Soil-transmitted helminth infections are among the most common infections in humans, caused by a group of parasites commonly referred to as worms, including roundworms, whipworms and hookworms. Those living in poverty are most vulnerable to infection which can impair nutritional status by causing:

• internal bleeding which can lead to loss of iron and anaemia;
• intestinal inflammation and obstruction;
• diarrhoea; and
• impairment of nutrient intake, digestion and absorption.

Evidence shows that preventive chemotherapy, or the periodic large-scale administration of anthelminthic medicines to populations at risk, can dramatically reduce the burden of worms caused by soil-transmitted helminth infections.

Preventive chemotherapy is an important part of a comprehensive package to eliminate morbidity due to soil-transmitted helminths in at-risk populations. However, long-term solutions to soil-transmitted helminth infections will need to address many factors, including improvements in water, sanitation and hygiene.