Soil-transmitted worms (roundworm, whipworm and hookworm) are among the most common infections in children worldwide, especially where sanitation is poor. In areas where these worms are common, WHO recommends regular deworming of children, once or twice a year, with a single dose of albendazole or mebendazole, together with handwashing, toilet use and wearing shoes to prevent reinfection.
How children get worms
- Eggs in soil contaminated by human faeces get onto hands, food or water and are swallowed (roundworm, whipworm)
- Hookworm larvae in soil enter through bare skin, usually the feet
- Threadworms (pinworms) spread through scratching and contaminated hands, bedding and clothes
Signs your child may have worms
- Tummy pain, bloating, diarrhoea or nausea
- Poor appetite or always hungry with poor weight gain
- Tiredness, pale skin and poor concentration (anaemia, especially with hookworm)
- Itchy bottom, especially at night (threadworms)
- Seeing worms in stool or vomit
- Coughing in some cases, as larvae pass through the lungs
Many children have no symptoms, which is why regular deworming is recommended in high-risk areas.
Why deworming matters
Heavy worm infections can cause anaemia, malnutrition, stunted growth and poor school performance. Deworming is cheap, safe and is often given in schools and alongside vitamin A campaigns.
How often should children be dewormed?
- WHO recommends preventive deworming once a year where 20% or more of children are infected, and twice a year where 50% or more are infected.
- It is given to young children (from 12 months), preschool and school-age children, adolescent girls and women of reproductive age in these areas, and to pregnant women after the first trimester where recommended.
- Follow your national programme or ask a health worker. Doses depend on age, so ask a pharmacist, nurse or doctor for the correct dose for your child.
Safety
- Albendazole and mebendazole are very safe at recommended doses.
- Mild side effects can include tummy pain, nausea or diarrhoea, especially in heavily infected children.
- Crush or chew tablets for young children to prevent choking; never force a whole tablet into a small child’s mouth.
- Pregnant women should only be dewormed as advised by a health worker.
Preventing reinfection
- Wash hands with soap after using the toilet and before eating or preparing food
- Use a toilet or latrine; avoid open defecation
- Wear shoes or sandals outdoors
- Wash fruit and vegetables with safe water
- Drink safe water
- Keep nails short and clean
- For threadworms: treat the whole household together and wash bedding and underwear
For nurses and community health workers
- Record deworming on the child health card
- Combine deworming with growth monitoring, vitamin A and immunisation checks
- Screen for anaemia in children with pallor
- Teach hygiene with demonstrations, not just leaflets
Frequently asked questions
At what age can a child be dewormed?
WHO deworming programmes typically start from 12 months of age. Ask a health worker for younger children.
Should adults deworm too?
Adults with symptoms should be tested or treated as advised. In some programmes, women of reproductive age are included.
Can I deworm my child every month?
No. Follow recommended intervals; frequent unnecessary treatment isn’t helpful.
Related reading: Child growth monitoring and MUAC · Childhood diarrhoea, ORS and zinc · Community health nursing questions
Source: WHO fact sheet on soil-transmitted helminth infections. Updated 5 November 2026.