Roundworms: Symptoms, Causes, and Prevention Guide
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What are roundworms?
Roundworms are small parasites that infect the human intestines or muscles, typically spread through the fecal-oral route, contaminated soil or undercooked meat. Common types include pinworms and hookworms. Symptoms vary but often include stomach pain, itching or fever. Diagnosis uses blood or stool tests, and prescription medication such as albendazole usually destroys the parasites. [1]
What the research says
Handwashing is linked to lower infection. A meta-analysis of 94 studies found that washing hands before eating (odds ratio 0.38) and after using the toilet (odds ratio 0.45) were each linked to lower odds of Ascaris lumbricoides infection, and soap use or availability was linked to lower odds of infection with any soil-transmitted worm (odds ratio 0.53). Most of the evidence was observational (Strunz et al., PLoS Med, 2014). [2]
Wearing shoes helps against soil-borne worms. In a meta-analysis of 53 studies, footwear use was associated with lower odds of hookworm infection (odds ratio 0.48), strongyloidiasis (odds ratio 0.56), and any soil-transmitted worm infection (odds ratio 0.57) (Tomczyk et al., PLoS Negl Trop Dis, 2014). [3]
Treatment works well for some worms and less well for others. In a network meta-analysis of randomized trials, a single dose of albendazole cured 79.5% of hookworm infections (95% CI 71.5% to 85.6%), but all four recommended drugs had low efficacy against whipworm, with mebendazole performing best at a 42.1% cure rate (Moser et al., BMJ, 2017). [4]
What are roundworms, and how do these parasites affect people?
Roundworms are small organisms that can reside in the human intestine for extended periods. As parasites, they require a host, either a human or an animal, to survive and mature into egg-laying adults. While hundreds of millions of people are infected globally, many types are uncommon in the United States, often associated with international travel to regions with limited sanitation. However, pinworms remain highly prevalent in the U.S., affecting between 20 million and 42 million people, many of them children. [1]
What are the common types of roundworms and their symptoms?
The symptoms of a roundworm infection depend significantly on the specific type of parasite involved. While some individuals may experience no symptoms, others may face severe discomfort or complications. [1]
Roundworm Type | Common Symptoms | Primary Transmission Route |
|---|---|---|
Pinworms | Intense itching around the anus or vagina, disturbed sleep. | Touching infected surfaces or eggs (fecal-oral). |
Ascariasis | Abdominal pain, vomiting, fever, cough, wheezing, growth delay. | Poor hygiene and hand-to-mouth contact. |
Hookworms | Anemia, fatigue, diarrhea, mild abdominal cramps. | Walking barefoot on contaminated soil. |
Strongyloidiasis | Abdominal burning, nausea, weight loss, chronic diarrhea. | Skin contact with contaminated soil. |
Trichinellosis | Muscle pain, high fever, swelling in the face, eye infections. | Eating undercooked meat (pork, wild game). |
Whipworms | Bloody stool, stomach pain, weight loss, anemia. | Ingesting food grown in contaminated soil. |
How do roundworm infections spread?
Roundworms enter the body through various routes depending on their species. Many enter through the mouth when a person touches contaminated soil or surfaces and then touches their mouth without washing their hands. Eggs can also be ingested through contaminated food or water. In certain cases, such as hookworms or strongyloidiasis, the larvae can penetrate the body directly through the skin. Pets can also spread roundworms if their infected waste is not handled properly. [1]
How are roundworm infections diagnosed and treated?
If you suspect a roundworm infection, especially after traveling or coming into contact with infected animals, it is essential to consult a healthcare provider. Diagnosis typically involves a review of medical history followed by blood tests or stool sample analysis to detect eggs or larvae. [1]
Most roundworm infections are treated with the same type of medication, such as albendazole. This prescription drug prevents larvae from multiplying, allowing the body to pass the worms through stool. Treatment is usually effective within three days, though some infections may require a follow-up dose a few weeks later to ensure all parasites are eliminated. If the infection has caused secondary issues like anemia, iron supplements may also be prescribed. [1]
How can roundworm infections be prevented?
Preventing roundworm infections relies heavily on maintaining good hygiene and practicing safety around pets and food. [1]
Category | Prevention Strategies |
|---|---|
Personal Hygiene | Wash hands thoroughly with soap and hot water after outdoor activities or handling pets. |
Pet Safety | Deworm pets regularly and promptly clean up animal waste in yards. |
Food Safety | Wash all garden-grown produce well; avoid raw or undercooked meats. |
Travel Safety | Drink only bottled water and avoid raw produce in areas with poor sanitation. |
Conclusion
Roundworm infections are common parasitic conditions that, while uncomfortable, are generally not life-threatening and respond well to treatment. By practicing consistent handwashing, ensuring food is properly cooked, and keeping pets healthy, most people can significantly reduce their risk of infection. If you notice persistent stomach pain, unexplained weight loss, or see evidence of worms in stool, seek medical evaluation promptly.
What are the next steps if you suspect a roundworm infection?
If you or your child are experiencing symptoms like persistent itching or abdominal pain, schedule an appointment with a healthcare provider today to discuss testing and treatment options.
Trusted resources: Centers for Disease Control and Prevention (CDC) Parasitic Diseases, World Health Organization (WHO) fact sheet on soil-transmitted helminth infections.
Related reading on Rinnit: Parasites: Types, Symptoms, and Prevention Strategies
Frequently Asked Questions
What are the most common symptoms of roundworms?
Symptoms vary but often include abdominal pain, diarrhea, fever, and nausea. Pinworms specifically cause intense itching around the anus. [1]
How do humans get roundworms?
Infection typically occurs by ingesting eggs from contaminated soil, food, or water, or through skin contact with larvae in the soil. [1]
Are roundworms contagious?
Yes, they can spread through contact with infected stool or contaminated surfaces like toys, bedding, and doorknobs. [1]
Can I get roundworms from my dog or cat?
Yes, humans can be exposed to eggs or larvae found in pet waste. Regular pet deworming is essential. [1]
How long does it take to treat roundworms?
Most medications work within three days, though a second dose may be needed a few weeks later. [1]
What is the most common roundworm in the U.S.?
Pinworms are the most prevalent, especially among school-aged children. [1]
Can roundworms live outside the body?
Pinworm eggs can survive on surfaces like bedding or furniture for up to two weeks. [1]
Do roundworms cause weight loss?
Severe or long-term infections, particularly with whipworms or strongyloidiasis, can lead to unexplained weight loss. [1]
Is it possible to see roundworms in stool?
Yes, in some infections like ascariasis, live worms or pieces of worms may be visible in the poop. [1]
What is trichinellosis?
Trichinellosis is a type of roundworm infection acquired by eating undercooked meat, which affects the muscles rather than the intestines. [1]
Can roundworms cause anemia?
Yes, hookworms and whipworms can cause blood loss in the intestines, leading to anemia and fatigue. [1]
Should I wash my bedding if someone in my house has pinworms?
Yes, washing bedding and towels in hot water is recommended to kill any eggs and prevent re-infection. [1]
Can roundworms be prevented?
Yes, through good hygiene, proper food preparation, and regular pet care. [1]
References
Cleveland Clinic. Roundworms. Cleveland Clinic. May 18, 2021. https://my.clevelandclinic.org/health/diseases/15240-roundworms
Strunz EC, Addiss DG, Stocks ME, et al. Water, sanitation, hygiene, and soil-transmitted helminth infection: a systematic review and meta-analysis. PLoS Med. 2014;11(3):e1001620. PMID 24667810. https://doi.org/10.1371/journal.pmed.1001620
Tomczyk S, Deribe K, Brooker SJ, et al. Association between footwear use and neglected tropical diseases: a systematic review and meta-analysis. PLoS Negl Trop Dis. 2014;8(11):e3285. PMID 25393620. https://doi.org/10.1371/journal.pntd.0003285
Moser W, Schindler C, Keiser J. Efficacy of recommended drugs against soil transmitted helminths: systematic review and network meta-analysis. BMJ. 2017;358:j4307. PMID 28947636. https://doi.org/10.1136/bmj.j4307
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
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