Let us now read the parasitic intestinal worms also known as soil-transmitted helminths.
World Health Organisation (WHO) estimates more than 1.5 billion people or 24% of the world‘s population are infected with soil-transmitted helminths.
Asia alone accounts for 70% of this burden where national population prevalence is 21% being higher in rural population as compared that in urban population the prevalence of Roundworm, Hookworm and whipworm has been reported to be ranging between 0.4 and 71.8%, 0.14 and 42.0% and 0.3 and 29.3% in various regions of India respectively.
In India which represents 68% of children in this age group and approximately 28% of all children at risk of soil-transmitted helminths globally.
- Roundworms (Ascaris lumbricoides)
- Hookworms (Ankylostomaduodenale and Necator americanus)
- Whipworms (Trichuris trichuriasis)
In India, they are mostly roundworms (Ascaris lumbricoides), Hookworms (Ankylostomaduodenale and Necator americanus), and whipworms (Trichuris trichuriasis).
People of all age groups and both sexes suffer from soil-transmitted helminths. However, children and adolescents are the most sufferers having an overall prevalence rate ranging between 7.6 and 78.3 %. WHO estimates that approximately 241 million children between the ages of 1 and 14 years are at risk of soil-transmitted helminths.
Effect of Soil-Transmitted Helminths Infections
- Worm infestation affects the human body in several ways e.g. Worms feed on host tissue including blood which leads to a loss of iron and protein and thus often contributes to anemia.
- Worms can increase the malabsorption of nutrients.
- Worms can decrease vitamin- A availability in the Intestine. Roundworm especially when an increase in large number they may cause loss of appetite reduce nutrition intake and physical fitness and sometimes may block intestinal passage. Some worms can cause diarrhea and dysentery.
- The worms have negative effects on the physical and mental development of children. Children often remain underweight and have and stunted growth due to anemia caused by a decrease in nutrition intake due to worm infestations.
- Children with heavy worm infestation become too sick or too tired to concentrate at school or even to attend school. Subsequently, these children have poor educational and lower lifetime income outputs. Women with worms have poor pregnancy outcomes. Worms also increase child mortality.
Mode of Spread of Intestinal Worms and Risk Factors for Transmission of Helminths
- Soil-transmitted worms are transmitted by eggs present in human feces which contaminated soil in areas with poor sanitation e.g. Through open field defecation. Adult worms live in the human intestine for food and survival where they produce thousands of eggs each day. When infected people defecate in outdoors (fields) these eggs come out with faeces and contaminate soil. Transmission occurs when
- Eggs that are attached to vegetables are ingested without being carefully washed; peeled or cooked.
- Eggs are ingested through contaminated water e.g. Pond water
- Eggs are ingested through the soil if children play in contaminated soil and put their hand in the mouth without washing.
- However, the larvae directly enter through skin who do not put on footwear.
Risk factors responsible for transmission
People those who are:
- socioeconomically backward classes
- open field defecation
- work with bare feet in fields
- poor personal hygiene
- unhygienic feeding habits and
- unsafe drinking water.
Symptoms and Signs, Diagnosis and Treatment of WormInfestations
People with mild infection usually have no symptoms. When worm infestation becomes heavy, the symptoms and signs start becoming prominent which include diarrhoea abdominal pain, weakness easy fatigue and loss of appetite may times patient or child may complain of passing worms in the faeces.
Diagnosis of worm infestations
Presence of worms in the intestine is confirmed either by seeing live/dead worm in the feaces or by identifying the ova and cyst of worms present in the samples of faeces (stool) with the help of microscope in the laboratory of the hospital.
Treatment of worm infestations
In the community, Albendazole has been considered a safe de-worming drug presently being made available by the Government of India for the treatment of persons with worm infestation under National De-worming Programme. For children between the ages of 2 and 19 years, 1 tablet (400 mg) and half tablet for children of age 1–2 years are recommended. For younger children should be broken into half and crushed and then administered with water under the supervision of a health worker. All adults are administered one full tablet each.
Note: Sick children should not be given a tablet. Every child should first chew the tablet then swallow. Do not allow the child to take a tablet at home.
Who should be given treatment
WHO recommends prevention and control of soil-transmitted worms related morbidity through the periodic treatment of at-risk populations living in endemic countries like India particularly preschool and school-age children and women of childbearing age (including pregnant women in the second and third trimester and breastfeeding women). The de-worming treatment is to be given without previous individual diagnosis to all at-risk people in endemic areas once a year where the prevalence of worm infection is over 20% and twice a year when prevalence is more than 50% for this celebration of National De-worming Day (NDD) has also been recommended.
In India, NDD is been observed on 10th Feb. every year since 2015. Side effects of De-worming treatment
The de-worming treatment has very few side effects. There may be some mild side effects like dizziness, nausea, headache, and vomiting, and abdominal pain all likely due to worms being passed. However, these side effects disappear after some time, and hospitalization is not required. Severe side effects are fatal, life-threatening, disabling, or incapacitating e.g. Choking hazard/asphyxia. The patient needs to be taken immediately to the nearest health facility for quick treatment. While doing so health workers should stop de-worming others and stay calm, should call helpline no. try to arrange a vehicle /ambulance. He / She should inform the attendance of the patient/child about the condition and need for emergency treatment. Soil-transmitted infections can be eliminated from the country as observed in several countries e.g. US, South Korea.
Note: Albendazole tablet can be administered with IFA tablet & Vitamin- A
De-worming and Prevention
The spread of soil-transmitted infections can be prevented by taking precautions such as using the sanitary toilet and not defecating in an open field, washing hands particularly before eating and after using the toilet, wearing slippers and shoes, drinking safe and clean water, keeping nails short and clean, eating properly cooked food and storing it safely, washing fruits and vegetables in safe and clean water.
Advantages of de-worming
- The child grows faster and remains healthier.
- He/she becomes more resistant to infections.
- He/she learns better and remain more active in school.
- He/she attends school more regularly.
- Anaemia decreases and nutrition improve, and better pregnancy outcome for pregnant women.
Calculation of albendazole tablets (400 mg) for one deworming round
You can calculate the demand for albendazole tablets (400 mg) required for one deworming round using the formula given below:1 × No. of children (1–19 years in the area) + 10% of total requirement as a buffer (for wastage and spoilage)