Tapeworm and the brain

Prof. H. Foyaca-Sibat, University of Transkei

A neurologist based in the former Transkei region of South Africa profiles a seldom heard  of neurological ailment which affects more than 50 million people world-wide. The catch is not knowing you may have it. In southern Africa where many are living with HIV, a bleak picture is painted.

Neurocysticercosis(NCC) is the most common parasitic infection of the brain affecting more than 50 million people all over the world. NCC is caused by infection of the larvae of the pig tapeworm Taenia solium(TS). Pigs become infected when they ingest contaminated human faeces. If  someone ingests diseased (measly) pork meat containing larva forms of this tapeworm or ingests its eggs when eating contaminated foods, the parasite fins its way to the small intestine where they become mature. From here the parasite spreads to the brain to form of cystic lesions, also affecting the eyes, muscles or spinal cord.

This parasite can live for years sometimes for entire life-times in the brains of humans who can be free of symptoms, particularly so in HIV infected patients. In HIV patients where the immune system is compromised the parasite remains alive far longer in the brain, but its is a two way street. Neurocysticercosis debilitates the body's defense system and these patients become much more susceptible to get infection and are more prone to develop AIDS. In HIV-positive patients with NCC, epilepsy, epileptic attacks and seizures are the  symptoms most commonly observed.

In non-HIV patients the parasite symptoms differ from country to country but in general the most common symptoms include epileptic attacks , headaches, visual and skin problems, and psychiatric manifestations. Any person living, visiting or in close contact with persons from endemic areas such as Latin American, Asian, or African countries could be a candidate for NCC. If you are in that group and you developed epilepsy later in your life (though younger ages are not an exclusion criteria) you could be a candidate.  Diagnosis by a health professional could rule out NCC as a cause. Radiographic tests such as Computer Tomography (CT Scan) of the brain is the best confirmatory test, as it identifies most of the cystic lesions and also the head of the parasites (see image to the right). The CT Scan test is available in most cities in South Africa and for patients requiring special care the New Nelson Mandela Academic Hospital a National  Reference Center is an option. Alternative ways do exist in case CT Scan is not available. 

The medication of choice for infection of the brain by this tapeworm is praziquantel or albendazol taken with steroids under medical supervision. These anti-parasitic medications kill parasites in all stages of their development in the human brain, eyes or muscles. Most patients respond very well to one-day treatments with praziquantel. However, for people living in endemic areas who remain susceptible to re-infection, periodical treatment is necessary.

The good news is that after the treatment the damage to the brain is 100 % reversible in most cases and only a few require intensive medical attention.

National figures for NCC remain unknown. NCC is a disease of poverty and underdevelopment and its dissemination is permanent in areas where the population have a limited or non-existent access to primary health care attention, health education, proper access to toilet facilities, proper refuse disposal, safe and clean water, electricity, employment, and money. The former Transkei areas of Southern Africa are perhaps hardest hit. According to Prof Foyaca patients are treated for NCC with young children more so than adults. While this situation persists the number of infected immigrants to developed areas will continue increasing.  Patients diagnosed in Soweto, Cape Town, and other places are migrants from impoverished regions of Southern Africa. Although we can't expect radical changes we may contribute to reduce the risks to this disease by: 

  • spreading this information
  • encouraging all people with a high suspicion of NCC to be seen by health professionals,
  • educating our population towards better personal hygiene, hygienic food preparation,
  • freezing suspected pork meat when it is possible or simply overcooking it ,
  • educating people to limit access of pigs to human feces.

June 2002