The most common infections throughout the world are caused by intestinal parasites or worms. People of all ages and in all living conditions are susceptible to worms. Small children are particularly prone because they play in the mud and dirt, suck their fingers, eat soil, run barefoot outdoors and sometimes have less than ideal toilet hygiene. Three of the most common types of worms in humans are pinworm, roundworm and hookworm.
WHAT HAPPENS WHEN A CHILD GETS PINWORM?
Children become infected with pinworms by swallowing pinworm eggs which are transferred to their mouths via contaminated food, drinks or hands. The eggs hatch in the small intestine, releasing immature worms (larvae) to the lower intestine and rectum, where they live. At night, the female worm migrates out through the anus. After laying a large number of eggs, she dies. The entire cycle, from swallowing the eggs to new eggs' being hatched, takes four to six weeks.
In children, the most common symptom is itching in the anal area at night. Girls may also have itching in the vaginal area. Other possible symptoms include insomnia, irritability, restlessness, stomach pain and loss of appetite.
Infection is spread when the child scratches the anal area, picks up the eggs, then reinfects himself or passes them on to someone else. The eggs also can be spread through the air, when sheets or egg-laden underclothes are shaken out.
WHAT HAPPENS WHEN A CHILD GETS ROUNDWORM?
Roundworm eggs are deposited in the stool of an infected person. Another person can become infected by eating food grown in soil in which contaminated stool has been deposited or by ingesting dirt containing roundworm eggs.
The eggs hatch into larva in the intestine. From there, they are absorbed into the bloodstream, then carried in the blood to the lungs. They pass up the windpipe and are then swallowed. The larvae mature into adult worms in the small intestine, where female worms produce a large number of eggs. The eggs pass out into feces, which again enter the soil. Adult roundworms can live in the small intestine for one year or longer.
Some people with roundworms have no symptoms. Others develop wheezing, a dry cough and difficulty breathing, as well as vomiting, nausea, cramping or distention of the abdomen. A worm may be passed through the rectum or vomited. Severe infestations can lead to intestinal blockage or malnutrition.
WHAT HAPPENS WHEN A CHILD GETS HOOKWORM?
Hookworm eggs are spread when an infected person's feces are deposited in soil. These eggs hatch into larvae, which can penetrate the skin.
Once hookworm larvae enter the skin, they travel through the bloodstream to the lungs. They are then coughed up and swallowed. The larvae attach themselves to the lining of the small intestine, where they mature. The females lay eggs, which leave the body in the feces, and the process begins again.
Symptoms of hookworm infection include an itchy rash called ground itch at the point where the larvae entered the skin. When in the lungs, hookworms can cause a dry cough, difficulty breathing, a low-grade fever and sputum tinged with blood. When they reach the intestine, about two weeks after entering the skin, hookworms can cause loss of appetite, diarrhea and stomachache. Iron-deficiency anemia, due to chronic blood loss in the stool, is a common complication.
HOW CAN THE PEDIATRICAIN TELL IF MY CHILD HAS WORMS?
Pinworms may be diagnosed by finding eggs in the anal area of a child with a severe night itch. The best method for detecting this worm is to press a piece of clear tape, sticky side down, on the anal region first thing in the morning, before the child goes to the bathroom or washes. If eggs are present, they will adhere to the sticky surface and can be transferred to a slide. Under a microscope, they are easy to identify.
Roundworms may first be suspected when adult worms are seen in the stool or vomit. However, the diagnosis is established through microscopic examination of a stool sample for roundworm eggs. Hookworms are also diagnosed in this manner.
WHAT TREATMENTS ARE AVAILABLE FOR THESE TYPES OF WORMS? Antihelminthic drugs, which kill only worms and not their eggs, are usually effective. Sometimes therapy must be repeated so that the medicine can eradicate larvae hatched after the first treatment.
When a child has pinworms, the entire family should be treated. Depending on the drug, single or multiple treatments may be necessary. In general, only the affected individual needs treatment for roundworm or hookworm.
COPING WITH WORMS
• When one member of a family has worms, other members, especially children, should be examined for them.
• In some cases, medication may need to be repeated in two or four weeks in order to kill worms hatched since initial treatment.
• To prevent reinfestation, wash hands carefully before eating or handling food and after using the toilet. Wash bedding frequently and keep fingernails trimmed.
GETTING HELP
Call your doctor if:
• Your child or another member of the family develops symptoms suggesting worm infestation. Particularly noteworthy are bloody stools and an intense perianal itch occuring at night.
• You plan on visiting a country or region where sanitary conditions are poor.
