Seroprevalencia y factores de riesgo de cisticercosis en dos comunidades rurales del norte del estado Anzoátegui, Venezuela / Seroprevalence and risk factors of cysticercosis in two rural communities in Anzoátegui state, Venezuela

Resumen Introducción. La cisticercosis es causada por las larvas de Taenia solium, las cuales se localizan principalmente en el sistema nervioso central y causan neurocisticercosis. En Venezuela se han hecho pocos estudios epidemiológicos de esta enfermedad. Objetivo. Determinar la seroprevalencia y los factores de riesgo de la cisticercosis en dos comunidades rurales del estado Anzoátegui, Venezuela. Materiales y métodos. Se hizo una encuesta para recolectar datos sobre los posibles factores de riesgo y los signos y síntomas de la enfermedad, y se tomaron 182 muestras de los habitantes de las comunidades de Boquerón y Punto Lindo. Se determinaron los anticuerpos IgG contra cisticercos de T. solium mediante ensayo inmunoenzimático (ELISA). Resultados. En Boquerón, se presentó una seroprevalencia de 3,3 %; debido al bajo número de muestras positivas no se pudo hacer el análisis estadístico. Sin embargo, las tres personas positivas tenían conocimiento de la enfermedad, antecedentes de tenencia de cerdos no confinados, consumo de carne de cerdo semicruda y cefalea frecuente. En Punto Lindo, la seroprevalencia fue de 28,9 %. No hubo diferencias estadísticamente significativas en cuanto al sexo y la edad, sin embargo, se encontró mayor frecuencia en menores de 20 años. Con respecto a los factores de riesgo y los signos y síntomas, se encontró asociación significativa con el consumo de carne de cerdo semicruda (odds ratio, OR=18; IC95% 5,78-55,9), cefalea frecuente (OR=3,6; IC95% 1,15-11,4), convulsiones (OR=18,9; IC95% 2,15-166,5) y problemas de visión (OR=5,7; IC95% 2,13-15,34). Conclusión. Los resultados demostraron que había poca transmisión de cisticercosis en Boquerón, pero mucha en Punto Lindo, sobre todo en niños, lo cual sugeriría que se trata de transmisión reciente.

Abstract Introduction: Cysticercosis is caused by Taenia solium cysticerci, which are located mainly in the central nervous system causing neurocysticercosis. In Venezuela, few epidemiological studies on this disease have been conducted. Objective: To determine the seroprevalence and risk factors for cysticercosis in two rural communities in Anzoátegui state. Material and methods: We conducted a survey to collect data on possible risk factors and signs and symptoms of the disease, and we took 182 samples in two communities, Boquerón and Punto Lindo. Detection of IgG antibodies against T. solium cysticerci was performed by ELISA. Results: Seroprevalence in Boquerón was 3.3%; due to the low number of seropositives the statistical analysis was not possible. However, the three seropositive persons had knowledge of the disease, and a history of consumption of undercooked pork meat, and presence of headache. In Punto Lindo, seroprevalence was 28.9%. There were no significant differences by sex or age; however, we found more seropositives among individuals younger than 20 years. With regard to risk factors and signs and symptoms, significant associations were found with consumption of undercooked pork (OR=18; 95% CI: 5.78 to 55.9), headaches (OR=3.6; 95% CI: 1.15 to 11.4), seizures (OR=18.9; 95% CI: 2.15 to 166.5) and visual problems (OR=5.7; 95% CI: 2.13 to 15.34). Conclusions: The results showed low transmission of cysticercosis in Boquerón, and high in Punto Lindo, where the high prevalence in children suggests recent transmission.

Diagnóstico do complexo teníase-cisticercose bovina em São João Evangelista, Minas Gerais, Brasil / Diagnosis of Bovine Taeniasis-Cysticercosis Complex in São João Evangelista, Minas Gerais, Brazil

Com o objetivo de diagnosticar a situação do complexo teníase-cisticercose bovina em Minas Gerais, Brasil, foi selecionado o município de São João Evangelista, onde foram coletadas amostras de sangue de 339 bovinos em 15 propriedades rurais, sorteadas aleatoriamente. Em cada propriedade, foi aplicado um questionário socioeconômico para a análise de fatores que favorecem a manutenção do complexo teníase-cisticercose bovina. Foi realizado também o diagnóstico de teníase humana por meio de exame coproparasitológico dos habitantes das propriedades. Encontrou-se a prevalência de 4,1% para cisticercose bovina e a frequência de 2,94% para teníase humana. Entre os fatores de risco para a manutenção do complexo teníase-cisticercose analisados, foi observada uma relação estatisticamente significativa (P=0,042) entre a ocorrência de cisticercose bovina e a ingestão de carne malpassada pelos entrevistados. Concluiu-se que a cisticercose bovina está presente no município de São João Evangelista, MG, em índices considerados endêmicos, sendo o consumo de carne malpassada e não inspecionada o principal fator de risco para a manutenção do complexo teníase-cisticercose, o que reforça a necessidade da adoção de medidas de controle com contínua vigilância epidemiológica e sanitária.

In order to diagnose the situation of bovine taeniasis-cysticercosis complex in the state of Minas Gerais, Brazil, the city of São João Evangelista was selected, and blood samples were collected from 339 cattle in 15 randomly selected farms. A socioeconomic questionnaire was filled in each property for the analysis of the factors that favor the maintenance of the taeniasis-cysticercosis complex. Additionally, there was the diagnosis of human taeniasis verified by stool examinations of the properties' inhabitants. A prevalence of 4.1% for bovine cysticercosis and the frequency of 2.94% for human taeniasis were found. Among the risk factors, a statistically significant relation (p = 0.042) was found between the occurrence of bovine cysticercosis and the ingestion of undercooked meat. It was concluded that bovine cysticercosis is broadly distributed in the city of São João Evangelista, with rates considered endemic, being the consumption of raw and not-inspected meat the main risk factors for the maintenance of complex taeniasis-cysticercosis, reinforcing the need to adopt control measures with continuous epidemiological and health surveillance.

Evaluación del impacto de un programa de control de la teniasis-cisticercosis (Taenia solium) / Evaluation of the impact of a control program against taeniasis-cysticercosis (Taenia solium)

Objetivo. Evaluar el impacto de un programa de control de la teniasis-cisticercosis por Taenia solium con fines de erradicación, basado en educación de la comunidad y vacunación de cerdos. Material y métodos. Se estimó la prevalencia de cisticercosis porcina por medio de la palpación de lengua, ultrasonido y presencia de anticuerpos en suero, antes de iniciar el programa y tres años después, en tres regiones del estado de Guerrero. Resultados. Se observó una reducción significativa en la prevalencia de cisticercosis porcina de 7 a 0.5% y de 3.6 a 0.3%, estimadas por examen de lengua y ultrasonido, respectivamente (p<0.01), y una disminución no significativa de la seroprevalencia de 17.7 a 13.3%. Conclusiones. La reducción de la prevalencia de teniasis-cisticercosis comprueba la efectividad del programa para prevenir la infección. La presencia sostenida de anticuerpos es compatible con continuos contactos con Taenia solium u otros helmintos relacionados, y señala la necesidad de mantener las intervenciones para lograr su erradicación.

Objetive. The impact of a control program is evaluated to eventually eradicate taeniasis-cysticercosis (Taenia solium) based on education and vaccination of pigs. Materials and methods. The prevalence of porcine cysticercosis was estimated using tongue inspection, ultrasound and determination of antibodies, before and three years after the application in three regions of the state of Guerrero. Results. A significant reduction in the prevalence of porcine cysticercosis of 7 to 0.5% and 3.6 to 0.3% estimated by tongue examination or ultrasound respectively (p<0.01) and a no significant decrease in seroprevalence from 17.7 to 13.3% were observed. Conclusions. The reduction of the prevalence of taeniasis-cysticercosis establishes the program's effectiveness in preventing infection. The sustained presence of antibodies, compatible with contact of Taenia solium or other related helminths, underlines the importance of maintaining interventions to achieve eradication.

Rattus norvegicus como indicador de la circulación de Capillaria hepatica y Taenia taeniaeformis en la Plaza Minorista de Medellín, Colombia / Rattus norvegicus as an indicator of circulation of Capillaria hepatica and Taenia taeniaeformis on a groceries trade center of Medellín, Colombia

Introducción. Rattus norvegicus cumple un papel epidemiológico en el mantenimiento y dispersión de agentes zoonóticos bacterianos, virales y parasitarios de interés en salud pública. La presencia de infección por helmintos en especies Rattus cercanas a poblaciones expuestas en condiciones ambientales propicias, puede convertirse en un factor de riesgo de transmisión. Objetivo. Reportar la frecuencia de infección con Capillaria hepatica y formas larvarias de Taenia taeniaeformis en ratas silvestres (R. norvegicus) capturadas en una zona urbana de Medellín. Materiales y métodos. Se capturaron 254 ejemplares de R. norvegicus. Los hígados de 54 ejemplares que presentaron lesión hepática macroscópica durante la necropsia, fueron examinados por histopatología convencional. Resultados. La frecuencia de infección por C. hepatica fue de 20,1 % (51/254). Seis hígados fueron también positivos para larvas de T. taeniaeformis con una frecuencia de 2,4 % (6/254). Los hígados infestados con C. hepatica exhibían parásitos en el estadio adulto o juvenil y huevos ovalados con opérculos bipolares, asociados con hepatitis granulomatosa leve a moderada multifocal y acompañada por infiltrado leucocitario. Se observaron lesiones granulomatosas en resolución y fibrosis residual o calcificada que contenía huevos. Donde se encontraron cisticercos de T. taeniaeformis, el hallazgo más frecuente fueron quistes hepáticos que contenían larvas, y lesiones inflamatorias y fibróticas. Conclusión. Estos resultados indican que helmintos de potencial zoonótico circulan en R. norvegicus de ambientes urbanos. Debe investigarse la verdadera distribución de estos parásitos, para determinar el riesgo potencial que corren las poblaciones animales y humanas expuestas a adquirir este tipo de infecciones.

Introduction. Rattus norvegicus, the Norway rat, plays a pivotal role in the maintenance and spread of several zoonotic bacterial, viral and parasitic pathogens of public health interest. The presence of helminthic infections near susceptible human populations can, under appropriate environmental conditions, become a risk factor for their transmission. Objective. Frequencies of infection were reported for Capillaria hepatica and larval forms of Taenia taeniaeformis in wild rats (R. norvegicus) captured in an urban area. Materials and methods. Two hundred and fifty-four adult specimens of R. norvegicus were collected in an urban zone of Medellín, Colombia. The livers of 54 specimens that showed macroscopic hepatic lesions during necropsy were examined by conventional histopathology. Results. The frequency of infestation with C. hepatica was 20.1% (51/254). Six livers (2.4%) were also positive for larvae of T. taeniaeformis. Livers infested with C. hepatica exhibited adult or juvenile parasites and oval eggs with bipolar opercula, and were associated with mild to moderate multifocal granulomatous hepatitis with leucocyte infiltrate. Granulomatous lesions and calcified residual fibroses were found with eggs but without adult parasites. Those animals with cysticerci of T. taeniaeformis showed a high frequency of hepatic cysts containing larvae as well as inflammed and fibrotic lesions. Conclusion. Zoonotic helminths circulate at high frequency in R. norvegicus that occur in urban environments. Further research about the distribution of these parasites will determine the level of health threat they present for susceptible human and domestic animal populations.

Cenurose em ovinos no sul do Brasil: 16 casos / Coenurosis of sheep in southern Brazil: 16 cases

Neste trabalho são descritos casos de doença neurológica causada por Coenurus cerebralis em 16 ovinos provenientes de nove propriedades rurais do Rio Grande do Sul. Os casos ocorreram entre janeiro de 1990 e dezembro de 2006. A evolução clínica variou de 30-90 dias e os ovinos afetados apresentavam depressão (9/16), isolamento do rebanho (8/16), andar cambaleante (7/16), cegueira (4/16), desvio da cabeça (3/16), incoordenação (3/16), movimentos de pedalagem (2/16), quedas (2/16), andar em círculos, deficiência proprioceptiva nos membros torácicos e pélvicos, estrabismo, midríase, opistótono, tremores e rigidez dos membros (1/16 cada). Os achados macroscópicos foram restritos ao sistema nervoso central e caracterizados por cistos de 2 a 9cm de diâmetro preenchidos por líquido translúcido e revestidos por fina membrana. Na parte interna da membrana, havia numerosas estruturas levemente alongadas e brancas de aproximadamente 1mm de diâmetro (escólices). Na maioria dos ovinos, os cistos eram localizados no telencéfalo (12/16); em três, os cistos estavam no cerebelo e em um ovino havia um cisto no cerebelo e um na medula espinhal. Em todos os casos havia acentuada compressão e deslocamento do tecido nervoso adjacente aos cistos. Histologicamente, os cistos parasitários eram formados por dupla membrana fracamente eosinofílica da qual evaginavam múltiplos escólices esféricos acelomados. Adjacente à parede da vesícula eram observadas sucessivas camadas compostas por uma zona de necrose e mineralização, circundadas por infiltrado inflamatório composto por macrófagos epitelióides e células gigantes multinucleadas, com uma cápsula externa de tecido fibrovascular e infiltrado inflamatório linfoistioplasmocitário perivascular. Adicionalmente, havia compressão e atrofia das substâncias branca e cinzenta adjacentes. O diagnóstico de cenurose foi realizado com base nos achados epidemiológicos, clínicos e macroscópicos, e confirmado pela histopatologia.

Sixteen cases of neurologic disease caused by Coenurus cerebralis occurring in sheep from nine farms in Rio Grande do Sul, Brazil, from January 1990 to December 2006, are described. Clinical courses varied from 30 to 90 days and affected sheep developed depression (9/16), isolation from the herd (8/16), staggering (7/16), blindness (4/16), head tilt (3/16), incoordination (3/16), paddling (2/16), falls (2/16), circling, proprioceptive deficits in fore and hindlimbs, strabismus, mydriasis, opisthotonus, trembling and rigidity of the limbs (1/16 each one). Macroscopic findings were restricted to central nervous system and consisted of 2 to 9cm fluid filled cysts with numerous slightly elongated 1 mm white scolices attached to the inner wall surface of the capsule. Cysts were located in the telencephalon (12/16); in the cerebellum (3 sheep); and in the cerebellum and spinal cord (1 sheep). All cases showed severe compression and displacement of the adjacent nervous tissue. Histologically, the cyst walls were characterized by a thin walled eosinophilic vesicle in which evaginated multiple spherical acelomated scolices. The cyst wall was surrounded by successive layers consisting of an internal necrotic and mineralized band, a layer of epithelioid macrophages with abundant number of multinucleated giant cell and an external fibrovascular capsule with perivascular lymphohistioplasmacytic infiltrate. Adjacent white and gray matter were compressed and atrophied. The diagnosis was based on epidemiologic, clinical and pathologic findings and confirmed by histopathology.

Taeniasis-cysticercosis in Southern Ecuador: assessment of infection status using multiple laboratory diagnostic tools

Taenia solium-taeniasis and cysticercosis were studied in the human and porcine populations of a rural community in the Southern Ecuadorian Andes. From the 1059 inhabitants, 800 serum samples and 958 stool samples could be collected. In addition, 646 from the estimated 1148 pigs were tongue inspected. Circulating antigen was detected by enzyme linked immunosorbent assay (Ag-ELISA) in 2.25 percent of the human population, whereas intestinal taeniasis was detected in 1.46 percent by the formalin-ether technique. Following treatment and recovery of tapeworm fragments these were all identified as T. solium. Porcine cysticercosis was diagnosed in 3.56 percent of the pigs by tongue inspection. In addition, enzyme linked immunoelectrotransfer blot (EITB) was performed on a subset group of 100 humans to confirm the results of the Ag-ELISA. One hundred serum samples from pigs were also analysed by EITB. It appeared that 43 and 74 percent of humans and pigs had antibodies against T. solium cysticerci, respectively. It is concluded that contrary to the high exposure of the human population to T. solium that is suggested by EITB, the number of active cysticercosis cases, diagnosed by Ag-ELISA, was low, which may indicate endemic stability. The further use of complementary diagnostic methods for a better understanding of the epidemiology of T. solium is suggested.

La teniosis y cisticercosis por Taenia solium / Taeniosis and cysticercosis due to Taenia solium

La teniosis y la cisticercosis ocasionadas por Taenia solium son problemas de salud pública que prevalecen tanto en áreas urbanas como rurales, donde se asocian a las prácticas tradicionales de crianza de cerdos, malas condiciones sanitarias e higiénicas, ignorancia y pobreza. La cisticercosis se encuentra en Africa, Asia y Latinoamérica; en particular, México y Brasil son los países que informan las frecuencias más altas.12 La contribución que tiene la cisticercosis humana en las tasas de morbilidad y mortalidad es resultado del desarrollo del cisticerco en el sistema nervioso central (SNC), lo que frecuentemente causa discapacidad física y en ocasiones la muerte.1-5 Se ha sugerido que la principal consecuencia de la teniosis en la salud es la desnutrición, aunque aún no se ha demostrado en forma concluyente como con otras parasitosis

Aspectos epidemiológicos da teníase-cisticercose na área endêmica de Lagamar, MG / Epidemiological aspects of cysticercosis due to Taenia solium in the endemic area of Lagamar, MG

An epidemiological inquiry of humancysticercosis due to Taenia solium was carried out in Lagamar, Minas Gerais State, Brazil, in 1992. A survey of 1109 houses with 3344 inhabitants was made. The inquiry included 875 (86 per cent) families and the questionnaire was answered by an informer, who was the father in 80 per cent of the cases. One hundred pigsties, sheltering 406 swines in extremely precarious conditions, were found in 100 (11.4 per cent) houses. A history on taeniasis in some member of the family was verified in 300 (34.2 per cent) houses. A history of seizures was referred to by 125 (14.2 per cent) of families. The outset of convulsion in adult age was characterized in 39 (37.8 per cent) families. A history of mental disorder was reported in 53 (6.0 per cent) of houses. Stool examinations were positive for Taenia spp in 24 (1.3 per cent) of samples examined per cent.