Helminthic Parasites

Vocabulary flashcards covering key terms and definitions related to helminthic parasites, their morphology, epidemiology, life cycle, symptoms, diagnosis, and treatment.

Enterobius vermicularis

Commonly known as pinworm, a type of nematode parasite.

Morphology of pinworm

Adults are small, thin, white; females are 8-13 mm and males are 2-5 mm with a curved tail, three lips, and a prominent esophagal bulb.

Ovoid eggs

Pinworm eggs are translucent, asymmetrical, and flattened on one side, measuring 25-55µm.

Epidemiology of Enterobius vermicularis

A cosmopolitan parasite that commonly infects school children, especially in temperate zones.

Transmission of pinworm infection

Infection spreads via fecal-oral route through ingestion or inhalation of embryonated eggs, and can be facilitated by scratching the perianal region.

Life cycle of Enterobius vermicularis

Females deposit eggs around the anus, which can lead to self-infection through contaminated hands and surfaces.

Symptoms of pinworm infection

The most common symptom is an itchy anal region, which may cause insomnia and restlessness.

Diagnosis of pinworm infection

The diagnosis is often made by detecting eggs or adult worms in perianal skin folds or using the Scotch tape test.

Treatment options for pinworm infection

Mebendazole, albendazole, and pyrantel are effective treatments generally administered in one dose followed by a second dose two weeks later.

Prevention of pinworm infection

Prevention includes practicing good hygiene, frequent hand washing, and changing underclothes and bedding regularly.

Ascaris lumbricoides

Known as the common roundworm, it is the largest roundworm parasitizing the human intestine.

Symptoms of ascariasis

Non-specific symptoms may include abdominal discomfort, pain, vomiting, and diarrhea. Heavy infections may cause intestinal blockage.

Diagnosis of ascariasis

Identifiable by eggs or adults in stool samples, though eggs may be difficult to find in light infections.

Trichuris trichiura

Commonly referred to as whipworm, it is a roundworm with a characteristic whip-like anterior part.

Symptoms of trichuriasis

Light infections are often asymptomatic, while heavy infections can lead to abdominal pain and rectal prolapse.

Diagnosis of whipworm infection

Diagnosis is made by identifying whipworm eggs in stool samples.

Toxocara canis and Toxocara cati

Roundworms causing toxocariasis, with T. canis typically affecting dogs and T. cati affecting cats.

Symptoms of toxocariasis

May include fever, cough, and damage to the liver or lungs, particularly in visceral forms.

Wuchereria bancrofti

A filarial worm responsible for lymphatic filariasis, transmitted by mosquito bites.

Symptoms of lymphatic filariasis

Can include asymptomatic stages, lymphedema, elephantiasis, and tropical pulmonary eosinophilia.