HELMINTHES Flashcards
What are helminths?
Helminths are multicellular parasitic worms, including nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes), that infect humans.
How are helminths transmitted?
Transmission occurs through ingestion of eggs or larvae (e.g., Ascaris lumbricoides), skin penetration (e.g., hookworms), or insect vectors (e.g., filariasis).
What are the clinical features of ascariasis (Ascaris lumbricoides)?
Symptoms include abdominal pain, malnutrition, intestinal obstruction, and respiratory symptoms due to migrating larvae.
How is ascariasis diagnosed?
Diagnosis is made by identifying eggs in stool samples or imaging for complications like obstruction.
What is the treatment for ascariasis?
Albendazole or mebendazole is the drug of choice.
How is hookworm infection transmitted?
Hookworms are transmitted by larvae penetrating the skin, often through contact with contaminated soil.
What are the clinical features of hookworm infection?
Symptoms include iron-deficiency anemia, fatigue, and malnutrition, along with localized skin irritation at the site of larval entry.
How is hookworm infection diagnosed?
Diagnosis is based on stool examination to detect eggs.
What is the treatment for hookworm infection?
Albendazole or mebendazole is used to treat hookworm infections, along with iron supplementation for anemia.
What are the clinical features of schistosomiasis (Schistosoma species)?
Symptoms include hematuria (urinary schistosomiasis) or diarrhea, abdominal pain, and hepatosplenomegaly (intestinal schistosomiasis). Chronic cases can lead to organ damage.
How is schistosomiasis transmitted?
Schistosomiasis is transmitted by contact with freshwater containing larvae released by infected snails.
How is schistosomiasis diagnosed?
Diagnosis involves detecting eggs in stool or urine and serological tests for chronic infections.
What is the treatment for schistosomiasis?
Praziquantel is the drug of choice for all forms of schistosomiasis.
What are the clinical features of taeniasis (Taenia solium and Taenia saginata)?
Symptoms include mild gastrointestinal discomfort. In cysticercosis (caused by larval stages), seizures and neurological symptoms can occur.
How is taeniasis transmitted?
Humans acquire taeniasis by ingesting raw or undercooked meat containing cysticerci (larval forms of the parasite).
How is taeniasis diagnosed?
Diagnosis involves stool microscopy to identify eggs or proglottids and imaging (e.g., CT or MRI) for neurocysticercosis.
What is the treatment for taeniasis?
Intestinal infections are treated with praziquantel or niclosamide, while neurocysticercosis is treated with albendazole and corticosteroids.
How is lymphatic filariasis transmitted?
Filariasis is transmitted through mosquito bites, particularly by Anopheles, Culex, or Aedes species.
What are the clinical features of lymphatic filariasis?
Symptoms include lymphedema, elephantiasis, and hydrocele due to chronic inflammation of lymphatic vessels.
How is lymphatic filariasis diagnosed?
Diagnosis involves detecting microfilariae in blood smears or antigen detection tests.
What is the treatment for lymphatic filariasis?
Diethylcarbamazine (DEC) or ivermectin is used for treatment, along with measures to manage lymphedema.
How is strongyloidiasis (Strongyloides stercoralis) transmitted?
Transmission occurs when larvae in contaminated soil penetrate the skin.
What are the clinical features of strongyloidiasis?
Symptoms include gastrointestinal discomfort, urticaria (skin rash), and in severe cases, disseminated infection in immunosuppressed individuals.
How is strongyloidiasis diagnosed?
Diagnosis is made by detecting larvae in stool samples or through serological tests.
What is the treatment for strongyloidiasis?
Ivermectin is the preferred treatment for strongyloidiasis.
Ascaris lumbricoides - Transmission
Fecal-oral route through ingestion of eggs in contaminated food or water.
Ascaris lumbricoides - Site of Infection
Primarily the small intestine; larvae can migrate through the lungs.
Ascaris lumbricoides - Mechanism of Infection
Larvae hatch in the intestine, migrate through the bloodstream to the lungs, are coughed up and swallowed, then mature in the intestine.
Ascaris lumbricoides - Clinical Presentation
Abdominal pain, malnutrition, intestinal obstruction, and pulmonary symptoms during larval migration (e.g., Loeffler’s syndrome).
Ascaris lumbricoides - Diagnosis
Stool examination for eggs; imaging may reveal worms in intestines.
Ascaris lumbricoides - Treatment
Albendazole or mebendazole.
Hookworms - Transmission
Larvae penetrate the skin, often through bare feet.
Hookworms - Site of Infection
Small intestine; larvae migrate through the lungs.
Hookworms - Mechanism of Infection
Larvae enter the bloodstream, travel to the lungs, are coughed up, swallowed, and mature in the intestine.
Hookworms - Clinical Presentation
Iron deficiency anemia, fatigue, abdominal pain, cutaneous larva migrans at the site of entry.
Hookworms - Diagnosis
Stool examination for eggs.
