e-Library of Evidence for Nutrition Actions (eLENA)

Deworming to combat the health and nutritional impact of helminth infections

Helminths are a group of parasites commonly referred to as worms and include schistosomes and soil-transmitted helminths. Schistosome and soil-transmitted helminth infections are among the most common infections in developing countries and can impair nutritional status by causing:

  • internal bleeding which can lead to loss of iron and aenemia;
  • malabsorption of nutrients;
  • diarrhoea; and
  • loss of appetite which can lead to a reduction in energy intake.

Infections can also cause cognitive impairment as well as tissue damage that may require corrective surgery.

The nutritional impairment caused by schistosome and soil-transmitted helminth infections during childhood has been shown to have a significant impact on growth and development of children. Periodic treatment (deworming) of children together with improvement of water and sanitation, and health education can reduce the transmission of schistosome and soil-transmitted helminth infections.

WHO recommendations

To reduce the worm burden, WHO recommends periodic drug treatment (deworming) of all school-age children living in endemic areas.

WHO also recommends health and hygiene education, and the provision of adequate sanitation.

This is a summary of WHO recommendations. The full set of recommendations can be found in the guidance documents, under ‘WHO documents’ below.

WHO documents

GRC-approved guidelines

Status: not currently available

Other guidance documents


Related Cochrane reviews
Other related systematic reviews
Clinical trials

Last update:

13 November 2014 14:20 CET

Category 2 intervention

Systematic review(s) have been conducted but no recent guidelines yet available that have been approved by the WHO Guidelines Review Committee