2.AA
Primary symptoms of C. parvum infection are acute, watery, and non-bloody diarrhoea. C. parvum infection is of particular concern in immunocompromised patients, where diarrhea can reach 10–15L per day. Other symptoms may include anorexia, nausea/vomiting and abdominal pain.Infection is caused by ingestion of sporulated oocysts transmitted by the fecal-oral route
Entamoeba histolytica is an anaerobic parasitic protozoan.The active (trophozoite) stage exists only in the host and in fresh loose feces; cysts survive outside the host in water, in soils, and on foods, especially under moist conditions on the latter.
http://upload.wikimedia.org/wikipedia/co...ocytes.JPG
http://en.wikipedia.org/wiki/File:Entamo...cle-en.svg
Giardia lamblia is a flagellated protozoan parasite that colonizes and reproduces in the small intestine, causing giardiasis. The giardia parasite attaches to the epithelium by a ventral adhesive disc, and reproduces via binary fission. Giardiasis does not spread via the bloodstream, nor does it spread to other parts of the gastro-intestinal tract, but remains confined to the lumen of the small intestine.
http://upload.wikimedia.org/wikipedia/co..._lores.jpg
Giardia infection can occur through ingestion of dormant cysts in contaminated water, food, or by the faecal-oral route (through poor hygiene practices). The Giardia cyst can survive for weeks to months in cold water, and therefore can be present in contaminated wells and water systems, especially stagnant water sources such as naturally occurring ponds, storm water storage systems, and even clean-looking mountain streams.
http://en.wikipedia.org/wiki/File:Giardi...cle_en.svg
Strongyloides stercoralis is a nematode that can parasitize humans. The adult parasitic stage lives in tunnels in the mucosa of the small intestine.Strongyloides stercoralis is a nematode that can parasitize humans. The adult parasitic stage lives in tunnels in the mucosa of the small intestine.
Many people infected are usually asymptomatic at first. Symptoms include dermatitis: swelling, itching, larva currens, and mild hemorrhage at the site where the skin has been penetrated. If the parasite reaches the lungs, the chest may feel as if it is burning, and wheezing and coughing may result, along with pneumonia-like symptoms (Löffler's syndrome). Eventually, the intestines could be invaded, leading to burning pain, tissue damage, sepsis, and ulcers. In severe cases, edema may result in obstruction of the intestinal tract as well as loss of peristaltic contractions.
Strongyloidiasis in immunocompetent individuals is usually an indolent disease. However, in immunocompromised individuals, strongyloidiasis can cause a hyperinfective syndrome (also called disseminated strongyloidiasis) due to the reproductive capacity of the parasite inside the host. This hyperinfective syndrome has a mortality rate of close to 90%.
http://en.wikipedia.org/wiki/File:Strong..._larva.jpg
wikipedia