Microbes of the Blood: African Trypanosomes and Filarial Worms 2024 - PDF

FOM 6: Parasites of the Blood African Trypanosomes and Filarial Worms Michelle Steinauer, Ph.D. "Trypanosoma-evansi-rat-blood-Giemsa-stain" by Alan R Walker - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.  Learning Objectives Fo...

FOM 6: Parasites of the Blood African Trypanosomes and Filarial Worms Michelle Steinauer, Ph.D. "Trypanosoma-evansi-rat-blood-Giemsa-stain" by Alan R Walker - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.  Learning Objectives For Filarial worms: – Know the major species of filarial worms and Their general life cycle Their vectors The major disease syndromes caused – Understand the disease course be able to recognize a case of filariasis/onchocerciasis/loaiasis given the symptoms, disease course, epidemiologic factors, and/or diagnostics – Understand how to diagnose infection For African trypanosomiasis: – Understand the life cycle and transmission – Know the two types of African trypansomiasis and where they occur – Understand the disease course be able to recognize a case of African Trypanosomiasis given the symptoms, disease course, epidemiologic factors, and/or diagnostics. – Understand how to diagnose infection  Background Reading Despommier, Griffin, Gwadz,Hotez, Knirsch. Parasitic Diseases, 7th Edition – Free Download: https://parasiteswithoutborders.com/books/  Pathogens of the B & L Protozoal infections – Malaria: Plasmodium spp. (protozoa) – Babesiosis: Babesia spp. (protozoa) – Leishmania spp. (Leishmaniasis) – African Trypanosomes: Trapanosoma brucei gambiense, Trypanosoma brucei rhodesiense (African sleeping sickness) – American Trypanosomes: Trapanosoma cruzi Chagas disease Helminths – Wuchereria bancrofti (lymphatic filariasis) – Loa Loa (Eye worm) Filarial Worms – Onchocerca volvulus (River Blindness) – Schistosoma spp. (schistosomiasis) – Dracunculus medinensis Bacterial Infections – Borrelia burgdorferi (Lyme disease) – Borrelia recurrentis (relapsing fever) – Francisella tularensis (Tularemia) – Bartonella henslae (cat scratch fever) – Pasteurella spp. (animal bites) – Rickettsia rickettsii (tick bite) – Anaplasma (Tick Bite) – Ehrlichia (Tick Bite)  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lymphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  Filarial Worms: Nematoda Phylum: Nematoda (roundworms) huge number of species – found in/on almost every living organism most are non-pathogenic (free-living) Dioecious Direct and Indirect life cycles Molt – Juvenile stages J1,J2,J3,J4 adult 6  Filarial Worms: Blood and Lymph Nematodes Vector Borne – Mosquito – Biting Fly juveniles in circulation or lymphatics Microfilaria  Life Cycle Adult worms in lymphatics, Biting insect subcutaneous ingest juveniles. tissue, or eye Insect injects juveniles (species into blood and juveniles develop into adults dependent) Release larvae into peripheral blood or lymph  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lymphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  Lymphatic Filariasis Wuchereria bancrofti Brugia malayi >120 million infected, 40 million with clinical symptoms https://parasitesandvectors.biomedcent Distributed: ral.com/articles/10.1186/s13071-020- 04024-2 – Tropical areas South Asia Africa Americas https://askhematologist.com/filariasis/ Lymphatic Filariasis  Lymphatic Filariasis Wuchereria bancrofti/ Brugia malayi – Adults in lymph system – Microfilariae in blood (blood smear for diagnosis--nighttime) Symptoms: – Many are subclinical – Inflammatory response leads to dilation of vessels and blockage – Acute lymphadenitis: fever and painful swelling of lymph nodes (inguinal) Some patients progress to chronic disease – Lymphedema: Damage to lymph system and blockage. Thickening of skin, higher susceptibility to infections – Swelling of peripheral limbs, legs, scrotum breasts. Diagnosis: Blood smear, serologic tests Treatment: Diethylcarbamazine (DEC)  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lymphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  Loiasis: Eye Worm Eye Worm: Loa loa Central and West Africa https://www.youtube.com/watch? v=BwlNw_GaMUE https://medizzy.com/feed/796211  Loa loa Fly Vector Chrysops spp. (Deer/horse/mango flies)  Loiasis: Eye Worm Eye Worm: Loa loa – Adults form nodules in skin or eye. Movement seen. – Microfilariae move to lymph then lungs, migrate to blood occasionally – Adults live 17 years – Do not typically damage eye. – Symptoms: Symptomless in those living in endemic regions Itching, hives, muscle pain Diagnosis: Removal of worm from eye or nodule. Microfilariae can be detected in blood smear (daytime). Treatment: diethylcarbamazine (DEC) (graded treatment)  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lymphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  Onchocerciasis: River Blindness River Blindness: Onchocerca volvulus Distributed: – Africa and Middle East https://www.sciencedirect.com/science/article/a bs/pii/B9780323555128001162  Onchocerca volvulus Fly Vector Black Fly Simulidae Filarial Worms: Blood and Lymph Nematodes River Blindness: Onchocerca volvulus Adults in subcutaneous nodule, microfilariae throughout lymph. Adults live 10-15 years, microfilariae 10-15 months. – Symptoms due to immune reaction as worms die. Itching, skin rashes Lesions on cornea Skin damage→ change in pigmentation, loss of elasticity, and thinning Diagnosis: Skin snip Treatment: Ivermectin every 6 months for the worm’s life span https://www.medindia.net/patients/patientinfo/onchocerciasis.htm  Summary Filarial Worms Vector borne – Mosquitoes – Flies Nematodes – Find in blood smears – In subcutaneous tissue – In eyes Wuchereria bancrofti – lymphatic filariasis Loa loa Skin and eye worm Ochocerca volvulus River Blindness Chronic infections  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lymphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  African Trypanosomiasis American Trypanosomiasis – Trypanosoma cruzi Chagas Disease African Trypanosomiasis Trypanosoma brucei gambiense – Chronic Trypanosoma brucei rhodesiense – Acute – maladie du sommeil https://www.microbe. tv/twip/twip-104/  African Trypanosomiasis Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense Chronic: Years Acute: Weeks Lundkvist et al 2004. Why trypanosomes cause sleeping sickness  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lyphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness Life Cycle African Trypanosomiasis Trypanosoma brucei gambiense Key Points Vector Borne Disease Tsetse Fly (Glossina) Parasite in blood and lymph, can move to CSF Diagnostics: Find parasite in blood smear Cattle and wildlife are reservoirs for some species or subspecies of parasites  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lyphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness  African Trypanosomiasis Clinical Syndrome Highly fatal if untreated Acute v. Chronic Presentation depending on parasite species – Few weeks or few years Two stages: – Hemolymphatic Stage – Meningioencephalatic Stage Chancre at site of bite Febrile period: Intermittent fever, headache, extreme fatigue, joint pain, Lymphadenopathy (Winterbottom’s sign) CNS: Severe headache, confusion, personality changes, stiff neck, seizures, loss of consciousness, coma Diagnosis: Blood smear, CSF smear Treatment: Best early in infection. – Pentamidine – Suramin – Melarsoprol  Summary African Trypanosomiasis Vector born – Tsetse fly (Glossina) Chronic and Acute forms (subspecies) – Hemolymphatic Stage – CNS stage Diagnostics – Parasites in blood smear, CSF, serologic tests  Outline Filarial Worms – General Characteristics Distribution Life cycle and development – Species and syndromes Wuchereria bancrofti and Brugia malayi: Lyphatic filariasis Loa loa: Loiasis or eye worm Onchocerca volvulus: River blindness African Trypanosomiasis – Species Trypanosoma brucei gambiense Trypanosoma brucei rhodesiense – Distribution – Life Cycle – Clinical Sleeping sickness Review Questions  How do you diagnose filarial worm disease? (Look at notes section for answer)  How do you treat filarial worm disease? (Look at notes section for answer)  How do you diagnose African sleeping sickness? (Look at notes section for answer)  How do you treat African sleeping sickness? (Look at notes section for answer)  Which pathogen is consistent with the following symptoms: – Intermittent fever, headache, extreme fatigue, joint pain, cervical lymphadenopathy (Winterbottom’s sign). – Then neurologic symptoms-confusion then loss of consciousness. A. Loa loa B. Wuchereria bancrofti C. Trypanosoma cruzi O D. Trypanosoma brucei gambiense E. Plasmodium falciparum  Which pathogen is consistent with the following symptoms: – Lymphedema – Thickening of skin A. Loa loa O B. Wuchereria bancrofti C. Trypanosoma cruzi D. Trypanosoma brucei gambiense E. Plasmodium falciparum  Case Report: https://www.ajol.info/index.php/sjms/article/view/114535 A 21-year-old patient in Tanzania presented with progressive unilateral swelling of the vulva over 2 years. A blood smear showed what is in the photograph. Which is the most likely pathogen? A. Loa loa O B. Wuchereria bancrofti C. Oncocerca volvulus D. Trypanosoma brucei gambiense E. Plasmodium falciparum