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group_2_presentation_1_-_ascariasis [2020/01/29 21:08] gandhr11 [Pathophysiology] |
group_2_presentation_1_-_ascariasis [2020/02/02 13:42] (current) mumtaa1 [Acaris subtypes] |
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| - | <box 40% width centre|> {{ :wiki1.jpg?direct&200 |}} </box| Figure 1. Intestine Ascariasis cross section .> | + | <box 40% width centre|> {{ :wiki1.jpg?direct&200 |}} </box| Figure 1. Intestine Ascariasis cross section. Retrieved from: https://parasitecleansers.com/parasites-in-humans/intestinal-parasites/roundworm/ascaris/ .> |
| ====== What is Ascariasis? ====== | ====== What is Ascariasis? ====== | ||
| - | One of the most prevalent yet neglected tropical diseases worldwide with 800 million-1.2billion annual cases (Shah & Shahidullah, 2018). Ascariasis is caused by roundworms that usually target the intestines. Similar to other parasites, they develop within the host from larvae or egg to a mature adultworm. The parasites that achieve biological maturity and are capable of reproducing are typically 12 inches or 30cm in length (Mayo Clinic, 2018 | + | One of the most prevalent yet neglected tropical diseases worldwide with 800 million-1.2 billion annual cases (Shah & Shahidullah, 2018). Ascariasis is caused by roundworms that usually target the intestines. Similar to other parasites, they develop within the host from larvae or egg to a mature adult-worm. The parasites that achieve biological maturity and are capable of reproducing are typically 12 inches or 30cm in length (Mayo Clinic, 2018). |
| ====== History====== | ====== History====== | ||
| The presence of ascariasis can date back to 2277 BC, where A. lumbricoides eggs were discovered in the fossilized feces of a human from Peru (Cox, 2002). Ascariasis is an ancient disease with records dating back to 1938 and 1600 BC of A. lumbricoides in a Middle Kingdom Egyptian mummy and from the Ming Dynasty in China between AD 1368 and 1644 (Cox, 2002). | The presence of ascariasis can date back to 2277 BC, where A. lumbricoides eggs were discovered in the fossilized feces of a human from Peru (Cox, 2002). Ascariasis is an ancient disease with records dating back to 1938 and 1600 BC of A. lumbricoides in a Middle Kingdom Egyptian mummy and from the Ming Dynasty in China between AD 1368 and 1644 (Cox, 2002). | ||
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| The first detailed anatomy of A. lumbricoides was depicted in the late 17th century by an English physician - Edward Tyson (Cox, 2002). Soon after, Francesco Redi wrote a book describing the worm; it was one of the first books of parasitology (Cox, 2002). The study of helminthology reached its peak in the 19th century, partly due to these two publications (Cox, 2002). Scientist began attempting to understand the infections caused by Ascaris and how to treat them (Cox, 2002). | The first detailed anatomy of A. lumbricoides was depicted in the late 17th century by an English physician - Edward Tyson (Cox, 2002). Soon after, Francesco Redi wrote a book describing the worm; it was one of the first books of parasitology (Cox, 2002). The study of helminthology reached its peak in the 19th century, partly due to these two publications (Cox, 2002). Scientist began attempting to understand the infections caused by Ascaris and how to treat them (Cox, 2002). | ||
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| In 1878, Italian physician and zoologist, Giovanni Battista Grassi, was the first to demonstrate the infectivity of A. lumbricoides by ingesting the eggs found in the feces of those who died from the disease (Cox, 2002; Silva, 2019). It wasn’t until 1922 when a Japanese pediatrician, Shimesu Koino, infected both a volunteer and himself, that he discovered the life cycle of Ascaris in the human body (Cox, 2002). | In 1878, Italian physician and zoologist, Giovanni Battista Grassi, was the first to demonstrate the infectivity of A. lumbricoides by ingesting the eggs found in the feces of those who died from the disease (Cox, 2002; Silva, 2019). It wasn’t until 1922 when a Japanese pediatrician, Shimesu Koino, infected both a volunteer and himself, that he discovered the life cycle of Ascaris in the human body (Cox, 2002). | ||
| ==== Acaris subtypes ==== | ==== Acaris subtypes ==== | ||
| - | Ascaris Lumbricoides typically infects human populations whereas Ascaris suum is most commonly observed in animal populations. The two parasites are also referred to as geo-helminths suggesting that the infection is primarily transmitted via contaminated soil (Center for Control and Disease [CDC], n.d.). Ascaris eggs in the soil are capable of surviving upto 10 years, and only take 10-15 days to become infective in the soil (CDC, n.d.) | + | |
| + | Ascaris Lumbricoides typically infects human populations whereas Ascaris suum is most commonly observed in animal populations. The two parasites are also referred to as geo-helminths suggesting that the infection is primarily transmitted via contaminated soil (Center for Control and Disease [CDC], n.d.). Ascaris eggs in the soil are capable of surviving up to 10 years, and only take 10-15 days to become infective in the soil (CDC, n.d.) | ||
| The two roundworms are drastically different genetically, in fact in the past it has been debated whether they should be classified as two different species. However, recently following a molecular analysis extreme similarities in the worms’ nucleotide and amino acid sequences have led researchers to classify them as a single species (Monteiro et al., 2019). Additionally, both roundworms have been observed to infect humans and pigs supporting the notion that despite certain genetic differences the two worms are the same species. Furthermore, they’re almost indistinguishable morphologically and follow a similar infectious pathway once inside the host. The subtle morphological differences such as the shape of lips and size of teeth can be detected through an Electron microscope (Monteiro et al., 2019). | The two roundworms are drastically different genetically, in fact in the past it has been debated whether they should be classified as two different species. However, recently following a molecular analysis extreme similarities in the worms’ nucleotide and amino acid sequences have led researchers to classify them as a single species (Monteiro et al., 2019). Additionally, both roundworms have been observed to infect humans and pigs supporting the notion that despite certain genetic differences the two worms are the same species. Furthermore, they’re almost indistinguishable morphologically and follow a similar infectious pathway once inside the host. The subtle morphological differences such as the shape of lips and size of teeth can be detected through an Electron microscope (Monteiro et al., 2019). | ||
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| The worms are both anthroponotic and zoonotic meaning that cross-transmission of the infection is bi-directional. Humans and pigs are both capable of transmitting the infection to each other (Monteiro et al., 2019). | The worms are both anthroponotic and zoonotic meaning that cross-transmission of the infection is bi-directional. Humans and pigs are both capable of transmitting the infection to each other (Monteiro et al., 2019). | ||
| - | <box 40% width centre|> {{ :group2a.jpg?direct&300 |}} </box| Figure 2. Even though they are two different, they come from one single species .> | + | |
| + | <box 80% width centre|> {{ ::group2a1.jpg |}} </box| Figure 2. Even though they are different, they come from one single species .> | ||
| ====== Statistics ====== | ====== Statistics ====== | ||
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| ====== Life Cycle ====== | ====== Life Cycle ====== | ||
| - | Ascaris infections are contracted via the oral route, often from ingesting infective A. lumbricoide eggs (Murrell et al., 1997). A female adult worm can produce approximately 200,000 eggs per day, which are then passed with the feces of the host (CDC - Ascariasis - Biology, 2019). These eggs can be non-infective if the eggs are unfertilized, however larvae within fertile eggs will develop to infectivity after 18 days to several weeks (CDC - Ascariasis - Biology, 2019). Although, how quickly they develop to infectivity is highly dependent on its environmental conditions; with the optimum environment being warm and moist with shaded soil (CDC - Ascariasis - Biology, 2019). Following the ingestion of an infective egg, it will hatch in the small intestine and migrate to the lungs through the portal, then systemic circulation (CDC - Ascariasis - Biology, 2019). Once the larvae is at the lungs, it will mature for 10 to 14 days before penetrating the alveolar walls and ascending the bronchial tree to reach the throat before being swallowed once more (CDC - Ascariasis - Biology, 2019). Hence, the larvae returns to the small intestine where it will develop into adult worms (CDC - Ascariasis - Biology, 2019). Female adult worms take 2 to 3 months from ingestion of the infective eggs to produce more eggs, while the male adult worms can live one to two years within its host (Mayo Clinic Staff, 2018). | + | Ascaris infections are contracted via the oral route, often from ingesting infective A. lumbricoide eggs (Murrell et al., 1997). A female adult worm can produce approximately 200,000 eggs per day, which are then passed with the feces of the host (CDC - Ascariasis - Biology, 2019).These eggs can be non-infective if the eggs are unfertilized, however larvae within fertile eggs will develop to infectivity after 18 days to several weeks (CDC - Ascariasis - Biology, 2019). Although, how quickly they develop to infectivity is highly dependent on its environmental conditions; with the optimum environment being warm and moist with shaded soil (CDC - Ascariasis - Biology, 2019). Following the ingestion of an infective egg, it will hatch in the small intestine and migrate to the lungs through the portal, then systemic circulation (CDC - Ascariasis - Biology, 2019). Once the larvae is at the lungs, it will mature for 10 to 14 days before penetrating the alveolar walls and ascending the bronchial tree to reach the throat before being swallowed once more (CDC - Ascariasis - Biology, 2019). Hence, the larvae returns to the small intestine where it will develop into adult worms (CDC - Ascariasis - Biology, 2019). Female adult worms take 2 to 3 months from ingestion of the infective eggs to produce more eggs, while the male adult worms can live one to two years within its host (Mayo Clinic Staff, 2018). |
| <box 40% width centre|> {{ :group2b.jpg?direct&300 |}} </box| Figure 3.Life Cycle of Ascaris (CDC-Ascariasis-Biology, 2019).> | <box 40% width centre|> {{ :group2b.jpg?direct&300 |}} </box| Figure 3.Life Cycle of Ascaris (CDC-Ascariasis-Biology, 2019).> | ||
| ====== Clinical Manifestation====== | ====== Clinical Manifestation====== | ||
| - | {{ ::natural-remedies-for-intestinal-parasites-88232_final-df66327f179d4afe9c24c296d29d255c.png?direct&300 |}} | + | <box 40% width centre|> {{ :natural-remedies-for-intestinal-parasites-88232_final-df66327f179d4afe9c24c296d29d255c.png?300 |}} </box| Figure 4. Possible symptoms of parasite infection. Usually there no symptoms but in rare cases these are possible symptoms. Retrieved from: https://www.verywellhealth.com/natural-remedies-for-intestinal-parasites-88232.> |
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| **What are the symptoms?** | **What are the symptoms?** | ||
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| ====== Etiology ====== | ====== Etiology ====== | ||
| - | There is no clear answer for what causes ALS; however, studies have shown that both genetics and the environment plays a role in acquiring the disease. | + | Ascaris lumbricoides which is a soil transmitted roundworm causes ascariasis (Lima & Horrall, 2019). The adult male can reach up to 15-20 cm in length while the adult female reaches up to 20-30 cm (Lima & Horrall, 2019).Female worms are also thicker compared to male worms (Lima & Horrall, 2019). On average, an adult parasite lives for a year. After parasite dies, it leaves the digestive tract (Lima & Horrall, 2019).A person can become infected with ascariasis after accidentally ingesting A. lumbricoides eggs (Ascariasis, 2019). This infection can also occur through eating or drinking contaminated food or water, especially if the individual did not wash the food and his/her hands (Fletcher, 2018). For instance, an individual can contract ascariasis from the consumption of uncooked raw vegetables grown in soil contaminated by roundworm eggs (Ascariasis, 2019). These eggs are usually found in soil that is contaminated with human feces (Ascariasis, 2019). Finally, children are often infected after playing in contaminated soil and putting their hands in their mouth (Fletcher, 2018). |
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| - | ==== Genetics ==== | + | |
| - | Genetics impacts the development of ALS due to many various factors. Firstly various gene mutations can cause ALS. Scientists discovered that gene mutations in the SOD1 genes were connected to familial ALS as they had the ability to degenerate motor neurons (Mayo Clinic, 2018). ALS can also be due to chemical imbalances. People with ALS usually have high levels of glutamate, a chemical messenger in the brain, which is toxic to neurons (Mayo Clinic, 2018). Lastly, ALS can be due to an altered immune system in which the immune system attacks nerve cells, leading to its death (Mayo Clinic, 2018). | ||
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| - | ==== Environment ==== | ||
| - | ALS can also be caused by the environment (Mayo Clinic, 2018). Kamel et al. (2005) believe that exposure to toxins or infectious agents cause ALS – especially in those who are exposed to high levels of lead (Kamel et al., 2005). Secondly, studies show that physical traumas and previous hospitalization are correlated to a higher risk of ALS. Specific studies also show that physical traumas at earlier ages leads to a higher risk in ALS (Seals, Hansen, Gredal, & Weisskopf, 2016). Lastly, a study by Swash (2018) has shown that increased physical activity has a linear association with ALS as it is linked to excitotoxicity, or nerve cell death of the central nervous system (Swash, 2018). | + | |
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| The pathophysiology of ascariasis is linked to considerable organ damage (Das, 2014). The larvae entering into the intestinal mucosa and the liver leads to hypersensitivity and increased immune response (Kakihara et al., 2004). Upon the response and activation and attachment of eosinophils to the larvae itself, some may be immobilized and restricted for further movement (Kakihara et al., 2004). The stoppage and restriction of many larvae can cause the formation of aggregation of granulomas, a collection of macrophages that have the capacity to calcify and harden (Khuroo, 1996). | The pathophysiology of ascariasis is linked to considerable organ damage (Das, 2014). The larvae entering into the intestinal mucosa and the liver leads to hypersensitivity and increased immune response (Kakihara et al., 2004). Upon the response and activation and attachment of eosinophils to the larvae itself, some may be immobilized and restricted for further movement (Kakihara et al., 2004). The stoppage and restriction of many larvae can cause the formation of aggregation of granulomas, a collection of macrophages that have the capacity to calcify and harden (Khuroo, 1996). | ||
| - | <box 18% width centre|> {{ :group2d.png?direct&200 |}} </box| Figure x. Granuloma skin disorder caused by the stoppage and restriction of larvae. Retrieved from:https://www.aad.org/public/diseases/a-z/granuloma-annulare-treatment .> | + | <box 18% width centre|> {{ :group2d.png?direct&200 |}} </box| Figure 5. Granuloma skin disorder caused by the stoppage and restriction of larvae. Retrieved from:https://www.aad.org/public/diseases/a-z/granuloma-annulare-treatment .> |
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| ==== Tests and Examinations ==== | ==== Tests and Examinations ==== | ||
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| + | Adult female ascariasis worms lay eggs in the intestine (Ascariasis, 2018). These eggs then travel through the digestive system and can eventually be found in the stool (Ascariasis, 2018). Eggs take at least 40 days to appear in the stool sample after an individual is infected. If the individual is infected with male worms, then there would be no eggs (Ascariasis, 2018). Diagnosis usually happens by a doctor through examining a stool sample for parasites and eggs. Stool sample is analyzed under a microscope to identify ascaris eggs (CDC, 2018). It might be hard to find eggs in light infections. Therefore, a concentration procedure is recommended (CDC, 2018). Concentration procedure increases the chance of identifying ascaris eggs even when eggs are present in small numbers (CDC, 2016). This occurs by separating parasites from fecal debris (CDC, 2016). | ||
| + | If the person is diagnosed with this disease then an imaging tests such as x-ray, ultrasound, CT scan, or MRI might be required (Ascariasis, 2019). To begin with, x-rays are electromagnetic radiations that produce images of the structures inside the body (Lucas, 2018). X-ray can show the worm’s mass in the abdomen. Also, a chest x-ray can identify the larvae in the lungs (Ascariasis, 2018). Ultrasound uses high frequency soundwaves to view internal organs. This imaging technique can show worms in the liver or pancreas (Ascariasis, 2018). CT scans and MRI can detect worms that are blocking ducts in the pancreas or liver (Ascariasis, 2018). These tests can show the doctor the location of worms inside the body and also the number of worms that have reached maturity (Ascariasis, 2019). Finally, in some cases of heavy infestation, it is possible for worms to come out of nostrils or mouth after coughing or vomiting (Ascariasis, 2018). In this situation it is recommended to take the worm to a doctor so the doctor can identify the worm and prescribe a treatment (Ascariasis, 2018). | ||
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| + | <box 80% width centre|> {{ :group2c.jpg?direct |}} </box| Figure 6. Different imaging techniques showing ascariasis. A. CT scan B.X-ray C. Ultrasound D. MRI. Retrieved from https://prod-images-static.radiopaedia.org/images/9266208/0674081a3cd727a37588ee4b3160ed_gallery.jpg; Retrieved from https://radiopaedia.org/articles/biliary-ascariasis?lang=us; Retrieved from https://radiopaedia.org/articles/biliary-ascariasis?lang=us; Retrieved from https://ak1.picdn.net/shutterstock/videos/26476841/thumb/1.jpg .> | ||
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| - | {{ :group2c.jpg?direct |}} | ||
| ====== Current Treatment and Therapeutics ====== | ====== Current Treatment and Therapeutics ====== | ||
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| {{:anthelminthic_drugs_animation_mebendazole_and_albendazole.mp4|}} | {{:anthelminthic_drugs_animation_mebendazole_and_albendazole.mp4|}} | ||
| - | <box 40% width left|> {{:unnamed.gif?direct |}} </box| Figure x. Chemical Structure of Ivermectin. Retrieved from:http://www.chm.bris.ac.uk/motm/ivermectin/ivermectinh.htm .> | + | <box 40% width left|> {{:unnamed.gif?direct |}} </box| Figure 7. Chemical Structure of Ivermectin. Retrieved from:http://www.chm.bris.ac.uk/motm/ivermectin/ivermectinh.htm .> |
| **2. Ivermectin** | **2. Ivermectin** | ||
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| Pyrantel is a nicotinic acetylcholine receptor agonist (Silva, R.D., 2019). This type of medication acts by causing spastic muscle paralysis in the parasitic worms (Silva, R.D., 2019). This is a result of a constant release of acetylcholine in the body wall muscle of the parasitic worms (Silva, R.D., 2019). Hence, the worm becomes incapable of moving, allowing the body to sweep the worm out naturally through the host’s stool (Silva, R.D., 2019). However, this medication is also poorly absorbed in the host’s intestinal tract (Silva, R.D., 2019). | Pyrantel is a nicotinic acetylcholine receptor agonist (Silva, R.D., 2019). This type of medication acts by causing spastic muscle paralysis in the parasitic worms (Silva, R.D., 2019). This is a result of a constant release of acetylcholine in the body wall muscle of the parasitic worms (Silva, R.D., 2019). Hence, the worm becomes incapable of moving, allowing the body to sweep the worm out naturally through the host’s stool (Silva, R.D., 2019). However, this medication is also poorly absorbed in the host’s intestinal tract (Silva, R.D., 2019). | ||
| - | <box 40% width 40% height centre|> {{ :pyrantel.png?direct&200|}} </box| Figure x. Chemical Structure of Pyrantel. Retrieved https://en.wikipedia.org/wiki/Pyrantel .> | + | <box 40% width 40% height centre|> {{ :pyrantel.png?direct&200|}} </box| Figure 8. Chemical Structure of Pyrantel. Retrieved https://en.wikipedia.org/wiki/Pyrantel .> |
| ==== Surgery ==== | ==== Surgery ==== | ||
| In the case of heavy infestation, surgery may be required to remove large amounts of worms and to repair the damages that they have caused. According to Mayo Clinic, some complications that require surgery include: intestinal obstruction or perforation, appendicitis, and bile duct obstruction (Mayo Clinic Staff, 2018). During surgery, the worms may be manually removed by massaging the worms out the intestine through a cut opening (Silva, R.D., 2019). | In the case of heavy infestation, surgery may be required to remove large amounts of worms and to repair the damages that they have caused. According to Mayo Clinic, some complications that require surgery include: intestinal obstruction or perforation, appendicitis, and bile duct obstruction (Mayo Clinic Staff, 2018). During surgery, the worms may be manually removed by massaging the worms out the intestine through a cut opening (Silva, R.D., 2019). | ||
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| + | ====== References ====== | ||
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| + | Ascariasis. (2018, May 17). Retrieved January 22, 2020, from https://www.mayoclinic.org/diseases-conditions/ascariasis/diagnosis-treatment/drc-20369597 | ||
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| + | Ascariasis: Causes, Symptoms, and Treatments. (2019, April 17). Retrieved from https://www.healthline.com/health/ascariasis | ||
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| + | Ben-Joseph, E. P. (Ed.). (2019, November). Ascariasis (for Parents) - Nemours KidsHealth. Retrieved from https://kidshealth.org/en/parents/ascariasis.html | ||
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| + | CDC - Ascariasis - Biology. (2019, July 19). Retrieved January 22, 2020, from https://www.cdc.gov/parasites/ascariasis/biology.html | ||
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| + | CDC - Ascariasis - Diagnosis. (2018, February 15). Retrieved from https://www.cdc.gov/parasites/ascariasis/diagnosis.html | ||
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| + | CDC - DPDx - Diagnostic Procedures - Stool Specimens. (2016, May 3). Retrieved from https://www.cdc.gov/dpdx/diagnosticprocedures/stool/specimenproc.html | ||
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| + | CDC - Ascariasis - Resources for Health Professionals. (2019, August 28). Retrieved January 22, 2020, from | ||
| + | https://www.cdc.gov/parasites/ascariasis/health_professionals/index.html#tx | ||
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| + | Centers for Disease Control and Prevention. (n.d.). Ascariasis. Retrieved from https://www.cdc.gov/parasites/ascariasis/ | ||
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| + | Cox, F. E. (2002). History of human parasitology. Clinical microbiology reviews, 15(4), 595-612. | ||
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| + | Dold, C., & Holland, C. V. (2011). Ascaris and ascariasis. Microbes and Infection, 13(7), 632–637. doi: 10.1016/j.micinf.2010.09.012 | ||
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| + | Fletcher, J. (2018, July 3). Ascariasis: Causes, symptoms, and treatment. Retrieved from https://www.medicalnewstoday.com/articles/322340.php#causes | ||
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| + | Hall A., Hewitt G, Tuffrey V. (2008). A review and meta-analysis of the impact of intestinal worms on child growth and nutrition. Maternal and Child Nutrition. 4: 118–236. doi:10.1111/j.1740-8709.2007.00127.x | ||
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| + | Lima Corvino, D. F. D., & Horrall, S. (2020). Ascariasis [Jan 12 2019]. Treasure Island , FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK430796/ | ||
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| + | Lucas, J. (2018, October 5). What Are X-Rays? Retrieved from https://www.livescience.com/32344-what-are-x-rays.html | ||
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| + | Mayo Clinic. (May 17, 2018). Ascariasis: Symptoms and Causes. Retrieved from https://www.mayoclinic.org/diseases-conditions/ascariasis/symptoms-causes/syc-20369593 | ||
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| + | Monteiro, K. J., Calegar, D. A., Santos, J. P., Bacelar, P. A., Coronato-Nunes, B., Reis, E. R. C., ... & Jaeger, L. H. (2019). Genetic diversity of Ascaris spp. infecting humans and pigs in distinct Brazilian regions, as revealed by mitochondrial DNA. PloS one, 14(6), e0218867. | ||
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| + | Murrell, K. D., Eriksen, L., Nansen, P., Slotved, H. C., & Rasmussen, T. (1997). Ascaris suum: a revision of its early migratory path and implications for human ascariasis. The Journal of parasitology, 255-260. | ||
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| + | Shah, J., & Shahidullah, A. (2018). Ascaris lumbricoides: a startling discovery during screening colonoscopy. Case reports in gastroenterology, 12(2), 224-229. | ||
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| + | Smith, J. (2014, December). Ivermectin. Retrieved January 22, 2020, from https://www.dermnetnz.org/topics/ivermectin/ | ||
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| + | Stephenson, L.S. (1987). The Impact of Helminth Infections on Human Nutrition. London: Taylor & Francis. | ||
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| + | Török M. Estée., Cooke, F. J., & Moran, E. (2017). Oxford handbook of infectious diseases and microbiology. Oxford: Oxford University Press. | ||
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| + | WHO. Preventive chemotherapy in human helminthiasis: coordinated use of anthelminthic drugs in control interventions: a manual for health professionals and programme managers. Crompton DWT, editor. WHO Library. Geneva, Switzerland: WHO Press; 2006. | ||
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