[Biology Class Notes] on Ascaris Life Cycle Pdf

Parasites are a type of creature which uses another creature’s body to survive. Roundworm is one of the most prevalent parasites found in the human body. Ascaris is a type of roundworm, which lives in the small intestine of humans.

Moreover, Ascaris Lumbricoides is the species of roundworm responsible for this infection. The larvae and adult worms live and develop in the small intestine and cause this disease. These worms draw nutrition from the human body and mature over time. Furthermore, adult worms can be more than 30 centimeters long.

Read on to know about the Ascaris life cycle.

Life Cycle of Ascaris Lumbricoides

Ingestion: The microscopic ascariasis eggs cannot become infective without coming into contact with soil. Moreover, individuals can accidentally come into contact with such contaminated soil by consuming any undercooked vegetables or fruits grown in any infected soil. Otherwise, the lack of proper washing of hands before eating is another source of catching this parasite.

Migration: The second part of the life history of Ascaris lumbricoides is migration. These eggs then hatch within the small intestine of an individual and produce larvae. After that, they penetrate the intestinal wall and move into the lungs with the help of the bloodstream or lymphatic system. Furthermore, these larvae mature in the lungs for around a week. After that, they break into the airway, where they are coughed up and swallowed.

Maturation: Once back into the intestine, these parasites develop into either male or female worms. Female worms are more than 40 centimeters (15 inches) long and less than 6 millimeters (quarter inch) in diameter. However, male worms are smaller than female ones.

Reproduction: The reproduction process takes place in the small intestine. Moreover, female worms can produce around 200,000 eggs each day. These eggs leave the human body through feces. Furthermore, these fertilized eggs must stay in the soil for at least 18 days before they become infective.

Additionally, this entire process takes around 2-3 months to complete successfully. Moreover, the life history of Ascaris within an individual can go up to 2 years.

Symptoms of Ascaris

Individuals cannot detect the signs of this parasite in the beginning. However, when the infestation within the small intestine develops, patients can notice symptoms such as –

Additionally, in advance stages where these parasites travel to the lungs, an individual may notice the following symptoms –

• Fever

• Gagging cough

• Bloody mucus

• Discomfort in chest

• Wheezing

• Breathing problems

Diagnosis of Ascaris

The primary process to diagnose the presence of Ascaris suum life cycle in a human is by collecting a stool sample. However, this process may not work during the early infestation stages.

On the other hand, imaging tests are always helpful to determine the number of eggs inside a person. MRI, endoscopy, CT scan, ultrasound, etc. are used for this purpose.

Treatment of Ascaris

Mostly, anti-parasitic drugs are prescribed to counter this situation. However, in case of a severe condition surgery is the only option.

Prevention from Ascaris

The best way to defend against the Ascaris life cycle is to maintain good hygiene. Washing hands before eating and cleaning fruits and vegetables can protect you from this disease. 

The Ascaris life cycle can prove to be a significant health issue if neglected for too long. Otherwise, proper treatment can cure it quickly. 

Moreover, students can learn more about roundworms and their types from the detailed study notes offered by . You can also download our app for convenient access to these notes and online interactive sessions for clarity.

Ascaris Lumbricoides is a species of roundworm, which when it infects the small intestines, the infection caused by it is known as Ascariasis. Roundworms are parasitic worms, infections caused by which are very common. People can get the infection through contaminated food or water. There are usually no symptoms caused by the infection but if the infection or the number of worms increases it can cause problems in the intestines or lungs.

Causes of Ascariasis

A person can get affected with Ascariasis if he ingests the eggs of Ascaris Lumbricoides. The roundworm eggs can be found in contaminated soil with human feces or uncooked food or contaminated water. According to WHO, kids who play in contaminated soil and put their hands in their mouths are more likely to get affected by Ascariasis. 

Life Cycle of an Ascaris

• Adult worms is present in the lumen of the small intestine. A female produces approximately 20000 eggs which are passed in the feces.

• Unfertilized eggs are not infectious, only fertile eggs after 18 days to several weeks start to spread the infection.

• The fertility of the eggs depends upon environmental conditions such as warm, moist, shaded soil, etc. 

• Once the infective eggs are swallowed, the larvae start to hatch in the small intestine.

• Then the larvae move through the bloodstream to the lungs.

• Once the larvae are matured, they leave your lungs and travel towards the throat.

• The roundworms are again swallowed and travel back to the intestines.

• The roundworms will again mate in the intestines and will lay more eggs.

• This cycle continues where some eggs are excreted through the feces while the others hatch and return back to the lungs.

Symptoms of Ascariasis

Diagnosis of Ascariasis

To diagnose acariasis, there are-

1. Stool Tests- Stools can be examined under a microscope for eggs and larvae. Eggs do not appear in the stool at least 40 days before the infection.

2. Blood Tests- Blood can be examined for an increased number of white blood cells which indicates the possibility of the infection.

3. X-rays- Abdomen X-Ray can reveal the larvae in the abdomen while chest X-rays can reveal the larvae in the lungs.

4. Ultrasound- Ultrasound can reveal the larvae in the pancreas or liver.

5. CT Scans or MRIs- With the help of both these tests, doctors can detect the worms that block the ducts in the liver or the pancreas.

Treatment of Ascariasis

The treatment for the beginning stage of ascariasis includes antiparasitic medicines which kill the worms in around 2-3 days. In case of heavy infestation, surgery is required to remove the worms and repair the damages they’ve caused to the body.

Prevention of Ascariasis

The preventative measures are taken to avoid ascariasis is-

1. Maintaining good hygiene which includes washing hands before eating food and after leaving the bathroom.

2. Avoid unwashed raw food and vegetables.

3. Eating fresh, healthy, and cooked food.