10 -1 -10 4 (supplementary data 4).; for all 47 positive samples we identified the fecal giardia load based on the correlations between obtained ct values and quantification (10 -1 -10 5 cells per qpcr reaction; table 2 and table 4 ; supplementary data 1).; supplementary data 5 presents information concerning asymptomatic giardia -positive individuals."

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"Author contributions: Field work: KB, ZL, OK; Conceptualization: KB, MJ, KJ, CRS; Methodology and investigation: KB, ZL, MJ, DK; Funding acquisition and project administration: KB, KJ; Software: KB, KJP, PS; Validation: KB, KJ, PS, KJP; Draft writing: KB, KJ, KJP, CRS. All authors contributed to the article and approved the submitted version."