Soil-transmitted helminth infections are among the most common infections worldwide and affect the poorest and most deprived communities. It is an infestation with one or more intestinal parasitic roundworms that include whipworms, hookworms and ascaris.
They are transmitted by eggs present in human faeces which in turn contaminate soil in areas where sanitation is poor. The main species that infect people are the roundworm (Ascaris lumbricoides), the whipworm (Trichuris trichiura) and the hookworms (Necator americanus and Ancylostoma duodenale).
These worms are regarded as the most important causes of intellectual and physical setbacks in children.
Intestinal worms can cause diarrhoea, abdominal pain, a generalized feeling of discomfort and weakness. Hookworms are known to cause chronic intestinal blood loss and can result in anaemia and chronic fatigue. In some people, intestinal worms do not cause any symptoms or they may be irregular.
Infected people excrete helminth eggs in their faeces that can contaminate the soil in areas with inadequate sanitation. Hookworm eggs hatch in the soil and mature into a form that can penetrate the skin of humans. Walking barefoot on contaminated soil is the primary cause of hookworm infestation.
Ingesting eggs or larvae causes whipworm. Infestation can occur from consuming fruits and vegetables that have not been thoroughly washed, peeled or cooked. Children are at the greatest risk of whipworm by putting their fingers in their mouth after playing or even eating contaminated dirt. Once swallowed, worms can produce eggs for a year or more.
Latest estimates indicate that more than 880 million children are in need of treatment for these parasites. Populations at risk in the WHO African Region is estimated at 350 million.