Is deworming still a valid practice today?

Deworming: Current Validity and Recommendations

Deworming remains a valid practice today for individuals with confirmed parasitic infections, but routine mass deworming in areas with low prevalence is no longer supported by evidence.

Current Evidence on Deworming

Targeted vs. Mass Deworming

The approach to deworming has evolved significantly based on recent evidence:

• For individuals with confirmed parasitic infections, treatment with appropriate antiparasitic medications remains essential and effective 1
• Mass deworming programs in endemic areas with high prevalence (>20%) of soil-transmitted helminths may still be justified 1, 2
• However, routine deworming of all children in areas with low prevalence has shown limited benefits in recent studies 3

A 2015 Cochrane review found that mass deworming programs:

• Had little to no effect on average weight gain (MD 0.08 kg, 95% CI 0.11 kg less to 0.27 kg more)
• Showed no significant impact on average height, hemoglobin levels, cognitive function, exam performance, or mortality
• Demonstrated inconsistent effects on school attendance 3

Specific Treatment Recommendations

For confirmed parasitic infections, treatment should be targeted to the specific pathogen:

1. Ascariasis (roundworm):

   • Albendazole 400 mg orally as a single dose OR
   • Mebendazole 500 mg orally as a single dose 1, 4

2. Strongyloidiasis:

   • Ivermectin 200 μg/kg orally daily for 1-2 days 1, 5
   • Follow-up with at least three stool examinations over three months 1

3. Pinworms:

   • Mebendazole 100 mg once, may repeat in 2 weeks 4
   • All household members should be treated simultaneously 1

4. Hookworm and Whipworm:

   • Mebendazole 100 mg twice daily for 3 consecutive days OR
   • Albendazole 400 mg daily for 3 days 1, 4

Prevention and Control Strategies

Effective prevention strategies remain crucial regardless of treatment approach:

• Hygiene measures:

  • Frequent handwashing with soap, especially before eating and after using the toilet
  • Keeping fingernails short and clean
  • Daily changing of underwear
  • Environmental cleaning of living spaces 1

• Sanitation improvements:

  • Access to improved sanitation facilities has been associated with lower infection intensities (mIIR 0.6,95% CI: 0.4-0.9) 2
  • Proper disposal of human waste to prevent soil contamination 6

Special Considerations

Monitoring for Adverse Effects

• Patients treated with albendazole for >14 days should be monitored for:
  • Hepatotoxicity (elevated liver enzymes in up to 16% of cases)
  • Leukopenia (up to 10% of patients) 7, 1

Emerging Resistance

• Reduced efficacy has been documented in some helminth species:
  • Trichuris trichiura (48% cure rate with albendazole)
  • Strongyloides stercoralis (62% cure rate with albendazole)
  • Emerging resistance in hookworms and possibly Ascaris lumbricoides 1

Pregnancy Considerations

• Pregnant women should avoid albendazole and mebendazole if possible
• Treatment should be deferred until after the first trimester unless benefits outweigh risks 1

Conclusion on Current Validity

The practice of deworming remains valid but requires a more nuanced approach than in the past:

1. Valid for targeted treatment: Individuals with confirmed parasitic infections should receive appropriate antiparasitic treatment

2. Valid for high-prevalence settings: Mass deworming may still be beneficial in areas with high prevalence of soil-transmitted helminths

3. Less valid for routine mass administration: In areas with low prevalence, routine deworming of all children has shown limited benefits for nutritional status, hemoglobin, cognition, school performance, or survival 3

The most effective approach combines targeted treatment with comprehensive prevention strategies focusing on improved sanitation, hygiene education, and environmental interventions.