10 facts about neurocysticercosis

Updated April 2017

Tapeworm infection of the central nervous system is a leading cause of epilepsy worldwide

Neurocysticercosis is a preventable parasitic infection of the central nervous system and is caused by the pork tapeworm Taenia solium. Humans become infected after consuming undercooked food, particularly pork, or water contaminated with tapeworm eggs, or through poor hygiene practices.

Taeniasis is the intestinal infection of the adult tapeworm. When left untreated, a more serious condition known as cysticercosis develops as T. solium larvae invade body tissues. When larvae build up in the central nervous system, muscles, skin and eyes, it leads to neurocysticercosis – the most severe form of the disease and a common cause of seizures worldwide.

This fact file features key information about neurocysticercosis.

1 / 10 WHO/C. Gaggero Fact 1: Pigs become infected with T. solium when they come into contact with human faecal waste Millions of tapeworm eggs are excreted into the environment through the faeces of infected people. When pigs ingest these eggs or eggs from the environment, small cysts develop throughout the animal’s body. Humans are infected by consuming food, such as raw or undercooked pork, or water contaminated with tapeworm eggs, or through poor hygiene practices. WHO/J. Soares Gusmao Fact 2: Neurocysticercosis and taeniasis are two different diseases caused by the same parasite When the parasite T. solium is transmitted to human beings, it causes an intestinal infection of the adult tapeworm known as taeniasis. If left untreated, the tapeworm can survive inside the body for many years, leading to more serious conditions. Cysticercosis develops when the larvae of T. solium invade body and develop in the muscles, skin and eyes. If larvae invade the central nervous system, the infection leads to neurocysticercosis. WHO/I. Brown Fact 3: 50 million people are affected by epilepsy. More than 80% live in the developing world Neurocysticercosis is the most frequent preventable cause of epilepsy in the developing world. It is a common infection of the human nervous system and a growing public health concern. Symptoms of neurocysticercosis can include chronic headaches, blindness, seizures, meningitis and dementia. WHO/J. Soares Gusmao Fact 4: T. solium was recently named the food-borne parasite of "greatest global concern" WHO together with the Food and Agriculture Organization recently issued the warning to highlight the importance of cross-sector collaboration in tackling the spread of the disease. The combined efforts of sectors such as health, veterinary services and education can largely help to control T. solium infections. Behaviour change efforts can also be integrated with other disease programmes and interventions in settings where such resources are limited. WHO Fact 5: Neurocysticercosis is prevalent mainly in developing countries For decades, Latin America has had a serious problem with cysticercosis and neurocysticercosis. The disease is endemic in South and South-East Asia, and is emerging in parts of sub-Saharan Africa, particularly in rural areas where animal husbandry practices allow pigs to come into contact with human faeces. In many countries, a lack of awareness and understanding about the condition means it is largely a neglected disease. WHO/S. Lim Fact 6: Neurocysticercosis mainly affects rural farming communities The disease occurs in countries where families engage in community farming practices and raise free-roaming pigs. It is also common in areas where animals are slaughtered outside approved abattoirs and in the absence of meat inspections. T. solium infection in pigs affects the livelihood of many communities as pigs lose their market value. WHO Fact 7: Food handlers can also transmit T. solium Neurocysticercosis is not just limited to rural areas or disadvantaged communities lacking basic sanitation. A growing concern is the lack of hygiene practices among food handlers where the practice of regular hand-washing is important. Food safety, improved sanitation and hygiene are all crucial to preventing the transmission of T. solium. Cooking pork thoroughly also kills the parasite. WHO/S. Volkov Fact 8: Diagnosis of neurocysticercosis is difficult in rural regions Diagnosis of suspected neurocysticercosis currently requires computed tomography scans (CT scans). These facilities are not usually available in rural areas, where the disease is most prevalent, making it difficult to identify and treat patients. It is important to control the parasite by finding and treating people with the condition – and therefore avoid chances of transmission. WHO/A. Craggs Fact 9: Treatment for neurocysticercosis can be long, complicated and costly Neurocysticercosis is creates tremendous economic burden on health systems as treatments need to be tailored according to individual needs. Long courses of praziquantel and/or albendazole, as well as supportive epileptic therapy can improve the quality of life for patients. Fortunately, pigs can now be treated with anti-parasitic medications and vaccinated against T. solium. This prevents the parasite from being transmitted to humans. WHO Fact 10: Eliminating neurocysticercosis requires breaking the life cycle of T. solium Thorough case finding, better diagnosis and treatment, and public health information campaigns are crucial to effectively control and break the life cycle of the parasite. Many sectors need to be included with activities which can reduce the risk of infection. WHO is working with countries to tailor intensified control strategies for T. solium and improve management of neurocysticercosis patients. Partners include the FAO, the World Organisation for Animal Health, private sector, NGOs and academia.

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