Life cycle hookworm

Question 1

What is the classification of Hookworm?

Answer 1

Extracellular helminth in the category of nematode

Soil transmitted helminths

Question 2

What hookworm species can infect humans?

Answer 2

Anclostoma duodenale, Necator americanus and Anclostoma Ceylanicum.

Question 3

How is Hookworm transmitted?

Answer 3

Eggs in feces to soil to larvae that penetrate skin

Question 4

What are the steps of the Hookworm lifecycle outside of the human host?

Answer 4

1. Begins as an egg layed inside the human by another hookworm.
2. Eggs are passed in the feces of the infected human
3. After 24 to 48 hours these eggs hatch and morph into Rhabditiform larva and they mostly grow to become larger
4. After about 7 days they develop into filariform larva in the environment and become infectious. Until a worm infects someone it can survive for about a month outside depending on the conditions. It strives in warm moist soil but can stand direct sunlight
5. When the host, a human, walks barefoot on such soil the parasite can attach itself to the skin and infection starts.

Question 5

What are the lifecycle steps of Hookworm lifecycle in the human host?

Answer 5

6. The intense 10 day trip in the human body begins that starts in the skin where the larva finds a blood vessel for transportation. With the bloodstream it travels upwards passing the heart and entering the pulmonary circulation. Here it manages to cross the endothelial layer into the alveoli. Once inside the lungs it travels further up into the trachea until it reaches the throat. It turns around and dives into the esophagus down the gastro intestinal tract and finally arrives in the small intestine. The trip from the lungs to the intestine takes about a month.
7. In the small intestine the worm attaches itself to the mucosal wall of the intestine with it’s hook formed head and teeth to feed and where it matures into adulthood.
8. Adult hookworms mate in the intestine to produce offspring through eggs. They can last up to 2 years before they get eliminated by the human host.
9. The eggs leave the body through feces and the cycle starts again.

Question 6

What type of life cycle does Hookworm have?

Answer 6

Direct life cycle

Humans are definitive host

Question 7

What is a reservoir for hookworms?

Answer 7

Soil

Question 8

What are the symptoms of Hookworm infection?

Answer 8

Different stages have different symptoms:

Larvae penetrating the skin –> Skin rash

Larvae in the lungs –> Cough and sore throat

Adult worm in intestine –> Abdominal pain, diarrhea, weight loss, anaemia and protein deficiency due to blood loss at the site where worms attach to the intestinal walls. For Children who get frequently infected the loss of iron and protein can retard growth and mental development over the years.

Question 9

Where is Hookworm endemic?

Answer 9

Worldwide in warm and moist climates

Question 10

How is Hookworm diagnosed?

Answer 10

Microscopy of hookworm eggs in fresh stool samples. It should be examined within several hours after defecation. Concentration procedure is recommended as eggs might be difficult to be found in light infections
In a very early stage when during the time of penetration of larva and appearance of eggs in the stool it is possible to perform a blood test for eosinophilia. This is a higher then normal number of eosinophils. During this time this is the only laboratory abnormality of people infected with hookworm.