Nematoda

What is the course of infection for Trichuris trichiura?

A host ingests an embryonated egg from contaminated hands or food.

In the small intestine, the eggs hatch and release larvae which penetrate the villi.

After a few days, the larvae travel through the tissue to the large intestine and mature into adults.

After reproduction, the posterior end of females sticks into the large intestine and deposit unembryonated eggs.

The eggs are then passed with the feces.

Due to the invasion of the mucosa and wandering, there can be damage, edema, inflammation, and bleeding.

The infection is mostly asymptomatic, but dysentery, anemia, prolapses, and growth retardation in children can occur.

How do you diagnose Trichuris trichiura and what do you use to treat it?

You diagnose by taking a fecal sample and looking for unembryonated eggs.

Treatment with mebendazole.

What are factors that play into the epidemiology of Trichuris trichiura?

Most prevalent in tropical countries (India), method and manner of waste disposal, and children most infected.

What is the course of infection for Trichinella spiralis?

The host ingests encysted larva from undercooked meat.

In the small intestine, the larvae are released and burrow into the mucosa.

They mature into adults, reproduce, and the larvae are released.

The larvae travel through the circulation to striated muscle and encyst.

The cells are turned into nurse cells and the larvae go dormant.

The migration of the adults can cause damage, respiratory difficulty, and inflammation to the intestinal mucosa, leading to vomiting, diarrhea, and cramps.

The migration of the larvae causes damage blood vessels, edema, weakness of infected muscles, and inflammation, leading to fever, myalgia, eosinophilia, and illness specific to the muscle infected.

How do you diagnose Trichinella spiralis and how do you treat it?

You diagnose by serodiagnosis or muscle biopsy.

Treat with albendazole.

What are factors that play into the epidemiology of Trichinella spiralis?

Found mostly in temperate zones (USA),

What are factors that play into the epidemiology of Ascaris lumbricoides?

What are factors that play into the epidemiology of Enterobius vermicularis?

What are factors that play into the epidemiology of hookworms (Necator americanus/Ancylostoma duodenale)?