Giardiasis: Treatment, Prevention and Diagnostic Methods

Document Type


Publication Date



Giardiasis is an infection of the small intestine which most often causes severe diarrhea in patients (Hooshyar, Rostamkhani, Arabi & Delavari, 2019). The species responsible for the complications associated with infection is Giardia lamblia (synonymous with G. duodenalis and G. intestinalis). Giardia is a unicellular flagellated protozoan parasite which is harmful when it infects humans.The life cycle is divided into two main stages: cyst and trophozoite. The inactive cyst is very robust and can survive in the environment in harsh conditions for up to 3 months, whereas the trophozoite is the more sensitive, mobile and active feeding form (Rumsey & Waseem, 2019). Giardia lamblia disease is caused by the trophozoite form, and is transmitted through the fecal-oral route. An estimated 280 million cases of giardiasis occur annually around the globe, with about 200 million of those cases originating in Africa, Asia, and Latin America. In the US, about 1.2 million cases occur each year, although experts speculate this figure is under-reported because symptoms vary drastically between patients (Rumsey & Waseem, 2019). While fortunate patients are asymptomatic, others have severe diarrhea, flatulence, stomach cramps, and weight loss. Because this parasitic infection is so widespread, efficient diagnostic testing is critical. A literature review was conducted to evaluate current diagnostic methods and treatments to identify areas where additional research is necessary. Currently, many cases of giardiasis are diagnosed microscopically with the traditional ova and parasite exam. In individuals that have an acute infection or very low amounts of parasitic DNA, more sensitive diagnostic methods may be required (Rumsey & Waseem, 2019). Recently scientists investigated micro RNA present in Giardia to implement as a novel diagnostic tool (Meninger et al.,2019). With improvements, new diagnostic methods, like the aforementioned micro RNA technology, could lower the number of patients infected and lead to better health standards worldwide.

First Advisor

Kari Potter

Research Area

Medical Laboratory Science

This document is currently not available here.