Roundworm
Roundworm - Summary
The common human roundworm is a nematode, Ascaris lumbricoides.
Infection occurs when Ascaris eggs in contaminated food, soil, or water are ingested.
Ascaris infestation is rare in the UK, and is likely to have been contracted abroad. Roundworm is highly prevalent in tropical and subtropical areas, which includes many regions of Africa, China, South East Asia, and Central and South America.
The clinical features of roundworm infestation are non-specific (e.g. heavy worm burdens may cause colic, diarrhoea, vomiting) and cannot be used on their own to make the diagnosis. Roundworm infestation is confirmed when ova are found in a stool sample. Roundworm infestation can also be diagnosed if worms are passed, or seen on radiographic/ultrasound imaging, or detected by endoscopy.
A stool sample should be taken to confirm infestation in anyone who has been abroad within the last 1–2 years to a region where roundworm is endemic (e.g. Africa, China, South East Asia, Central and Southern America) and has non-specific gastrointestinal symptoms (such as colic, diarrhoea, vomiting) that persist for more than 10–14 days or if a worm is passed, or worms are detected by radiological imaging or endoscopy.
Roundworm is treated with anthelmintics:
Mebendazole is the anthelmintic of choice in the UK for adults and children aged over 1 year.
Piperazine is recommended for children aged 3–11 months.
If systemic symptoms of roundworm are suspected, advice from a specialist centre should be followed. Specialist centres include:
Birmingham (Department of Infection and Tropical Disease, Heartlands and Solihull Hospitals) 0121 424 0357.
Liverpool (School of Tropical Medicine) 0151 708 9393.
London (University College Hospitals, Hospital for Tropical Diseases) 020 7383 0080.
Scottish Centre for Infection and Environmental Health, 0141 300 1130.
For registered users of Travax only, www.travax.scot.nhs.uk.
Alternative treatments that may be recommended by specialists include:
Albendazole.
Levamisole.
Ivermectin.
Pyrantel.
Have I got the right topic?
This CKS topic covers the treatment of infestation with the roundworm Ascaris lumbricoides.
This CKS topic does not cover the treatment of threadworm, tapeworm, hookworm, or other more unusual worm infestations.
There is a separate CKS topic on Threadworm.
The target audience for this CKS topic is healthcare professionals working within the NHS in the UK, and providing first contact or primary health care.
How up-to-date is this topic?
How up-to-date is this topic?
Changes
November 2011 — revised. A literature search was conducted in October 2011 to identify evidence-based guidelines, UK policy, systematic reviews, and key RCTs published since the last revision of the topic. No changes to clinical recommendations have been made. Issued in December 2011.
Previous changes
March 2011 — topic structure revised to ensure consistency across CKS topics — no changes to clinical recommendations have been made.
February to June 2007 — converted from CKS guidance to CKS topic structure. The evidence-base has been reviewed in detail, and recommendations are more clearly justified and transparently linked to the supporting evidence.
There are no major changes to the recommendations.
October 2005 — minor technical update. Issued in November 2005.
September 2003 — reviewed. Validated in December 2003 and issued in February 2004.
March 2001 — rewritten. Validated in March 2001 and issued in June 2001.
June 1998 — reviewed.
September 1997 — written.
Update
New evidence
Evidence-based guidelines
No new evidence-based guidelines since 1 October 2011.
HTAs (Health Technology Assessments)
No new HTAs since 1 October 2011.
Economic appraisals
No new economic appraisals relevant to England since 1 October 2011.
Systematic reviews and meta-analyses
No new systematic reviews or meta-analyses since 1 October 2011.
Primary evidence
No new randomized controlled trials published in the major journals since 1 October 2011.
New policies
No new national policies or guidelines since 1 October 2011.
New safety alerts
No new safety alerts since 1 October 2011.
Changes in product availability
No changes in product availability since 1 October 2011.
Goals and outcome measures
Goals
To support primary health care professionals:
To eradicate roundworm (Ascaris lumbricoides) infestation
Background information
Definition
What are human roundworms?
The common human roundworm is a nematode, Ascaris lumbricoides.
Life cycle of Ascaris lumbricoides:
The host (almost always human) becomes infected by ingesting Ascaris eggs in contaminated food, soil, or water.
Ingested eggs hatch in the duodenum. The larvae invade the intestinal wall, and are carried through the blood system to the lungs. The larvae then ascend the bronchial tree to the throat and are swallowed. Upon reaching the small intestine, they develop into adult worms, which live for up to 2 years.
Mature female roundworms may be up to 30–35 cm long, and produce up to 200,000 eggs a day.
The time from ingestion of eggs to the first passage of ova in the stools is about 60–70 days.
Ascaris eggs can remain viable in soil for several years.
Ascaris lumbricoides infects only humans. Rarely, a related roundworm, Ascaris suum, can be acquired from pigs.
Prevalence
Ascaris infestation is rare in the UK, and is likely to have been contracted abroad:
In the third quarter of 2006, 12 cases of Ascaris lumbricoides infestation were reported in the UK, having been acquired abroad [HPA, 2006].
Roundworm is highly prevalent in tropical and subtropical areas, which includes many regions of Africa, China, South East Asia, and Central and South America.
It is estimated that over 1 billion people worldwide are infected with Ascaris. The worldwide burden of Ascaris infestation is difficult to calculate, and estimates of morbidity and mortality vary widely.
Complications and prognosis
Adult worms usually cause little pathology if they remain in the small intestine.
Occasionally the worm migrates to other locations such as the liver, lungs, heart, or genito-urinary tract. This may cause acute problems such as appendicitis, biliary disease, cholecystitis, liver abscess, or pancreatitis [Khuroo, 1996].
Intestinal obstruction and biliary tract obstruction are rare but life-threatening complications.
There is evidence that infestation with Ascaris lumbricoides is associated with asthma (odds ratio 1.34, 95% CI 1.05 to 1.71) [Leonardi-Bee et al, 2006].
Serious allergic reactions to the worms rarely occur.
Nutritional deficiencies (e.g. vitamin A deficiency) and anaemia can be caused by heavy worm loads. In the UK there is unlikely to be any adverse effect on nutritional status in otherwise healthy, normally nourished people. However, in developing countries where nutritional status is often marginal, nutritional deficiencies can be induced by roundworm infestation, and have been associated with impaired growth and learning in children [O'Lorcain and Holland, 2000].
Diagnosis
Diagnosis of roundworm
Clinical features
What are the clinical features of roundworm infestation?
The clinical features of roundworm infestation are non-specific (e.g. heavy worm burdens may cause colic, diarrhoea, vomiting) and cannot be used on their own to make the diagnosis.
Symptoms caused by heavy worm burdens are more common in children than in adults.
Symptoms (e.g. cough) caused by larval migration of Ascaris lumbricoides from the small intestine to other organs, can mimic many other systemic illnesses.
Roundworm (Ascaris lumbricoides) infestation is confirmed when ova are found in a stool sample. Roundworm infestation can also be diagnosed if worms are passed, or seen on radiographic/ultrasound imaging, or detected by endoscopy.
Basis for recommendation
Basis for recommendation
Recommendations on the diagnosis of roundworm are based on expert opinion from a review article [Bethony et al, 2006].
When to take stool sample
When should a stool sample be taken to confirm the diagnosis of roundworm?
A stool sample should be taken to confirm Ascaris infestation:
In anyone who has been abroad within the last 1–2 years to a region where roundworm is endemic (e.g. Africa, China, South East Asia, Central and Southern America) and has non-specific gastrointestinal symptoms (such as colic, diarrhoea, vomiting) that persist for more than 10–14 days.
If a worm is passed, or worms are detected by radiological imaging or endoscopy.
Basis for recommendation
Basis for recommendation
CKS recommends obtaining a stool sample before starting treatment for roundworm. This is pragmatic advice because symptoms are non-specific and Ascaris infestation is rare in the UK. Requesting a stool sample will also confirm or exclude the presence of other intestinal parasites.
Differential diagnosis
What else might it be?
Other intestinal parasites are often found in people with Ascaris. This is because the risk factors for Ascaris lumbricoides infestation (including poor personal and community hygiene) are also risk factors for other intestinal parasites.
Ascaris suum, a pig nematode, may also cause disease in humans.
Basis for recommendation
Basis for recommendation
Information on the differential diagnosis of roundworm is based on expert opinion from review articles [St Georgiev, 2001; Bethony et al, 2006].
Management
Management
Scenario: Management: covers the management of person with confirmed roundworm.
Scenario: Management
Scenario: Management of roundworm
Managing roundworm
How should I manage someone with roundworm?
For adults and children aged over 1 year: give a 3-day course of mebendazole.
For children aged 3–11 months: give a single dose of piperazine.
Advise people to wash their hands thoroughly after using the toilet or changing nappies, and before eating or preparing food.
Seek advice from a specialist centre for tropical diseases if you suspect that roundworm is causing systemic symptoms (e.g. cough, pneumonia).
Admit anyone who presents with intestinal obstruction or biliary tract obstruction.
Basis for recommendation
Basis for recommendation
Mebendazole
CKS recommends mebendazole as the drug of choice for roundworm treatment in primary care, because there is good evidence that it is highly effective, there are few contraindications, and the manufacturer reports that post-marketing surveillance has revealed no serious safety concerns [ABPI Medicines Compendium, 2005].
Mebendazole 500 mg as a single dose is effective, but it is not licensed in the UK. Therefore the 3-day course (which is licensed) is recommended.
Mebendazole binds to beta-tubulin in nematodes, and inhibits polymerisation of microtubules in the parasite. This takes several days to kill adult worms.
Mebendazole is poorly absorbed from the gastrointestinal tract; thus, juvenile roundworms that are outside the gastrointestinal tract are not killed by oral mebendazole [Bethony et al, 2006].
Although mebendazole is not licensed for use in children aged from 12 months to 2 years of age, there are trial data for its use in this age group [Nanivadekar et al, 1984; Bethony et al, 2006].
Piperazine
Piperazine (with senna) is recommended for children aged 3–11 months because, unlike mebendazole, it is licensed for use in this age group. However, in older age groups it is less preferred than mebendazole because there are fewer studies to assess its efficacy, more contraindications to its use, and it is systemically absorbed which increases the likelihood of adverse effects.
Pregnancy or breastfeeding
How should I manage a woman with roundworm who is pregnant or breastfeeding?
First trimester of pregnancy: where possible, delay treatment until the second trimester of pregnancy.
There is no risk of infection to the fetus, or to the baby during birth.
If drug treatment cannot be delayed (e.g. due to complications of roundworm), seek advice from specialist topical disease centres, or from the UK Teratology Information Service (UKTIS), (formerly the National Teratology Information Service [NTIS]), on 0844 892 0909.
Second or third trimester of pregnancy: mebendazole can be used (unlicensed use).
Breastfeeding: mebendazole can be used (unlicensed use).
Basis for recommendation
Basis for recommendation
CKS recommends mebendazole as the drug of choice for roundworm treatment in primary care, because there is good evidence that it is highly effective, there are few contraindications, and the manufacturer reports that post-marketing surveillance has revealed no serious safety concerns [ABPI Medicines Compendium, 2005].
Mebendazole 500 mg as a single dose is effective, but it is not licensed in the UK. Therefore the 3-day course (which is licensed) is recommended.
Mebendazole binds to beta-tubulin in nematodes, and inhibits polymerisation of microtubules in the parasite. This takes several days to kill adult worms.
Mebendazole is poorly absorbed from the gastrointestinal tract; thus, juvenile roundworms that are outside the gastrointestinal tract are not killed by oral mebendazole [Bethony et al, 2006].
Although mebendazole is not licensed for use in children aged from 12 months to 2 years of age, there are trial data for its use in this age group [Nanivadekar et al, 1984; Bethony et al, 2006].
Piperazine (with senna) is recommended for children aged 3–11 months because, unlike mebendazole, it is licensed for use in this age group. However, in older age groups it is less preferred than mebendazole because there are fewer studies to assess its efficacy, more contraindications to its use, and it is systemically absorbed which increases the likelihood of adverse effects.
Where to seek specialist advice
Where can I seek specialist advice about roundworm treatment from?
For specialist advice on the management of roundworm, contact:
Birmingham (Department of Infection and Tropical Disease, Heartlands and Solihull Hospitals) 0121 424 0357.
Liverpool (School of Tropical Medicine) 0151 708 9393.
London (University College Hospitals, Hospital for Tropical Diseases) 020 7383 0080.
Scottish Centre for Infection and Environmental Health, 0141 300 1130.
For registered users of Travax only, www.travax.scot.nhs.uk.
Specialist treatments
What other treatments might be recommended by specialists?
Alternative treatments that may be recommended by specialists include:
Albendazole
Levamisole
Ivermectin
Pyrantel
Albendazole, levamisole, ivermectin, and pyrantel can be acquired on a named-patient basis through IDIS.
Basis for recommendation
Basis for recommendation
Albendazole is similarly effective to mebendazole. Levamisole, ivermectin, and pyrantel are also effective against roundworm infection [Nanivadekar et al, 1984; Marti et al, 1996; Belizario et al, 2003].
However, these drugs are not commercially available in the UK.
Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://medicines.org.uk/emc), or the British National Formulary (BNF) (www.bnf.org).
Mebendazole
Mebendazole is largely unabsorbed and systemic adverse effects are minimal. Transient abdominal pain or diarrhoea occasionally occurs, especially in people with heavy infestations [ABPI Medicines Compendium, 2005].
Although mebendazole is recommended for treatment from the age of 1 year, it is not licensed for use in children younger than 2 years of age [ABPI Medicines Compendium, 2005].
Piperazine
Gastrointestinal disturbances including abdominal pain, nausea, vomiting, colic, and diarrhoea are the most common adverse effects in people taking piperazine.
Piperazine should be avoided in people with epilepsy, renal impairment, or hepatic impairment, since neurotoxic reactions resulting in convulsions have been reported (rarely) in such cases.
Evidence
Evidence
Supporting evidence
Mebendazole and albendazole
Evidence on treatment of Ascaris lumbricoides infestation with mebendazole and albendazole
CKS found one extensive, although not systematic, review of single dose or multidose treatments against Ascaris lumbricoides [Bennett and Guyatt, 2000] and a subsequent systematic review of single dose treatments against Ascaris lumbricoides [Keiser and Utzinger, 2008]. Mebendazole 500 mg single dose, mebendazole 100 mg twice daily for 3 days, and albendazole 400 mg single dose are all highly effective against Ascaris lumbricoides.
Review of single or multidose treatments for Ascaris lumbricoides [Bennett and Guyatt, 2000]
How was the evidence for the review found?
A database of relevant studies was built by hand searching all journals publishing work on public health and epidemiology housed at the London School of Tropical Medicine and Hygiene, and by electronically searching bibliographic databases such as Medline [Guyatt, Personal Communication, 2007].
Included studies:
Were published between 1973 and 1990.
Had information on drug used, dosage, pretreatment quantification of infestation (eggs per gram of stool) for egg response rate, and sample size.
Used mebendazole 500 mg single dose or 600 mg multiple dose (100 mg twice daily, for 3 days), or albendazole 400 mg single dose (doses recommended by WHO).
Had a minimum sample size of 30 for clinical response rates and 10 for egg response rates.
What is the evidence on benefits?
The review included 146 studies of treatments for Ascaris lumbricoides.
The authors presented their results graphically. The key data (read off the graph) are summarized in Table 1.
All regimens are highly effective against Ascaris lumbricoides.
Comment
The authors did not discuss whether the person's age might cause differences in effectiveness and/or a need for different doses.
The authors did not discuss possible harmful effects or safety during pregnancy and breastfeeding.
Table 1. Effectiveness of treatments for Ascaris lumbricoides.| Intervention | Cure rateMedian (interquartile range), number of studies | Reduction of mean egg countMedian, number of studies |
|---|---|---|
| Albendazole 400 mg single dose | 95% (90–96%), 34 | 99–100%, 21 |
| Mebendazole 500 mg single dose | 95% (94–97%), 7 | 99–100%, 5 |
| Mebendazole 100 mg twice daily for 3 days | 97% (96–100%), 15 | 99–100%, 14 |
Systematic review of the effectiveness of a single dose of albendazole 400 mg or mebendazole 500mg against Ascaris lumbricoides [Keiser and Utzinger, 2008]
Cure rate of Ascaris lumbricoides with albendazole compared to placebo:
Ten randomized controlled trial were identified, including 557 individuals, that compared the cure rate of a single dose of albendaziole 400 mg with placebo.
Overall, a single dose of 400 mg of albendazole resulted in a cure rate of 88% (95% CI, 79-93%).
Cure rate of Ascaris lumbricoides with mebendazole compared to placebo:
Three randomized controlled trials were identified, including 309 individuals, that compared the cure rate of a single dose of mebendazole 500 mg with placebo.
Overall, a single dose of mebendazole resulted in a cure rate of 95% (95% CI, 91-97%).
Piperazine
Evidence on piperazine used to treat Ascaris lumbricoides infestation.
Piperazine has been used for more than 50 years to treat intestinal worm infestations. CKS found no systematic review of the use of piperazine for Ascaris infestation. Its use is based more on long-term clinical experience than on randomized controlled trials. However, a study in the 1980s found that it was similarly effective to other anthelmintics, but had a higher incidence of adverse effects.
A multi-centre study in India with 1358 participants assessed the efficacy of levamisole, mebendazole, piperazine, and pyrantel for treating roundworm infection [Nanivadekar et al, 1984].
Problem and population:
Participants aged 1–60 years who were suspected of having intestinal worms and had no history of having taken any anthelmintics during the preceding month were asked to provide a stool sample. Those whose stool samples were positive for eggs of roundworm (Ascaris lumbricoides). Pregnant women were excluded from the study.
Seventy percent of the study population was children under the age of 12 years.
Of the 1358 participants enrolled, 1256 completed the study protocol and were included in the analysis.
Comparisons:
Participants were randomly assigned to three series, with roughly 200 participants in each arm of the series:
Series A: pyrantel or mebendazole
Series B: pyrantel or piperazine
Series C: pyrantel or levamisole
The doses of drugs used were:
Levamisole 50 mg as a single dose (children under 6); levamisole 150 mg as a single dose (children over 6 and adults)
Mebendazole 100 mg twice a day for 3 days (all ages)
Piperazine 750 mg per year of age up to a maximum of 4.5 g as a single dose (all ages)
Pyrantel 10 mg per kg body weight, rounded to the nearest 100 mg, as a single dose (all ages).
The roundworm egg count per gram of faeces (calculated using Kato's quantitative thick smear method) was recorded before treatment, and 14–28 days after treatment. The pathologist carrying out these tests was blind to the treatment used.
Cure rates:
Series A: pyrantel 93%, mebendazole 87.9% (p < 0.05)
Series B: pyrantel 86%, piperazine 82.5%
Series C: pyrantel 92%, levamisole 85.4% (p < 0.05)
Harms:
Gastrointestinal adverse effects (e.g. griping pain, diarrhoea, nausea, vomiting) were reported for all study drugs.
Griping pain in the abdomen, fever, giddiness, and nausea occurred statistically more often in the piperazine group compared to the overall incidence of adverse effects (p < 0.05). Headache occurred more frequently in the pyrantel group.
Conclusions:
Pyrantel was more effective than levamisole or mebendazole in this study of roundworm infestation in India.
There was no difference in efficacy between pyrantel and piperazine in this study, however the cure rates in this arm of the study were substantially lower than in the other study arms.
Additional comments:
Analysis was per protocol, not intention to treat.
The lower cure rates in the pyrantel versus piperazine arm (series B) could be due to chance, or could be due to some systematic bias that the authors were unable to identify.
Piperazine has been withdrawn from the markets of many developed countries due to concerns about toxicity [DynaMed, 2007].
Search strategy
Scope of search
A literature search was conducted for guidelines, systematic reviews and randomized controlled trials on primary care management of roundworm.
Search dates
2007 - October 2011.
Key search terms
Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline and these were adapted for other databases. Further details are available on request.
exp ascariasis/, exp ascaris lumbricoides/, ascariasis.tw., ascaris.tw., ascarid$.tw., ascaricide$.tw., roundworm$.tw., round worm$.tw.
Table 1. Key to search terms.| Search commands | Explanation |
|---|---|
| / | indicates a MeSh subject heading with all subheadings selected |
| .tw | indicates a search for a term in the title or abstract |
| exp | indicates that the MeSH subject heading was exploded to include the narrower, more specific terms beneath it in the MeSH tree |
| $ | indicates that the search term was truncated (e.g. wart$ searches for wart and warts) |
Sources of guidelines
National Institute for Health and Clinical Excellence (NICE)
Scottish Intercollegiate Guidelines Network (SIGN)
National Guidelines Clearinghouse
British Columbia Medical Association
Institute for Clinical Systems Improvement
Guidelines International Network
National Library of Guidelines
National Health and Medical Research Council (Australia)
University of Michigan Medical School
Michigan Quality Improvement Consortium
Royal Australian College of General Practitioners
National Resource for Infection Control
NHS Scotland National Patient Pathways
Agency for Healthcare Research and Quality
UK Ambulance Service Clinical Practice Guidelines
RefHELP NHS Lothian Referral Guidelines
Medline (with guideline filter)
Driver and Vehicle Licensing Agency
NHS Plus (occupational health practice)
Sources of systematic reviews and meta-analyses
Systematic reviews
Protocols
Database of Abstracts of Reviews of Effects
Medline (with systematic review filter)
EMBASE (with systematic review filter)
Sources of health technology assessments and economic appraisals
NIHR Health Technology Assessment programme
NHS Economic Evaluations
Health Technology Assessments
Canadian Agency for Drugs and Technologies in Health
International Network of Agencies for Health Technology Assessment
Sources of randomized controlled trials
Central Register of Controlled Trials
Medline (with randomized controlled trial filter)
EMBASE (with randomized controlled trial filter)
Sources of evidence based reviews and evidence summaries
DynaMed
Central Services Agency COMPASS Therapeutic Notes
Sources of national policy
Health Management Information Consortium (HMIC)
Sources of medicines information
The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.
British National Formulary (BNF)
electronic Medicines Compendium (eMC)
European Medicines Agency (EMEA)
References
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Belizario, V.Y., Amarillo, M.E., de Leon, W.U. et al. (2003) A comparison of the efficacy of single doses of albendazole, ivermectin, and diethylcarbamazine alone or in combinations against Ascaris and Trichuris spp. Bulletin of the World Health Organization 81(1), 35-42. [Abstract] [Free Full-text]
Bennett, A. and Guyatt, H. (2000) Reducing intestinal nematode infection: efficacy of albendazole and mebendazole. Parasitology Today 16(2), 71-74. [Abstract]
Bethony, J., Brooker, S., Albonico, M. et al. (2006) Soil-transmitted helminth infections: ascariasis, trichuriasis, and hookworm. Lancet 367(9521), 1521-1532. [Abstract]
DynaMed (2007) Ascariasis. DynaMed..EBSCO Publishing.www.dynamicmedical.com
Guyatt, H. (2007) Personal communication. University of Oxford: Oxford.
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Marti, J., Haji, H.J., Savioli, L. et al. (1996) A comparative trial of a single-dose ivermectin versus three days of albendazole for treatment of Strongyloides stercoralis and other soil-transmitted helminth infections in children. American Journal of Tropical Medicine & Hygiene 55(5), 477-481. [Abstract]
Nanivadekar, A.S., Gadgil, S.D. and Apte, V.V. (1984) Efficacy of levamisole, mebendazole, piperazine and pyrantel in roundworm infection By National Anthelmintic Study Group. Journal of Postgraduate Medicine 30(3), 144-152.
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Stephenson, L.S., Latham, M.C. and Ottesen, E.A. (2000) Malnutrition and parasitic helminth infections. Parasitology 121(Suppl), S23-S38. [Abstract]
St Georgiev, V. (2001) Pharmacotherapy of ascariasis. Expert Opinion on Pharmacotherapy 2(2), 223-239. [Abstract]
Thornton & Ross Limited (2004) Summary of product characteristics for Pripsen (piperazine citrate powder). Huddersfield: Thornton & Ross Limited.