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36 Cards in this Set
- Front
- Back
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What are the main types |
Ascaris lumbricoides Hook worm - ancylostoma duodenale, necatar americanus Whip worm - trichuris trichiura Threadworm - strongyloides stercoralis |
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Lifecycle of ascaris lumbricoides |
Most common Faecal oral transmission Of eggs. After ingestion the larvae penetrate intestinal mucosa Migrate to pulmonary circulation and swallowed into small intestine Mature it I don’t worms 10 to 40 cm, can live for 1 to 2 years and produce thousands of eggs daily. Passing the stool and can live in the soil for years |
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Whipworm lifecycle |
Trichuris trichuira Faecal oral transmission No pulmonary migration Remain intestine and mature to worms (less than 5 cm) Hatch thousands of eggs daily for several years These pass in faeces |
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Hookworm lifecycle |
Ancylostoma duodenale (temperate climates), necator americanus (tropics) Larvae Live in soil and infect people by penetrating the skin Typically Barefeet Larvae travel via the lungs to the large bowel Adult worm (1 cm) lives off blood in the small intestine for months and excretes eggs into the stool These eggs hatch into larvae Zoonotic ancylostoma causing cutaneous larva migrans Hookworm anaemia - attach to intestinal mucosa and rupture small blood vessels. Ingest blood by active suction, secrete anticoagulants |
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Threadworm life cycle? |
Strongyloides stercoralis - Can penetrate the skin and migrate to lungs and then intestine Faecal oral transmission also possible Chronic Strongyloides – through autoreinfection. Larvae re-invade the colon wall and enter a new maturation cycle in the same host again. Can cause life threatening hyper acute infection |
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Pathology? |
Cause a type one hypersensitivity reaction – Loeffler syndrome. During pulmonary migration. Larger worms cause bath ology such as obstruction All cause mucosal bleeding and anaemia. Hookworm is the commonest cause of anaemia worldwide |
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Clinical presentation |
With low worm burden there are no clinical symptoms Loeffler syndrome – eosiniphilic pneumonia- Due to transient migration through pulmonary tissue. Cough wheeze urticaria dyspnoea haemoptysis Vague gastrointestinal symptoms. Distension, weight loss, discomfort, change in bowel habit Iron deficiency anaemia and symptomatic anaemia. Lead to growth retardation and intellectual impairment Trichuriasis - dysentery, rectal prolapse Trichuriasis - child with rectal prolapse and adult worms attached. Massive infantile trichuriasis- low protein, severe anaemia, finger clubbing Larger ascaris lumbricoides- acute abdomen - bleeding, obstruction, perforation, peritonitis Wandering worm surgical syndromes: Biliary colic, acute cholecystitis, acute pancreatitis, acute cholangitis, Hepatic abscess, appendicitis. Don’t give anti helminth drug acutely as worm will die and need surgery |
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Extra features of Strongyloides |
Minor gastric symptoms Autoreinfection – causes chronic which persist for decades and there is a risk for dissemination and hyperinfection Subcutaneous migration of larvae during autoreinfection causes Larva currens (itchy wheal that comes and goes within hours) In conjunction with immunosuppression there can be spread to any organ including CNS (meningitis) Hyperinfection causes severe dysentry and sepsis |
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Stool microscopy – saying eggs larvae or worms Loeffler syndrome – sputum/lavage/biopsy to identify Eosinophilia, raised IgE and anaemia Chest x-ray – discrete densities or more widespread infiltrate Antibody testing is being developed – no acute infection antigen test Field tests – Kato-Katz technique (for schistosomiasis) |
Stool microscopy – saying eggs larvae or worms Loeffler syndrome – sputum/lavage/biopsy to identify Eosinophilia, raised IgE and anaemia Chest x-ray – discrete densities or more widespread infiltrate Antibody testing is being developed – no acute infection antigen test Field tests – Catto cats technique (four sisters my assistant) Imaging – ultrasound/CT/MRI for bowel and liver Endoscopy Strongyloides- difficult to diagnose. No eggs in stool and few larvae. Larva currens and eosinophilia warrants treatment |
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Treatment |
Ascaris lumbricoides, hook worm, whipworm - Oral albendazole or mebendazole – stat or in divided doses for 3 days. For whipworm and in pregnancy - mebendazole is preferred Pulmonary support – bronchodilators and steroids Treat anaemia Strongyloides- PO/IV Ivermectin for 2/7. PO albendazole for 7/7 |
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Public health |
World health organisation recommends mass drug administration if any of the worms are at above 20% prevalence and biannual treatment if prevalence is greater than 50% This typically occurs prior school. Currently donated free but only to school age kids access to clean water, sanitation and education is essential |
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Public health |
World health organisation recommends mass drug administration if any of the worms are at above 20% prevalence and biannual treatment if prevalence is greater than 50% This typically occurs prior school. Currently donated free but only to school age kids access to clean water, sanitation and education is essential |
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Other less important ones... Trichinosis, trichinella spiralis, trichinella murrelli |
Infection occurs due to ingestion of undercooked meat of pigs and horses Adult worms live in small intestine but Lava travels to skeletal muscle where they cause a distinctive spiral pattern Also travel to heart kidney liver lungs and CNS – they are toxic to cells Symptomatic in most people but can cause eosinophilia, facial oedema, conjunctivitis, fever, myalgia and end organ damage. Diagnosed by antibody test and PCR |
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Public health |
World health organisation recommends mass drug administration if any of the worms are at above 20% prevalence and biannual treatment if prevalence is greater than 50% This typically occurs prior school. Currently donated free but only to school age kids access to clean water, sanitation and education is essential |
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Other less important ones... Trichinosis, trichinella spiralis, trichinella murrelli |
Infection occurs due to ingestion of undercooked meat of pigs and horses Adult worms live in small intestine but Lava travels to skeletal muscle where they cause a distinctive spiral pattern Also travel to heart kidney liver lungs and CNS – they are toxic to cells Symptomatic in most people but can cause eosinophilia, facial oedema, conjunctivitis, fever, myalgia and end organ damage. Diagnosed by antibody test and PCR |
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Pin worm - enterobius vermicularis |
Most common in children Causes itchy anus Identified by Sellotape test Treatment – albendazole/Mebendazole |
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Public health |
World health organisation recommends mass drug administration if any of the worms are at above 20% prevalence and biannual treatment if prevalence is greater than 50% This typically occurs prior school. Currently donated free but only to school age kids access to clean water, sanitation and education is essential |
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Other less important ones... Trichinosis, trichinella spiralis, trichinella murrelli |
Infection occurs due to ingestion of undercooked meat of pigs and horses Adult worms live in small intestine but Lava travels to skeletal muscle where they cause a distinctive spiral pattern Also travel to heart kidney liver lungs and CNS – they are toxic to cells Symptomatic in most people but can cause eosinophilia, facial oedema, conjunctivitis, fever, myalgia and end organ damage. Diagnosed by antibody test and PCR |
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Pin worm - enterobius vermicularis |
Most common in children Causes itchy anus Identified by Sellotape test Treatment – albendazole/Mebendazole |
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Toxocara canis/cati |
Host are cats and dogs Humans are accidental host Causes various ophthalmic lesions As humans are accidental hosts there will be no eggs in stool Treatment – albendazole/mebendazole |
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Ancylostoma cambium/A. Braziliense |
Hookworm of animals – dogs Acquired walking without shoes Causes Cutaneous Larva migrans Diagnosis – clinical treatment - albendazole/ivermectin stat |
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Gnathostomiasis? |
In humans - mostly due to gnathostoma spinigerum (zoonotic nematode that has freshwater cycle) Endemic in Southeast Asia, central/South America and Africa Cats and dogs are definitive host humans are affected by the intermediate host of freshwater fish,crabs, shrimps, frogs, birds and pork In humans often occurs in outbreaks |
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Gnathostomiasis? |
In humans - mostly due to gnathostoma spinigerum (zoonotic nematode that has freshwater cycle) Endemic in Southeast Asia, central/South America and Africa Cats and dogs are definitive host humans are affected by the intermediate host of freshwater fish,crabs, shrimps, frogs, birds and pork In humans often occurs in outbreaks |
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Clinical features of gnathostomiasis |
In humans Lava penetrate the intestinal wall and wander around the body There is marked eosinophilia. Malaise and diarrhoea and vomiting may occur in the first weeks Four weeks – patient develops a oedematous itchy and painful migratory swelling with a rash tracking it’s route Migrates extensively throughout the viscera and can cause CNS infections of brain/spine. This includes eosinophilic meningitis |
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Gnathostomiasis? |
In humans - mostly due to gnathostoma spinigerum (zoonotic nematode that has freshwater cycle) Endemic in Southeast Asia, central/South America and Africa Cats and dogs are definitive host humans are affected by the intermediate host of freshwater fish,crabs, shrimps, frogs, birds and pork In humans often occurs in outbreaks |
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Clinical features of gnathostomiasis |
In humans Lava penetrate the intestinal wall and wander around the body There is marked eosinophilia. Malaise and diarrhoea and vomiting may occur in the first weeks Four weeks – patient develops a oedematous itchy and painful migratory swelling with a rash tracking it’s route Migrates extensively throughout the viscera and can cause CNS infections of brain/spine. This includes eosinophilic meningitis |
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Diagnosis of gnathostomiasis |
Migratory swellings and eosinophilia and exposure Microscopy – parasite Radiological evidence Serology CSF – eosinophilia |
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Gnathostomiasis? |
In humans - mostly due to gnathostoma spinigerum (zoonotic nematode that has freshwater cycle) Endemic in Southeast Asia, central/South America and Africa Cats and dogs are definitive host humans are affected by the intermediate host of freshwater fish,crabs, shrimps, frogs, birds and pork In humans often occurs in outbreaks |
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Clinical features of gnathostomiasis |
In humans Lava penetrate the intestinal wall and wander around the body There is marked eosinophilia. Malaise and diarrhoea and vomiting may occur in the first weeks Four weeks – patient develops a oedematous itchy and painful migratory swelling with a rash tracking it’s route Migrates extensively throughout the viscera and can cause CNS infections of brain/spine. This includes eosinophilic meningitis |
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Diagnosis of gnathostomiasis |
Migratory swellings and eosinophilia and exposure Microscopy – parasite Radiological evidence Serology CSF – eosinophilia |
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Treatment of gnathostomiasis |
Albendazole Ivermectin |
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Gnathostomiasis? |
In humans - mostly due to gnathostoma spinigerum (zoonotic nematode that has freshwater cycle) Endemic in Southeast Asia, central/South America and Africa Cats and dogs are definitive host humans are affected by the intermediate host of freshwater fish,crabs, shrimps, frogs, birds and pork In humans often occurs in outbreaks |
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Clinical features of gnathostomiasis |
In humans Lava penetrate the intestinal wall and wander around the body There is marked eosinophilia. Malaise and diarrhoea and vomiting may occur in the first weeks Four weeks – patient develops a oedematous itchy and painful migratory swelling with a rash tracking it’s route Migrates extensively throughout the viscera and can cause CNS infections of brain/spine. This includes eosinophilic meningitis |
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Diagnosis of gnathostomiasis |
Migratory swellings and eosinophilia and exposure Microscopy – parasite Radiological evidence Serology CSF – eosinophilia |
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Treatment of gnathostomiasis |
Albendazole Ivermectin |
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Summary table |
Back (Definition) |
