Intestinal Worms
Introduction
Worm infections are very common worldwide, although they mainly occur in areas with poor sanitation and hygiene, and are usually associated with poverty. They are spread in a variety of ways.
Recommendations for Travellers
The risk of infection is greatest when visiting rural parts of the developing world or areas with low standards of sanitation and hygiene.The risk is greater in children.
To avoid infection during travel you should:
- observe strict food and water hygiene
- maintain good personal/hand hygiene
- avoid walking barefoot or sitting/lying/playing directly on soil or sand potentially contaminated by animal/human faeces.
Overview of the Diseases
Worm infections occur in a variety of ways, depending on the type of worm (Hookworms, Round worms, Whipworms, Tapeworms). Infection may be acquired by:
- eating uncooked food or drinking untreated water contaminated with worm eggs.
- eating raw or undercooked meat or fish containing cysts of worm larvae
- poor hand hygiene – handling contaminated soil/surfaces or faeces may transfer worm eggs from the environment into the mouth if good hand hygiene is not observed
- walking barefoot on, or handling contaminated soil/sand - larvae present in soil/sand can penetrate skin and result in infection.
The Illnesses
Worm infections often cause very few symptoms. Abdominal bloating, pain, discomfort and altered bowel habit may occur. Infection may only be noticed when whole worms (round worms), or worm segments (in tapeworm infections) are seen in bowel motions or vomited.
Some type of worm infections can cause skin rashes, whilst others can produce serious illness due to the formation of larval cysts inside the body, including in the brain, liver and lungs. This is very rare in travellers.
Most infections are easily diagnosed by laboratory examination of stool samples for worm eggs (they are microscopic), larvae, or worm fragments/segments.
Treatment
Intestinal worms are usually easily treated with a single dose, or short course of deworming tablets.