Worms: aliens in human bodies

In the Philippines, there are three worms that cause the most health problems: roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma duodenale).

These three have been a burden to humanity for centuries. They are called soil-transmitted helminthiasis and are found in the soil.

Helminths. Helminths are really parasitic worms (like aliens) that use the human body as a host to feed on and in which they replicate themselves.

An adult ascaris (roundworm) can grow to one foot long, and there are children with hundreds of worms inside their bodies! Whipworms reach around four centimeters long and hookworms, one cm.

Data in 2004 show seven out of 10 Filipino children aged one to six years have ascaris. In 2006, a study by Dr. Vicente Belizario Jr. found that in children six to 12 years old, more than half or 54 percent have ascaris.

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

Life cycle. An infected person passes out thousands of parasite eggs in the stool. 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.

These infective eggs can now get into our bodies via several ways. First, these eggs may contaminate raw vegetables in the field. Second, sources of drinking water can be contaminated with human wastes. Third, young kids often play in the soil and these microscopic eggs can get on their hands. If the children do not wash their hands, they can unknowingly ingest the eggs.

Hookworm eggs in the soil will hatch into larvae, which can directly penetrate the skin. When a person walks barefoot on the soil, the larvae can penetrate the skin between the toes.

Once inside the host, eggs and larvae will mature and grow to become adult worms in about two to three months.

Pathways. Ascaris eggs in the human body will hatch into larvae in the small intestines. From the intestines, they will hitch a ride inside the blood vessels and eventually go 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 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.

Risk factors
Youth. Many who have parasitic worms are 10 years old or younger: children like to play in the soil and often put fingers in their mouths.
Warm weather. These worms thrive better in countries that are warm throughout the year.
Poor hygiene and sanitation. High infection rates are found in areas with poor sanitation and hygiene. Communities that use human feces as soil fertilizer are at high risk.

Symptoms. Symptoms usually depend on the parasite load in the body. Some infected persons do not feel anything. However, children may complain of vague abdominal pain and being tired, and do poorly 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 have traveled inside the body.

Sometimes a live worm can be found in the stool 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. A stool exam can be done to check for parasite eggs. A complete blood count can be helpful in detecting anemia and an elevation of a certain type of white blood cell called eosinophils. Both findings will bolster suspicions concerning the presence of worms.

Treatment and prevention. One dose of oral medicine such as Mebendazole 500 mg tablet or Albendazole 400 mg tablet can be given. Children one to two years old can be given half a dose of Albendazole.

Because of the huge number of Filipino children with parasitic infection, the Department of Health in 1999 started a program of giving purging medicine every six months.

Children 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 using the toilet.

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 is safer to eat thoroughly cooked meals.

Drink purified, bottled or boiled water. It is uncertain if tap water is free from bacteria and parasites.

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

Always wear slippers or shoes. Do not 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. — First published in Tulay Fortnightly, Chinese-Filipino Digest 27, nos. 1-2 (June 17-July 7, 2014): 22.