General Parasitology

The following presentation is a general introduction to the field of parasitology, using roundworms as a specific example.

General Parasitology © 2021 by E. Nomi is licensed under CC BY-NC-SA 4.0

Transcript

1. E. Nomi Parasitology - A brief introduction. Photo: medicine.wustl.edu E. Nomi, Dec. 2021
2. E. Nomi 4 Infection Domains
3. E. Nomi 4 Infection Domains - Bacteria Photo: “Tongue Bacteria, SEM” by Steve Gschmeissner, via fineartamerica.com Escherichia coli
4. E. Nomi 4 Infection Domains - Bacteria - Viruses Photo: medicalnewstoday.com SARS-CoV-2 virus
5. E. Nomi 4 Infection Domains - Bacteria - Viruses - Fungi Photo: “Aspergillus fumigatus as seen under a scanning electron microscope” by Koichi Makimura via theconversation.com Aspergillus fumigatus
6. E. Nomi 4 Infection Domains - Bacteria - Viruses - Fungi - Parasites Photo: “Ancylostoma duodenale” by David Scharf via Science Source Ancylostoma duodenale
7. E. Nomi Q: Where could you pick up a parasite? Photos: campus.sg/wp-content; nairobileo.co.ke E. Nomi
8. E. Nomi Answer: Either location! Photos: campus.sg/wp-content; nairobileo.co.ke E. Nomi
9. E. Nomi Parasitology Myth: Parasites are a disease of poverty. Fact: While lack of resources, infrastructure and poor sanitation can increase rates of infection, parasites can be present anywhere there are animals. This includes industrialized nations. Photos: campus.sg/wp-content; nairobileo.co.ke E. Nomi
10. E. Nomi Parasites can spread by: -Direct contact - Air - Water - Soil - Contaminated food Scabies - Sarcoptes scabiei • Scabies infections affect >200 million people globally 1 • Transmitted through skin contact • Mites burrow into top layer of the epidermis • Itching, raised blisters, secondary bacterial infection Photo: parasites.czu.cz Photo: sciencecodex.com E. Nomi
11. E. Nomi Parasites can spread by: - Direct contact -Air - Water - Soil - Contaminated food Photo: afro.who.int Photo: geneticist.tumblr.com Map: cdc.gov/malaria/about/distribution Malaria - Plasmodium • 241 million malaria cases, 627,000 deaths globally in 2020 2 • Caused by several species of Plasmodium • Enters bloodstream via mosquito bite, infects red blood cells • Fever, headache, chills. If untreated, severe illness and death Transmission not known to occur Transmission occurs in some places Transmission occurs throughout E. Nomi
12. E. Nomi Parasites can spread by: - Direct contact - Air -Water - Soil - Contaminated food Giardiasis - Giardia intestinalis • Infects 280 million people per year, globally 3 • Cysts transmitted in contaminated drinking water • Hatch in digestive system, attach to intestinal wall • Diarrhea, gas, cramping, foul-smelling, greasy stools Photo: Dr. Stan Erlandsen, USCDCP via Pixnio Photo: hyperoutdoor.com Photo: matadornetwork.com E. Nomi
13. E. Nomi Parasites can spread by: - Direct contact - Air - Water -Soil - Contaminated food Photo: medicine.wustl.edu Photo: atsdr.cdc.gov Photo: puppytoob.com Soil-Transmitted Helminth Infections •Variety of species infecting >1.5 billion people worldwide (24% of world population). More prevalent in tropical climates 4 •Worms live in intestines, eggs pass in faeces and spread through soil •Most cause gastrointestinal disease, diarrhea and abdominal pain E. Nomi
14. E. Nomi Parasites can spread by: - Direct contact - Air - Water - Soil - Contaminated food Photo: theveganinsider.com Photo: E-Anjei via Getty Images Photo: Figure 1, Madi et al. 2013 Photo: doctorsbeyondmedicine.com Foodborne Parasitic Disease • About 23.2 million cases and 45,927 deaths/year worldwide 5 • Anisakis from raw fish • Tapeworm from unwashed contaminated fruits and vegetables E. Nomi
15. E. Nomi Perfect example of a parasite: the roundworm - Completely dependent on host to survive and reproduce - Distinct internal and external life stages - Causes significant disease Photo: parasitecleanse.net E. Nomi
16. E. Nomi • A common soil-transmitted helminth infection and foodborne disease - Worm eggs ingested from contaminated soil or unwashed fruits and vegetables - Eggs persist in environment for several weeks to several years 6 • Life cycle requires host for maturation stage - Ingested eggs hatch into larvae in digestive tract - Larvae can migrate to the liver, lungs, and other organs - Adults return to digestive tract to lay eggs • One of the most common types of parasitic infections 6 - Infect dogs, cats, humans, pigs, and other animals Roundworms Photo: parasitecleanse.net E. Nomi
17. E. Nomi Photos: parasitecleanse.net, onlinewebfonts.com Two of the most common roundworm infections: 7,8 • Ascariasis - Caused by Ascaris spp. • Toxocariasis - Caused by Toxocara spp. Roundworms E. Nomi
18. E. Nomi Ascariasis • Zoonotic infection: - Pig roundworm (Ascaris suum) - Infects humans, incidence unknown 9 - OR - • Human-to-human infection: - Human roundworm (Ascaris lumbricoides) - Infects 807 million–1.2 billion people world- wide 10 Photos: link.vet.ed.ac.uk, thenounproject.com E. Nomi
19. E. Nomi Ascariasis • Symptoms: - Many carriers are asymptomatic 10 - Abdominal pain, diarrhea - Respiratory symptoms if larvae migrate to lungs • Treatment: - Albendazole, mebendazole or ivermectin - Surgical removal of worms Photos: foxnews.com, istockphoto.com, flickr.com E. Nomi
20. E. Nomi Toxocariasis • Zoonotic infection caused by: - Dog roundworm (Toxocara canis) - Cat roundworm (Toxocara cati) • Larvae can migrate through intestines to liver, lungs, central nervous system, eyes, or other tissues Photos: onlinewebfonts.com, nytimes.com, ilbaccarodublin.com E. Nomi
21. E. Nomi Toxocariasis Photos: parasitophilia.blogspot.com, imagebank.asrs.org, cdc.gov/dpdx/toxocariasis • Symptoms: - Many carriers are asymptomatic 11 - Cough, inflammation, rash, fever - Tissue damage to organs • Treatment: - Albendazole - Mebendazole E. Nomi
22. E. Nomi Photos: chegg.com, “Toxocara Canis” by Sinclair Stammers/science via fineartamerica.com Worm stage E. Nomi
23. E. Nomi Photos: chegg.com, “Toxocara Canis” by Sinclair Stammers/science via fineartamerica.com Egg stage E. Nomi
24. E. Nomi Photos: stickerbrand.com, grainsduquebec.ca, bp.blogspot.com, Life Cycle of Roundworms
25. E. Nomi Photos: stickerbrand.com, grainsduquebec.ca, bp.blogspot.com, Life Cycle of Roundworms Inter nal
26. E. Nomi Photos: stickerbrand.com, sobretumascota.blogspot.com Life Cycle of Roundworms Exter nal
27. E. Nomi Photos: stickerbrand.com, bp.blogspot.com, sobretumascota.blogspot.com, srpplayground.com Life Cycle of Roundworms Exter nal Eggs in soil Inter nal
28. E. Nomi Photos: stickerbrand.com, bp.blogspot.com, sobretumascota.blogspot.com Life Cycle of Roundworms Exter nal Fertilized eggs mature Inter nal
29. E. Nomi Photos: stickerbrand.com, bp.blogspot.com, sobretumascota.blogspot.com, simplemost.com, atsdr.cdc.gov Life Cycle of Roundworms Eggs ingested, hatch Inter nal Exter nal
30. E. Nomi Photos: stickerbrand.com, bp.blogspot.com, sobretumascota.blogspot.com, istockphoto.com Life Cycle of Roundworms Inter nal Exter nal Larvae can migrate to different parts of the body
31. E. Nomi Photos: stickerbrand.com, bp.blogspot.com, sobretumascota.blogspot.com, grainsduquebec.ca, caribbeanmedicaljournal.org, cram.com Life Cycle of Roundworms Inter nal Exter nal Mature worms in intestines lay eggs
32. E. Nomi Photos: stickerbrand.com, grainsduquebec.ca, bp.blogspot.com, sobretumascota.blogspot.com, dogster.com, “Roundworm In Dog Feces” by John Daniels via fineartamerica.com Life Cycle of Roundworms Eggs passed back into soil Exter nal Inter nal
33. E. Nomi Photos: stickerbrand.com, grainsduquebec.ca, bp.blogspot.com, sobretumascota.blogspot.com Life Cycle of Roundworms Inter nal Exter nal
34. E. Nomi • Wash hands after being outdoors or handling animals • Wash fruits and vegetables before eating • Regularly deworm your pets, keep animal pens clean Prevention Photos: dogsaholic, clipartkey.com, dreamstime.com
35. E. Nomi Photo: sciencebusiness.net, mebendazole_ivermectinsales, albendazole_salvavidaspharma WHO recommended medicines: • Mebendazole (500 mg) Anthelmintic Drugs • Albendazole (400 mg) • The WHO recommends periodic deworming treatment to all at-risk people living in endemic areas, with or without a diagnosis.
36. E. Nomi Growing Drug Resistance • Some worms survive treatment • The survivors breed • Drug resistance genes spread through population • Drug stops working = Resistant = Susceptible
37. E. Nomi Why Does Parasitology Matter? • Parasites can cause diseases • Parasites can be found almost everywhere • The diseases they cause are getting worse - Warming climate causing parasites to spread further 12 - Growing resistance to drug treatments worldwide 13 Photo: theveganinsider.com
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40. E. Nomi Thank You! Photo: medicine.wustl.edu
41. E. Nomi References 1. The World Health Organization. (2020, August 16). Scabies. Retrieved December 13, 2021, from https://www.who.int/news-room/fact-sheets/detail/scabies 2. World Health Organization. (2021). World malaria report 2021. Retrieved December 13, 2021, from https://apps.who.int/iris/handle/10665/350147 3. Laishram, S., Kang, G., & Ajjampur, S. S. R. (2012). Giardiasis: A review on assemblage distribution and epidemiology in India. Indian Journal of Gastroenterology, 31(1), 3–12. https://doi.org/10.1007/s12664-012-0161-9 4. World Health Organization. (2020, March 02). Soil-transmitted helminth infections. Retrieved December 13, 2021, from https://www.who.int/news-room/fact-sheets/detail/soil-transmitted-helminth-infections 5. Torgerson, P. R., Devleesschauwer, B., Praet, N., Speybroeck, N., Willingham, A. L., Kasuga, F., Rokni, M. B., Zhou, X. N., Fèvre, E. M., Sripa, B., Gargouri, N., Fürst, T., Budke, C. M., Carabin, H., Kirk, M. D., Angulo, F. J., Havelaar, A., & de Silva, N. (2015). World Health Organization Estimates of the Global and Regional Disease Burden of 11 Foodborne Parasitic Diseases, 2010: A Data Synthesis. PLoS medicine, 12(12), e1001920. https://doi.org/10.1371/journal.pmed.1001920 6. The Centers for Disease Control and Prevention. (2021). What Every Pet Owner Should Know About Roundworms & Hookworms [Fact sheet]. U.S. Department of Health & Human Services. https://www.cdc.gov/parasites/resources/pdf/roundworms_hookworms.pdf 7. The Centers for Disease Control and Prevention. (2020, October 27). Parasites - Soil-transmitted helminths. Retrieved December 27, 2021, from https://www.cdc.gov/parasites/sth/index.html 8. The Centers for Disease Control and Prevention. (2021). Neglected Parasitic Infections in the United States Toxocariasis [Fact sheet]. U.S. Department of Health & Human Services. https://www.cdc.gov/parasites/resources/pdf/npi_toxocariasis.pdf 9. Silva, T., Barbosa, F. S., Magalhães, L., Gazzinelli-Guimarães, P. H., Dos Santos, A. C., Nogueira, D. S., Resende, N. M., Amorim, C. C., Gazzinelli-Guimarães, A. C., Viana, A. G., Geiger, S. M., Bartholomeu, D. C., Fujiwara, R. T., & Bueno, L. L. (2021). Unraveling Ascaris suum experimental infection in humans. Microbes and infection, 23(8), 104836. https://doi.org/10.1016/j.micinf.2021.104836 10. The Centers for Disease Control and Prevention. (2020, November 23). Parasites - Ascariasis. Retrieved December 7, 2021, from https://www.cdc.gov/parasites/ascariasis/ 11. The Centers for Disease Control and Prevention. (2021). Neglected Parasitic Infections in the United States Toxocariasis [Fact sheet]. U.S. Department of Health & Human Services. https://www.cdc.gov/parasites/toxocariasis/resources/toxocariasis_provider_fact_sheet.pdf 12. Pozio, E. (2019). How globalization and climate change could affect foodborne parasites. Experimental Parasitology, 107807. https://doi.org/10.1016/j.exppara.2019.107807 13. Sierra, J. M., Fusté, E., Rabanal, F., Vinuesa, T., & Viñas, M. (2017). An overview of antimicrobial peptides and the latest advances in their development. Expert Opinion on Biological Therapy, 17(6), 663–676. https://doi.org/10.1080/14712598.2017.1315402 14. Murdaca, G., Greco, M., Borro, M., & Gangemi, S. (2021). Hygiene hypothesis and autoimmune diseases: A narrative review of clinical evidences and mechanisms. Autoimmunity Reviews, 20(7), 102845. https://doi.org/10.1016/j.autrev.2021.102845 15. Wang, M., Wu, L., Weng, R., Zheng, W., Wu, Z., & Lv, Z. (2017). Therapeutic potential of helminths in autoimmune diseases: helminth-derived immune-regulators and immune balance. Parasitology Research, 116(8), 2065–2074. https://doi.org/10.1007/s00436-017-5544-5
42. E. Nomi Other References Belleza, Marianne. (2021, February 11). Roundworms (Ascariasis). Nurselabs. Retrieved December 7, 2021, from https://nurseslabs.com/roundworms-ascariasis/ Fialho, P. M., & Corrêa, C. R. (2016). A Systematic Review of Toxocariasis: A Neglected But High-Prevalence Disease in Brazil. The American journal of tropical medicine and hygiene, 94(6), 1193–1199. https://doi.org/10.4269/ajtmh.15-0733 Kenyon, F., Hutchings, F., Morgan-Davies, C., van Dijk, J., & Bartley, D. J. (2017). Worm Control in Livestock: Bringing Science to the Field. Trends in Parasitology, 33(9), 669–677. https://doi.org/10.1016/j.pt.2017.05.008 L’Ollivier, C., & Piarroux, R. (2013). Diagnosis of human nematode infections. Expert Review of Anti-Infective Therapy, 11(12), 1363–1376. https://doi.org/10.1586/14787210.2013.851001 Moxon, C. A., Gibbins, M. P., McGuinness, D., Milner, D. A., & Marti, M. (2019). New Insights into Malaria Pathogenesis. Annual Review of Pathology: Mechanisms of Disease, 15(1). https://doi.org/10.1146/annurev- pathmechdis-012419-032640 Nazer, H. (2018, October 1). Giardiasis. Retrieved December 13, 2021, from https://www.who.int/news-room/fact-sheets/detail/scabies Pearson, Richard D. (2020, September). Toxocariasis. SD Manual. Retrieved December 21, 2021, from https://www.msdmanuals.com/professional/infectious-diseases/nematodes-roundworms/toxocariasis Stepek, G., Buttle, D. J., Duce, I. R., & Behnke, J. M. (2006). Human gastrointestinal nematode infections: are new control methods required?. International journal of experimental pathology, 87(5), 325–341. https://doi.org/10.1111/j.1365-2613.2006.00495.x The Centers for Disease Control and Prevention. (2013). Neglected Parasitic Infections in the United States Toxocariasis [Fact sheet]. U.S. Department of Health & Human Services. https://www.cdc.gov/parasites/toxocariasis/resources/toxocariasis_fact_sheet.pdf The Centers for Disease Control and Prevention. (2020, November 23). Parasites - Ascariasis. Retrieved December 7, 2021, from https://www.cdc.gov/parasites/ascariasis/gen_info/faqs.html The Centers for Disease Control and Prevention. (2021, February 26). Parasites - Giardia, Illness and Symptoms. Retrieved December 20, 2021, from https://www.cdc.gov/parasites/giardia/illness.html The World Health Organization. (2021, December 6). Malaria. Retrieved December 14, 2021, from https://www.who.int/news-room/fact-sheets/detail/malaria