welcome to parasitic diseases - columbia university
TRANSCRIPT
![Page 1: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/1.jpg)
1
Welcome to Parasitic DiseasesDiseasesFall 2009
Dickson Despommier, Ph.D.
Fall 2009
Dickson Despommier, Ph.D.Charles Knirsch, MPH, MD
Josh Stillman, MDCharles Knirsch, MPH, MD
Josh Stillman, MD
ParasiteAny organism that takes metabolic
advantage of another organismVirusesVirusesRickettsiaebacteriaFungiProtozoa*Helminths*Helminths
Nematodes - round worms Cestodes - segmented flat wormsTrematodes - non-segmented flat worms
Arthropods* - six and eight-legged critters
* Covered in Parasitic Diseases
![Page 2: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/2.jpg)
2
Highly Recommended textbook*Available at bookstore.
* Lots of really gross pictures!!!
Helminths (Worms) Nematodes - non-segmented
round worms
Cestodes - segmented flat worms
Trematodes - non-segmentedflat worms
![Page 3: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/3.jpg)
3
Nematodes Nematodes -- round wormsround worms
1. All are eukaryotes 1. All are eukaryotes -- Caenorhabitis elegansCaenorhabitis elegans is is thethe best known example and is freebest known example and is free living inliving inthe the best known example and is freebest known example and is free--living in living in
soil.soil.
2. Most nematodes are non2. Most nematodes are non--parasitic.parasitic.
3. Almost 4 billion people harbor at least one 3. Almost 4 billion people harbor at least one species of parasitic nematode. Many have species of parasitic nematode. Many have
more than one.more than one.
Geohelminths
Enterobius vermicularis Enterobius vermicularis (Pinworm)(Pinworm)
Trichuris trichiura Trichuris trichiura (Whipworm)(Whipworm)
Ascaris lumbricoides Ascaris lumbricoides (Giant intestinal worm)(Giant intestinal worm)
Toxocara canis and T. cati Toxocara canis and T. cati (Visceral larva migrans)(Visceral larva migrans)
HookwormsHookwormsAncylostoma duodenaleAncylostoma duodenaleNecator americanusNecator americanusNecator americanusNecator americanus
Strongyloides stercoralisStrongyloides stercoralis
![Page 4: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/4.jpg)
4
Use of human fecesas fertilizer is commonplace
Wash all produce before eating
![Page 5: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/5.jpg)
5
Why 1/2 of the world’s humans harbor parasites
Immunity and Parasitism
Parasiteantigen
Worm infections elicit Th2 protective immune responses.Protozoan infections elicit Th1 protective immune responses.
![Page 6: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/6.jpg)
6
Cytokines and Immunity to Parasites
*most important in immune expulsion of protozoa and worms
Helminths:Nematoda
Enterobius vermicularis(Pinworm)
![Page 7: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/7.jpg)
7
Adult Female Enterobius vermicularis
HeadTail
Ovary with eggs
2 mm
![Page 8: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/8.jpg)
8
Adults on perianum deposit eggs
Photo: Martin Weber, MD, Children’s Hospital; Hannover Medical School; Hannover, Germany
Eggs of Enterobius vermicularis
Larva
Unembryonated Embryonated
![Page 9: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/9.jpg)
9
Enterobius vermicularis in appendix
Alae
Clinical Disease:Clinical Disease:
None
![Page 10: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/10.jpg)
10
Diagnosis:Eggs found on microscopic examination of clear sticky tape.
larva
Drug of Choice:
Mebendazole
Mode of Action: De-polymerizes invertebrate tubulins, only.
![Page 11: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/11.jpg)
11
Prevention and Control:
Prevention is impossible among school-aged children, especially those attending day care facilities and lower grades. We “out-grow” our pinworm infections once we reach puberty.
Helminths:Nematoda
Trichuris trichiura(Whipworm)
![Page 12: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/12.jpg)
12
Female adult Trichuris trichiura
Head
Tail
Adult male Trichuris trichiura
Curved tail
HeadHead
![Page 13: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/13.jpg)
13
Adult Trichuris muris in situ (SEM)
![Page 14: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/14.jpg)
14
Pathogenesis:
Trichuris adults secrete a pore-forming protein that may play a role in diarrhea. Adult worms do not feed directly on blood or other host tissues. Mechanism of anemia still unknown.
1: Parasitol Res. 2007 Apr;100(5):921-7. Epub 2007 Jan 6. LinksThe use of Trichuris suis and other helminth therapies to treat Crohn's disease.Reddy A, Fried B.
Crohn’s Disease and iatrogenic Trichuris infection
Department of Biology, Lafayette College, Easton, PA 18042, USA. [email protected] with gastrointestinal (GI) nematodes are prevalent worldwide, despite the fact that anti-helminthic medications are regarded as safe, efficient, and widely available globally. In thisreview, we highlight the potential therapeutic benefits that may be realized through the clinicaluse of Trichuris suis and other helminths for Crohn's disease (CD). Long-lived helminthicparasites are remarkable in their ability to down-regulate host immunity, protecting themselvesfrom elimination, and also minimize severe pathological host changes. This review summarizeswhat is known about the underlying mechanisms that may account for the observed patterns inhumans treated with helminths for CD. The Th2 arm of the immune system is emphasized as acomponent of primary importance in the association between the host immune system and GInematode infections. Although GI nematode infections in humans cause significant morbidityand mortality, the existence and nature of protective mechanisms these helminths may conferremain largely unclear.
![Page 15: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/15.jpg)
15
Prolapsed rectum with many adult Trichuris trichiura
Trichuris adults
Clinical Disease:
1 Diarrhea1. Diarrhea
2. Anemia
3. Malnutrition (protein calorie deficiency?)
![Page 16: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/16.jpg)
16
Diagnosis:Microscopic examination of feces for eggs
25 μm
Fertilized, unembryonated egg
Drug of choice: Mebendazole
Mode of Action:De-polymerizes invertebrate microtubules, only
![Page 17: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/17.jpg)
17
Prevention and Control:
Sanitary disposal of feces
Helminths:Nematoda
Ascaris lumbricoides(Giant intestinal worm)
![Page 18: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/18.jpg)
18
Adult Ascaris lumbricoides
Tail
Head
3 cm
Jar of Ascaris adults
Collected from one ruralCollected from one rural village in Bangladesh in a single day.
![Page 19: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/19.jpg)
19
![Page 20: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/20.jpg)
20
Cross section of adult Ascaris lumbricoides
Larvae of Ascaris lumbricoides in liver
Larvae
![Page 21: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/21.jpg)
21
Larva of Ascaris lumbricoides in lung
Pathogenesis:
1. “Verminous” pneumonia, lung tissue damage due to migratory larvae.
2. Bowel obstruction - too many adult worms.
3. Parasite secretes trypsin inhibitor, prevents host from digesting proteins; cause of malnutrition.
4. Aberrant migration of adult worms to:a. Ampula of Vaterb. Common duct c. Liver d. Pharynxe. Peritoneum
![Page 22: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/22.jpg)
22
Clinical Disease:
1. Light infections are asymptomatic as long as the adult worms do not migrate.
2. Heavy infection leads to: a. protein calorie malnutrition - “failure
to thrive” syndrometo thrive syndrome.b. bowel obstruction. c. aberrant migratory events.
Child with heavy Ascaris lumbricoidesinfection
![Page 23: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/23.jpg)
23
The result of successful treatment
Infant with heavy Ascaris infection
![Page 24: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/24.jpg)
24
Bolus of Ascaris lumbricoides in small intestine
Ascaris lumbricoides adult in appendix
![Page 25: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/25.jpg)
25
Ascaris adults in liver (fatal case)
Bolus of Ascaris lumbricoides (fatal case)
![Page 26: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/26.jpg)
26
Diagnosis:Microscopic examination of feces for eggs
30 μmFertilized, unembryonated egg
Drug of choice:MebendazoleMebendazole
Mode of Action:De-polymerizes invertebrate microtubules, only
![Page 27: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/27.jpg)
27
Medical Ecology
Number of worms per person
Prevention and Control:
Sanitary disposal of feces
![Page 28: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/28.jpg)
28
Helminths:Nematoda
Toxocara canisToxocara cati
Vi l d l l iVisceral and ocular larva migrans
Adult Toxocara canis
Female
Head
MaleTail
1 cm
![Page 29: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/29.jpg)
29
Embryonated egg of Toxocara canis
Larva
45 μm
![Page 30: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/30.jpg)
30
Pathogenesis:g
Tissue damage (systemic) due to migratory 3rd stage larva
Clinical Disease:
1. Fever
2. Loss of visual acuity
3 Blindness3. Blindness
4. Learning disabilities
![Page 31: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/31.jpg)
31
Granuloma in retina due to Toxocara canis
Larvae of Toxocara canis in mouse brain
Larvae
![Page 32: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/32.jpg)
32
Diagnosis:Serological tests (ELISA-based)
Drugs of choice:
Mebendazole
Steroids
Prednisolone
![Page 33: Welcome to Parasitic Diseases - Columbia University](https://reader030.vdocuments.mx/reader030/viewer/2022020703/61fb434c2e268c58cd5c1834/html5/thumbnails/33.jpg)
33
Prevention and Control:
Sanitary disposal of dog and cat fecesfeces
Cover sand boxes at night
Regular treatment of petsRegular treatment of pets