Roundworms (nematodes) are worms that belong to the phylum Nematoda, which consists of numerous species. These slender worms have a round, cylindrical body with a length that may vary from one millimeter to a meter. There are roundworms that can be seen with the naked eye, but some are visible only with the help of a microscope. While some of these nematodes are found to be beneficial for organic pest control, there are some others which are parasitic on humans. There are different types of parasitic roundworms that can infect humans and cause various health problems.
How Roundworms Infect Humans?
The eggs and larvae of the roundworms are found in the soil and enter the human body mainly due to poor hygienic practices. While in most cases, roundworms get access to the human body through the mouth (eggs and larvae stick to the hands that carry them to the mouth), some others enter the body through the skin. Apart from poor sanitation and personal hygiene, contact with human or animal feces, consumption of undercooked meat and multiple insect bites are also considered as risk factors for this infection. Roundworm infections are more common in the warm regions across the world, and the most common form is 'ascariasis,' caused by the worm 'Ascaris lumbricoides.' The symptoms of roundworm infection may vary with the type of the causal agent.
Types of Roundworm Infections
Ascariasis - Giant Roundworm Infection
Common Symptoms - cough, chest pain, breathing trouble, stomach pain, cramps, nausea
This is the most common type of parasitic infection in humans and is caused by Ascaris lumbricoides. These roundworms are large and can grow up to 14 inches in length. Once their eggs reach the intestine, larvae are produced, which in turn perforate the intestinal wall and enter the lungs through the bloodstream. Once inside the lungs, these worms can cause cough, chest pain and breathing trouble. From the lungs, they travel to the airways and to the back of the mouth, from where they are ingested again. They reach the intestine and lay thousands of eggs per day. Large numbers of roundworms in the intestine can result in symptoms like stomach pain, cramps, and nausea, and can also cause intestinal blockage or rupture.
Enterobiasis - Pinworm Infection
Common Symptoms - itching around the anus, abdominal cramps and pain, loss of appetite
Enterobius vermicularis is another type of roundworm which is known as pinworm or threadworm. They are small and thread-like in appearance. The eggs hatch in the duodenum and the larvae travel through the small intestine to the colon. Once they mate, the males die and females settle down and move to the rectum. Then they move out through the anus and lay eggs on the skin around the anus. The eggs are transmitted through clothes, bed linen, toilet seats and hands. So, pinworms inhabit the colon and rectum of humans, especially children. The most common symptom of pinworms in children is itching around the anus, which gets worse at night. Pinworm infection does not cause any serious health problems. The common symptoms include abdominal pain, cramps and fever.
Ancylostomiasis - Hookworm Infection
Common Symptoms - itchy rash, cough, wheezing, abdominal pain, diarrhea, blood in stool
Another common type of roundworm infection is caused by hookworms (Ancylostoma duodenale and Necator americanus), and the condition is called ancylostomiasis. Hookworm larvae can penetrate human skin and in most cases, this happens when people walk barefoot over contaminated soil. These larvae penetrate the skin, enter the bloodstream and reach the lungs. From the lungs, they travel to the windpipe and to the intestine, where they mate and lay eggs. The eggs are expelled through feces. Hookworms may produce symptoms like itchy rashes, cough, wheezing, breathing trouble, abdominal pain, diarrhea, loss of appetite and weight loss. Severe infection may lead to anemia and malnutrition.
Trichuriasis - Whipworm Infection
Common Symptoms - intermittent stomach pain, bloody stools, diarrhea, weight loss, anemia
This condition is caused by Trichuris trichiura, commonly known as whipworms, which are very thin and have a whip-like shape. The eggs that are ingested, reach the small intestine and develop to larvae, which then move to the large intestine. Once they reach there, they get themselves attached to the wall of the intestine. Though mild infections do not cause any health problems, once they multiply in large numbers, they can cause intermittent stomach pain, bloody stools, diarrhea, and weight loss in adults. However, in children, serious whipworm infection may cause anemia, rectal prolapse, and developmental retardation. Long-term infection may also result in damage to the walls of the colon.
Toxocariasis - Caused by Roundworms in Cats and Dogs
Common Symptoms - cough, skin rash, headache, high fever, tissue swelling, eye infections
Toxocariasis is a form of roundworm infection in humans. It is caused by the larvae of roundworms that are commonly found in cats, dogs and fox. They include Toxocara canis (roundworms in dogs and fox) and Toxocara cati (roundworms in cats). The eggs of these roundworms enter the human body and reach the intestine, where they hatch. In case of severe infection, the larvae travel to other parts of the body and infest the lungs, heart, brain, liver, and the eyes, and produce symptoms like coughing bouts, skin rash, high fever, and tissue swellings called granulomas. The symptoms may vary with the severity of the infection, immune response of the affected person and the organs affected. It can also lead to major health problems like inflammation of the liver and lungs, and eye infections.
Filariasis - Caused by Filarial Roundworms
Common Symptoms - skin rash, arthritis, vision problems, edema, skin thickening
This parasitic disease is caused by certain types of roundworms that are called filariae. There are around eight species of these roundworms that affect humans and cause different health problems. These parasites are classified into three groups. While one group attacks the lymphatic system and can cause elephantiasis, those in the second group lodge in the serous cavity of the abdomen causing serous cavity filariasis. The third group is found in the fat layer of the skin and cause subcutaneous filariasis. They can lead to loiasis and river blindness that can affect vision.
In short, the symptoms of roundworm infection may vary with the specific type of roundworm and the severity of infection. Physical examination, stool and urine test, blood test, etc. are usually done to diagnose the condition. Other tests like X-ray, ultrasound and muscle and skin biopsy may also be required.
How to Treat Roundworms in Humans?
Treatment for roundworm infection is decided according to the type of infection. Most of the roundworms in humans require anti-parasitic drugs like mebendazole and albendazole. But in some cases, surgery is recommended to deal with the obstructions caused by the roundworm infestation in the intestine and other organs. It is also claimed that vitamin A supplementation can be a cure for roundworms in humans. In some cases analgesics, anti-inflammatory medicines, antihistamines, and antibiotics may also be prescribed for relief from the symptoms. Apart from the conventional treatment methods, a balanced and nutritious diet is also good to get rid of roundworms in humans. You can also include herbs and spices like garlic, cloves, figs, cayenne pepper, cinnamon, wormwood, turmeric and olive leaf, as they are said to be beneficial for fighting roundworm infection in humans. Drink enough water and exercise regularly.
It is always better to prevent this type of parasitic infection, by maintaining good personal hygiene. As the infection is mainly caused by ingestion of roundworm eggs/larvae through the mouth, you have to make it a habit to wash your hands properly before eating food. It is also advisable to clean fruits and vegetables thoroughly before consumption. Avoid walking barefoot. Roundworms in humans may lead to severe complications, if left untreated. So it is advisable to treat the condition, as soon as you notice the symptoms.
Disclaimer: This article is for informational purposes only and should not be used as a replacement for expert medical advice. Visiting your physician is the safest way to diagnose and treat any health condition.