Taenia solium cysticercosis: new challenges for an old scourge

Abstract

The taeniasis/cysticercosis disease complex is a public health challenge for most of the developing world, and is increasingly recognized in developed countries due to mass immigration, refugee movements, international travelling and overseas business affairs. This parasitic disease is caused by the pork tapeworm Taenia solium which normally inhabits—in its adult form—in the small intestine of man, producing vague intestinal complaints or no symptoms at all; humans become Taenia carriers after being infected by eating undercooked pork containing cysticerci, the larval stage of the parasite. While pigs are the natural hosts for the larval stage of this tapeworm (intermediate host), humans may also become infected with the cystic larvae, thus developing cysticercosis. Recent evidence favors the concept that human cysticercosis is a disease mainly transmitted from person-to-person, i.e., a healthy individual ingesting T. solium eggs directly from a Taenia carrier by the fecal-oral route or through non-hygienic handling of food. As per most zoonosis, taeniasis/cysticercosis is closely linked to poverty and disproportionately affects underserved populations. While taeniasis and cysticercosis have long been known and clinically well described, advances in the diagnosis and treatment of neurocysticercosis during the past few decades have increased the knowledge on this disease and improved the prognosis of most affected patients. Development of modern neuroimaging in the late 1970s, the introduction of specific antiparasitic drugs soon after, and improved serological diagnosis and monitoring are rapidly changing our views on the disease. Epidemiological evidence has demonstrated much larger endemic regions along the world, including most of Africa and vast parts of China, as well as clear trends of the introduction of imported cases in non-endemic countries. However, much remains to be learned and some controversial aspects in the taeniasis/cysticercosis complex remain open to discussion. This issue of Pathogens & Global Health is devoted to basic and clinical aspects of T. solium cysticercosis. The increased epidemic burden of neurocysticercosis in the US, the high prevalence of the disease in South Africa, recent advances in immunological diagnosis of neurocysticercosis, as well as clinical manifestations of the disease, the relationship between neurocysticercosis and epileptogenesis, recent advances in therapy, and control measures directed to eradicate Taenia solium taeniasis/cysticercosis, are discussed by experts in the subject, all of them researchers with extensive hands-on experience on this parasitic disease. Taeniasis/cysticercosis continues to be a serious public health problem in most of the world. Much has been gained in understanding the disease, as well as on its diagnosis and management, and more recently, some hopes of elimination and perhaps eradication have arisen. In this context, this issue will be a welcome addition to the bookshelves of physicians working on this parasitic disease and a reference volume for updated information.