The Influence of Selected Factors on the Detection of Giardia intestinalis by Microscopic and Immunoenzymatic Methods

Abstract

Background: Giardia intestinalis is one of the most common parasites in humans. Contaminated food and water can be a source of infection. Substances added to food are intended to increase its safety. We aimed to determination of the influence of various microorganisms and compounds that stimulate digestive functions, as well as preservatives and antioxidants on the detection of G. intestinalis by microscopic and immunoenzymatic methods.

Methods: Twenty stool samples, archived in 1998-2018 in the Provincial Sanitary and Epidemiological Station in Bydgoszcz (Poland), collected both from patients referred for parasitic examinations by a doctor of a medical facility and from private individuals, were used to assess the impact of selected factors (such as bacterial strains, viruses and substances added to food) on the detection of G. intestinalis by microscopic and immunoenzymatic methods.

Results: G. intestinalis was detected by both microscopic and immunoenzymatic methods with the same sensitivity (100%). The result of the G. intestinalis determination was positive in 90% of the samples after the addition of potassium sorbate, and in 25% of the samples after the addition of citric acid.

Conclusion: The presence of other microorganism such as bacteria and viruses does not influence on the detection of G. intestinalis by microscopic and immunoenzymatic methods in stool samples. Citric acid as an antioxidant added to foods affects the detection of G. intestinalis. Due to the small number of samples used, it is necessary to continue research on the impact of various factors on the detection of protozoa.