Haemoflagellates

blood parasites

1. HAEMOFLAGELLATES SHILPA.K MICROBIOLOGY TUTOR AIMSRC

2. H AEMOFLAGELLATES INTRODUCTION : These are the flagellates lie in the blood or tissues of man or animals as the definitive hosts.

3. Kingdom: Protista Phylum: Sarcomastigophora Class: Zoomastigophora Order: Kinetoplastida Family : Trypanosomatidae Genus: Trypanosoma Species: brucei, cruzi , rangeli HAEMOFLAGELLATES

4. STRUCTURE INCLUDE : BODY NUCLEUS KINETOPLAST FLAGELLUM UNDULATING MEMBRANE

5. Developmental stages 2. Promastigote - elongated form and kinetoplast anterior to nucleus ; flagellum arising near it and emerging from the anterior end of body; e.g. Leptomonas 1. Amastigote - rounded or oval forms devoid of external flagellum; e.g. Leishmania

6. 4 . Trypomastigote - the “true” trypanosome type; postnuclear Kinetoplast ; flagellum arising near it to run along a long undulating membrane. 3. Epimastigote - elongated form with a juxta nuclear kinetoplast; flagellum arising near it and emerging from the side of the body to run along short undulating membrane; e.g . Blastocrithidia

7. Generalized life cycle of the Trypanosoma spp Life cycle

8. Pathogenesis T . brucei primarily invade the blood, lymph, and spinal fluid. The course of T. brucei infections depend on the susceptibility of the animals involved. Horses , mules, and even dogs are acute sufferers and can die within 2 weeks of infection. Symptoms of the infection include: anemia, edema and fever. Cattle suffer the same kinds of symptoms but often live a few extra months. Pigs can recover from the infection.

9. Trypanosomes Salivarian trypanosomes ( African trypanosomiasis ) Stercorarian Trypanosomes (South american trypanosomiasis) Sleeping sickness Chag’s disease West African (Gambian) East African (Rhodesian)

10. 1- Trypanosoma brucei gambiense (West A frican) 2- Trypanosoma brucei rhodesiense (East A frican) Definitive Host: Humans , Not pathogenic to any other species. Native ruminates serve as reservoirs for T.b.rhodesiense , but not T.b.gambiense . Intermediate Host: Tsetse fly ( Glossina ) Mode of transmission: Bite of infected tsetse fly. Tsetse fly ( Glossina )

11. Geographic Distribution T. b. gambiense : Found in west central and central Africa. T. b. rhodesiense : F ound in central and east central Africa T. b. gambiense T. b. rhodesiense

12. 1- Trypanosoma brucei gambiense (West African) 2- Trypanosoma brucei rhodesiense (East African) Location: Throughout the body in the blood and tissues. Pathology: Both subspecies cause African Sleeping Sickness. T.b . gambiense causes chronic, long-term form. T.b . rhodesiense causes an acute form. Starts with a small sore at bite. Trypimastigotes divide rapidly and spread throughout body.

13. Life cycle of Trypanosoma brucei

14. Clinical Disease Trypanosoma brucei gambiense (West African) : frequently goes to CNS Causes the chronic, sleepiness associated with African Sleeping Sickness Apathy , mental dullness, disturbance of coordination Increase in sleepiness, finally to coma, and death. Death may also occur from malnutrition, falling, or other infections

15. 2- Trypanosoma brucei rhodesiense (East African ) rarely invade the CNS but causes death much faster. Usually due to invasion of heart tissue Both subspecies produce intermittent periods of fever, particularly in early stages. Due to antigen shifts of the parasite. They can also take antigens from host body and put them on their body Much pathology may be due to heightened immune response killing uninfected body cells.

16. Lab diagnosis Examination of Blood : a ) Thick and Thin Blood Films. b ) Triple Centrifugation Technique. c ) Miniature anion-exchange centrifugation technique. d) Buffy Coat Examination. 2. Examination of Lymph Gland Aspirates. 3. Examination of CSF. 4. Detection of trypanosomal antibodies in the serum.

17. Trypansoma brucei sp. in thick blood smears stained with Giemsa . Trypanosoma brucei sp. in a thin blood smear stained with Giemsa .  The trypomastigote is beginning to divide; dividing forms are seen in African trypanosomes, but not in American trypanosomes .

18. T. b. gambiense and rhodesiense : two forms of trypomastigote can be seen in peripheral blood : Trypanosoma brucei gambiense and rhodesiense : the terminal stage of the infection ("sleeping sickness") is the result of a chronic meningoencephalomyelitis . (H&E stain).

19. Treatment Trypan blue and trypan red S uramin sodium Melarsoprol Difluoromethylornithine Eflornithine

20. Prevention Bug control. eradication of nests. Treating infected person & exclusion of donors by screening blood. Development of vaccine. Using dichlorodiphenyltrichloroethane (DDT ).

21. American Trypanosomiasis

22. American Trypanosomiasis (Chag’s disease ) Definitive Host : Humans , dogs, cats, opossums, armadillos, and wood rats. Intermediate Host : Reduviid bugs (Kissing bug or assassin bugs ). Location in the Definitive Host : Throughout the body. Trypomastigotes in blood. Amastigotes most common in spleen , liver , and muscles, including heart. Mode of Transmission : Invertebrate hosts. Blood transfusion. Sexual and congenital transmission.

23. Geographic Distribution Throughout much of central and South America. 12-19 million infected Annually. 2-3 million with chronic symptoms. 45,000 die from disease every year. A few cases in U.S. in Maryland, Georgia , Florida , Texas, Arizona, New Mexico, California , Alabama, and Louisiana.

24. Life cycle of Trypanosoma cruzi

25. Clinical Syndrome 1.Acute stage : Immediate reaction to infection. Only occurs in about1 % of people infected. Swelling of the eye, tiredness, fever, rash, loss of appetite. Can be fatal for infants, young children and immuno compromised recipients. 2.Intermediate : 8 to 10 weeks after infection No symptoms. 3. Chronic : 10 to 20 years after infection. Enlarged heart and digestive tract. Can result in heart failure. Little effective therapy (toxic drugs/low cure rates)

26. Lab diagnosis 1. Examination of blood : Thick and thin blood films. Buffy coat examination. Trypanosoma cruzi can often be seen in C, U or S shapes in stained films. 2. Xenodiagnosis Blood Culture Serology Tests : IFAT indirect fluorescence antibody test CFT complement fixation test IHAT indirect hem agglutination test ELISA enzyme linked immunoabsorbent assay

27. Lab diagnosis T . cruzi in blood sample, Giemsa stain . T . cruzi amastigotes within host cell. Giemsa stain

28. T. cruzi trypomastigote in cerebrospinal fluid (CSF) stained with Giemsa .

29. immunofluorescence assay showing T.cruzi amastigotes after treatment with anti-T . cruzi polyclonal mouse sera.

30. Treatment Nifurtimox Allupurinol Benznidazole Diuretic treatment Surgical intervention

31. Control Bug control. eradication of nests. Treating infected person & exclusion of donors by screening blood. Development of vaccine . Using dichlorodiphenyltrichloroethane (DDT)

32. References : Hemoflagellates Cultivation of Clinically Significant 10.1128/CMR.15.3.374-389.2002 . Clin . Microbiol . Rev. 2002, 15(3):374. DOI: Frederick L. Schuster and James J. Sullivan.