Systematic Review of Diagnostic Approaches for Human Giardiasis: Unveiling Optimal Strategies

Abstract

Giardiasis, caused by the protozoan Giardia intestinalis, affects around 400 million people worldwide, emphasizing the critical need for accurate diagnosis to enhance human health, especially in children. Prolonged giardiasis in childhood can lead to intellectual deficits and other complications. A variety of diagnostic tools, including microscopic, immunological, and molecular methods, are available for detecting G. intestinalis infection. Choosing the most suitable method can be challenging due to the abundance of options. This systematic review assesses the reliability and applicability of these diagnostic modalities. Utilizing the Dimensions and Wordart platforms for data analysis, we focus on relevant literature addressing diagnostic methods for human giardiasis. Microscopic techniques, particularly Ritchie's method, emerge as the primary choice, followed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). PCR's limited use is attributed to its high cost and infrastructure challenges in developing nations. In conclusion, our analysis supports microscopic methods as the gold standard for giardiasis diagnosis. However, in cases where symptoms persist despite a negative diagnosis, employing more sensitive diagnostic approaches is advisable.

Keywords: ELISA; Giardia; PCR; diagnostic; microscopy; systematic review.

Figure 1

Comprehensive overview of the study selection process for the systematic review.

Figure 2

Comprehensive analysis of selected articles on diagnostic methods for Giardiasis. (a) Presents the number of articles selected for this study, categorized by method groups: Immune Assay, Molecular, and Microscopy. (b) Highlights the percentage of each methodology’s usage in the analyzed articles, considering whether it is employed independently or in combination with other techniques. (c) Illustrates the number of articles published every 4 years over a 64-year period.

Figure 3

Analysis of the number of articles published in each country. (a) Articles were categorized according to the country of publication. (b) Proportion of methodologies used in each country.

Figure 4

Detailed analysis of the specific diagnostic method for giardiasis from selected articles. (a) Illustrates the variety of microscopic diagnostic methods employed in giardiasis diagnosis. Articles that did not specify the methods used or recommended were categorized as “unspecified.” (b) Provides details on the types of dyes applied to samples processed by microscopic methods. (c) Showcases the most prevalent immunoassays in giardiasis diagnosis. (d) Identifies the types of antigens and kits used in the analyzed articles related to immunological assays. (e) Highlights the most frequently used molecular assays in giardiasis diagnosis. (f) Addresses the genetic targets employed in giardiasis diagnosis by molecular methods. MIFC: Merthiolate-Iodine Formaldehyde Concentration; RMT: rapid membrane test; LAMP: loop-mediated isothermal amplification; TPI: triose-phosphate isomerase; GDH: glutamate dehydrogenase; SSU rRNA: small subunit ribosomal RNA.

Figure 5

Sensitivity and specificity rates analysis for the microscopic diagnostic method of giardiasis based on selected articles. (a) Categorization of studies according to sensitivity rates. (b) Categorization of studies according to specificity rates. (c) Percentage representation of sensitivity rates for techniques employed in the microscopic method. (d) Percentage representation of specificity rates for techniques utilized in the microscopic method.

Figure 6

Analysis of specificity and sensitivity rates for the immunoassay diagnostic method of giardiasis from selected articles. (a) Categorization of studies on giardiasis immunoassay diagnostics based on sensitivity rates. (b) Categorization of studies on giardiasis immunoassay diagnostics based on specificity rates. (c) Percentage representation of sensitivity rates for techniques employed in the immunoassay method. (d) Percentage representation of specificity rates for techniques utilized in the immunoassay method.

Figure 7

Classification of articles for the molecular diagnostics of giardiasis from selected sources. (a) Categorization of giardiasis molecular diagnostic articles based on sensitivity rates. (b) Categorization of giardiasis molecular diagnostic articles based on specificity rates. (c) Percentage representation of sensitivity rates for techniques employed in the molecular method. (d) Percentage representation of specificity rates for techniques utilized in the molecular method.