Taenia solium Cysticercosis: The Case of Cuba

Cysticercosis is a neglected zoonotic disease attributable to infection with the metacestode larval stage of the tapeworm Taenia solium. Humans are the sole final hosts, carrying the adult tapeworm in the intestine (taeniosis). Pigs are the main intermediate host, but humans also may accidentally get infected through the ingestion of T. solium eggs (shed in human feces) that later develop into oncospheres. When cyst formation occurs in the brain, the disease is called neurocysticercosis (NCC), which is increasingly recognized as the leading cause of epilepsy in large parts of Africa, Asia, and Latin America [1]. Cysticercosis is a poverty-associated disease, and its burden is known to be substantial in the Latin American continent [2–4]. On the other hand, based on limited numbers and often outdated reports, cysticercosis does not seem to be a common disease in the Caribbean [5], with the exception of Haiti, where several case reports have been published in the past decades [6,7]. Also, a recently conducted cross-sectional serological survey in Port-au-Prince revealed prevalences of cysticercal antibodies of 2.8% (6/216) in healthy adults [8], which is comparable to those found in some Latin American and African countries. Here, we compiled the available information on cysticercosis/ taeniosis in Cuba and supplemented this with data from a recently conducted survey on NCC in patients with epilepsy in order to evaluate the importance of Taenia solium cysticercosis in the country. A literature search was conducted in the MEDLINE, PUBMED, LILACS (Latin American and Caribbean Health Science database, http://lilacs.bvsalud.org/en/), and CUMED databases with the keywords Taenia solium, cysticercosis, Cuba, and neurocysticercosis on October 15, 2012. In addition, references of retrieved reports were checked for additional information. The outcome is summarized in Table 1. Only a few case reports exist, and two dedicated surveys, spread over a period of more than 70 years. A case report from 1984 describes the identification of a T. solium tapeworm upon treatment of a Cuban man who had recently travelled to Angola [9]. The first case report on human cysticercosis dates from 1901 and is considered the first report ever on the disease for Mexico and Cuba. The author describes the history of a Cuban patient who died in a psychiatric asylum in Mexico and multiple cysts were found during autopsy [10]. Since then, only four additional case reports have been published: two in 1967 [11] and three more than twenty years thereafter, one in 1989 [12] and two in 1991 [13]. In most cases, cysticercosis was confirmed by histopathology (Table 1). In 1999, a retrospective study reviewed clinical cases of patients admitted to the Instituto de Neurologı́a y Neurocirugı́a in Havana (INNH, which is the reference centre for epilepsy in Cuba) between 1964 and 1989, in search of patients diagnosed with NCC [14]. Only five patients with confirmed NCC were identified out of the 33,424 admissions over 25 years. Three of the patients were foreigners, and there was evidence that the two Cuban patients had acquired the disease abroad. The authors concluded that cysticercosis was absent in Cuba. This was followed by a reply a few years later [15], urging not to rush to such firm conclusions. The authors stated that NCC was not absent in Cuba, but very rare, and referred to their earlier case reports [11–13]. They also mentioned the habit of pork consumption in the country, and emphasized the need for continuous education to prevent disease transmission. The last published study on cysticercosis in Cuba is a serological survey conducted in 2001. The presence of T. solium cysticercal antibodies was assessed in the cerebrospinal fluid of 384 children who had attended the emergency ward of a hospital because of seizures. None of them was found positive [16]. However, the origin of the seizures and the epidemiological antecedents of the children were unknown, and little is known about the sensitivity and specificity of the diagnostic assay used. National surveys on intestinal helminth infections detected no or only few Taenia spp. eggs (reviewed by [17]). The most recent survey conducted in 2009 detected only six cases infected with Taenia spp out of the 5,850 individuals surveyed [18]. There are no reports on porcine cysticercosis in Cuba, and it has thus far never been detected in abattoir screenings (Dr. Mendez and Dr. Rafmari, Instituto de Medicina Veterinaria, personal communication). Recently, the INNH requested our assistance for the diagnosis of NCC in a group of patients with unknown causes of epilepsy. To this end, we combined two serological tests: 1) the detection of antibodies by enzyme immuno transfer blot (EITB), which is the gold standard for serodiagnosis of cysticercosis but does not allow differentiation between past and current infection; and 2) the detection of circulating cysticercal antigen by ELISA, which has a high sensitivity for the detection of viable and colloidal cysts [19]. The cohort consisted of 158 people with epilepsy (PWE), above five years of age, who attended the epilepsy consult in the period from January to July 2010 and