Week 6 Nematodes (PDF)

11/18/2024 Microbiology and HS260 NRS413 Parasitology in Nursing Microbiology and Parasitology in Nursing ROSUZEITA BINTI FAUZI 1 2 1 ...

11/18/2024 Microbiology and HS260 NRS413 Parasitology in Nursing Microbiology and Parasitology in Nursing ROSUZEITA BINTI FAUZI 1 2 1  11/18/2024 Microbiology and HS260 NRS413 Parasitology in Nursing Endoparasites Classification of Helminths Nematodes Flatworms (Roundworm) Cestodes Trematodes Enterobius vermicularis (Flukes) (Tapeworm) (pin worm) Class Activity Taenia Saginata, Taenia Solium Ascaris lumbricoides Dibothriocephalus Trichuris trichiura Schistosoma spp latum Paragonimus spp Hookworm (Necator americanus and Ancylostoma duodenale) 3 Microbiology and HS260 NRS413 Parasitology in Nursing Lesson overview Learning objectives Upon completion of this lesson , students should be able to: 1. Describe the life cycle of helminths (Nematodes, Cestodes, Trematodes) 2. Explain how helminths infect humans and the common ways people get these infestations. 3. Identify the infective stage of helminths and how it leads to infestation in humans. 4. State the diagnostic tests used to detect helminths. Standards 5. Explain the manifestations in patients with helminth infestations. 6. List treatments for helminth infestations. 7. Explain ways to prevent and control helminth infestations, including hygiene, health practices, and environmental measures to reduce spread. 4 2  11/18/2024 Microbiology and HS260 NRS413 Parasitology in Nursing Classification & description of Helminths o Description of Life Cycle o Mode of Infection o Infective stage o Diagnostic stage o Treatment o Control & Prevention o Nursing Responsibilities 5 Microbiology and HS260 NRS413 Parasitology in Nursing 6 3  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Microbiology and HS260 NRS413 Nursing Parasitology in Nursing Nematodes (Roundworm) Enterobius vermicularis (pin worm) Trichuris trichiura o Description of Life Cycle o Mode of Infection o Infective stage o Diagnostic stage Ascaris lumbricoides o Treatment Hookworm o Control & Prevention o Nursing Responsibilities 7 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Endoparasites Major Classes of Helminths Nematoda (roundworms) Members of the phylum ASCHELMINTHE (roundworms) MOST COMMON helminths which infect humans. CYLINDRICAL SHAPE, covered by a TOUGH OUTER covering called a CUTICLE & a COMPLETE DIGESTIVE SYSTEM (including mouth & anus). SEPARATE SEXES exist with the FEMALES typically being LARGER than the males. OVA & LARVAE are the most common DIAGNOSTIC FORMS and the shape may vary in FERTILIZED and UNFERTILIZED. Most intestinal nematodes which cause human infection have DIRECT LIFE CYCLES, being transmitted from person-to-person with NO INTERMEDIATE HOSTs. 8 4  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Enterobius vermicularis 9 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Enterobius vermicularis Pinworms also known as threadworm Cacing jarum atau cacing benang causes the medical condition pinworm infestation also known as ENTEROBIASIS E. vermicularis is called the PINWORM because of the LONG, POINTED tail (resembling a pin). The FEMALE worm LARGER than the male (measures 7 – 13 mm). FEMALE adult worm: POSTERIOR END is STRAIGHT, MALE adult worm: POSTERIOR END is CURVED. The egg/ova of E. vermicularis is OVAL, FLATTENED one side and has a THICK and COLORLESS SHELL. 10 5  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LIFE CYCLE Enterobius vermicularis 1 Gravid adult female Enterobius vermicularis deposit eggs on perianal folds. 2 Infection occurs via self-inoculation (transferring eggs to the mouth with hands that have scratched the perianal area) or through exposure to eggs in the environment (e.g. contaminated surfaces, clothes, bed linens) 3 Following ingestion of infective eggs, the larvae hatch in the small intestine. 4 and the adults establish themselves in the colon, usually in the cecum. The time interval from ingestion of infective eggs to oviposition by the adult females is about 1 month. At full maturity adult females measure 8 to 13 mm, & adult males 2 to 5 mm > adult life span is about 2 months. 5 Gravid females migrate nocturnally outside the anus & oviposit while crawling on the skin of the perianal area. FERTILIZED EGG/OVA 1 The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under are deposited on PERIANAL FOLDS. optimal conditions. Rarely, eggs may become airborne & be inhaled and swallowed. Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown. 11 3. Heat from beneath Enterobius vermicularis Host Geographic Distribution o Humans are considered the only host for o E. vermicularis occurs worldwide, with infections E. vermicularis, although occasional occurring most frequently in school- or preschool- infections have been reported in captive children & in crowded conditions. chimpanzees. 12 6  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Endoparasites Nematoda (roundworms) Enterobius vermicularis TRANSMISSION SELF-INFECTION occurs by transferring infective egg/ova to the mouth with hands that have scratched the perianal area (ingestion of eggs). PERSON-TO-PERSON transmission can also occur through handling of contaminated clothes or bed lines. Enterobiasis may also be acquired through surfaces in the environment that are contaminated with pinworm egg/ova (e.g. bed comforter, carpeting). RETROINFECTION is also possible, where some of the pinworm larvae which hatch on the anus return to the gastrointestinal tract of the host. RETROINFECTION 13 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis MANIFESTATIONS 14 7  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis LABORATORY DIAGNOSIS The diagnosis of enterobiasis is best accomplished using the GRAHAM SCOTCH TAPE Diagnosis depends on the demonstration of the eggs or adult worms technique. The specimen should be taken early morning BEFORE the child bathing & defecation. It’s collected by applying TRANSPARENT CELLOPHANE TAPE to the PERIANAL AREA late at NIGHT or in the MORNING, after female worm migration has occurred. The tape is then presses onto a clean microscope slide and examined microscopically for the presence of typical EGG/OVA (the tape method should be conducted on 3 CONSECUTIVE MORNINGS). The ADULT WORM may occasionally be found in stool samples. EGG/OVA can also be found but less frequently in the stool and occasionally are encountered in the urine or vaginal smears. 15 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis LABORATORY DIAGNOSIS GRAHAM SCOTCH TAPE technique. Enterobius vermicularis eggs. The eggs of Enterobius vermicularis measure 50—60 µm by 20—30 µm. They are transparent, elongate to oval in shape, and slightly flattened on one side. 16 8  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis adult worms. Adult males of Enterobius vermicularis measure up to 2.5 mm long by 0.1-0.2 mm wide; adult females measure 8-13 mm long by 0.3-0.5 mm wide. Adult males have a blunt posterior end with a single spicule; females possess a long pointed tail. In both sexes, there are cephalic expansions. 17 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) TREATMENT Enterobius vermicularis Antihelminth MEBENDAZOLE, PYRANTEL PAMOATE or ALBENDAZOLE may be used to treat enterobiasis in symptomatic individuals (Pyrantel pamoate is available without prescription). Any of these drugs are given in 1 DOSE initially & then another single dose of the same drug 2 WEEKS later. The drug does not reliably kill pinworm eggs. Therefore, the SECOND DOSE is to prevent re-infection by adult worms that hatch from any eggs not killed by the first treatment. In households where more than one member is infected, it is recommended that ALL HOUSEHOLD members be TREATED at the same time. 18 9  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis PREVENTION & CONTROL WASH HANDS regularly especially after using the restroom. SHOWER DAILY and make sure wash anal area well. CHANGE UNDERWEAR, CLOTHING and BEDDING daily/frequently. WASH underwear, clothing, towels & bedding in HOT WATER. Try to keep ANAL area DRY and AVOID SCRATCHING. DRY underwear, clothing, towels and bedding on HIGH HEAT to kill any possible contamination. 19 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Enterobius vermicularis 20 10  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Ascaris lumbricoides 21 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Ascaris lumbricoides causes the medical condition ASCARIASIS Known as the LARGE INTESTINAL ROUNDWORM with the adult female often measuring more than 30 cm (male worm is about half this length). Sexes separated Female adult worm: POSTERIOR end is STRAIGHT, Male adult worm: POSTERIOR end is CURVED. The mouth opens at the anterior end, it is surrounded by 3 finely toothed lips. 22 11  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) The eggs may live in the soil for even years. Ascaris lumbricoides The fertilized egg/ova is broadly OVAL (measures 45 – Unfertilized egg/ova are more 75 µm in length and 35 – 50 µm in width). ELONGATED (60 – 90 µm long) The egg/ova usually has a THICK, TRANSPARENT showing disorganized globular SHELL surrounded by a YELLOW/BROWN BILE- internal contents. STAINED outer covering (albumin). Cannot develop into an infective larva as it is unfertilized. When the ALBUMIN outer covering is ABSENT, the egg/ova is said to be DECORTICATED. Can still develop into an infective larva as it is fertilized, just without the bile-stained coating. 23 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LIFE CYCLE Ascaris lumbricoides 1 Adult worms live in the lumen of the small intestine. 2 Female may produce approximately 200,000 eggs per day, which are passed with the feces. Unfertilized eggs may be ingested but are not infective. 3 Larvae develop to infectivity within fertile eggs after 18 days to several weeks, depending on the environmental conditions (optimum: moist, warm, shaded soil). 4 After infective eggs are swallowed 5 Larvae hatch , invade the intestinal mucosa, & are 6 carried via the portal, then systemic circulation to the lungs. 7 Larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, & are swallowed. Upon reaching the small intestine, they develop into adult worms. Between 2 & 3 months are required from ingestion of the infective eggs to oviposition by the adult female. Adult worms can live 1 to 2 years. 24 12  11/18/2024 3. Heat from beneath Ascaris lumbricoides Geographic Distribution Host o Ascariasis is the most common human helminthic o Humans &swine are the major hosts for infection globally. Ascaris o The burden is highest in tropical & subtropical regions, > areas with inadequate sanitation. o Natural infections with A. lumbricoides sometimes occur in monkeys & apes. o Generally rare to absent in developed countries, but sporadic cases may occur in rural o Some cases in these areas where human transmission is negligible have direct epidemiologic associations to pig farms. 25 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides TRANSMISSION Transmitted by FECAL-ORAL route. Humans become infected by INGESTING FERTILIZED EGG/OVA from contaminated WATER or FOOD (raw vegetables or fruits). Children PLAYING in contaminated soil may acquire the parasite from their hands. FLY and COCKROACH can be the MECHANICAL VECTOR (carry out the fertilized ova). Areas with inadequate sanitation 26 13  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides MANIFESTATIONS Vast majority of cases are asymptomatic Most infections are ASYMPTOMATIC but in heavy infections, NUTRITIONAL DEFICIENCIES may develop (especially in CHILDREN). Migrating worms may lead to obstruction such as INTESTINAL BLOCKAGE. LARVAE in the LUNGS may cause INFLAMMATION of the lungs known as LOEFFLER’S SYNDROME (pneumonia-like symptoms). Other symptoms e.g. Abdominal discomfort , Low grade fever, NAUSEA, ANOREXIA and WHEEZING. More severe symptoms e.g. WORM IN STOOL or WORM IN VOMIT. 27 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides LABORATORY DIAGNOSIS The diagnosis of infection with A. lumbricoides is made by the identification of fertilized, unfertilized or decorticated EGG/OVA in human STOOL samples. FORMALIN-ETHER CONCENTRATION and KATO-KATZ techniques are recommended for processing these samples. ADULT worms may sometimes be passed in stool or may pass out of a body e.g. ANUS, NOSE or MOUTH. LARVAL worms may sometimes be detected in SPUTUM. EOSINOPHILIA can be found particularly during larval migration through the lungs. Eosinophilia is a nonspecific immune response and is often associated with parasitic infections 28 14  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LABORATORY DIAGNOSIS Ascaris lumbricoides unfertilized eggs. Fertilized and unfertilized Ascaris lumbricoides eggs are passed in the stool of the infected host. Unfertilized eggs are elongated and larger than fertile eggs (up to 90 µm in length). Their shell is thinner and their mammillated layer is more variable, either with large protuberances or practically none. Unfertile eggs contain mainly a mass of refractile granules. 29 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LABORATORY DIAGNOSIS lumbricoides fertilized eggs Fertilized and unfertilized Ascaris lumbricoides eggs are passed in the stool of the infected host. Fertilized eggs are are rounded and have a thick shell with an external mammillated layer that is often stained brown by bile. Fertile eggs range from 45 to 75 µm in length. 30 15  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LABORATORY DIAGNOSIS lumbricoides fertilized, decorticated eggs. In some cases, the outer layer is absent (known as decorticated eggs). 31 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites LABORATORY DIAGNOSIS Larvae of A. lumbricoides hatching from eggs. Adults of A. lumbricoides. Adults of Ascaris lumbricoides are large roundworms. Females measure 20–35 cm long with straight taisl; males are smaller at 15–31 cm and tend to have curved tails. Adults of both sexes possess three “lips” at the anterior end of the body. 32 16  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides TREATMENTS Anthelmintic drugs e.g. 500mg ALBENDAZOLE (1 day), MEBENDAZOLE (100mg BD for 3 days) or PYRANTEL PAMOATE- are effective in eliminating adult worms. 33 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Helminths Nematoda (roundworms) Ascaris lumbricoides PREVENTION & CONTROL Prevention of infection requires the maintenance of ADEQUATE SANITARY FACILITIES to prevent contamination of the soil with human stool. LIMIT using human feces as fertilizer. WASH hands with soap and water before handling food. NO defecating outdoors. EFFECTIVE sewage disposal systems. 34 17  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides Nursing Diagnosis Fluid volume deficit related to fluid loss secondary to diarrhea. Impaired sense of comfort: pain related to smooth muscle spasm secondary to migration of parasites in the stomach. Imbalanced Nutrition: less than body requirements related to anorexia and vomiting. Hyperthermia related to decrease in circulation secondary to dehydration. 35 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Ascaris lumbricoides Nursing Management Improve fluid and electrolyte balance. Monitor intake and output of fluids; observe signs of dehydration; give oral rehydration solution to assist in adequate hydration; observe accurate intravenous fluid administration. Reduce pain and discomfort. Assess the extent and characteristics of pain; give a warm compress on the abdomen; teach a method of distraction to reduce pain; set a comfortable position that can reduce pain. Improve nutrition. Give adequate and nutritious food; measure body weight every day; explain the importance of adequate nutrition, and maintain good oral hygiene. Maintain normothermia. Teach the client and family the importance of adequate feedback; monitor fluid intake and output; monitor the temperature and vital signs; provide tepid sponge baths, and administer analgesics as indicated. 36 18  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Trichuris trichiura 37 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Cacing rambu atau cacing cambuk Trichuris trichiura also called the human whipworm. T. trichiura is referred to as the WHIPWORM. The length of the adult worm is in the range of 30 – 50 mm. The adult male is SMALLER than the female. FEMALE adult worm: POSTERIOR end is STRAIGHT, MALE adult worm: POSTERIOR end is COILED. The egg/ova of T. trichiura are BILE-STAINED & OVAL to BARREL-SHAPED, with a thick, lives for about 1-3 years smooth shell & a clear prominent polar plug at each end. The egg/ova measure 45 – 55 µm in width. Figure A: Egg of T. Figure B: Egg of T. trichiura in an trichiura in an iodine- unstained wet mount. stained wet mount. 38 19  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LIFE CYCLE Trichuris trichiura 1 The unembryonated eggs are passed with the stool 2 In the soil, the eggs develop into a 2-cell stage 3 an advanced cleavage stage 4 and then they embryonate 5 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 6 Mature and establish themselves as adults in the colon 7 The adult worms (approximately 4 cm in length) live in the cecum and ascending colon. The adult worms are fixed in that location, with the anterior portions threaded into the mucosa. The females begin to oviposit 60 to 70 days after infection. Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The life span of the adults is about 1 year. 39 3. Heat from beneath Trichuris trichiura Geographic Distribution Host o The third most common round worm of humans. o Definitive Host: Humans are the primary & only natural definitive host for Trichuris o Worldwide, with infections more frequent in areas trichiura. with tropical weather and poor sanitation practices, and among children. o The adult worms live in the large intestine, where they can cause trichuriasis. o It is estimated that 800 million people are infected worldwide. 40 20  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Trichuris trichiura TRANSMISSION Infection occurs after ingestion of fertilized egg/ova in CONTAMINATED FOOD (fruits or vegetables) or WATER or directly from SOIL (FECAL-ORAL TRANSMISSION). Often occurs in areas where HUMAN FECES is used as FERTILIZER or where DEFECATION ONTO SOIL happens. FLY & COCKROACH can be the MECHANICAL VECTOR (carry out the fertilized egg/ova). 41 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Trichuris trichiura MANIFESTATIONS Most infections are ASYMPTOMATIC. (Light infections (less than 100 worms) NAUSEA, DYSENTERY, ABDOMINAL PAIN, VOMITING, HEADACHES , WEIGHT LOSS & possibly growth retardation may occur with a heavy worm burden. Heavy infections (hundreds to thousands of worms) Severe infection > BLOOD LOSS in serious infections may result in ANEMIA & serious infections may lead to RECTAL PROLAPSE. Figure 1. (a) This adult female Trichuris whipworm is a soil-transmitted parasite. (b) Trichuris trichiura eggs are ingested and travel to the intestines where the larvae emerge and take up residence. (c) Rectal prolapse is a condition that can result from whipworm infections. It occurs when the rectum loses its attachment to the internal body structure and protrudes from the anus. (credit a, b, c: modification of work by Centers for Disease Control and Prevention) 42 21  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) T. trichiura eggs. Trichuris trichiura LABORATORY DIAGNOSIS Microscopic identification of whipworm eggs in feces is evidence of infection. The diagnosis of infection is usually made by the identification of typical, oval egg/ova, displaying the prominent polar plugs at each end using FORMALIN-ETHER CONCENTRATION & KATO-KATZ technique. Adult worms are rarely seen in stool samples Examination of the rectal mucosa by proctoscopy (or directly in case of prolapses) can occasionally demonstrate adult worms. Trichuris trichiura eggs are 50-55 micrometers by 20-25 micrometers. They are barrel-shaped, thick-shelled and possess a pair of polar “plugs” at each end. The eggs are unembryonated when passed in stool. 43 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) T. trichiura adults. Trichuris trichiura LABORATORY DIAGNOSIS Adult males of Trichuris trichiura are 30-45 millimeters long, with a coiled posterior end. Adult females are 35-50 millimeters with a straight posterior end. Both sexes have a long, whip-like anterior end. Adults reside in the large intestine, cecum and appendix of the host. 44 22  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Trichuris trichiura TREATMENTS The drug of choice are ALBENDAZOLE (1 day) & MEBENDAZOLE (needs to be taken for 3 days). It will gets rid of any adult stage or egg/ova in the human body. IRON SUPPLEMENTS may also be prescribed if the infected person suffers from anemia. iron > supporting the production of red blood cells & addressing symptoms of fatigue. 45 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Trichuris trichiura PREVENTION & CONTROL Prevention requires adherence to GOOD PERSONAL HYGIENE & avoidance of contaminated food or water e.g. washing hands, boil drinking water, peel or cook food thoroughly before eat. AVOIDANCE of the use of human feces as fertilizer is necessary to prevent infection. Installing effective SEWAGE DISPOSAL SYSTEMS. 46 23  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Trichuris trichiura Nursing Management Nursing responsibilities focus on managing symptoms, preventing the spread of infection, and supporting the patient's overall health. Assessment Nutritional Support Monitor vital signs, abdominal pain, and symptoms Encourage a high-protein, nutrient-rich diet. (diarrhea, rectal bleeding). Monitor for anemia and provide iron supplements if Assess nutritional status due to risk of malnutrition. prescribed. Infection Control Patient Education Enforce hand hygiene and environmental cleanliness. Teach handwashing, safe food, and water practices. Promote proper sanitation to avoid reinfection. Medication Administration Give prescribed antiparasitic meds (albendazole or mebendazole). Provide symptomatic relief as needed (pain relievers, antidiarrheal). 47 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Hookworm Cacing cangkut Typically affect the intestines of humans. 2 main species that infect humans are ANCYLOSTOMA DUODENALE & NECATOR AMERICANUS. Their morphology shares many similarities, but there are some distinctions as well. Shape & Size Small, cylindrical, & slightly curved. Bodies have a slight "hook" appearance at the head end, giving them their name. Males are generally SMALLER (8-11 mm in length) than females (10- 13 mm). 48 24  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Centre for Nursing Studies Hookworm 49 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Hookworm Body Structure Covered by a cuticle > protective outer layer helps to survive in the harsh environment. Male & Female Differences Males have a copulatory bursa at the posterior end, which is a fan- like structure used during mating. Females are generally larger and have a pointed tail. 50 25  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Hookworm Cacing cangkut BUCCAL CAPSULES The BUCCAL CAPSULES (which are PRIMITIVE MOUTHS) of the two hookworms differ in structure. A. duodenale is characterized by TEETH, while the mouth parts of N. americanus consist CUTTING PLATES. These well-developed structures account for the firm ATTACHMENT of the adult worms to the INTESTINAL MUCOSA & feed on the host’s blood. Differentiation of the two genera of hookworms requires the EXAMINATION of the MOUTH PARTS of the ADULT WORMS. 51 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Morphology Hookworm Cacing cangkut The egg/ova of the two hookworms although slightly different in size but usually are not used to distinguished them. Egg – Released in feces, hatches in soil.Rhabditiform Larva – Free-living, non-infective larva in soil.Filariform Larva – Infective larval stage that penetrates skin.Adult – Lives in the host’s intestine, feeds on blood, and produces eggs. 52 26  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm Morphology 1st stage - RHABDITIFORM LARVA (the NON-INFECTIVE 2nd stage -FILARIFORM LARVA (INFECTIVE STAGE) is not capable of living independently and must find a FREE-LIVING FORM) which measures about 270 µm is HOST. characterized by a prominent primitive mouth called a This form is characterized by an ESOPHAGUS, notable BUCCAL CAVITY and a SMALL GENITAL PRIMORDIUM. shorter than that of the rhabditiform larva and by the presence of a LONG and POINTY TAIL. 53 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LIFE CYCLE Hookworm 1 Eggs are passed in the stool & under favorable conditions (moisture, warmth, shade), larvae hatch in 1 to 2 days and become free-living in contaminated soil. 2 These released rhabditiform larvae grow in the feces and/or the soil image 3 after 5 to 10 days (and two molts) they become filariform (third-stage) larvae that are infective image. These infective larvae can survive 3 to 4 weeks in favorable environmental conditions. 4 On contact with the human host, typically bare feet the larvae penetrate the skin & are carried through the blood vessels to the heart and then to the lungs. They penetrate into the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed 5 The larvae reach the jejunum of the small intestine, where they reside & mature into adults. Adult worms live in the lumen of the small intestine, typically the distal jejunum, where they attach to the intestinal wall with resultant blood loss by the host. Most adult worms are eliminated in 1 to 2 years, but the longevity may reach several years. 54 27  11/18/2024 3. Heat from beneath Hookworm Geographic Distribution Host o Humans are the principal host for both A. o Hookworm species have a worldwide distribution, duodenale & N. americanus. mostly in areas with moist, warm climates where larvae can survive in the environment. o A. ceylanicum may be zoonotic, as 2 o Both Necator americanus & Ancylostoma haplotypes have been identified, 1 found duodenale are found in Africa, Asia, Australia & only in humans thus far & the other Americas. found in humans, dogs, & cats. o A. ceylanicum is highly endemic throughout much of Southeast. 55 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm TRANSMISSION There are 2 primary ways people become infected: 1. SKIN-TO-SOIL: When humans walk barefoot, hookworm larvae burrow their way through the foot and into the body. 2. INGESTION: When people defecate in the soil or use their stool as fertilizer, hookworm eggs can contaminate food or water sources and be ingested by humans. N. americanus is known as “NEW-WORLD HOOKWORM” causing infection predominantly in NORTH and SOUTH AMERICA. duodenale is called “OLD-WORLD HOOKWORM” because of its prevalence in AFRICA, INDIA, CHINA, SOUTHERN EUROPE and JAPAN. Some species of hookworms are ZOONOTIC (usually dog and cat), therefore humans can be infected by larvae of animal hookworms and cause CUTANEOUS LARVAL MIGRANS. 56 28  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm MANIFESTATIONS o They generally start with ITCHINESS and SMALL RASH caused by an allergic reaction in the area that the larvae entered your skin. o This is followed by DIARRHEA as the hookworms grow in your intestine. o Other symptoms include ABDOMINAL PAIN, NAUSEA, FEVER and LOSS OF APPETITE. o The most serious effects are the development of ANEMIA and PROTEIN DEFICIENCY. 57 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm LABORATORY DIAGNOSIS The diagnosis of hookworm infection is made by identifying typical hookworm egg/ova in HUMAN STOOLS using FORMALIN-ETHER CONCENTRATION technique. Because of the similarity of the ova of both agents, “HARADA- MORI” culture technique is needed to identify the species. 58 29  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm LABORATORY DIAGNOSIS Hookworm eggs. The eggs of Ancylostoma and Necator cannot be differentiated microscopically. The eggs are thin-shelled, colorless and measure 60-75 µm by 35-40 µm. 59 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) LABORATORY DIAGNOSIS Hookworm Hookworm rhabditiform larvae. Hookworm filariform larvae. Rhabditiform (L1) larvae that hatch from eggs are 250-300 µm Infective, third-stage (L3), filariform larvae are 500—700 µm long. long & approximately 15-20 µm wide. Have a pointed tail Have a long buccal canal & an inconspicuous genital primordium. L3 are found in the environment and infect the human host by Rhabditiform larvae are usually not found in stool, but may be PENETRATION OF THE SKIN. found there is a delay in processing the stool specimen. 60 30  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm LABORATORY DIAGNOSIS Adult hookworms. Adult hookworms reside in the small intestine of their hosts. A. duodenale males measure approximately 8—12 mm long, and females measure approximately 10—15 mm long. N. americanus males are 5—9 mm long, females 9—11 mm. Males are bursate, with two spicules that are fused at the distal end in Necator spp. but not in Ancylostoma spp. Adults of both sexes have a buccal capsule containing sharp teeth (Ancylostoma) or cutting plates (Necator). 61 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm TREATMENTS Some hookworm infections are ASYMPTOMATIC and require little treatment. ALBENDAZOLE & MEBENDAZOLE are recommended for treatment of symptomatic infection (these drugs are generally taken once to treat the infection). Severe cases of ANEMIA may require IRON REPLACEMENT THERAPY. If have ASCITES (abnormal buildup of fluid in the abdomen and will cause increased abdominal size, abdominal discomfort and shortness of breath), > to add additional PROTEIN diet. 62 31  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm PREVENTION & CONTROL WEARING SHOES when you walk outdoors. DRINKING SAFE WATER and avoid eating food that could be contaminated. AVOID skin contact with soil. NOT defecating outdoors. EFFECTIVE sewage disposal systems. 63 Microbiology and Parasitology in HS260 NRS413 Nursing Endoparasites Nematoda (roundworms) Hookworm Nursing Management Nursing management for hookworm infection focuses on treatment, symptom relief, patient education, and preventing re-infection. 1. Assessment and Diagnosis Assess for signs of anemia (pallor, fatigue, weakness), malnutrition, abdominal discomfort. Monitor Laboratory Results: Hemoglobin levels, iron levels & results if stool samples 2. Treatment Administration Administer Anthelmintic - albendazole or mebendazole > help eliminate the parasite from the intestines. Iron Supplements: If the patient has anemia, provide iron supplements > help restore blood levels. Nutritional Support: Encourage a high-protein, iron-rich diet. 3. Symptom Management Monitor for Complications > severe anemia & ascites 4. Health Education Wearing shoes when walking outdoors Drinking safe, clean water and avoiding contaminated food. Handwashing Promote proper use of sanitation facilities and the importance of effective sewage disposal 64 32  11/18/2024 Microbiology and Parasitology in HS260 NRS413 Microbiology and HS260 NRS413 Nursing Parasitology in Nursing TREMATODES (Flukes) Schistosoma spp Paragonimus spp 65 3. Heat from beneath TREMATODES (Flukes) Class Activity HS2601A Group 1 Group 2 66 33  11/18/2024 3. Heat from beneath Class Activity HS2601B Group 1 Group 2 67 Microbiology and Parasitology in HS260 NRS413 Nursing REFERENCES Bauldoff, G., Gubrud, P., & Carno, M. (2019). LeMone and burke’s medical-surgical nursing: Clinical reasoning in patient care (7th ed.). Upper Saddle River, NJ: Pearson. Perry, A.G., & Potter, P.A. (2018). Clinical Nursing Skills & Techniques (9th ed.). St. Louis: Mosby Elsevier. Yadav, H., Chong, M. C., & See, T. L. (2019). Community health nursing (2nd ed.). Shah Alam: Oxford Fajar. 68 34