Worms: Aliens in human bodies

In this article, let me introduce to you a class of worms that has been a burden to humanity for centuries. These are the disease-causing worms found in the soil called soil-transmitted helminthiasis.

In the Philippines, the three worms causing the most health problems are (1) roundworms or Ascaris lumbricoides, (2) whipworms or Trichuris trichiura, and (3) hookworms (called Necator americanus and Ancylostoma duodenale).

How does an ascaris worm infect a person? These worms are really parasites (like an alien) that use the human body as a host to feed upon and wherein they replicate themselves. An adult ascaris can reach up to one foot long, and there are children with hundreds of worms inside their bodies! (Whipworms reach around four centimeters in length and hookworms are one cm.)

Local data in 2004 shows that seven out of 10 Filipino children ages one to six years are positive for these parasites. In 2006, a study by Dr. Vicente Belizario, Jr. found that in children between six to 12 years old, more than half or 54 percent have these parasites.

Worldwide, experts estimate that roundworms infect over 1 billion people, whipworm infection is at 795 million, and hookworms afflict 740 million people. Majority of cases are found in Africa, China and East Asia.

Life cycle of worms

An infected person passes out thousands of parasite eggs in the stools. In areas where there are no toilets, these human wastes can become mixed with the soil, garbage and stagnant water. In developing countries, there is a practice called “night soil” wherein human feces are used as fertilizer for the soil. This is a dangerous practice because the soil will help the excreted eggs mature and become infective in two to three weeks time.

These infective eggs can now get into our bodies via several ways. First, these eggs may contaminate raw vegetables in the field. Second, our sources of drinking water could become contaminated with human wastes. Third, young kids often play in the soil and these microscopic eggs can get stuck on their hands. And if kids don’t wash their hands, they can unknowingly ingest the eggs.

In the case of hookworms, the parasite eggs found in the soil will hatch into larvae, which can directly penetrate the skin. When a person walks barefoot on the soil, these hookworm larvae can penetrate the skin between the toes.

Bigger than life: A magnified hookworm

Now, what happens once these eggs or larvae enter our bodies? Once inside the host, they will mature and grow to become adult worms in approximately two to three months.

The pathway that these worms take inside the body is quite scary. In the case of ascaris, the eggs will hatch into larvae in the small intestines. From the intestines, they will hitch a ride inside the blood vessels eventually finding their way to the lungs. The larvae will mature further in the lungs and slowly climb up the lung’s air passages (bronchus), reaching the throat when we cough, and then to be swallowed again! On this second trip to the intestines, the larvae will now mature as adult male and female ascaris worms.

Take note that one female worm can produce up to 240,000 eggs per day, and these are continuously expelled in the feces. Once the eggs get into the soil, the cycle of egg maturating and human infection repeats itself again.

 

Who are at risk

Young age. Many people who have parasitic worms are 10 years old or younger. This is because children like to play in the soil and often put their fingers in their mouths.

Warm weather. These worms thrive more in countries with warm temperatures throughout the year.

Developing countries. High infection rates are found in areas with poor sanitation and hygiene. Communities who use human feces as fertilizer for the soil are at high risk.

Symptoms

The symptoms usually depend on the parasite load in the body. Some infected persons don’t feel anything. However, children may complain of vague abdominal pain, tiredness and poor performance in school.

Those with moderate to heavy infestations can experience abdominal pain, nausea, diarrhea, weakness, fatigue, weight loss, pale skin, bloody stools, and a variety of symptoms depending on where the worms travel inside the body. Sometimes a live worm can be found in the stools or may unexpectedly exit through the nose or mouth.

Occasionally, complications can arise such as blockage of the worms inside the narrow passages in the liver, pancreas and intestines. This can cause severe pain and may warrant an emergency operation.

Diagnosis

To find out if a person has these parasites, the easiest way is to perform a stool exam test to check for parasite eggs. A complete blood count (CBC) can be helpful in detecting anemia and an elevation of a certain type of white blood cell called eosinophils. Both findings will bolster our suspicion concerning the presence of worms.

 

Treatment and prevention

Treatment for worm infestation is by giving oral medicines like mebendazole 500 mg tablet or Albendazole 400 mg tablet given for one dose only. Children between one to two years old can be given half the dose of Albendazole at 200 mg.

Because of the huge number of Filipino children with parasitic infection, the Department of Health in 1999 started a program of giving purging medicines every 6 months. Children between the ages of one to 12 years old are the prime target for mass treatment. These purging drugs have an excellent safety record. Nevertheless, in patients with heavy infestation of worms, there could be some side effects from the dying worms such as mild abdominal pain or diarrhea.

 

Prevention tips

Practice good personal hygiene. Be squeaky clean. These parasite eggs are so small that they are invisible to the eyes. Wash your hands thoroughly with soap and water before eating and after defecating.

Cut the fingernails short, especially for children. Parasite eggs have a way of living underneath the nails.

Advise children not to play in the soil and other dirty places. Millions of worm eggs could be living in the soil.

Eat only clean and safe food. Wash vegetables and fruits thoroughly. Food handlers should at least have a stool exam test to make sure that they are not carriers of these parasites. It’s safer to eat thoroughly cooked meals.

Drink purified, bottled or boiled water. We cannot be sure if our tap water is free from bacteria and parasites.

In rural areas, it is important to dispose of human wastes properly. Use a toilet if available. Otherwise, bury human wastes far away from the water sources of the community.

Always wear slippers or shoes. Don’t walk barefoot because hookworm larvae can easily penetrate the skin.

Finally, keep your surroundings clean. Practice these common sense tips to keep the aliens away.

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