Tapeworms: a real and present danger
The tapeworm is a long way from being relegated to an academic curiosity: in parts of South Africa it is still a serious health risk. ELMIEN WOLVAARDT reports.
In early May this year, the media and the Eastern Cape Department of Health reported that several children in a remote village in the province showed symptoms that suggested the presence of tapeworm cysts in their brains.
One child was reported to have died of an uncontrolled, epileptic-like fit, and 26 other children were treated in hospital.
Although diagnostic proof of the presence of the cysts is still to come, the outbreak drew attention to the serious risks associated with the practice of keeping free-ranging pigs, which is common in the Eastern Cape.
Since pigs are not constrained to a specific area, they inevitably eat human waste because they are scavengers. This is the main cause of the cycle of tapeworm infection between humans and pigs.
And without adequate knowledge of hygiene around sanitation and food preparation, the tapeworm cycle can lead to the condition (called neurocysticercosis) suspected of having caused the Eastern Cape child's death.
Generally, human beings get intestinal tapeworms after eating raw or undercooked pork that contains tapeworm cysts. This is part of an age-old cycle: pigs, in turn, became infected by ingesting the faeces - containing large numbers of tapeworm eggs - of people whose intestines are already host to adult tapeworms.
People are known to have lived for many years with intestinal tapeworms, although it is certainly a risky situation for themselves and others. The health impact of tapeworms, as opposed to the cysts, is usually weight loss or inadequate weight gain. Infection can be controlled by discarding infected meat or by thoroughly cooking it, alternatively by ensuring that pigs are unable to access human faecal pollution resulting from inadequate sanitation.
However, if a person is already infected with tapeworm, there is the possibility that even minute particles of their faeces - containing the tapeworm eggs - can contaminate their hands, food or utensils. They are then at high risk of swallowing the eggs. In addition, infected people can transfer eggs to others through food preparation or by intimate contact.
Once the eggs are ingested, the tapeworm larvae hatch, penetrate blood vessels and can reach any organ, including muscles, the brain, the eyes and the spinal cord. Eventually, hard cysts form around the larvae. Pressure from the cysts, together with degenerative changes in the tissue around them, can cause headaches, seizures, paralysis, blindness and even death. In fact, neurocystircercosis is the main cause of epilepsy in people from areas where pigs are allowed to roam freely.
Prevention is of paramount importance as this is a difficult condition to treat. Medicine can kill the cysts, but they still leave a calcified shell that can only be removed by surgery.
Dr John Fincham of the MRC's Nutritional Intervention Research Unit and a team of collaborators and funders have developed comprehensive educational materials about both the tapeworm cycle and the steps that need to be taken to prevent related health problems.
The materials consist of a poster and a slide show that can be used by the media, by communities, and in schools. They are available in Afrikaans, English and isiXhosa.
'Tapeworm-related diseases can be prevented by sanitation, hygiene, keeping pigs enclosed, and not eating raw or lightly cooked meat. An effective and sustained information service covering these points is needed,' Dr Fincham said.