Neglected tropical diseases

WHO seeks united approach to eliminate tapeworm infection

FAO and OIE join WHO to devise framework for tackling leading cause of epilepsy
10 July 2014 | Geneva
Cysticercosis cycle: intervention points

WHO, the Food and Agriculture Organization of the United Nations (FAO) and the Organisation for Animal Health (OIE) are uniting to tackle neurocysticercosis, a major cause of preventable epilepsy and disability in the world.

Download the cysticercosis cycle: intervention points [pdf, 239kb]

Neurocysticercosis, an infection of the central nervous system, is caused by the larval form of the tapeworm Taenia solium. People become infected by accidentally ingesting the eggs of the tapeworm excreted in human faeces, and by eating raw or undercooked infected pork.

Countries are seeking guidance from WHO on how best to approach this growing public-health problem, which has wide-ranging economic and social consequences. A multisectoral strategic framework is needed to ensure success in intensified control of cysticercosis,” says Dr Bernadette Abela-Ridder, who heads the Neglected Zoonotic Diseases team of WHO’s Department of Control of Neglected Tropical Diseases. “We also need improved management of patients adapted to low-income settings.

Neurocysticercosis is an important non-communicable parasitic disease associated with poverty and poor sanitation. More than 80% of the world’s 50 million people who are affected by epilepsy live in developing countries, many of which are endemic for T. solium infections in people and pigs. Cases occur in countries where families engage in community farming practices and raise free-roaming pigs, and where animals are slaughtered outside approved abattoirs.

Cysticercosis has been a serious problem in Latin America for decades. The disease is endemic in South and South-East Asia, and is emerging in large parts of sub-Saharan Africa. New reports of neurocysticercosis cases are re-emerging in the developed world, with recent cases in Europe and the United States of America.

WHO, in collaboration with FAO and OIE as well as other partners, are in the process of identifying a ‘best-fit’ strategy with countries to interrupt transmission of T. solium infection and to improve case detection and management of neurocysticercosis.

On 17–18 July 2014, global experts, stakeholders and endemic country representatives will formulate a framework for control to provide the proof of concept that intensified control is possible. Since the last international consultation in Vientiane, Lao People’s Democratic Republic in 2009, new intervention tools have become available.

The disease

The tapeworm T. solium is a parasite transmitted between humans and pigs that causes taeniasis. Humans become infected with the tapeworm by eating raw or undercooked infected pork. Millions of tapeworm eggs (too small to be seen by the naked eye) are excreted into the environment through infected people’s stool. Pigs get infected by eating human stool containing eggs or by ingesting eggs from the environment. Eggs develop into small cysts throughout the pig’s body (porcine cysticercosis).

Humans can also become infected with T. solium eggs by ingesting contaminated food or water (human cysticercosis) or as a result of poor hygiene. Tapeworm larvae (cysticerci) develop in the muscles, skin, eyes and the central nervous system. When cysts develop in the brain they may cause a condition called neurocysticercosis. Symptoms include epilepsy, severe headache and blindness and can lead to death. Neurocysticercosis is the most frequent preventable cause of epilepsy worldwide.