Describe the soil-transmitted helminths and the national deworming programme.

The Soil-transmitted Helminths

• Enterobius is not a soil-transmitted helminth, despite being an intestinal nematode — its eggs are infective within hours and spread directly, which is why it occurs in every social class and is not addressed by these programmes
• The burden in India is very large — a substantial proportion of children aged 1 to 14 are estimated to be at risk, with the heaviest burdens in states with poor sanitation
• The harm is chronic and cumulative rather than acute — iron deficiency anaemia, protein-energy malnutrition, impaired growth, reduced school attendance and measurably poorer cognitive performance. Deaths are few; the loss is in development
• Worm burden determines morbidity, and the distribution is overdispersed — most infected people carry few worms while a small minority carry very heavy burdens and account for most of the disease and most of the transmission

The National Deworming Programme

• India's national deworming day (NDD) is held on 10 february each year, with a mop-up round about a week later for children missed. It is among the largest public health campaigns in the world by number of people reached
• Target group — all children and adolescents aged 1 to 19 years, delivered through schools and anganwadi centres, which reaches the age group most affected at negligible cost and without a separate delivery system
• The drug is albendazole 400 mg as a single dose (200 mg for children aged 1 to 2), given chewed or crushed, and after a meal, not on an empty stomach
• Frequency — once or twice yearly depending on the local prevalence, in line with WHO recommendations: annual treatment where prevalence exceeds 20%, and twice yearly where it exceeds 50%
• Expected mild adverse effects — nausea, abdominal pain, vomiting, and occasionally the passage of worms; these are commoner in heavily infected children and reflect worm death rather than drug toxicity. Anticipating and explaining them is essential, since a cluster of children feeling unwell after a campaign readily becomes a rumour that stops the programme
• Complementary measures — iron and folic acid supplementation, since deworming without iron leaves the anaemia; the Swachh Bharat Mission for sanitation; safe water; handwashing with soap; and footwear, which is the specific measure against hookworm and Strongyloides

Applied Aspects

• Deworming alone does not solve the problem — reinfection occurs within months where sanitation is unchanged, which is why the programme is periodic and why it must run alongside sanitation rather than instead of it
• Give iron with deworming in anaemic populations; the two together address the parasite and the deficit it caused
• Albendazole is avoided in the first trimester of pregnancy but is given in the second and third in endemic areas, where the benefit to maternal anaemia and birth weight is well established
• Watch for resistance; benzimidazole resistance is already widespread in veterinary practice from exactly this pattern of use, and monitoring of cure rates in human programmes is a stated concern
• Explain the expected side effects in advance to teachers and parents; programme failures have followed rumours after entirely predictable mild reactions
• Footwear and toilets are the durable interventions, and deworming is a holding measure that buys a generation of children better growth and schooling while those are built