Definition:- This is an infestation caused by Giardia intestinalis (also called G. lamblia and duodenalis). Maximum infections are sporadic due to fecal contamination of food or drink, by person to person or anal-oral sexual contact. Travelers, campers, male homosexuals and persons with low immune status are also affected.
Incubation period 1-3 weeks.
Clinical Features-Children are mostly affected (more than 20% in developing countries) though adults are not immune to it. It is possible that achlorhydria, malnutrition, low IgA secretion from the gut and low gammaglobulin level in blood may predispose to infection. Children often produce symptoms whereas adults usually do not. Symptoms include diarrhoea, with characteristic foul smelling, bulky, greasy, frothy stool, abdominal pain, distension, flatulence and gradual emaciation. Symptoms may suggest amoebiasis or sprite syndrome. Anorexia, nausea, vomiting, fever may sometimes develop. In severe cases malabsorption syndrome may be seen. This may result in fat and protein losing enteropathy associated with Disaccharidase and Vitamin B12 deficiency, which may persist for a long time f% en after apparent cure. Allergic manifestations may also develop. Diagnosis This is done by finding the characteristic vegetative and cyst -ms of G. intestinalis in the stool. Concentration method also be used. When stool examination is negative Duodenal or jejunal aspirates of mucus obtained by string test endoscopy may be examined for the parasite. Coproantigen z7S by ELISA and IFA are also very specific (90%400%) and sensitive (85%-90%). Radiological investigation may also show increased transit time, thickened mucosa, altered motility of small intestine.
Treatment Drugs- Metronidazole 1 tab (250 mg) thrice daily for 7-10 days may be given. A higher dose of 350-750 mg three times daily for 10 days or even 2 gm once daily for 3 days have also been recommended for some patients.
Gastrointestinal side effects, e.g., nausea, vomiting, metallic taste in the mouth are commonly seen. Other reactions include headache, giddiness, candidial over growth and disulphirum like reaction in alcoholics. However, in some parts of the world this drug is not recommended in Giardiasis for its mutagenicity. Tinidazole It may also be used in a dose of 150 mg thrice daily for 8 days. A single dose of 0.5-2 gm may also be helpful. Side effects as in Metronidazole therapy may be seen but are less marked.
Quinacrine hydrochloride (Mepacrine) 0.1 gm thrice daily for 5-7 days is given. It should not be given in psoriatic subjects.
Furazolidone (Furoxone) 100 mg 4 times daily for 7 days may be used. Of all these drugs the first two drugs are very often used by the practitioners as they have practically little side effects.