WHAT ARE THEY?
VOL: 99, ISSUE: 33, PAGE NO: 26
WHAT ARE THEY?
- Threadworms are a common parasitic nematode (Enterobius vermicularis).
- They measure from 2.5 to 12mm and look like white cotton threads.
- Threadworms are harmless but can be very irritating, disturbing sleep.
- Female threadworms produce large numbers of tiny eggs, which are invisible to the naked eye.
- The eggs are ingested from contaminated hands or food.
- They hatch in the intestine and quickly develop into adult worms.
- The female worms lay their eggs in the perianal area at night.
- The female secretes mucus, which causes intense itching and promotes scratching by the host.
- Reinfection occurs when eggs are ingested from contaminated hands.
SIGNS AND SYMPTOMS
- The main symptom is itching of the anal area, especially at night.
- Some people have no symptoms.
- Diagnosis is confirmed if threadworms are seen in the perianal area or in the stool.
- Threadworms most commonly affect children 5-10 years old but they may affect the whole family.
- Higher rates of infection can occur in residential institutions such as children’s homes.
- In a general practice of 10,000 patients, about 40 consultations a year are due to threadworm (McCormick et al, 1991).
- Good hygiene measures should be encouraged in all family members.
- All family members should be treated simultaneously.
- Mebendazole acts by inhibiting the uptake of glucose by the worms.
- Piperazine blocks the neurotransmitter acetylcholine in the worm, paralysing it.
- Both mebendazole and piperazine have cure rates of about 90 per cent.
- Threadworm infection can be treated solely by meticulous attention to hygiene for six weeks. This may be considered when drug treatment is not wanted or is not recommended, for example, in pregnant women.
- It is not necessary to exclude children from school.
- Where diagnosis is uncertain, a sticky-tape test may be useful.
- Keep nails cut short.
- Wash hands and scrub nails after each visit to the toilet.
- Wash hands and scrub nails before each meal.
- Disinfect toilet seat, toilet handle, and door handle regularly.
- Damp dust and vacuum clean bedrooms daily.
- Wear pyjamas or pants in bed.
- Scratching of the perianal region can lead to excoriated skin and secondary infection.
- In rare cases the adult worms can spread to other organs and lead to complications such as: vulvovaginitis, salpingitis, urinary tract infection or hepatitis.
- Perianal itching in adults may be due to irritation by deodorants, tight nylon underclothes, haemorrhoids, perianal eczema, and pruritus ani.
- Roundworms may occasionally be passed in the stool (adult worms are approximately 30cm long).
- Tapeworm infection often only becomes evident when segments are passed in the stool - these are called proglottids and are ribbon-like, approximately 5cm long and, unlike threadworms, do not move.