Medical Parasitology

1. Medical Parasitology Trypanosoma and Leishmania http://www.uqu.edu.sa/lmalkazmi Email: lmalkazmi@uqu.edu.sa By Dr. Luay Alkazmi

4. طائفة السوطيات Class: Mastigophora طائفة السوطيات الحيوانية Class: Zoomastigophora تقسيم السوطيات الحيوانية: • Blood flagellates • Extracellular flagellates • Endocellularflagellates • سوطيات معوية - Gastric flagellates • سوطيات البولي التناسلي Sexual & urine canal flagellates

5. (Extra cellular flagellates). • رتبة الكينيتوبلاستيدا (Kinetoplastida) • جنس التريبانوسوما (Tripanosomaspp) • نوع تريبانوسوما جامبيا الافريقية (Tripanosomabrucei gambiense)West African trypanosomiasis – nagana – soma • نوع تريبانوسوما روديزنس (Tripanosoma b. rohdeisense)East African trypanosomiasis • نوع التريبانوسوما الامريكية (Chagas disease) American trypanosomiasis

6. (Trypanosoma gambiense): Stages of parasite:

9. An infected triatomine insect vector (or “kissing” bug) takes a blood meal and releases trypomastigotes in its feces near the site of the bite wound. Trypomastigotes enter the host through the wound or through intact mucosal membranes, such as the conjunctiva ملتحمة العين1 .Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes2 . The amastigotes multiply by binary fission 3 and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes 4 . Trypomastigotes infect cells from a variety of tissues and transform into intracellular amastigotes in new infection sites. Clinical manifestations can result from this infective cycle. The bloodstream trypomastigotes do not replicate (different from the African trypanosomes). Replication resumes only when the parasites enter another cell or are ingested by another vector. The “kissing” bug becomes infected by feeding on human or animal blood that contains circulating parasites 5 . The ingested trypomastigotes transform into epimastigotes in the vector’s midgut 6 . The parasites multiply and differentiate in the midgut 7 and differentiate into infective metacyclic trypomastigotes in the hindgut 8

10. symptoms & signs Fever سخونة severe headachesصداع شديد irritability حساسيةextreme fatigueإعياء شديد swollen lymph nodesإنتفاخ للغدد اللمفاوية and aching muscles and joints الم عضلات ومفاصل Some people develop a skin rash حساسية جلدية وطفح Progressive confusionإرتباك تدريجي , personality changes تغير السلوك and other neurologic problems occur after infection has invaded the central nervous system.

11. Diagnosis The diagnosis of Chagas disease can be made by observation of the parasite in a blood smear by microscopic examination. A thick and thin blood smear مسحات دم سميكة ورقيقة are made and stained for visualization of parasites. However, a blood smear works well only in the acute phase of infection when parasites are seen circulating in blood. Diagnosis of chronic Chagas disease is made after consideration of the patient’s clinical findings, as well as by the likelihood of being infected, such as having lived in an endemic country. Diagnosis is generally made by testing with at least two different serologic tests.

12. Treatment The specific drug and treatment course will depend on the type of infection (T. b. gambiense (WAT) or T. b. rhodesiense (EAT)) and the disease stage (i.e. whether the central nervous system has been invaded by the parasite). Pentamidine, which is the recommended drug for first stage T. b. gambiense infection, is widely available in the U.S. The other drugs (suramin حقن السورامين, melarsoprolميلاسوبورال, eflornithineإيفلورنيثين, and nifurtimoxنيفروتيموكس) used to treat African trypanosomiasis are available in the U.S. only from the CDC There is no test of cure for African trypanosomiasis. After treatment patients need to have serial examinations of their cerebrospinal fluid for 2 years, so that relapse can be detected if it occurs.

14. السوطيات داخل خلوية (Endoflagellate): جنس اللشمانيا (Leishmaniesis) أنواعها: اللشمانيا الجلدية (البثرة الشرقية) cutaneous leishmaniasis قرح جلدية في أماكن لدغ الحشرة اللشمانيا البرازيلية mucosal leishmaniasis (الانسجة الجلدية والمخاطية) اللشمانياالحشويةvisceral leishmaniasis (تهاجم الاعضاء الداخلية أو الوجه مسببة مرض الكلازار - kalazar

15. Leishmania tropica أماكن تواجده : • المناطق الرطبة والحارة معيشته: • الطور عديم الاسواط يعيش في الخلايا البلعمية تحت الجلد (إنسان أو فقاريات أخرى) • الخلايا الشبكية للأوعية الدموية • الطور المعدي ذي السوط والشكل المغزلي في الغدد اللعابية لحشرة ذبابة الرمل.

16. Promastigote Promastigote Amastigote

17. Symptoms Breathing difficultyصعوبة التنفس . Skin soresقروح جلدية , which may become a skin ulcerحرقة جلدية that heals very slowly. Stuffy noseسيلان الانف , runny nose, and nosebleeds. Swallowing difficultyصعوبات في البلع .

18. Diagnosis Cutaneous leishmaniasis Your doctor may take a small amount of skin for a biopsy خزعة by scraping one of the ulcers. They’ll often look for the DNA, or genetic material, of the parasite. They can use a variety of methods to identify the species of parasite causing the infection. Visceral leishmaniasis Many times, people don’t remember a bite from a sand fly. This can make the condition hard to diagnose. Observe and investigate the sand-flyفحص عينات من الذباب الرملي

19. Treatment Cutaneous leishmaniasisالجلدية : Cutaneous ulcers will often heal without treatment. However, treatment can speed healing, reduce scarringالندب , and decrease risk of further disease. Any skin ulcers that cause disfigurement التشوهmay require plastic surgery. Mucocutaneous leishmaniasisالمخاطية : These lesions don’t heal naturally. They always require treatment. Liposomal amphotericin B ليبوسومالامفوتيرسين بيand paromomycinبرومومايسنcan treat mucocutaneous leishmaniasis. Visceral leishmaniasisالوعائية Several medications are available. Commonly used medicines include sodium stibogluconate (Pentostamبنتوستام), amphotericin B, paromomycin, and miltefosineميلتيفوسين (Impavidoإمبافيدو).

21. Sample of exam questions Multiple choices Amoebic parasites move by: • Pseudopodes • Flagella • Cilia • Foot • gingelia Infective stage of Leishmaniasis is: • pseuodomastigotes • amastigotes • promastigotes • Foot • epimastigotes

22. Sample of exam questions Explain the life cycle of trypanosoma b. gambience: See the lecture note What are the treatments for leishmaniasis? Antiparasitic drugs, such as amphotericin B (Ambisome), treat this condition. Your doctor may recommend other treatments based on the type of leishmaniasis you have. Cutaneous leishmaniasis Cutaneous ulcers will often heal without treatment. However, treatment can speed healing, reduce scarring, and decrease risk of further disease. Any skin ulcers that cause disfigurement may require plastic surgery. Mucocutaneous leishmaniasis These lesions don’t heal naturally. They always require treatment. Liposomal amphotericin B and paromomycin can treat mucocutaneous leishmaniasis. Visceral leishmaniasis Visceral disease always requires treatment. Several medications are available. Commonly used medicines include sodium stibogluconate (Pentostam), amphotericin B, paromomycin, and miltefosine (Impavido).

23. What is Chagas disease? How do people get Chagas disease? If I have Chagas disease, should my family members be tested for the infection? In what parts of the world is Chagas disease found? What are the signs and symptoms of Chagas disease? What should I do if I think I have Chagas disease? What if I’ve been diagnosed with Chagas disease but have a normal EKG? How is Chagas disease treated? I plan to travel to a rural area of Latin America that might have Chagas disease. How can I prevent infection?

24. What is leishmaniasis? What is the differences between leishmaniasis and leishmania? What are the symptoms and signs of cutaneous leishmaniasis? What are the symptoms and signs of visceral leishmaniasis? How common is leishmaniasis in the world? In what parts of the world is leishmaniasis found? Is leishmaniasis found in the United States? How do people get infected with Leishmania parasites? Who is at risk for Leishmania infection? If I were bitten by an infected sand fly, when would leishmaniasis develop? What should I do if I think I might have leishmaniasis? How is leishmaniasis diagnosed? Does leishmaniasis have to be treated? I plan to travel to an area of the world where leishmaniasis is found. What can I do to prevent infection? If I have already had leishmaniasis, could I get it again?