PARASITOLOGY I: GI parasites Mark K. Huntington, MD PhD FAAFP Sioux Falls Family Medicine Residency Program - University of South Dakota Sanford School of Medicine

2 Activity Disclaimer ACTIVITY DISCLAIMER It is the policy of the AAFP that all individuals in a position to control content disclose any relationships with commercial interests upon nomination/invitation of participation. Disclosure documents are reviewed for potential conflicts of interest (COI), and if identified, conflicts are resolved prior to confirmation of participation. Only those participants who had no conflict of interest or who agreed to an identified resolution process prior to their participation were involved in this CME activity. Dr. Huntington has indicated he has no relevant financial relationships to disclose.

3 Additional Disclaimer This lecture was amply illustrated with breathtaking images – those that were selected because of their ability to make even a calloused trauma surgeon squirm! Alas, collected from myriad sources over more than a quarter of a century of teaching parasitology, copyright attribution and permission could not be established and obtained. While the Fair Use clause of the US Copyright Law permits a teacher to use small portions of a work to illustrate a point in a lecture, their reproduction in this database is generally considered to be outside the limits of the Fair Use intent. That is certainly the AAFP’s position. Too bad; guess you should have been here in person! “The 1961 Report of the Register of Copyrights on the General Revision of the U.S. Copyright Law cites examples of activities that courts have regarded as fair use: “quotation of excerpts in a review or criticism for purposes of illustration or comment; quotation of short passages in a scholarly or technical work, for illustration or clarification of the author’s observations; use in a parody of some of the content of the work parodied; summary of an address or article, with brief quotations, in a news report; reproduction by a library of a portion of a work to replace part of a damaged copy; reproduction by a teacher or student of a small part of a work to illustrate a lesson; reproduction of a work in legislative or judicial proceedings or reports; incidental and fortuitous reproduction, in a newsreel or broadcast, of a work located in the scene of an event being reported.” (emphasis added)

Take-home points How do you get it? –Food? Person-to-person? Vector (which one)? What does it look like? –The disease AND the parasite How do you diagnose it? –Clinically and laboratory (mainly the former) What are control/treatment strategies?

Supplemental resources Despommier’s Parasitic Diseases Markell & Voge’s Medical Parasitology Ash et al’s Parasites: A Guide to Laboratory Procedures & Identification

Symptom-based:* Diarrhea & Dysentery Assorted bowel trouble Hepatobiliary issues Tissue-dwelling, GI acquired *with occasional detours to related parasites Where we are heading

[Deleted – ancient manuscript illustration of man passing worms.] [Deleted – photo of medical student holding worm he passed after global health rotation.] PG PRETTY GRUESOME These lectures are amply illustrated with pictures designed to make even calloused surgeons squirm.

Diarrhea [Deleted – Bristol stool chart]

Cases 8 yr old female presents with diarrhea. –Afebrile –Several stools/day; watery, nonbloody –Mucous membranes tacky 48 year old female presents with diarrhea –Afebrile, tachycardia –Many stools/day; watery, nonbloody –Disaster setting (post-hurricane)

Diarrhea Viral causes –Rotavirus, enterovirus Bacterial causes –Cholera –Travelers’ diarrhea –Tropical sprue (?) Parasitic causes –Giardiasis –Coccidian infections –Balantidium [Deleted – sprue histology] [Deleted – rice water stool]

Giardiasis

[Deleted – Lifecycle]

[Deleted – photomicrograph]

[Deleted – electron micrograph]

[Deleted – another electron micrograph]

[Deleted – histology]

Giardiasis Main symptom: malabsorptive diarrhea To treat, or not to treat…

Coccidian infections Cryptosporidium Cyclospora Isospora Microspora

[Deleted – Lifecycle]

[Deleted – electron micrograph]

[Deleted – stool stain sample]

Balantidiasis

[Deleted – Lifecycle]

[Deleted – photomicrograph]

Balantidium & Cryptosporidium Main symptoms: Diarrhea

Dysentery Significant blood and mucous in diarrhea [Deleted – photo of dysentery]

Case 8 yr old female presents with diarrhea. –Afebrile –Several stools/day; watery, bloody –Mucous membranes tacky

Dysentery Bacterial causes –Shigella –E. coli O157:H7 Parasitic causes –Amoebae –Trichuris [Deleted – electron micrograph] [Deleted – micrograph]

Amoebae Entamoeba histolytica – the main pathogenic amoebae E. coli – appearance is similar to E. histolytica Other GI dwellers –Iodamoeba butschlii –Endolimax nana Naegleria and Acanthamoebae

[Deleted – table comparing commensal amoebae]

[Deleted – Lifecycle]

[Deleted – photomicrograph]

Emerging Infectious Diseases 2012;18:719 (and other sources) [Deleted – colonoscopy image of amoebic ulceration] [Deleted – Histology] [Deleted – colonoscopic image of amoeboma] [Deleted – Histology] [Deleted – colonoscopy image of bowel edema]

[Deleted – CT of amoebic brain abscess] [Deleted – photo of percutaneous draining of amoebic liver abscess] [Deleted – photo of amoebic balantitis]

Non-GI amoeba Naegleria Acanthamoebae

Naegleria

[Deleted – photomicrograph of organism] [Deleted – funny picture illustrating acquisition] [Deleted – photomicrograph of LP sample]

[Deleted – map of cases ] [Deleted – News clipping of case from ]

[Deleted – electron micrograph]

Key points Normally, a free-living amoeba (may contain Legionella) Warm freshwater contact Encephalitis, meningitis

Acanthamoebae

Acanthamoebiasis [Deleted – photomicrograph of organism] [Deleted – close-up of infected eye] [Deleted – another eye]

[Deleted – electron micrograph]

Emerg Inf Dis 2009;15: [Deleted – map of cases]

Key points Normally, a free-living amoeba (may contain Legionella) Strongly associated with contact lenses

Dysentery Bacterial causes Parasitic causes –Amoebae –Trichuris [Deleted – electron micrograph] [Deleted – photomicrograph]

Trichuriasis (whipworm)

[Deleted – Lifecycle] [Deleted – micrograph of ova] [Deleted – electron micrograph of adult worm]

[Deleted – electron micrograph]

Trichuriasis Main symptoms: –diarrhea, may be bloody –tenesmus, –weight loss, –Rarely, rectal prolapse

[Deleted – startling photo of rectal prolapse]

Assorted bowel trouble

Cases 6 year old female with right-sided pelvic mass. –Afebrile, cough –cachexia, poor appetite, nontender 48 year old female with abdominal pain –Chronic –Nausea, fatigue

Ascariasis

Prototype geohelminth [Deleted – animated series of images illustrating the prototypical lifecycle of a geohelminth in a memorable way (involving famous public figures)]

[Deleted – Lifecycle] [Deleted – micrograph of ova] [Deleted –micrograph of migrating larvae] [Deleted – another micrograph of migrating larvae]

Ascaris Main Symptoms: asthma, biliary or colon obstruction After ingestion, larvae hatch and migrate to the liver, heart, lungs, and finally the GI tract.

[Deleted – photo of passing Ascaris bolus]

[Deleted – photo of passed Ascaris bolus]

[Deleted – comic relief photo]

Hookworms (Ancylostoma, Necator)

[Deleted – Lifecycle]

[Deleted – epidemiological map]

[Deleted – colonoscopic image]

[Deleted – photomicrograph]

[Deleted – electron micrograph of the monsters within]

Hookworms Main symptoms: –Anemia –Ground itch Prevention: shoes! [Deleted – photo of calloused feet]

Strongyloidiasis

[Deleted – Lifecycle]

Strongyloidiasis Main symptoms: –Diarrhea –Polymicrobial sepsis Found as larvae, not ova, in stool

[Deleted – stool photomicrograph]

Enterobiasis (pinworms)

[Deleted – Lifecycle]

[Deleted – close-up photograph of pinworms emerging from their lair]

Enterobiasis Main symptoms: pruritis ani Diagnosed via Scotch TM Tape Test

[Deleted – photo of technique]

[Deleted – photomicrograph of ova]

Anisakiasis

[Deleted – Lifecycle]

[Deleted – photo of sushi dinner]

[Deleted – series of images including electron micrograph of parasite penetrating mucosa, endoscopic view of granuloma, and photomicrograph of eosinophilic granuloma]

Anasakiasis Main symptoms: –Transient GI upset (can be severe) –Eosinophilic granulomas (often misdiagnosed)

[Deleted – background photo of extreme close-up of tapeworm] Tapeworms

Cestodes Diphyllobothrium Dipylidium Hymenolepsis Taenia Echinococcus

Prototype cestode Two hosts, two stages [Deleted – animated series of images illustrating the prototypical lifecycle of a cestode in a memorable way (involving famous public figures)]

[Deleted – Lifecycle]

[Deleted – another lifecycle]

[Deleted – historical advertisement for tapeworm eggs for weight loss]

Cestodes Diphyllobothrium (fish, B12 deficiency) Dipylidium (dog) Hymenolepsi s (rodent/arthropod) Taenia (beef/pork, cysticercosis) Echinococcus (dog, hydatid disease)

[Deleted – micrographs of ova [Deleted – endoscopic view of tapeworm

Proglottid [Deleted – anatomic diagram]

[Deleted – ancient illustration of passing a tapeworm]

[Deleted – photograph of tapeworm with proglotids detaching

Cestodes Main symptoms: –Diarrhea / malabsorption –Proglottid escape –(Tissue-dwelling phase symptoms are worse)

Extra-lumenal tapeworms Cysticercosis Hydatid disease

Cysticercosis

[Deleted – Lifecycle]

[Deleted – x-ray of cysticercosis]

[Deleted – MRI of neurocysticercosis]

[Deleted – photos of occular cysticercosis]

[Deleted – photos of lingular (yes, tongue!) cysticercosis]

Key points Most cysticera are asymtomatic Neurocysticercosis is a leading cause of seizure disorder in endemic regions Prevention: hygiene and sanitation

Hydatid disease

[Deleted – photograph of adult worms]

[Deleted – Lifecycle] [Deleted – photo of predator-prey relationship] [Deleted – photo of surprising predator-prey relationship!]

[Deleted – epidemiological map]

[Deleted – x-ray of cerebral hydatid disease]

[Deleted – MRI of cerebral hydatid disease]

[Deleted – autopsy photos of cerebral hydatid disease]

[Deleted – photo of patient with abdominal hydatid disease]

[Deleted – CT of patient with abdominal hydatid disease]

[Deleted – photograph of hydatid cyst] [Deleted – photomicrograph of hydatid sand]

Am. J. Trop. Med. Hyg., 2009;81(3):540–544 [Deleted – 3D CT of monkey with disseminated hydatid disease

Endoscopic treatment without drugs Pre (MRI)Post (CT) AJTMH 2011 [Deleted – brain MRI][Deleted – brain CT]

Key points Most hydatid cysts are symptomatic Highly allergenic Prevention: hygiene and sanitation

[Deleted – background picture of jaundiced face] HEPATOBILIARY SYMPTOMS

Cases 8 yr old male presents with ascites –Afebrile, nontender abdomen –No jaundice 48 year old female presents with jaundice –Afebrile, mild RUQ pain

HEPATOBILIARY SYMPTOMS Non-microbial causes –Medication/herbs –Alcohol –Neoplasm Viral causes –Hepatitic A, B, C… –EBV, CMV –Yellow fever Parasitic causes –Ascariais –Amoebiasis –Hydatid disease –Flukes –Larval migrans –Toxoplasmosis –Leishmaniasis –Malaria

[Deleted – background picture of liver fluke in situ] Flukes

Trematodes Liver flukes Bile flukes Mesenteric flukes Lung fluke

Prototype trematode [Deleted – animated series of images illustrating the prototypical lifecycle of a trematode in a memorable way]

[Deleted – Lifecycle]

[Deleted – another lifecycle]

[Deleted – photo of bile and liver flukes demonstrating comparative sizes]

[Deleted – epidemiological map]

Biliary and liver flukes May be asymptomatic Fever, malaise, weight loss Respiratory symptoms Abdominal pain Hepatomegaly Carcinoma

Schistosomiasis

[Deleted – multiple images based around lifecycle, including lifecycle, photomicrographs and electron micrographs of the parasite at different stages, stool photomicrographs, photographs of the vector, and photograph of caput medusa found in advanced disease.]

[Deleted – epidemiological map]

Other manifestations of schistosomiasis: Colon polyps Hematuria Bladder cancer Swimmer’s itch

Key points Vector = snail Transdermal, fresh-water exposure Immunological pathogenesis

Paragonimus

[Deleted – lifecycle]

[Deleted – CXR] [Deleted – photomicrograph of sputum with ova] [Deleted – photomicrograph of lung biopsy]

[Deleted – epidemiological map] [Deleted – clipping from MMWR of domestic case]

Tissue-dwelling, GI acquired parasites Protozoa Amoebae Toxoplasmosis Helminths Extra-lumenal tapeworms Guinea worm Trichinosis Larval migrans

Toxoplasmosis

[Deleted – Lifecycle]

What’s wrong with this picture?! [Deleted – photograph of pregnant woman with cat and litter box]

What’s wrong with this picture?! [Deleted – photograph of brain lesion on autopsy] [Deleted – x-ray of brain lesion] [Deleted – photograph of another brain autopsy] [Deleted – photograph of retinal lesion on autopsy]

Key points Common, generally asymptomatic Prenatal: part of TORCH syndrome Immunocompromise: HIV, etc. But wait…there’s more!

Psychoparasitism Parasite changed host’s behavior Women –More interested in cat odors –More warmhearted/easy-going –Less suspicious/jealous Men: –Less bound to social rules –More suspicious/jealous [Deleted – graph showing behavioral changes of infected and uninfected rats in response to scents of rats, cats, and humans]

Trichomoniasis (not GI or tissue-dwelling, but had to stick it somewhere!)

[Deleted – electron micrograph] [Deleted – photomicrograph]

Trichomoniasis Main symptoms: –Discomfort –Discharge

Dracontiasis

[Deleted – Lifecycle]

[Deleted – ancient woodcutting of guinea worm extraction] [Deleted – caduceus]

Key points a/k/a Guinea worm Treatment: physical > pharmacologic Control: clean water supply

Trichinosis

[Deleted – Lifecycle]

[Deleted – photograph of trichinosis patient] [Deleted – photomicrograph of muscle biopsy]

Key points From eating pink pork Parasite lives in “nurse cell” A public health success story

Larval migrans (Toxocara)

[Deleted – Lifecycle]

[Deleted – photograph of creeping lesion] [Deleted – photograph of another creeping lesion] [Deleted – fundascopic photograph of ocular larval migans] [Deleted – photomicrograph of visceral larval migrans]

Key points Toxocara canis and Toxocara cati Fecal-oral route; lost in migration Cutaneous and visceral forms Related to our pet addiction in U.S.

Symptom-based:* Diarrhea & Dysentery Assorted bowel trouble Hepatobiliary issues Tissue-dwelling, GI acquired *with occasional detours to related parasites Where we have been

Simplistic GI Antiparasitic Primer Roundworms: –Mebendazole –Pyratel pamoate –Thiabendazole –Ivermectin Tapeworms: –Niclosamine –Quinacrine –Praziquantel Flatworms: –Praziquantel Amoebae: –Metronidazole –Paromomycin Balantidium: –Tetracyline –Metronidazole Cryptosporidium: –Nitazoxanide

Questions or discussion 160

Credits Images utilized in this lecture were wantonly plagiarized from the following sources: –Ash et al, Parasites: A guide to laboratory procedures and identification, ASCP –Halstead et al, Disease of Travelers and Immigrants, Scope Publications –Katz et al, Parasitic Diseases, Springer-Verlag –Markell et al, Medical Parasitology, Saunders –Meyers et al, Pathology of Infectious Diseases, Vol. 1 Helminthiases, AFIP –Peters et al, A Color Atlas of Tropical Medicine and Parasitology, Wolfe –JF Williams, personal collection – image search Reference to commercial trademarks in this lecture is not an endorsement, and more likely causes their respective holders to cringe.