Soil-transmitted helminth infections are caused by different species of parasitic worms. Humans are infected through ingestion of eggs with contaminated soil or vegetables. Adult worms that live in the intestine of an infected individual produce thousands of eggs each day that are passed into the environment through faeces. Therefore the disease is prevalent where sanitation is poor. In addition, hookworm eggs hatch in the soil, releasing larvae that mature into a form that can actively penetrate the skin. Therefore people become infected with hookworm primarily by walking barefoot on the contaminated soil.
In 2001, delegates at the World Health Assembly unanimously endorsed a resolution (WHA54.19) urging endemic countries to seriously tackle parasitic worm infections, specifically schistosomiasis and soil-transmitted helminth infections. For soil-transmitted helminth infections, the goal is to control morbidity through the periodic treatment of at-risk people living in endemic areas (preventive chemotherapy intervention), and the global target is to eliminate morbidity in children by 2020, largely through school deworming programmes.
Most of the countries in the Western Pacific Region are endemic with soil-transmitted helminth infections. In 2013, 52.6 million school-aged children and 22.8 million preschool-aged children in 15 countries (Cambodia, China, Fiji, Kiribati, Lao People’s Democratic Republic, Marshall Islands, Federal States of Micronesia, Nauru, Papua New Guinea, Philippines, Solomon Islands, Tonga, Tuvalu, Vanuatu and Viet Nam) were estimated to require preventive chemotherapy interventions.