Ascaris lumbricoides & Trichuris trichiura
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Similaire à Ascaris lumbricoides & Trichuris trichiura
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Ascaris lumbricoides & Trichuris trichiura
- 1. THE NEMATODES G. Biteno, K.R. Feranil, K.K. Gregorio, K. Medina, C.W. Mendoza
- 2. NEMATODE Multicellular parasites that appear round in cross section Adult nematodes have a tapered, cylindric body with an esophagus and longitudinal muscles. Nematodes cause disease associated with the intestines and the skin.
- 3. What’s AheadIntestinal Species Enterobius vermicularis – Pinworm/ Seat worm/ Society worm Trichuris trichiura – Whipworm Ascaris lumbricoides – Large Intestinal Roundworm Necator americanus – New World Hookworm Ancylostoma duodenale – Old World Hookworm Strongyloides stercoralis – Threadworm Intestinal-Tissue Species Trichinella spiralis – Trichina worm Dracunculus medinensis – Guinea Worm
- 4. DEFINITION OF TERMS Copulation Mating of select worms Cuticle Surface covering present on adult nematodes Embryonated Fertilized egg Decorticated Eggs lacking an outer mammillated albuminous coating Larva Juvenile worms Unembryonated Unfertilized egg INFECTIVE STAGE Stage in the parasitic life cycle that is capable of invading a definitive host. AUTOREINFECTION Reinfecting oneself Buccal capsule Long oral cavity; also known as a buccal cavity Buccal cavity Long oral cavity; also known as a buccal capsule Chitin Shell made up of a thick nitrogen- containing polysaccharide coating Corticated Eggs containing a mammillated
- 5. Morphology and Life Cycle Members of the class Nematoda assume three basic morphologic forms: • Vary in size and shape • Located inside the fertilized eggs; emerge and continue to mature • Develop from the maturing larvae • Sexes separate (females larger than males) • Equipped with a digestive and reproductive system
- 6. Morphology and Life Cycle Life cycles of individual nematodes are similar but organism specific Intestinal nematode infection may be initiated in several ways. Fertilized adult female nematodes lay their eggs in the intestine and are then shed in the stool; they mature in the soil and infect a new host in 2- 4 weeks. Most members have the ability to exist independent of a host (free living).
- 7. ASCARIS LUMBRICOIDES G. Biteno, K. Feranil, K.K. Gregorio, K. Medina, C.W. Mendoza
- 8. Ascaris lumbricoides COMMON NAMES: Common associated disease and condition names: Large Intestinal Roundworm Roundworm of man Ascariasis Roundworm Infection
- 9. Ascaris lumbricoides A soil – transmitted helminth. Usual infection of 10-20 worms may not cause symptoms. Causes varying degrees of pathology: Tissue reaction to the invading larvae Intestinal irritation to the adult Other complications due to extraintestinal migration.
- 10. Ascaris lumbricoides Most common complain of the patient: VAGUE ABDOMINAL PAIN Fatal effects of A. lumbricoides are due to erratic migration of adult worms.
- 11. MORPHOLOGY UNFERTILIZED EGGS PARAMETER DESCRIPTION SIZE 85-95 um by 38-45 um; Size variations possible SHAPE Varies EMBRYO Unembryonated; Amorphous mass of protoplasm SHELL Thin Other features Usually corticated A. lumbricoides, unfertilized egg Amorphous mass of protoplasm Heavy Albuminous Coating Thin Shell
- 12. MORPHOLOGY A. lumbricoides, fertilized egg PARAMETER DESCRIPTION SIZE 40-75 um by 30-50 um SHAPE Rounder than non-fertilized version EMBRYO Undeveloped unicellular embryo SHELL Thick chitin Other features May be corticated or decorticated FERTILIZED EGGS Undeveloped unicellular embryo Thick chitin shellCoarse Mammilated Albuminous Coating (Corticated)
- 13. Unfertilized and Fertilized Eggs: Females will release unfertilized eggs, which are more elongated (left) than fertilized eggs (right). Unfertilized eggs may also lack the mammillated layer. Fertilized Egg: Undeveloped eggs are passed in the stool. Stained brown from bile. Fertilized Egg: Can be Decorticated. Developed Egg: This egg contains an infective larvae (L2) that could infect a person if ingested.
- 14. MORPHOLOGY ADULTS CHARACTERIS TIC FEMALE ADULT MALE ADULT SIZE (LENGTH) 22-35 cm Up to 30 cm COLOR Creamy white pink tint Creamy white pink tint Other features Pencil lead thickness; Paired reproductive organs Prominent incurved tail with 2 spicules 200,000 eggs/female/day A pair of female and male worms of A. lumbricoides. Notice the vulvar waist(arrow)of the female worm and the coiled end of the male worm.
- 17. LABORATORY DIAGNOSIS Specimen of choice for A. lumbricoides eggs: Stool Adult worms: may be recovered in several specimen types, depending on the severity of infection. (Intestine, Gallbladdder, Liver and Appendix)
- 18. StoolTests • DFS • Kato-katz Technique • Kato technique or cellophane thick methoda • BEAVER DIRECT SMEAR METHOD (semi- quantitative) • STOLL’S EGG COUNTING TECHNIQUE BloodTests • CBC • ELISA ImagingTests • X-Ray • CT Scan • Ultasound LABORATORY DIAGNOSIS
- 19. LIFE CYCLE
- 20. 1. Adult worms live in the lumen of the small intestine. * A female may produce up to 240,000 eggs per day, which are passed with the feces. LIFE CYCLE
- 21. 2.-3. Fertile eggs embryonate and become infective after 18 days to several weeks depending on the environmental conditions (optimum: moist, warm, LIFE CYCLE
- 22. Infective Stage: FULLY EMBRYONATED (with 2nd stage Larvae or Rhabditiform Larvae) EGG LIFE CYCLE 3 .
- 23. 4-5. After infective eggs are swallowed , the larvae hatch in the lumen of the SI and penetrate the intestine wall. LIFE CYCLE
- 24. Larvae enters the venule to go to the liver (through the portal vein) o to the heart and pulmonary vessels (7-10 days), where they break out the capillaries and enter the air sacs, ascend the bronchial tree. LIFE CYCLE 6.
- 25. In the lungs, larvae undergo molting before migrating to the larynx and oropharynx to be swallowed in the digestive tract. LIFE CYCLE 6.
- 26. LIFE CYCLE During the lung migration, the larvae may cause host sensitization resulting in allergic manifestations such as Eosinophilia and Loeffler’s syndrome may also be present during lung migration. Lung infiltration Asthmatic attacks Edema of the lips
- 27. Upon reaching the small intestine, they develop into adult worms. *Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female. Adult worms can live 1 to 2 years. LIFE CYCLE 7.
- 31. EPIDEMIOLOGY Estimated worldwide prevalence of 25% (0.8-1.22 billion people). Most common intestinal helminth infection in the world. Children are particularly vulnerable. Risk infection exists wherever fecal disposal is improper.
- 32. EPIDEMIOLOGY Remains endemic in Africa, South and Central America. The global prevalence in 2010: Estimated at 464.6 million people. In tropical countries, it ranges from 60 to 85%.
- 33. DISEASE PREVALENCE Philippines: 31 million East Asia and the Pacific: 204 million Sub-Saharan Africa: 173 million India: 140 million South Asia: 97 million China: 86 million Latin America and Carrabean: 84 million Middle East and North Africa: 23 million
- 34. TREATMENT Anti – helminthic drugs: Albendazole – drug of choice Mebenazole Pyrantel pamoate Piperazine citrate
- 35. PREVENTION AND CONTROL Prevention and control measures involve the ff: Sanitary disposal of human feces Health education (personal, family, and community hygiene) Mass chemotherapy done periodically
- 37. Trichuris trichiura COMMON NAME: Common associated disesase and condition names: A soil – transmitted helminth frequently observed occuring with A. lumbricoides. Trichuriasis Whipworm infection Whipworm
- 38. HISTORY (1740)Morgani –. discovered the residence of adult T. Trichuria worms in colon (1761) Roedere – gave a report of the exact morphologic description and provided accurate drawings of the parasite
- 39. MORPHOLOGY EGGS PARAMETER DESCRIPTION SIZE 50 – 55 um by 25 um SHAPE Barrel-shaped / Lemon shaped/ Football- shaped; Translucent hyaline polar plug at each end. SHELL Smooth; yellow-brown color because of host bile contact Smooth shell surface Hyaline polar plug
- 40. NICE TO KNOW Can you identify??
- 41. MORPHOLOGY • Less resistant to desiccation than A. lumbricoides EGGS • the larvae escape and penetrate the intestinal villi where they remain for 3 to 10 days. LARVA
- 42. MORPHOLOGY ADULTS PARAMETE R DESCRIPTION SIZE Male – 30-45 mm Female – 35-50 mm A female lays approximately 3000 to 10000 eggs per day. ANTERIOR END Colorless; resembles a whip handle; contains a slender esophagus resembling a string of beads Female worm Male worm
- 43. MORPHOLOGY PARAMETER DESCRIPTION POSTERIOR END Pinkish-gray; resembles whip itself; contains digestive and reproductive systems; Male- possess prominent curled tail with a single spicule and retractile sheath. Female -has a bluntly rounded •ADULTS Posterior part of male T. trichuria Posterior part of female T. trichuria
- 45. LABORATORY DIAGNOSIS Specimen of choice for T. trichiura eggs: Stool Adult worms may be visible on macroscopic examination of the intestinal mucosa. Adults may also be seen in the rectum in heavy infections.
- 46. LABORATORY DIAGNOSIS – highly recommended in diagnosis of trichuriases – used for egg counting to determine cure rate (CR), egg reduction rate (ERR), and intensity of infection. The T. trichiura eggs are particularly prominent in infected samples processed using ZSFMethod. DFS Kato thick smear method Kato-Katz technique Zinc Sulfate Floatation Method - Oval with transparent bipolar plugs
- 47. LIFE CYCLE
- 48. LIFE CYCLE The unembryonated eggs are passed with the stool.
- 49. LIFE CYCLE The unembryonated eggs are passed with the stool. In the soil, the eggs develop into a 2-cell stage , an advanced cleavage stage and then they embryonate
- 50. The unembryonated eggs are passed with the stool. Eggs become infective in 15 to 30 days. After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae IS: EMBRYONATED EGG In the soil, the eggs develop into a 2-cell stage , an advanced cleavage stage and then they embryonate
- 51. The unembryonated eggs are passed with the stool. Eggs become infective in 15 to 30 days. After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae In the soil, the eggs develop into a 2-cell stage , an advanced cleavage stage and then they embryonate Larva mature and establish themselves as adults in the colon
- 52. The unembryonated eggs are passed with the stool. Eggs become infective in 15 to 30 days. After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae In the soil, the eggs develop into a 2-cell stage , an advanced cleavage stage and then they embryonate Larva mature and establish themselves as adults in the colon The adult worms live in the cecum and ascending colon.
- 53. LIFE CYCLE Each female worm can produce a total of over 60 million eggs over an average lifespan of 2 years. Unlike A. lumbricoides, there is no heart to lung migration.
- 54. PATHOGENESIS AND CLINICAL MANIFESTATIONS The anterior portion of the worms (embedded in the mucosa) cause petechial haemorrhage which predispose amebic dysentery presumably because the ulcers provide suitable site for tissue invasion of E. histolytica Mucosa is hyperemic and edematous Enterorrhagia is common
- 55. PATHOGENESIS AND CLINICAL MANIFESTATIONS RECTAL PROLAPSE may occur if heavily infected Lumen of the appendix may be filled with worms and consequent irritation and inflammation may lead to appendicitis or granulomas Infection with 5,000 eggs/gram of feces is symptomatic. Infection with 20,000 eggs/gram of feces often develop severe diarrhea or dysenteric volume.
- 57. EPIDEMIOLOGY Considered as the 3rd most common helminth. Found primarily in warm climates of the world where poor sanitation practices are common, such as defecating directly into the soil or using human feces as fertilizer.
- 58. EPIDEMIOLOGY Estimated that 902 million are infested (as compare to 355 million in 1947). The global prevalence in 2010: Estimated at 464.6 million people. In tropical countries, it ranges from 60 to 85%.
- 59. DISEASE PREVALENCE Philippines:Prevalence is from 80 to 84%. Sub-Saharan Africa: Estimated at 20.9% (100million cases). Oceania: Estimated 1.2million infested persons, accounting for <1% of the global burden of Trichuriasis. South America: Estimated prevalence rates of 12.5%
- 60. TREATMENT Mebendazole – drug of choice Abendazole
- 61. PREVENTION AND CONTROL Infection in highly endemic areas may be prevented by: Treatment of infected individuals Sanitary disposal of human feces by construction of toilets and their proper use. Washing of hands with soap and water before and after meals Health education on sanitation and personal hygiene Through washing and scalding of uncooked vegetables especially in areas where night soil is used as fertilizer.
- 62. THANK YOU!
Notes de l'éditeur
- Ascariasis – STH; disease of poverty When a group of organisms has diversified into many different forms, this is referred to as an "adaptive radiation.“ In the process, as they have encountered new habitats or situations, the organisms have adapted to them. They contribute to impairment of cognitive performances and growth of children. Reduce work capacity and productivity of adults.
- Infection with Ascaris lumbricoides often causes no symptoms. Infections with a large number of worms may cause abdominal pain or intestinal obstruction. Adults feed on the contents of the small intestine and in heavy infections this may compound problems in malnourished individuals (especially children). Migration of larvae may cause localized reactions in various organs. Penetration of the larvae from capillaries into the lungs can lead to Loeffler's pneumonia, in which pools of blood and dead epithelial cells clog air spaces in the lungs. Resulting bacterial infections can be fatal.
- The larvae develops inside the egg about 3 weeks before becoming infective.
- Female is always larger than the male
- The worms may have terminal mouth with three lips and sensory papillae.
- Adult worms may be present in the stool, vomites up or removed from external nares, where they may attempt to escape.
- Since they have a high risk of ingesting embryonated A. lumbricoides.
- Centers for Disease Control and Prevention (CDC) estimated that worldwide ascariasis rates in 2005 (last updated 2014) Philippines – from WHO (2012)
- Mass chemotherapy – once, twice, thrice a year with children as the target population.
- Globally, trichuris trichuria also known as the human whipworm, is a very common intestinal helminthic infection. The history of T. Trichuria dates back to the times of prehistoric man; The whipworm derive its name from its characteristic whiplike shape. Poor hygiene is associated with trichuris transmission as well as the consumption of shaded moist soil, or food that may have been fecally contaminated. Children are especially vulnerable to infection
- 1740- first written record of T. Trichuria appeared when an Italian scientist Morgani discovered the residence of adult T. Trichuria worms in colon (1761) Roedere, a German physician-gave a report of the exact morphologic description and provided accurate drawings of the parasite
- One female Trichuris can lay 3,000-10,000 barrel-shaped ova daily. These are passed in the stool and measured 50-55 x 25 um. In passing through the human intestine, bile impregnates the outer portion of the thick shell and cause the ova to gain a brownish color.
- Capillaria spp ova are often misindentified with Trichuris. Capillaria spp. Are similar to other members of Trichuroida superfamily such as Trichuris but with slight differences in morphology of the anterior and posterior ends. Capillaria eggs have non-protruding polar plugs and are lightly smaller than Trichuris trichuris.
- After ingestion, intestinal juices in the duodenum weaken the shell of the egg. The larva is then freed and attaches itself to the villi of the proximal small bowel for about a week.
- Females are larger than males. Approx. 35-50 um long compared to males which 30-45 um. T. Trichuria has a narrow anterior esophageal end and a thicker posterior anus. They attach to the host through their slender anterior end and feed on tissue secretions instead of blood.
- These pinkish gray worms are threaded through the mucosa. The females have a bluntly round posterior end compared to their male counterparts with coiled posterior end.
- Anterior end-contains the pharynx, nerve ring, and excretory system of the parasite while the postertor end contains the digestive system and the reproductive system.
- Standard method for diagnosing the presence of whipworm is by microscopically identifying the whipworm eggs in a stool sample.
- It is important to be aware that samples examined from patients treated for whipworm infection may reveal distorted eggs, showing variety of unusual shapes. Kato katz-highly recommeded because of ease of its use and relatively low cost.
- Life cycle notes Ingestion of infective eggs initiates human infection. Larvae emerge from eggs in small intestine. Larvae return to the intestinal lumen and proceed to the cecum where maturation is complete. Adults take up residence in colon where they can live 4-8 years if untreated. Following copulation, adult female lays her eggs, which pass through stool. Eggs embryonate, usually in the soil, become infective, and another life cycle is initiated.