Giardia lamblia antigen test sheet from stool sample

Parasitic infections are still a very serious health problem worldwide today. Giardia lamblia is the most common common protozoan and a major cause of severe diarrhoea, especially in immunocompromised people. Giardia lamblia, also known as Giardia intestinalis, is a flagellated parasite that colonises and multiplies in the small intestine and causes giardiasis. The parasite binds to the intestinal epithelium by its enteral suckers where it reproduces by binary fission. An epidemiological study in 1991 described an upward trend in Giardia infections in the United States, with a prevalence rate of 6% out of 178 000 samples tested. In general, the disease is characterised by a short acute phase followed by a chronic phase. Infection by G. lamblia in the acute phase is associated with watery, dilute diarrhoea and elimination of trophozoites. In the chronic phase, stools return to normal with transient cyst discharge. The parasite, which lives on the wall of the duodenal epithelium, causes malabsorption. The disappearance and atrophy of villus cells in the duodenum and jejunum causes problems in the digestive tract, which can lead to weight loss and dehydration. Despite this, the majority of infections remain asymptomatic. The diagnosis of G. lamblia is made under the microscope, by flotation on zinc sulphate or by direct or indirect immunofluorescence or by non-concentrated samples visualised on a cut slide. The rapid test is based on the detection of the 65kDA glycoprotein coproantigen present in G. lamblia cysts and trophozoites and detects Giardia lamblia in faecal samples within 10 minutes.