Analysis morphologic and ultrastructural. Report of a case.

Contact Person: Alberto G Pizarro (rediegal@homonet.com.mx)

Introduction

Amebiasis is the third leading cause of death due to parasitic disease. Although amebiasis is often considered a disease of developing countries, it is an important public health problem throughout the world. At least 90% of infected patients are asymptomatic, but the remainder may present with clinical syndromes ranging from frank dysentery to abscesses of the liver, lungs, or brain.(1)(2)

The amebiasis is a disease produced by a protozoa call Entamoeba Histolytica. The infection starts when the trophozoites of the ameba invade colonic mucosa. (1)

The amebiasis affects everybody, but in certain geographical areas is more aggressive. The amebiasis prevails in countries where there is poverty and dirt. (1,2)

Morphology of the parasite:

Entamoeba Histolytica has two states : Trophozoites and cyst, The trophozoites that are the infect form;. Trophozoites have ameboid shapes and are usually 15 to 25 um., The cytoplasm contain abundant glycogen that stain with PAS is positive, it contains central Kariosome; The mature cyst has four nuclei. (2,3,4)

Clinical features:

In colon: discomfort of the lower abdomen, loose stools, and malodorous flatus, diarrhea, sometimes with mucus and blood, intermittent constipation and tenesmus. (1,2)

In liver: There is hepatomegaly and intensive pain to the tact. The laboratory results report anemia, leukocytosis and elevation of transaminases, lactic dehydrogenase and alkaline phosphatase. The serologic reaction to the seramiba is positive in 95% of the cases. (3,4,5)

In colon: Amebic ulcers are commonly limited to a preference region in rectum and sigmoides, but late are generalized; The typical amebianic ulcer is of rugged edge with a base but broad, the central portion or crater contains necrotic tissue gray that contains fibrine, cellular remains and trophozoites. The mucous among the ulcers is normal and has mucus. There is very few neutrophilic infiltrates; The presence of local eosinophilia does not has a clear. there is not eosinophilia in blood neither in bony marrow, in spite of have amebiasis invading. The ameba can be confused with a macrophage or embryonic cell. (1,2,3,4)

Complications:

The complications of the amebiasis are classified in:

1.- Ameboma

2.- amebic abscess of the liver

3.- cutaneous amebiasis

4.- fistulas

5.- pulmonary amebiasis

6.- brain amebiasis

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