Parasitic Worms

It’s important to realize that there are infections not commonly seen today in developed countries that may become major issues if a disaster throws you off the grid. Knowing which disease-causing organisms exist in your area, even if they are not major problems today, will be important to keep your loved ones healthy.

The word “parasite” comes from the Greek word Parastos, meaning “someone that eats at someone else’s table”. When we think of para- sites, none give us the creeps more than having worms.

Parasites like ticks, fleas, mites, and lice live on our skin or just beneath; these are called ectoparasites. Worms, also known as helminths, are endoparasites. They live deep in our intestines or other core organs, often gaining sustenance by sharing our partly-digested food. They are also egg-laying machines, with some depositing tens of thousands a day into their host.

Many different worms are known to infest the human body: nematodes, trematodes, flatworms, and flukes, are just a few. The diseases they cause are a major health issue in underdeveloped countries due to difficulties with sanitation. Even in developed nations, any disaster that impairs access to safe food and water could cause cases of parasitic worms to skyrocket.

Worm infestation is usually caused by ingesting soil that contains their eggs. While this may seem an unlikely happenstance to you, areas where people defecate openly and fail to wash their hands leads to contaminated soil. Some of this soil ends up on people’s hands, and then goes to their mouth when they touch their face.

Parasitic worms range in size from microscopic to very long, depending on the species. The most common infection we’ll see in the U.S. is the tiny Pinworm, which causes anal itching in 40 million Americans. However, almost a quarter of the world’s population has some type of worm infestation. Children are especially vulnerable and may experience stunted growth and developmental problems as a consequence.

Worm eggs or larvae enter the body through the mouth, nose, anus, or breaks in the skin. Amazingly, many helminths actually require human stomach acid to dissolve their egg shells to allow them to hatch. Once hatched, the acid-immune larvae travel from the stomach and attach themselves to the walls of the intestinal tract. Some species infest the liver and lungs as well.

SYMPTOMS OF WORM INFESTATIONS

Colonization by worms may be asymptomatic or, as in the case of pin- worms, just involve some itching in the anal area. With some species, however, a large concentration of organisms can cause serious problems.

Each type of worms cause different symptoms, but you should suspect their presence in otherwise-unexplained cases of:

• Constipation or diarrhea
• Abdominal swelling or gas
• Abdominal pain or cramps
• Nausea and vomiting
• Weight loss
• Constant urge to have a bowel movement.
• Unexplained skin rashes or sores.
• Anal itching
• Constant fatigue.
• Chronic muscle and joint aches.
• Malnutrition

The above represents a broad array of symptoms, and makes me wonder if the number of cases of worm infestation is underestimated, even in countries with modern infrastructures.

CONSEQUENCES OF WORM INFESTATIONS

In rare cases, the population of internal parasites is so high that it causes an obstruction of the bowels. Worm species that invade the liver or lungs can cause respiratory distress or a weakened metabolism. All of these complications may result in the death of the patient.

Your body knows when it has been invaded and sets up an immune response against the worm. Success is limited, however, and all the energy put into defense may weaken the ability to fight“secondary” infections that may occur. The more issues the body has to deal with, the less effective it is in fighting them.

Some worms actually compete with your body for the food that you take in. A species known as Ascaris, for example, will attach to the wall of your intestine and eat partially digested food that comes its way. This competition prevents you from absorbing nutrients effectively, and malnutrition results.

TYPES OF WORMS

There are numerous types of helminthic infections based on the species involved. Infections are often named for the species with the suffix “-asis” (for example, ascariasis), as opposed to other infections/inflammations, which often end with the body part affected and the suffix “-itis” (for example, tonsillitis).

Although there many worms that infect humans, some of the more common types are

Pinworms

Pinworms are a type of nematode called a roundworm. Reaching only 1/3 inch in length, they lay eggs around the host’s anus, usually at night. This leads to an itching sensation which can become severe. Pinworms are the most common parasitic worm infection in the United States

A cycle then develops where contaminated fingers from scratching come in contact with the mouth. This transports the eggs inside the body where they hatch.

You can test for pinworms simply by placing adhesive tape on the anal region of the patient. Inspect the tape for worms (eggs may also be seen with a low-power microscope) after a few hours or the next morning.

Hookworms

Hookworms are another roundworm and one of the most common helminth infections worldwide. The parasite feeds on blood from vessels in the intestinal walls. Hookworm infestation is sometimes asymptomatic, but can cause anemia as well as abdominal symptoms.

Occasionally, a larval (juvenile) hookworm that uses a non-human host may penetrate the skin of a human. Although it can’t go into the organs, it can cause a skin disease called “Larva Migrans”, once known as “creeping eruption”.

With Larva Migrans, you can see serpentine vein-like lesions with itching in the skin. As the larva move, areas where they previously were may become crusty and very itchy.

Ascaris

The largest intestinal roundworm, reaching 14 inches, is known as Ascaris. It is thought that there are 2 billion people that carry this worm, mostly in poorly developed countries.

Ascaris eggs, when ingested, become a larvae that enters the blood- stream through the small intestine. It reaches the lung, where it leaves the circulation and is eventually coughed up, swallowed, and goes back to the intestine, where it matures. Once mature, the female worm can produce up to 200,000 eggs a day.

Ascaris effects may include bloody phlegm, fever, cough, and abdominal symptoms. If the concentration of worms is high enough, they may begin to leave the body through the anus, nose, or mouth.

Tapeworms

Tapeworm is a type of infection caused by a flatworm that lives mostly in Asia and Africa. The worm is, indeed, flat. Tapeworm eggs can form
walled-off areas called “cysts” in body tissues and organs. If larvae are ingested, however, they will mature into adult tapeworms in the intestines. The adults are segmented and reach prodigious lengths up to 55 (!) feet long.

Symptoms are typical for other helminth infections but symptoms related to the infested organ may also be seen.

TREATMENT OF WORM INFESTATIONS

Medications that can kill parasitic worms are called “vermiculicides”. All are prescription drugs, although persons with travel plans to underdeveloped countries shouldn’t have trouble getting these from their physician.

Albendazole (brand name Albenza for roundworms) 400 mg once or twice.

Mebendazole (only available in generic form; most specific for pinworm infestation) 100 mg twice a day for 3 days or 500 mg

Pyrantel pamoate (common ingredient in heartworm meds for dogs) 11 mg/kg once, some species once daily up to 3 days.

Praziquantel (brand name Biltricide for tapeworms, various dosages depending on worm species)

Dosing may vary with some of these medications dependent on the type of worm. A second course of therapy is administered if the patient is not cured in 2-4 weeks.

Natural anti-helminthic plants also exist. Wormwood, Clove, Papaya, and Plumeria have been reported as effective. Interestingly, some believe that tobacco may help eliminate worms.

Careful attention to hygiene, wearing shoes when outside, and, among medical providers, strict glove use will decrease the likelihood of passing worms or their eggs from person to person. Hand washing, especially before preparing food, is considered especially important in preventing  community-wide outbreaks.

Joe Alton, MD