Question

A five-year-old girl from Canada experience severe diarrhea, abdominal pain and cramping, chronic weight loss, anorexia, chronic fatigue and flatulence. Examination by her pediatrician led him to order stool examination. The stool sample was submitted in the laboratory and the gross appearance was noted as liquid, with mucus and tinges of blood. It was immediately processed by standard techniques. The direct and concentrated saline wet preparation slide showed suspicious, irregularly shaped forms. The Medical technologist on duty decided to hold the report for further studies. The suspicious form seen in Iron Hematoxylin stain is shown in the diagram. This form measured 13 um. Questions to answer:

1. Which amoeba is the most likely to cause the infection?

2. State the key differential characteristics that will distinguish the parasites from other species.

3. State the life cycle of responsible parasite emphasizing the route of transmission, and infective and diagnostic stage.

4. What are the treatment options and how can this parasitic infection be prevented or controlled?

Answer 1

1.It is caused by protozoan parasite Entamoeba hystolytica​​​​​​​​​​.

Invasive parasitic infection can result bloody or mucus diarrhea, abdominal discomforts etc.

2.entamoeba hystolytica is an anaerobic parasitic amoebozoan, part of the genus entamoeba.

Characteristics used to distinguished,

Trophozoites:

Motility :progress or nonprogress

Cytoplasam:finely granular, coarsely granular inclusions erythrocytes, bacteria, molds.

Nucleus :number present

Peripheral chromatin present or absence

Size:sizes overlap, spherical shape

3.

transmission

The active(trophozoite)stage exit only in host and fresh looses feces

Cystes survive outside the host in water, soil, foods etc.the infection occur through mouth if the person touch the feces of the infected persons.

Infections may be asymptomatic or can lead to dycentry, amoebic liver abscess. Symptoms includes

1.fulminating dycentry

2.bloody and mucus diarrhoea

3.weight loss

4.fatigue

5.abdominal discomforts

Diangnosis

Diagnosis is confirmed by microscopic examination for trophozoites or cystes in the feces.a blood test is available but its recommended if the infection spreaded to beyond intestine(gut)to some other organs such as liver.stool antigen detection and PCR are available for diagnosis, and are more sensitive and specific than microscopy

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