Worm infections (Hookworms, Round worms, Whipworms, Threadworms, Tapeworms) are very common worldwide, although they mainly occur in areas with poor sanitation and hygiene, and are associated with poverty.
Infection occurs in a variety of ways, depending on the type of worm. 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/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 – hookworm larvae present in soil/sand can penetrate skin and result in infection.
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.
Intestinal worms are usually easily treated with a single dose, or short course of deworming tablets.
The risk of infection is greater when visiting rural parts of the developing world or areas with low standards of sanitation and hygiene.
Travellers should observe strict food and water hygiene, maintain good personal/hand hygiene and avoid walking barefoot or sitting/lying directly on potentially contaminated soil or sand.