It's worm-medicine time again!
Well it's that time again when parents do to their children what their own parents did to them - the back-to-school deworming. Of course, worm medicine was just the starter on the wash-out (laxative) menu of herb tea, Indian root pills and epsom salts to wash our troubles away.
Back in my day, I wrongly thought the worms we were trying to eradicate were the 'worms' (insect larva) I had consumed in those Blackie mangoes throughout the summer. As it turns out, about one-quarter of the world's population has worms of one kind or another anyway (especially roundworms) living in their gastrointestinal tracts.
Intestinal worms are parasites which invade and reside in our intestines. Some can grow to nine metres (30 feet) long. Children are susceptible and are often infected with more than one kind of worm. Roundworms, pinworms, threadworms, pork and beef tapeworms, threadworms, hookworms and whipworms are common.
We get intestinal worms (helminths) through walking barefooted in contaminated soil, from contaminated drinking water or undercooked meat or fish. Raw foods like fruits and vegetables which are not properly washed may have worm eggs on them too.
The hands and fingers help in the transmission of worm eggs from the seat of worm infection - the anus - to the mouth. Food handling without properly washing hands after toilet use is one possibility of food contamination with the eggs. The eggs (especially threadworm eggs) cause itching in the anus (especially at night) and when the contaminated scratching fingers make contact with other people's hands, mouths or food, the life cycle of the worm begins again.
Coughing, diarrhoea, fatigue, abdominal pain and loss of appetite are common symptoms of infection with worms. Worm infestation may lead to serious complications like bowel obstruction, malnutrition and loss of blood from the intestines, leading to iron deficiency and anaemia.
Controlling parasitic intestinal worms
Although we still do not know how some of the worm medicines (anthelmintics) act in eradicating worms, we know that most of them work by paralysing the worms so they can be easily expelled from the gut in faeces. The wash-out (laxative) afterwards only serves to hasten the expulsion of dead worms and so it is unnecessary.
For threadworm or pinworm infestation, all persons sharing the same housing should be treated together. Each anthelmintic is specific for particular worms, and the medical doctor should identify the nature of the infection before selecting the most appropriate treatment. However, most anthelmintics are available without a prescription, so choosing one which kills many types of worms is the common practice here. In severe infections a second course of treatment may be necessary.
Albendazole (Albendazole-MK, Las-Albendazole, Zentel) and levamisole (Levam) have a very impressive scope of activity and kill most types of worms. A single dose of either, is given after a meal, full stop. Threadworm treatment may involve repeated doses over three days. Albendazole is effective for 'creeping eruption' which occurs when dog or cat hookworm larvae enter our skin, usually creeping in the foot. Mebendazole (Vermox) and its combination with quinfamide (Amoebriz) are sound and popular choices too.
Dahlia McDaniel is a pharmacist and final-year doctoral candidate in public health at the University of London; email: firstname.lastname@example.org.