[PARA10N] Lec 2: Soil-Transmitted Parasites

Soil-transmitted helminths

Soil-transmitted helminths

Most common parasitic infections worldwide according to WHO

Stage 2

In this stage of STH infections, other individuals are infected through ingestion of food via contaminated food or dirty hands, or by larvae penetrating the skin

Stage 1

In this stage of STH infections, infected individuals contaminate soil with feces containing helminth eggs. Eggs develop in the soil into its infective stage.

Stage 3

In this stage of STH infections, , the eggs develop further in the infected individuals, thus repeating the cycle all over again. The eggs or larvae develop into adult worms which produce eggs.

Ascaris Lumbricoides

Most common intestinal roundworm

2 and 1/2 - 3 months

Duration of the life cycle of ascaris lumbricoides

Whipworm

Common name of Trichuris Trichiura

Large intestine (cecum)

Habitat of Trichuris Trichiura

Trichuris Trichiura: Adult Male

Identify the parasite being shown

Trichuris Trichiura: Adult Female

Identify the parasite being shown

Embryonated egg

Infective stage of Ascaris Lumbricoides

Selective deworming

Integrated helminth control program for women of childbearing age, pregnant women, and special population groups.

Strongyloides Stercoralis

Commonly called as Threadworm

Strongyloides Stercoralis

The only species capable of autoinfection

Stage 1

Identify which stage of the life cycle of Trichuris Trichiura is the following:

After the ingestion of embryonated eggs, the larvae hatch in the small intestines

Stage 3

Identify which stage of the life cycle of Trichuris Trichiura is the following:

Larvae matures into adults and inhabits the cecum and colon

Stage 2

Identify which stage of the life cycle of Trichuris Trichiura is the following:

Larvae penetrate the intestinal wall. This step takes 3-10 days

Stage 4

Identify which stage of the life cycle of Trichuris Trichiura is the following:

Reproduction takes place. Females lay embryonated eggs which will be passed out with feces and into the soil

Stage 5

Identify which stage of the life cycle of Trichuris Trichiura is the following:

In case the infected individual has poor defecating habits (e.g. defecates on the soil), the eggs develop and become embryonated within 2 -3 weeks

Neglected Tropical Disease

These are communicable diseases of viral, bacterial, or parasitic origin affecting poor communities globally

Diagnostic stage

This stage is usually seen in the feces of an individual infected with ascaris lumbricoides.

Male Adult Hookworm

Identify the parasite being shown

Female Adult Hookworm

Identify the parasite being shown

True

True or False

Both male and female adult hookworms have well-developed buccal capsules.

Adult male ascaris lumbricoides

Identify the parasite being shown

Adult female ascaris lumbricoides

Identify the parasite being shown

True

True or False

The presence of an unfertilized ascaris lumbricoides egg may be an indicator of the absence of males.

Soil-transmitted helminths

This is also called "diseases of the poor"

Embryonated egg

What do you call the inside of Trichuris trichiura's egg which is protected by a thick, brown egg shell?

Ancylostoma ceylanicum

What type of hookworm has 2 pairs of ventral teeth? (the outer pair is larger than the inner pair)

bura copulatrix

What is the fan-like formation in the posterior end of adult male hookworm?

False

True or False

Adult Trichuris trichiura males are generally longer than the adult females.

Filariform

Which larval form refers to the infective stage of hookworms and Strongyloides stercoralis?

5,000

For an infection of Trichuris trichiura be considered chronic, there should be more than _______ eggs/gm feces.

True

True or False

The treatment, control, and prevention measures for Trichuris trichiura and Ascaris are the same.

9,000 to 30,000

How many eggs can adult female hookworms lay per day?

Necator americanus and Ancylostoma duodenale

Two species of hookworms affecting man

Ancylostoma caninum and Ancylostoma braziliense

Two species of hookworms affecting animals

Forked or notched

Posterior - Hookworms: tapering Strongyloides stercoralis: ____________

Albendazole: 400 mg, single dose Mebendazole: 500 mg Pyrantel pamoate: 10 mg/kg body weight

Matching Type

Treatment of Ascaris lumbricoides infection

I. Albendazole II. Mebendazole III. Pyrantel pamoate

A. 500 mg B. 400 mg, single dose C. 10 mg/kg body weight