Seroprevalence of Antibodies Against Taenia solium Cysticerci Among Refugees Resettled in United States

Seth E. O'Neal; John M. Townes; Patricia P. Wilkins; John C. Noh; Deborah Lee; Silvia Rodriguez; Hector H. Garcia; William M. Stauffer


Emerging Infectious Diseases. 2012;18(3):431-438. 

In This Article

Abstract and Introduction


Neurocysticercosis (NCC) is a disease caused by central nervous system infection by the larval stage of the pork tapeworm, Taenia solium. In developing countries, NCC is a leading cause of adult-onset epilepsy. Case reports of NCC are increasing among refugees resettled to the United States and other nations, but the underlying prevalence among refugee groups is unknown. We tested stored serum samples from the Centers for Disease Control and Prevention Migrant Serum Bank for antibodies against T. solium cysts by using the enzyme-linked immunoelectrotransfer blot. Seroprevalence was high among all 4 populations tested: refugees from Burma (23.2%), Lao People's Democratic Republic (18.3%), Bhutan (22.8%), and Burundi (25.8%). Clinicians caring for refugee populations should suspect NCC in patients with seizure, chronic headache, or unexplained neurologic manifestations. Improved understanding of the prevalence of epilepsy and other associated diseases among refugees could guide recommendations for their evaluation and treatment before, during, and after resettlement.


Cysticercosis is a disease caused by infection with the larval stage of the pork tapeworm, Taenia solium. Humans and pigs acquire cysticercosis by ingesting T. solium eggs shed in the feces of humans with taeniasis (i.e., infected with an adult intestinal tapeworm). Upon ingestion, tapeworm eggs release oncospheres, which invade the intestinal wall and disseminate through the bloodstream to form cysts throughout the body. The natural lifecycle of T. solium tapeworms completes when a human eats pork contaminated by T. solium larval cysts because these can then develop into adult egg-producing intestinal tapeworms. This endemic lifecycle occurs primarily in regions where sanitation is poor and where pigs are allowed to roam and access raw human sewage.

Neurocysticercosis (NCC) occurs when cysts develop within the central nervous system (CNS); NCC is the primary cause of illness in T. solium infection. The clinical features of NCC cover a diverse range of neurologic manifestations, including seizures, headache, intracranial hypertension, hydrocephalus, encephalitis, stroke, cognitive impairment, and psychiatric disturbances.[1,2] In areas in which T. solium infection is endemic, it is a major cause of epilepsy, with 30% of seizure disorder attributable to NCC.[3–5]

Numerous reports document that cysticercosis in the United States occurs primarily among migrants and travelers who are presumed to have acquired their infection in another country.[6–9] Refugees represent a large group of migrants in which the frequency of T. solium infection has not been described. Approximately 690,000 refugees resettled in the United States during 2000–2010.[10] Resettlement from regions with known pockets of T. solium tapeworm endemicity, including Southeast Asia, central Asia, and sub-Saharan Africa, is common. Cysticercosis among resettled refugees has been reported, but the underlying prevalence in refugee populations is unknown.[11–15] Understanding the prevalence of T. solium infection could guide recommendations on evaluating and treating refugees before, during, and after resettlement.

During 2010, we used the classic enzyme-linked immunoelectrotransfer blot for lentil-lectin purified glycoprotein (EITB LLGP) to measure the seroprevalence of antibodies against T. solium cysts among several refugee populations resettled to the United States in previous years. We present the results, discuss clinical and public health implications, and suggest topics for further research.