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1.
Vet Parasitol Reg Stud Reports ; 23: 100533, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33678386

RESUMEN

Toxoplasma gondii is an important foodborne pathogen worldwide, with undercooked meat as the main source of human transmission. In this study, we determined the seroprevalence of T. gondii in free-range pigs from two adjacent villages in the Tumbes region of northern Peru, El Tutumo and Nuevo Progreso. We randomly selected 100 pig serum samples collected during a prior study and processed these using Western Blot to detect IgG anti-T. gondii antibodies. Results indicated a prevalence of 32% (32/100) to T. gondii in pigs. Free-ranging pigs from northern Peru represent a substantial risk for transmission of T. gondii to humans.

2.
Am J Trop Med Hyg ; 103(3): 1125-1128, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32602434

RESUMEN

Subarachnoid neurocysticercosis (SANCC) is a severe and progressive brain infection with Taenia solium. We performed a pilot study of noninvasive screening for SANCC in two endemic villages in northern Peru using a urine antigen screen followed by brain magnetic resonance imaging for participants with elevated levels of antigen. Among the 978 participants screened, we identified eight individuals with SANCC, many of whom were asymptomatic. This represents a minimum prevalence of 0.8% of SANCC, a level higher than expected based on prior studies, and a positive predictive value of 62% for our novel urine screening test. Future studies should confirm whether early detection and management improve clinical outcomes.


Asunto(s)
Antígenos Helmínticos/orina , Neurocisticercosis/diagnóstico por imagen , Espacio Subaracnoideo/inmunología , Taenia solium/inmunología , Teniasis/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Enfermedades Asintomáticas , Encéfalo/diagnóstico por imagen , Encéfalo/parasitología , Niño , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neurocisticercosis/epidemiología , Neurocisticercosis/parasitología , Perú/epidemiología , Proyectos Piloto , Teniasis/epidemiología , Teniasis/parasitología , Adulto Joven
3.
Parasit Vectors ; 13(1): 372, 2020 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-32709250

RESUMEN

BACKGROUND: The pork tapeworm, Taenia solium, is a serious public health problem in rural low-resource areas of Latin America, Africa and Asia, where the associated conditions of nuerocysticercosis (NCC) and porcine cysticercosis cause substantial health and economic harms. An accurate and validated transmission model for T. solium would serve as an important new tool for control and elimination, as it would allow for comparison of available intervention strategies, and prioritization of the most effective strategies for control and elimination efforts. METHODS: We developed a spatially-explicit agent-based model (ABM) for T. solium ("CystiAgent") that differs from prior T. solium models by including a spatial framework and behavioral parameters such as pig roaming, open human defecation, and human travel. In this article, we introduce the structure and function of the model, describe the data sources used to parameterize the model, and apply sensitivity analyses (Latin hypercube sampling-partial rank correlation coefficient (LHS-PRCC)) to evaluate model parameters. RESULTS: LHS-PRCC analysis of CystiAgent found that the parameters with the greatest impact on model uncertainty were the roaming range of pigs, the infectious duration of human taeniasis, use of latrines, and the set of "tuning" parameters defining the probabilities of infection in humans and pigs given exposure to T. solium. CONCLUSIONS: CystiAgent is a novel ABM that has the ability to model spatial and behavioral features of T. solium transmission not available in other models. There is a small set of impactful model parameters that contribute uncertainty to the model and may impact the accuracy of model projections. Field and laboratory studies to better understand these key components of transmission may help reduce uncertainty, while current applications of CystiAgent may consider calibration of these parameters to improve model performance. These results will ultimately allow for improved interpretation of model validation results, and usage of the model to compare available control and elimination strategies for T. solium.

4.
Clin Infect Dis ; 2020 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-32556276

RESUMEN

BACKGROUND: Neurocysticercosis (NCC) is a major cause of acquired epilepsy in most of the world. Larval cysts in the human brain eventually resolve and either disappear or leave a calcified scar that is associated with seizures. This study assessed the proportion of residual calcification in parenchymal NCC, and defined risk factors associated with calcification. METHODS: Data from 220 patients with parenchymal NCC from three randomized trials of antiparasitic treatment was assessed to determine what proportion of the cysts that resolved six months after antiparasitic treatment ended up in a residual calcification at one year. Also, we evaluated the risk factors associated with residual calcification. A multilevel Poisson regression model was used to estimate the risks of calcification. RESULTS: The overall proportion of calcification was 38% (188/497 cysts, from 147 patients). Predictors for calcification at the cyst level were cysts larger than 14 mm (RR 1.34; 95% C.I. 1.02-1.75), and cysts with edema at baseline (RR 1.39; 95% C.I. 1.05-1.85). At the patient level, having had more than 24 months with seizures (RR: 1.25, 95% C.I. 1.08-1.46), mild antibody response (RR: 1.14; 95% C.I. 1.002-1.27), increased dose albendazole regime (RR: 1.26; 95% C.I. 1.14-1.39), lower doses of concomitant dexamethasone (RR: 1.36; 95% C.I. 1.02-1.81), not receiving early antiparasitic re-treatment (RR: 1.45; 1.08-1.93), or complete cure (RR: 1.48; 1.29-1.71). CONCLUSIONS/SIGNIFICANCE: Approximately 38% of parenchymal cysts calcify after antiparasitic treatment. Some factors associated to calcification are modifiable and may be approached to decrease or avoid calcification, potentially decreasing the risk for seizure relapses.

5.
PLoS Negl Trop Dis ; 13(10): e0007746, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31589612

RESUMEN

We developed a novel and portable fluorescent sensor that integrates a lateral flow assay with a quantum dot (Qdots) label and a mobile phone reader for detection of specific antibodies in human serum. We evaluated the utility of this assay to test for antibodies to the Taenia solium rT24H antigen. It was a retrospective study by examining 112 positive human sera from patients with neurocysticercosis (NCC) including samples from patients with single viable cyst (n = 18), two or more viable cysts (n = 71), and subarachnoid (racemose) cysts (n = 23). These samples were collected from previous study subjects in Lima, Peru under an approved study protocol in Peru. The sera were made anonymous under a protocol approved by the CDC Institutional Review Board. Definitive diagnosis of the subject was established by computed-tomography and/or magnetic resonance imaging. To test the specificity of the assay, we evaluated a panel of serum samples obtained from patients with other infections (n = 24), and serum samples from persons in the United States and Egypt who had not traveled outside their country, and therefore are presumed negative for cysticercosis (n = 128). The assay specificity in the negative panel was 99% (95-100%) while assay sensitivity was 89% (79-95%) in NCC patients with two or more viable cysts. Our assay has performance characteristics similar to those of traditional platforms for the detection of NCC and shows promise as a mobile phone reader-based point-of-care test for antibody detection.


Asunto(s)
Anticuerpos Antihelmínticos/sangre , Formación de Anticuerpos , Teléfono Celular , Pruebas Inmunológicas/métodos , Neurocisticercosis/diagnóstico , Pruebas en el Punto de Atención , Puntos Cuánticos , Animales , Antígenos Helmínticos/inmunología , Cisticercosis , Estudios de Factibilidad , Humanos , Imagen por Resonancia Magnética , Neurocisticercosis/inmunología , Estudios Retrospectivos , Sensibilidad y Especificidad , Taenia solium
6.
Parasit Vectors ; 12(1): 352, 2019 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-31311596

RESUMEN

BACKGROUND: Taenia solium (cysticercosis) is a parasitic cestode that is endemic in rural populations where open defecation is common and free-roaming pigs have access to human feces. The purpose of this study was to examine the roaming patterns of free-range pigs, and identify areas where T. solium transmission could occur via contact with human feces. We did this by using GPS trackers to log the movement of 108 pigs in three villages of northern Peru. Pigs were tracked for approximately six days each and tracking was repeated in the rainy and dry seasons. Maps of pig ranges were analyzed for size, distance from home, land type and contact with human defecation sites, which were assessed in a community-wide defecation survey. RESULTS: Consistent with prior GPS studies and spatial analyses, we found that the majority of pigs remained close to home during the tracking period and had contact with human feces in their home areas: pigs spent a median of 79% (IQR: 61-90%) of their active roaming time within 50 m of their homes and a median of 60% of their contact with open defecation within 100 m of home. Extended away-from-home roaming was predominately observed during the rainy season; overall, home range areas were 61% larger during the rainy season compared to the dry season (95% CI: 41-73%). Both home range size and contact with open defecation sites showed substantial variation between villages, and contact with open defecation sites was more frequent among pigs with larger home ranges and pigs living in higher density areas of their village. CONCLUSIONS: Our study builds upon prior work showing that pigs predominately roam and have contact with human feces within 50-100 m of the home, and that T. solium transmission is most likely to occur in these concentrated areas of contact. This finding, therefore, supports control strategies that target treatment resources to these areas of increased transmission. Our finding of a seasonal trend in roaming ranges may be useful for control programs relying on pig interventions, and in the field of transmission modeling, which require precise estimates of pig behavior and risk.


Asunto(s)
Cisticercosis/veterinaria , Defecación , Heces/parasitología , Estaciones del Año , Enfermedades de los Porcinos/transmisión , Animales , Conducta Animal , Cisticercosis/epidemiología , Cisticercosis/transmisión , Femenino , Sistemas de Información Geográfica , Humanos , Masculino , Movimiento , Perú/epidemiología , Factores de Riesgo , Población Rural , Análisis Espacial , Porcinos/parasitología , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/parasitología , Taenia solium/aislamiento & purificación
7.
Am J Trop Med Hyg ; 100(6): 1490-1493, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30938282

RESUMEN

Cysticercosis, caused by Taenia solium, is a neglected disease that causes preventable epilepsy. We conducted an experiential learning workshop in northern Peru to educate community members on T. solium transmission and motivate participation in community-led prevention and control. The workshop included presentation of local economic and epidemiologic data, followed by hands-on participation in pig dissection, group discussion of the T. solium life cycle, and viewing of eggs and nascent tapeworms with light microscopes. Among heads of household, we used community survey data to compare knowledge of the three-stage parasite life cycle at baseline and 2 months postworkshop. Knowledge of the life cycle increased significantly after the workshop, with greater gains for workshop attendees than non-attendees. Prior knowledge and workshop attendance were significant predictors of postworkshop knowledge. The use of local evidence and experiential learning positively affected knowledge of T. solium transmission, laying the foundation for subsequent community-engaged control efforts.


Asunto(s)
Cisticercosis/patología , Cisticercosis/parasitología , Educación en Salud , Enfermedades de los Porcinos/parasitología , Taenia solium , Animales , Niño , Femenino , Humanos , Masculino , Población Rural , Porcinos , Zoonosis
8.
Parasit Vectors ; 12(1): 57, 2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30678700

RESUMEN

BACKGROUND: Taenia solium is an important zoonotic parasite that infects humans as definitive host (taeniasis) and pigs as intermediate host (cysticercosis). Serological diagnosis of porcine cysticercosis is limited to antigen detection using ELISA, which is known to cross-react with other Taenia species, and antibody detection using the lentil-lectin glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP EITB), which has not been adequately evaluated for cross-reactivity to other parasites. Field studies suggest that the GP50 diagnostic band of the LLGP EITB may cross-react to Taenia hydatigena, a common non-zoonotic parasitic infection of pigs. The objective of this study was to evaluate the specificity of the LLGP EITB assay in pigs infected experimentally with T. hydatigena and Echinococcus granulosus. RESULTS: Twelve three-month-old seronegative were divided into two groups; six were each given an oral challenge with a single gravid proglottid of T. hydatigena and the other six were each given an oral challenge with 50 gravid proglottids of E. granulosus. Serum samples were collected biweekly until 14 weeks when all pigs underwent a detailed necropsy. Taenia hydatigena cysticerci were found in two of six pigs from the first group. Four T. hydatigena-exposed pigs were seropositive at the GP50-band only on EITB LLGP; two of these had cysts at necropsy while no seronegative pigs had cysts. One E. granulosus-exposed pig was positive to EITB LLGP, again with reactivity only to GP50; all six pigs had hepatic echinococcosis on necropsy. CONCLUSION: These results provide definitive evidence that the GP50 diagnostic band in pigs cross-reacts with T. hydatigena. Evidence of cross-reaction with E. granulosus was not conclusive.


Asunto(s)
Antígenos Helmínticos/inmunología , Equinococosis/veterinaria , Echinococcus granulosus/inmunología , Immunoblotting/veterinaria , Enfermedades de los Porcinos/diagnóstico , Taenia/inmunología , Teniasis/veterinaria , Animales , Reacciones Cruzadas , Equinococosis/diagnóstico , Equinococosis/inmunología , Epítopos , Proteínas del Helminto/inmunología , Immunoblotting/métodos , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/parasitología , Teniasis/diagnóstico , Teniasis/inmunología
9.
Am J Trop Med Hyg ; 100(2): 314-322, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30560769

RESUMEN

The pork tapeworm, Taenia solium, is among the leading causes of preventable epilepsy in the world and is common in rural areas of developing countries where sanitation is limited and pigs have access to human feces. Prior studies in rural villages of Peru have observed clusters of T. solium cysticercosis among pigs that live near human tapeworm carriers. Such spatial analyses, however, have been limited by incomplete participation and substandard diagnostic tests. In this study, we evaluated the association between necropsy-confirmed cysticercosis in pigs and their distance to T. solium tapeworm carriers in six villages in northern Peru. A total of six (1.4%) tapeworm carriers were detected using copro-antigen enzyme-linked immunosorbent assay and seven of 10 (70%) pigs belonging to the tapeworm carriers were found with viable cyst infection on necropsy. This was significantly greater than the prevalence of viable cyst infection among pigs living < 500 m (11%) and > 500 m (0.5%) from a tapeworm carrier (P < 0.001 for distance trend). Similar statistically significant prevalence gradients were observed after adjustment for possible confounders and for other pig-level outcomes including infection with > 10 viable cysts, degenerated cyst infection, and serological outcomes. This investigation confirms that porcine cysticercosis clusters strongly around tapeworm carriers in endemic rural regions of northern Peru and supports interventions that target these hotspots.


Asunto(s)
Anticuerpos Antihelmínticos/sangre , Cisticercosis/epidemiología , Enfermedades de los Porcinos/epidemiología , Taenia solium/inmunología , Adulto , Animales , Autopsia , Análisis por Conglomerados , Cisticercosis/inmunología , Cisticercosis/transmisión , Heces/parasitología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Perú/epidemiología , Prevalencia , Población Rural , Análisis Espacial , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/transmisión , Taenia solium/aislamiento & purificación
10.
Am J Trop Med Hyg ; 100(1): 140-142, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30457096

RESUMEN

Reintroduction of Taenia solium into a region in Peru where it had been eliminated prompted evaluation of the possibility of reintroduction from an urban reservoir of taeniasis. In a cross-sectional study of an adjacent urban area, we found low prevalence of taeniasis (4/1,621; 0.25%), suggesting minimal risk of parasite reintroduction into rural areas through this route.


Asunto(s)
Neurocisticercosis/epidemiología , Teniasis/epidemiología , Población Urbana , Adulto , Anciano , Animales , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Perú/epidemiología , Prevalencia , Factores de Riesgo , Taenia solium/aislamiento & purificación , Teniasis/complicaciones , Teniasis/transmisión , Adulto Joven
11.
J Clin Microbiol ; 56(9)2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29875195

RESUMEN

Neurocysticercosis accounts for approximately 30% of all epilepsy cases in most developing countries. The immunodiagnosis of cysticercosis is complex and strongly influenced by the course of infection, the disease burden, the cyst location, and the immune response of the host. The main approach to immunodiagnosis should thus be to evaluate whether the serological results are consistent with the diagnosis suggested by imaging. Antibody detection is performed using lentil lectin-purified parasite antigens in an enzyme-linked immunoelectrotransfer blot format, while antigen detection uses a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Promising new assay configurations have been developed for the detection of both antibody and antigen, including assays based on synthetic or recombinant antigens that may reduce costs and improve assay reproducibility and multiplex bead-based assays that may provide simultaneous quantitative results for several target antigens or antibodies.


Asunto(s)
Cysticercus/inmunología , Inmunoensayo , Pruebas Inmunológicas , Neurocisticercosis/diagnóstico , Taenia solium/inmunología , Animales , Anticuerpos Antihelmínticos/sangre , Anticuerpos Antihelmínticos/líquido cefalorraquídeo , Anticuerpos Antihelmínticos/inmunología , Antígenos Helmínticos/sangre , Antígenos Helmínticos/inmunología , Cysticercus/aislamiento & purificación , Humanos , Neurocisticercosis/parasitología , Neurocisticercosis/patología , Reproducibilidad de los Resultados , Taenia solium/aislamiento & purificación
12.
Rev Peru Med Exp Salud Publica ; 35(1): 132-138, 2018.
Artículo en Español, Inglés | MEDLINE | ID: mdl-29924259

RESUMEN

Neurocysticercosis is a nervous system infection caused by the larvae (cysticercus) of the pork tapeworm (Taenia solium). Neurocysticercosis is the primary cause of acquired epilepsy worldwide and, therefore, a global public health problem. On the other hand, T. solium taeniasis/cysticercosis is one of very few infectious diseases considered to be potentially eradicable. Recently, a large-scale elimination program in Tumbes, Peru, demonstrated the feasibility of interrupting transmission. Based on these advances, a series of initial guidelines are proposed aimed at setting out the foundations for regional and national taeniasis/cysticercosis control programs, with simple and feasible local interventions as a starting point.


Asunto(s)
Cisticercosis/prevención & control , Teniasis/prevención & control , Cisticercosis/epidemiología , Humanos , Perú/epidemiología , Guías de Práctica Clínica como Asunto , Teniasis/epidemiología
13.
Am J Trop Med Hyg ; 98(6): 1748-1754, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29663901

RESUMEN

Infection of the brain with Taenia solium larvae (neurocysticercosis) is a leading cause of preventable epilepsy worldwide. Effective and sustainable strategies to control parasite transmission in rural endemic communities are needed to prevent the disease. Surveillance and targeted intervention around infected pigs (ring control strategy) have been shown to be effective when carried out by research teams. However, this strategy has not been implemented or tested as a community-based program. In this small trial in northern Peru, eight villages were randomly assigned to community-led surveillance and treatment (five villages, 997 residents) or control (three villages, 1,192 residents). In intervention villages, community-led surveillance and reporting were promoted by community health workers, radio advertisement, and school and household education. Each suspected pig infection was verified, with confirmed cases resulting in treatment with niclosamide for taeniasis and oxfendazole for pigs in clusters of homes nearby. No incentives beyond human and pig treatment were offered. Control villages received basic disease education but no treatment intervention in response to reports. Despite 14 case reports, community-based replication of ring control strategy did not replicate prior results. After 12 months, there was no change in seroincidence in intervention villages between the baseline and study end, and no difference compared with control villages. There was no difference in prevalence of taeniasis or porcine cysticercosis at study end. Community members described lack of knowledge as the main reason for not reporting infected pigs. Further exploration of methods to transfer ring strategy and other control interventions for cysticercosis to the community is needed.


Asunto(s)
Cisticercosis/epidemiología , Enfermedades Endémicas , Enfermedades de los Porcinos/epidemiología , Taenia solium/aislamiento & purificación , Animales , Agentes Comunitarios de Salud , Cisticercosis/parasitología , Cisticercosis/transmisión , Cysticercus/aislamiento & purificación , Notificación de Enfermedades , Femenino , Humanos , Masculino , Tamizaje Masivo , Perú/epidemiología , Proyectos Piloto , Prevalencia , Estudios Prospectivos , Población Rural , Porcinos , Enfermedades de los Porcinos/parasitología , Enfermedades de los Porcinos/transmisión , Zoonosis
14.
Rev. peru. med. exp. salud publica ; 35(1): 132-138, ene.-mar. 2018. tab
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1020770

RESUMEN

La neurocisticercosis es la infección del sistema nervioso por la larva (cisticerco) de la tenia del cerdo (Taenia solium). La neurocisticercosis es la mayor causa de epilepsia adquirida a nivel mundial y por ende un problema de salud pública global. De otro lado, la teniasis/cisticercosis por T. solium es una de las pocas infecciones consideradas potencialmente erradicables. Recientemente, un programa de eliminación de transmisión a gran escala en Tumbes, Perú, demostró la factibilidad de interrumpir la transmisión. Sobre la base de estos avances, se proponen una serie de lineamientos iniciales para poner las bases de programas de control regionales y nacionales de la teniasis/cisticercosis, partiendo de intervenciones simples y factibles a nivel local.


Neurocysticercosis is a nervous system infection caused by the larvae (cysticercus) of the pork tapeworm (Taenia solium). Neurocysticercosis is the primary cause of acquired epilepsy worldwide and, therefore, a global public health problem. On the other hand, T. solium taeniasis/cysticercosis is one of very few infectious diseases considered to be potentially eradicable. Recently, a large-scale elimination program in Tumbes, Peru, demonstrated the feasibility of interrupting transmission. Based on these advances, a series of initial guidelines are proposed aimed at setting out the foundations for regional and national taeniasis/cysticercosis control programs, with simple and feasible local interventions as a starting point.

15.
Am J Trop Med Hyg ; 98(3): 776-778, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29260655

RESUMEN

Taenia solium cysticercosis is difficult to eliminate without interventions or societal development. Atahualpa is a rural Ecuadorian village with documented low migration rate, where domestic pig raising is common and human cysticercosis is endemic. To assess neurocysticercosis (NCC) prevalence, 1,273 villagers aged ≥ 20 years underwent neuroimaging studies, which showed calcified lesions in 121 (9.5%) individuals, but no active disease. Likewise, positive reactions, apparently nonspecific, were found in only 3/200 subjects by the use of a monoclonal antibody-based enzyme-linked immunosorbent assay to detect T. solium antigens in urine. Only 2/418 pigs reacted to three antibody bands on serum western blot and none to more than three bands. This is the first time that spontaneously arrested T. solium transmission is documented in a known endemic village. Understanding why active transmission stopped could provide insights on potential targets for control interventions. Atahualpa could provide an optimal scenario for longitudinal studies on the consequences of calcified NCC.


Asunto(s)
Enfermedades Endémicas/prevención & control , Neurocisticercosis/prevención & control , Neurocisticercosis/transmisión , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/transmisión , Adulto , Crianza de Animales Domésticos , Animales , Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/orina , Ecuador/epidemiología , Heces/parasitología , Femenino , Humanos , Masculino , Neurocisticercosis/diagnóstico por imagen , Neurocisticercosis/epidemiología , Neuroimagen/métodos , Prevalencia , Población Rural , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/parasitología , Taenia solium/fisiología
16.
Am J Trop Med Hyg ; 98(2): 558-564, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29210354

RESUMEN

Neurocysticercosis causes substantial neurologic morbidity in endemic regions around the world. In this cross-sectional study, we describe the frequency of neurocysticercosis among a presumed high-risk group of people in an endemic community in northern Peru. Participants who screened positive on a nine-question seizure survey were evaluated clinically to diagnose epilepsy using International League Against Epilepsy criteria. Those with epilepsy were offered a noncontrast computerized tomography (CT) of the head. We also tested sera from all participants using the lentil lectin-bound glycoprotein enzyme-linked immunoelectrotransfer blot (EITB) to detect anti-cysticercus antibodies and enzyme-linked immunosorbent assay (ELISA) B60/B158 to detect cysticercosis antigens. Participants with strongly positive ELISA (ratio ≥ 3) were offered a noncontrast magnetic resonance imaging (MRI) of the brain. We diagnosed 16 cases of epilepsy among 527 people screened (lifetime prevalence 30 per 1,000). Twelve with epilepsy accepted CT scan and five (41.7%) had parenchymal calcifications. None had viable cysts. Of the 514 who provided a blood sample, 241 (46.9%) were seropositive by EITB and 12 (2.9%) were strongly positive by ELISA (ratio ≥ 3). Eleven accepted MRI and eight (72.3%) had neurocysticercosis, including five with extraparenchymal cysts, five with parenchymal vesicular cysts, and two with parenchymal granulomas. These findings show that clinically relevant forms of neurocysticercosis and epilepsy can be found by applying screening interventions in communities endemic to Taenia solium. Longitudinal controlled studies are needed to better understand which subgroups are at highest risk and which are most likely to have improved prognosis as a result of screening.


Asunto(s)
Neurocisticercosis/epidemiología , Población Rural/estadística & datos numéricos , Porcinos/parasitología , Adolescente , Adulto , Animales , Niño , Estudios Transversales , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Neurocisticercosis/etiología , Perú , Prevalencia , Estudios Prospectivos , Convulsiones/etiología , Encuestas y Cuestionarios , Taenia solium/parasitología , Taenia solium/patogenicidad , Tomografía Computarizada por Rayos X/métodos
17.
Am J Trop Med Hyg ; 97(6): 1830-1832, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29016332

RESUMEN

The lentil lectin glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP EITB, reported sensitivity 99% and specificity 100%) is used as a serologic marker of exposure to Taenia solium in pigs. However, only a limited number of parasites have been evaluated for cross reactivity. Pigs may host other related cestode infections, including Taenia hydatigena, which have not been formally evaluated for cross-reactions. We investigated a corral in Tumbes, Peru, a region where a cysticercosis elimination demonstration project was completed in 2012. In this corral, 14/19 (73.7%) 6-8-week-old piglets were reactive to GP50 on LLGP EITB, and all had circulating Taenia sp. antigens. From eight necropsied piglets; four were infected with T. hydatigena metacestodes whereas none had evidence of T. solium infection. Two resident dogs were subsequently confirmed to have T. hydatigena taeniasis. These results suggest GP50 cross-reactivity in T. hydatigena-infected pigs, although controlled experimental infection is needed to confirm this hypothesis.


Asunto(s)
Antígenos Helmínticos/sangre , Cisticercosis/diagnóstico , Cisticercosis/veterinaria , Proteínas del Tejido Nervioso/sangre , Taenia/aislamiento & purificación , Animales , Anticuerpos Antihelmínticos/sangre , Biomarcadores/sangre , Reacciones Cruzadas , Cisticercosis/sangre , Perros/parasitología , Interacciones Huésped-Parásitos , Perú , Sensibilidad y Especificidad , Porcinos/parasitología , Enfermedades de los Porcinos/sangre , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/parasitología , Taenia/clasificación
18.
Am J Trop Med Hyg ; 97(2): 583-586, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28829724

RESUMEN

Hymenolepis nana, the dwarf tapeworm, is a common intestinal infection of children worldwide. We evaluated infection and risk factor data that were previously collected from 14,761 children aged 2-15 years during a large-scale program in northern Peru. We found that 1,124 of 14,761 children (7.61%) had H. nana infection, a likely underestimate given that only a single stool sample was examined by microscopy for diagnosis. The strongest association with infection was lack of adequate water (adjusted prevalence ratio [aPR] 2.22, 95% confidence interval [CI] 1.82-2.48) and sanitation infrastructure in the house (aPR 1.94, 95% CI 1.64-2.29). One quarter of those tested did not have a bathroom or latrine at home, which doubled their likelihood of infection. Similarly, one quarter did not have piped public water to the house, which also increased the likelihood of infection. Continued efforts to improve access to basic water and sanitation services will likely reduce the burden of infection in children for this and other intestinal infections.


Asunto(s)
Heces/parasitología , Himenolepiasis/epidemiología , Hymenolepis nana/aislamiento & purificación , Parasitosis Intestinales/epidemiología , Adolescente , Factores de Edad , Animales , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Perú , Vigilancia de la Población , Prevalencia , Factores de Riesgo , Saneamiento , Cuartos de Baño
19.
PLoS Negl Trop Dis ; 11(4): e0005536, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28406898

RESUMEN

BACKGROUND: Taenia solium, a parasite that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. Geographic hotspots of pigs testing positive for serologic markers of T. solium exposure have been observed surrounding the locations of human tapeworm carriers. This clustered pattern of seropositivity in endemic areas formed the basis for geographically targeted control interventions, which have been effective at reducing transmission. In this study, we further explore the spatial relationship between human tapeworm carriers and infected pigs using necroscopic examination as a quantitative gold-standard diagnostic to detect viable T. solium cyst infection in pigs. METHODOLOGY/PRINCIPAL FINDINGS: We performed necroscopic examinations on pigs from 7 villages in northern Peru to determine the number of viable T. solium cysts in each pig. Participating humans in the study villages were tested for T. solium tapeworm infection (i.e., taeniasis) with an ELISA coproantigen assay, and the distances from each pig to its nearest human tapeworm carrier were calculated. We assessed the relationship between proximity to a tapeworm carrier and the prevalence of light, moderate, and heavy cyst burden in pigs. The prevalence of pig infection was greatest within 50 meters of a tapeworm carrier and decreased monotonically as distance increased. Pigs living less than 50 meters from a human tapeworm carrier were 4.6 times more likely to be infected with at least one cyst than more distant pigs. Heavier cyst burdens, however, were not more strongly associated with proximity to tapeworm carriers than light cyst burdens. CONCLUSION/SIGNIFICANCE: Our study shows that human tapeworm carriers and pigs with viable T. solium cyst infection are geographically correlated in endemic areas. This finding supports control strategies that treat humans and pigs based on their proximity to other infected individuals. We did not, however, find sufficient evidence that heavier cyst burdens in pigs would serve as improved targets for geographically focused control interventions.


Asunto(s)
Portador Sano/veterinaria , Cisticercosis/veterinaria , Quistes/veterinaria , Enfermedades de los Porcinos/epidemiología , Porcinos/parasitología , Taenia solium/aislamiento & purificación , Animales , Anticuerpos Antihelmínticos/sangre , Portador Sano/epidemiología , Cisticercosis/epidemiología , Quistes/parasitología , Femenino , Humanos , Modelos Logísticos , Masculino , Perú/epidemiología , Análisis Espacial , Enfermedades de los Porcinos/parasitología
20.
PLoS Negl Trop Dis ; 11(1): e0005282, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28056028

RESUMEN

BACKGROUND: Taenia solium inflicts substantial neurologic disease and economic losses on rural communities in many developing nations. "Ring-strategy" is a control intervention that targets treatment of humans and pigs among clusters of households (rings) that surround pigs heavily infected with cysticerci. These pigs are typically identified by examining the animal's tongue for cysts. However, as prevalence decreases in intervened communities, more sensitive methods may be needed to identify these animals and to maintain control pressure. The purpose of this study was to evaluate ultrasonography as an alternative method to detect pigs heavily infected with T. solium cysts. METHODOLOGY/PRINCIPAL FINDINGS: We purchased 152 pigs representing all seropositive animals villagers were willing to sell from eight communities (pop. 2085) in Piura, Peru, where T. solium is endemic. Tongue and ultrasound examinations of the fore and hind-limbs were performed in these animals, followed by necropsy with fine dissection as gold standard to determine cyst burden. We compared the sensitivity and specificity of ultrasonography with tongue examination for their ability to detect heavy infection (≥ 100 viable cysts) in pigs. Compared to tongue examination, ultrasonography was more sensitive (100% vs. 91%) but less specific (90% vs. 98%), although these differences were not statistically significant. The greater sensitivity of ultrasound resulted in detection of one additional heavily infected pig compared to tongue examination (11/11 vs. 10/11), but resulted in more false positives (14/141 vs. 3/141) due to poor specificity. CONCLUSIONS/SIGNIFICANCE: Ultrasonography was highly sensitive in detecting heavily infected pigs and may identify more rings for screening or treatment compared to tongue examination. However, the high false positive rate using ultrasound would result in substantial unnecessary treatment. If specificity can be improved with greater operator experience, ultrasonography may benefit ring interventions where control efforts have stalled due to inadequate sensitivity of tongue examination.


Asunto(s)
Cisticercosis/diagnóstico por imagen , Cisticercosis/veterinaria , Enfermedades de los Porcinos/diagnóstico por imagen , Ultrasonografía/métodos , Animales , Cisticercosis/diagnóstico , Cisticercosis/parasitología , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/parasitología , Taenia solium/fisiología , Ultrasonografía/veterinaria
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