Wednesday, March 31, 2021

Hookworm Life Cycle


Hookworms are blood sucking parasites that reside in the small intestine of human beings and cause an infection called helminthiases. Hookworms fall under the class Secernentea and the order Strongylida. An adult hookworm measures up to 11 mm in size. Study shows that A. Ceylanicum is a vital parasite infecting humans in certain parts of the world. The human hookworms include Ancylostoma duodenale and Necator americanus. The hookworm disease has infected approximately 740 million people worldwide. It affects the human lungs, skin and small intestine.

Let’s take a look at the life cycle of a hookworm to get a better understanding.

Life Cycle of Hookworm:

1) The Egg – Stage 1 –

The female hookworm stores eggs in the small intestine of the host. The eggs contain two to eight segmented embryos that are passed out into soil via human stool. It takes about 24 to 48 hours to transform into a larva and enter the next stage.

2) The Larvae – Stage 2 –

In this stage, under favourable conditions the larvae hatches in 1 or 2 days. The larvae grow in feces or in the soil. During this time, the larvae is not infective, but takes around two molts to become infective. The time period for two molting takes around 5 to 10 days, after which the larvae are infective. The larvae upon human contact penetrate through human feet, migrate through blood vessels to the heart and then to the lungs. Here, they penetrate through pulmonary alveoli, climb the bronchial tree to pharynx, and are then swallowed where it reaches the intestine.

3) The Adult – Stage 3 –

Jejunum is the part of the small intestine that is responsible for absorbing all the nutrients, fatty acids and amino acids. The larvae migrate to the jejunum part of the small intestine, where the larvae sexually mature and transform into adult hookworms. Adult hookworms reside in the lumen of the small intestine, where they attach to the walls causing blood loss in the host. Life expectancy of an adult hookworm is 1 to 2 years.

Conclusion:

Earlier A. duodenale and N. americanus were the primary intestinal hookworms species found worldwide. Today A. ceylanicum is one of the most prominent intestinal hookworm infecting human beings in all parts of the world.


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