PARA WEEK 15.pdf

PROTOZOA 15 class: mastigophora HEMOFLAGELLATES Include the Trypanosomes and Leishmanias May infect the blood, lymph nodes, muscles, and RES Four morphologies or stages: Amastigote: leishmanial form Promastigote: Leptomonal form Epimastigote: Crithidial form Trypomastigote:...

PROTOZOA 15 class: mastigophora HEMOFLAGELLATES Include the Trypanosomes and Leishmanias May infect the blood, lymph nodes, muscles, and RES Four morphologies or stages: Amastigote: leishmanial form Promastigote: Leptomonal form Epimastigote: Crithidial form Trypomastigote: Trypanosomal form 1. AMASTIGOTe Appearance: Round to oval Nucleus: One, usually off center Features: Kinetoplast present consisting of a dotlike blepharoplast NO FLAGELLA 2. PROMASTIGOTE Appearance: Long and slender Nucleus: One, located in or near center Features: Kinetoplast, located in anterior end Single free flagellum extending from anterior end 3. EPIMASTIGOTE Appearance: Long and slightly wider than promastigote form Nucleus: One, located in posterior end Features: Kinetoplast located anterior to the nucleus Undulating membrane - extending half of body length Free flagellum - extending from anterior end 4. TRYPOMASTIGOTE Appearance: C, S or U shape often seen in stained blood films long and slender Nucleus: One, located anterior to the kinteoplast Features: Kinetoplast located in the posterior end Undulating membrane – extending entire body length Free flagellum – extending from anterior end Leishmania spp. Depending on the species involved, infection with Leishmania spp. can result in cutaneous, diffuse cutaneous, mucocutaneous, or visceral disease. Leishmania spp. exist as amastigote: humans promastigote: insect Vector: Sandfly (Phlebotomus spp.) Diagnostic stage: Amastigotes Infective stage: Promastigotes Modes of Transmission: insect vector congenitally blood transfusion, contamination of bite wounds, direct contact with contaminated specimens life cycle: Promastigotes in proboscis of sandfly are injected into blood, multiplying in bloodstream and become amastigotes laboratory diagnosis: Montenegro Skin Test screening test similar to that of the tuberculin skin test Leishmania braziliensis complex vector: Lutzomiya Psychodopygus sandflies reservoir host: Dogs and forest rodents disease association: Mucocutaneous Leishmaniasis Chiclero Ulcer Espundia Forest Yaws Pian Bois Uta WEEPING LESIONS pathology: Large ulcers in the oral or nasal mucosa areas (mucocutaneous) develop after the initial invasion of the RES. Edema and secondary bacterial infections, combined with numerous mucosal lesions, may cause disfigurement of the patient’s face. Death is usually attributed to a secondary bacterial infection. Leishmania mexicana complex vector: Lutzomiya spp. sandfly reservoir host: Forest rodents disease association: New World Cutaneous Leishmaniasis Chiclero Ulcer Bay Sore pathology: Characterized by a single pus-containing ulcer, which is generally self- healing. Approximately 40% of infections affect the ear and can cause serious damage to the surrounding cartilage. - Infected patients initially develop a small red papule, located at the bite site, which is typically 2 cm or larger in diameter and may cause pruritis. Leishmania tropica complex vector: Phlebotomus spp. sandfly reservoir host: Rock hyrax dogs gerbils other rodents disease association: Old World Cutaneous Leishmaniasis Oriental Sores Delhi boils Baghdad boils Aleppo button Jericho boil DRY LESIONS pathology: Ulcer characteristics similar to Leishmania mexicana complex Thick plaques of skin, along with multiple lesions or nodules, usually result. Leishmania donovani complex vector: Phlebotomus Lutzomiya sandflies reservoir host: Dogs cats foxes jackals porcupines disease association: Visceral Leishmaniasis Kala-azar Dumdum Fever BLACK FEVER pathology: Visceral Leishmaniasis: Patients develop a nondescript abdominal illness and hepatosplenomegaly Early stages of disease may resemble malaria or typhoid fever with the development of fever and chills. Advanced stages of disease result in kidney damage (e.g., glomerulonephritis) and granulomatous areas of skin. A characteristic darkening of the skin may be noted. Trypanosoma brucei complex t. brucei East African Sleeping Sickness Tsetse fly rhodesiense (more rapid and fatal) Glossina palpatis t. brucei West African Sleeping Sickness Tsetse fly gambiense (Glossina morsitans) mode of transmission: Bite of insect vector needle prick placental Infective Stage: Metacyclic Trypomastigotes diagnostic Stage: Trypomastigotes “sleeping sickness” Characterized by an acute phase in which peripheral blood and lymph nodes are invaded, followed by a chronic phase in which the CNS is invaded, resulting in meningoencephalitis; comatose state develops commonly known as ”sleeping sickness” pathology Chancre (central eschar) – earliest sign Winterbottom’s Sign – inflammatory swelling of the lymph nodes Kerandel’s Sign – delayed sensation to pain Somnolence – excessive sleepiness Comatose lab diagnosis Febrile stage – blood and lymphatics Sleeping Sickness stage (CNS) – CSF Presence of IgM in serum and/or CSF is generally considered diagnostic Trypanosoma cruzi Agent of American Trypanosomiasis or “Chagas” Disease Described by a young medical student in Brazil named Carlos Chagas vector: Vector: Triatoma (kissing bugs, Reduviid bugs, Assassin bugs, cone nose bugs) Mode of Transmission: Contamination of the bite wound with the feces from the reduviid bug. Life Cycle: Metacyclic trypomastigotes will invade macrophages amastigotes will emerge and form trypomastigotes Infective Stage: Metacyclic Trypomastigotes Diagnostic Stage: Trypomastigotes Amastigotes lab diagnosis Febrile stage – blood and lymphatics Sleeping Sickness stage (CNS) – CSF Presence of IgM in serum and/or CSF is generally considered diagnostic pathology: Chagoma: erythematous nodule at the site of infection Romaña’s Sign: unilateral edema of the eyelids Myocarditis Megacolon: enlargement of the colon Megaesophagus Hepatosplenomegaly Cardiomegaly: enlargement of the heart HEMOFLAGELLATES Include the Trypanosomes and Leishmanias May infect the blood, lymph nodes, muscles, and RES Four morphologies or stages: Amastigote: leishmanial form Promastigote: Leptomonal form Epimastigote: Crithidial form Trypomastigote: Trypanosomal form 1. AMASTIGOTe Appearance: Round to oval Nucleus: One, usually off center Features: Kinetoplast present consisting of a dotlike blepharoplast NO FLAGELLA