trypanasoma cruzi

Everything you wanna know about Chagas disease and Trypanosoma cruzi in a nutshell, including the morphology and life-cycle of the parasite ,diagnosis treatment and prophylaxis of Chagas disease.

1. ROBIN T. VAVACHAN Trypanosoma cruzi Chagas’ Disease MD 1

2. INTRODUCTION Carlos Chagas- investigated. Caused by T rypanosoma cruzi 10 million people infected - mostly in Latin America. B ut it has now spread to other continents. Chagas disease is curable if treatment is initiated soon after infection . Habitat – in humans- amastigote(intracellular parasites) and trypomastigote (peripheral blood) forms. 2

3. Trypanosoma cruzi and Chagas’ Disease Transmitted by the insect vector Triatoma infestans (reduviid bug) Reduviid bugs live in mud filled walls of huts in rural areas The bug bites and transmits the disease . Amastigote form in midgut and metacyclic trypomastigote form in hindgut ---of the bug Triatoma infestans (Reduviid bug) Trypanosoma cruzi with human erythrocytes 3

4. Morphology 4 AMASTGOTE FORM Oval bodies- 2-4 μ m diameter- with nucleus and kinetoplast ( network of circular DNA) No flagellum – multiplication occurs in this stage. Found in muscles, nerves, reticuloendothelial cells. TRYPOMASTIGOTE Non-multiplying – flagellated . 2 forms in blood – long flagellates(20 μ m) & short stumpy(15 μ m ) When stained appear like alphabets- C, U / S. These forms taken up by the vector.

5. Morhology ( epimastigote form) Found in the vector. Has kinetoplast adjacent to nucleus. An undulating membrane runs along the anterior half of the parasite. Multiply by binary fission(hindgut). 5

6. 6 Completes in 2 hosts Definitive host – man, intermediate host – reduviid bug, reservoir host – armadillo, cat , dog and pigs. Domestic cycle in humans. Reduviid bugs 1. T riatoma infestans 2. Rhodnius prolixus 3. Panstrongylus megistus lifecycle

7. 7

8. Night biting bugs. bug defecates close to the bite. The parasites enter the body when the person instinctively smears the bug faeces in contact with mucous membranes. Also blood transfusion, organ transplantation & vertical transmission. Transmission Dr.T.V.Rao MD 8

9. Chagas Disease Incubation period : 1-2 weeks. Acute stage : Immediate reaction- 1-4 months. Often children < 2 yrs. Swelling of the eye, tiredness, fever, rash, loss of appetite Inoculation of parasite in conjunctiva causes unilateral, painless edema of periocular tissues in eye – R omana’s sign Chagoma : subcutaneous lesion. Hepatosplenomegaly, lymphadenopathy in some

10. 10 Chronic Chagas disease: Years after initial infection. inducing an inflammatory response, cellular destruction, fibrosis of muscles and nerves, that control tone of hollow organs like heart, oesophagus, colon etc .(intracellular amastigotes destroy the intramural neurons ) Leads to cardiomyopathy, megaesophagus, megacolon.

11. MICROSCOPY CULTURE Novy , Neal, Nicolle mediums. ANIMAL INOCULATION XENODIAGNOSIS Early phase detection, reduviid bugs reared and fed patients blood, organism detected from the faeces of bug. Diagnosis 11

12. HISTOPATHOLOGY SEROLOGY Antigen detection- ELISA Antibody detection-IHA, CFT, ELISA, IIF, DAT, and Chaga’s Radioimmune Precipitation Assay(RIPA) . INTRADERMAL TEST Using cruzin MOLECULAR DIAGNOSIS- PCR ECG and chest X-ray – right bundle branch block and left anterior fascicular block ENDOSCOPY 12

13. Treatment Dr.T.V.Rao MD 13 No effective specific treatment available. benznidazole and nifurtimox chemotherapy( SUCCESS IN BOTH ACUTE AND CHRONIC) Early detection and speedy treatment are the keys to an effective remedy Only kill extracellular trypanosomes & not intracellular. NIFUTRIMOX : 8-10 mg/kg – adults & 15 mg/kg – children, 4 doses a day for 90-120 days orally. BENZNIDAZOLE : 5-10 mg/kg for 60 days orally.

14. prophylaxis Insecticide spraying . personal preventive measures such as bed nets, insect repellent. good hygiene practices in food preparation, transportation, storage and consumption. screening of blood donors , testing of organ, tissue or cell donors and receivers. screening of new-borns from infected mothers, and siblings of infected children. 14

15. THANKS Dr.T.V.Rao MD 15