An otherwise well 24 year old woman was hiking in the mountains.She drank water from a mountain stream,but did not filter it.Two days later,she reported to an Emergency Department with intractable diarrhoea.An endoscopy biopsy of the small intestine was performed.A representative section is shown in the accompanying photomicrograph.Which one of the following infectious organisms is the most likely cause of these symptoms?

Question

Quizplus · Accepted Answer

The photomicrograph shows luminal Giardia lamblia organisms (G),along with a few erythrocytes (E),probably resulting from minor hemorrhage during the biopsy,as Giardia does not invade the mucosa,nor provoke much of an inflammatory responsEIt is commonly found in mountain streams.Epidemics can occur in the immunocompromised and in institutionalised patients.By contrast,Entamoeba histolytica causes invasive diseasE

An Otherwise Well 24 Year Old Woman Was Hiking in the Mountains.She