Treatment of Ascaris Lumbricoides Infection
For ascariasis, the recommended first-line treatment is either albendazole 400 mg, mebendazole 500 mg, or ivermectin 200 μg/kg, all given as a single oral dose. 1
Medication Options
First-line treatments:
- Albendazole 400 mg orally as a single dose 1, 2
- Mebendazole 500 mg orally as a single dose 1, 3
- Ivermectin 200 μg/kg orally as a single dose 1
Efficacy rates:
- Albendazole: 100% cure rate for Ascaris at 400 mg single dose 2
- Mebendazole: 98% cure rate for Ascaris according to FDA labeling 3
Diagnostic Considerations
Before initiating treatment, diagnosis should be confirmed through:
- Concentrated stool microscopy (first-line diagnostic test) 1, 4
- Fecal PCR (higher sensitivity alternative when available) 1, 4
- Direct visualization of adult worms passed in stool (diagnostic when present) 1, 4
Clinical Presentation
Most infections with Ascaris lumbricoides are asymptomatic, but patients may present with:
- Abdominal pain and diarrhea 1
- Gastrointestinal obstruction (particularly in children) 1
- Biliary obstruction (more common in adults) 1
- Loeffler's syndrome during larval migration phase (fever, dry cough, wheezing, urticarial rash) 1
- Expulsion of adult worms in stool or through regurgitation/sneezing 1
Treatment Considerations
Special populations:
- Pregnant women: Pyrantel pamoate is preferred due to safety profile 5
- Children: Both albendazole and mebendazole are indicated and effective 5
Treatment response:
- Single-dose therapy is highly effective with cure rates >96% for both albendazole and mebendazole 6
- Egg reduction rates approach 100% with standard dosing 2, 6
Treatment failures:
- In cases of heavy infection or treatment failure, repeating the dose may be necessary 7
- Three repeated doses of albendazole at 6-week intervals have shown complete eradication of Ascaris infection 7
Distribution and Transmission
- Ascaris is distributed worldwide but is most common in rural settings in Africa, Asia, and South America 1
- Transmission occurs through the fecal-oral route, typically in areas with poor sanitation 1, 5
- Prevalence is highest in young children 5
Monitoring and Follow-up
- Post-treatment stool examination can confirm clearance of infection 7
- No specific follow-up is typically needed after successful treatment unless symptoms persist 1