Amoebiasis Clinical Case 10

1. AmoebiasisClinical Case 10 Ellen Marie de los Reyes

2. EF, a fresh college graduate, is applying for a job at a pharmaceutical company. Routine laboratory examinations were requested. Fecalysis revealed (+) E histolytica cyst. Patient is asymptomatic.

3. 1. Give your Diagnosis

4. Amoebiasis • An infection with Entamoeba histolytica produced by the ingestion of cysts in the organism • In the intestines, the cysts develop into trophozoites that adhere to colonic epithelial cells by means of a lectin on the parasite

5. Amoebiasis • Lyses the host cell • invades the submucosa and secretes IFN-γactivated macrophages • This will result in dysentery • The parasite can invade the liver and can develop liver abscesses and an amoebic granulomas developing in the intestinal wall

6. Symptoms • gastrointestinal including diarrhoea, vomiting, abdominal pain or discomfort and fever. • Duration: few days to a few weeks but usually it is about two to four weeks. • Most are asymptomatic • has the potential to make the sufferer dangerously ill • Infections that sometimes last for years may be accompanied by • no symptoms (in the majority of cases), • vague gastrointestinal distress, • dysentery (with blood and mucus).

7. Asymptomatic Infection • the amoeba lives by eating and digesting bacteria and food particles in the gut. • It does not usually come in contact with the intestine itself due to the protective layer of mucus that lines the gut. • Disease occurs when amoeba comes in contact with the cells lining the intestine. • secretes toxic substances, including enzymes that destroy cell membranes and allow it to penetrate and digest human tissues, resulting in flask-shaped ulcers in the intestine.

8. Amoebiasis • Amoebiasis is transmitted: • fecal contamination of drinking water foods • direct contact with dirty hands • sexual contact

9. 2. How would you manage this case?

10. Main drugs • Metronidazole • Tinidazole • Diloxanide *These agents may be used in combination

11. Drugs of choice for various forms of Amoeboisis • Acute invasive intestinal amoeboisis resulting in acute severe amoebic dysentary> metronidazole followed by diloxanide • Chronic intestinal amoeboisis>diloxanide • Heptic amoeboisis>metronidazole followed by dilxanide • Carrier state>diloxanide

12. 3. Discuss the pharmacokinetics of the drug of choice.

13. Metronidazole • Kills the trophozoites of E. histolytica by damaging the DNA by toxic oxygen products generated by thedrug • But has no effect on the cysts • Most effective drug available for invasive amoebiasis

14. Pharmacokinetics • Usually given orally • Rapidly, completely absorbed • Peak plasma concentration 1-3 hrs • Half-life 7 hrs • Distributed rapidly through the tissues reaching high concentrations in the body fluids and CSF • Some are metabolized and most excreted in urine

15. Unwanted effects • Bitter taste in the mouth • Minor gastrointestinal disturbances • Dizziness, headache, sensory neuropathies • Drug interferes with alcohol metabolism

16. Tinidazole • Similar to metronidazole • Eliminated more slowly • Half-life 12-14 hrs

17. Diloxanide • Effective against the non-invasive intestinal parasite • Drugs have a direct amoebicidal action affecting the amoebae before encystment • Given orally • No serious adverse effects

18. And now we reached the end! Thank you!