Tapeworm alert in rural Eastern Cape
Dr John Fincham of the Medical Research Council has drawn attention to a
recent survey conducted in 21 villages in the Alfred Nzo and Oliver Tambo
districts in the Easter Cape, which found that between 28.2% and 52.2% of
free-ranging pigs had pork tapeworm cysts in their muscles. The cysts are
tapeworm larvae that develop into adult worms in people who eat under-cooked or
raw meat from an infested pig. The pork tapeworm (Taenia solium) is the cause of
most of the serious tapeworm-related disease in South Africa.
Early in May 2005 several children at a remote village in the Eastern Cape
suffered from fits and other symptoms. This outbreak has served as a timely
reminder of the danger posed by cysts of the pork tapeworm in the brain and
other vital organs. Brain cysts are the main cause of epilepsy in children and
adults in the Eastern Cape. Records show that almost 90% of 239 patients with
brain cysts seen in Cape Town hospitals were originally from that province.
Epilepsy was present in 79.5% of this series and 51.5% were children.
The situation in the village reflects the traditional practice of allowing
pigs to range freely when there is a lack of effective sanitation. While the
pigs are an important source of protein, they unfortunately scavenge exposed
human faeces containing tapeworm eggs. Numerous larval cysts develop in the pig
meat as a result.
It is also easy for a person to swallow tapeworm eggs, which they can get
from direct or indirect contact with a human tapeworm carrier. After ingesting
eggs, cysts, develop in human tissue (as in pigs). In people, there is a
preference for the central nervous system, which can lead to epileptic seizures
and other neurological problems. It is important to know that one does not need
to handle pigs or consume pork to become infected with the cysts.
During the recent outbreak at the village, one child died of an uncontrolled
epileptic-like fit, which might have been caused by tapeworm cysts in the brain,
and 26 were treated in hospital. There is an unconfirmed report that 17 of the
children had fits. A team investigating the outbreak reported that pigs roamed
freely through the village and there was a lack of effective sanitation.
“No definitive diagnosis has been possible because of the remoteness of the
village. A sensitive ELISA diagnostic test is available that detects circulating
antigen from cysts,” says Dr Fincham.
He says that brain scans, radiographs and/or electroencephalograms would
necessitate transporting the children for long distances to hospitals where
facilities are available, which would be expensive and hard to arrange. The
solution to the problem in this village and generally, is to develop effective
sanitation and a reliable supply of clean water, as well as to enclose pigs so
that they do not scavenge waste.
“Pork tapeworm cysts can also lodge and enlarge in the spinal cord, eye,
muscle or elsewhere in our bodies. Pressure from cysts can impair vision, cause
paralysis and have other seriously debilitating effects,” says Dr Fincham.
Pig production by emerging farmers in resource-poor situations in all the
South African provinces has increased substantially. Prevention of pork
tapeworm-related disease can be achieved by means of effective sanitation;
provision of clean water; cooking all pig meat sufficiently to destroy cysts;
and regular, effective treatment of people against tapeworm in rural areas where
pigs are produced and eaten.
“Hydatid disease caused by development of cysts of Echinococcus granulosus
(a tapeworm of dogs and wild carnivores) is another serious tapeworm-related
disease of humans in South Africa,” says Dr Fincham.
He says that the cysts develop mainly in the liver or lungs, but also in
other organs. Hydatid disease is much less frequent than pork tapeworm-related
disease, but it is very serious because the cysts continuously enlarge.
Treatment often includes radical surgery and cases are referred every year from
rural areas to hospitals in urban centres.
Dr Fincham mentions a few solutions, which are: treat dogs regularly with
effective anthelmintics, do not feed meat containing Echinococcus cysts to dogs,
keep dogs clean, and practice good personal hygiene (especially by washing hands
after handling dogs). - MRC
More information:
www.mrc.ac.za
Related articles:
Tapeworm and the brain
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