Evaluation of a New Immunochromatographic Test Using Recombinant Antigen B8/1 for Diagnosis of Cystic Echinococcosis.

Diagnosis of cystic echinococcosis (CE) is based on the identification of the cyst(s) by imaging, using immunodiagnostic tests mainly as complementary tools in clinical settings. Among the antigens used for immunodiagnosis, previous studies described a good performance of the recombinant antigen B8/1 (rAgB) in an enzyme-linked immunosorbent assay (ELISA) format; however, in remote parts of areas where the disease is endemic, the implementation of an ELISA is difficult, so a more simple, rapid, and reliable method such as the immunochromatographic test (ICT) is required. In this study, using a set of 50 serum samples from patients with surgically confirmed CE, we compared the performance of an ICT and that of an ELISA using the rAgB. The overall sensitivities of ICT and ELISA were not statistically different (78% versus 72%; P = 0.36). The overall agreement between both tests was moderate (κ = 0.41; P < 0.01). Concordance between ICT and ELISA was substantial or almost perfect for patients with liver involvement (κ = 0.65; P < 0.001) and patients with more than one hydatid cyst (κ = 0.82; P < 0.001), respectively. Moreover, specificity analysis using a total of 88 serum samples from healthy individuals (n = 20) and patients (n = 68) with other parasitic infections revealed that ICT had a specificity of 89.8%. ICT and ELISA had similar performance for the detection of specific antibodies to E. granulosus, and ICT had a high specificity, opening the possibility of using ICT as a screening tool in rural settings.

Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.

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.

Primary Giant Splenic Echinococcal Cyst Treated by Laparoscopy.

Cystic echinococcosis (CE) is a zoonosis caused by the larval stage of the dog tapeworm Echinococcus granulosus. Liver and lungs are the most commonly affected organs whereas splenic infection is rarer and its primary involvement occurs in less than 2% of abdominal CE. We report a case of primary giant splenic hydatid cyst in a 75-year-old Peruvian woman that was laparoscopically removed without any complications, perioperative prophylactic chemotherapy with albendazole 400 mg twice a day 5 days before, and 7 days after the surgical procedure was administered, postoperative recovery was uneventful, and; at her 3-month follow-up the patient remains asymptomatic and an abdominal computed tomography scan demonstrated a cystic cavity of 15 cm diameter with no daughter vesicles, neither other abdominal organ involvement. This case is in line with the existing literature on laparoscopical treatment of splenic cystic hydatid disease, suggesting that laparoscopical treatment is a safe and effective approach for large splenic hydatid cysts to be preferred to open surgical techniques.

Serological diagnosis of lung cystic hydatid disease using the synthetic p176 peptide.

Cystic hydatid disease (CHD) is a worldwide zoonosis caused by the larval stage of the dog tapeworm Echinococcus granulosus. Diagnosis is based on imagenological tools (abdominal ultrasound, chest X-rays, or computed tomography [CT] scan). Serological antibody-detecting assays, using diverse native antigens, have been used as a supportive diagnostic tool, but their sensitivities and specificities differ greatly. The use of synthetic peptides as antigens should provide more reliability and allow better assessment and comparison of test formats and case series. The synthetic peptide p176, corresponding to the N-terminal extreme of the subunit of antigen B (AgB8/1), has shown promising performances for diagnosis of CHD. We evaluated the performance of the synthetic peptide p176 for the diagnosis of pulmonary hydatid disease in an enzyme-linked immunosorbent assay (ELISA) format. Sixty-one serum samples from patients with a diagnosis of pulmonary hydatidosis confirmed by surgery and 128 from healthy volunteers were tested. The overall sensitivity and specificity of the p176 ELISA for lung CHD were 78.69% and 96.88%, respectively. On bivariate analysis, positive serum antibody reactions were associated with the presence of complications and with the number of cysts (single/multiple). Only the presence of persistent complications significantly associated with seropositivity on multivariate logistic regression analysis (odds ratio [OR], 9.58; 95% confidence interval [CI], 2.15 to 42.6; P = 0.003). The p176 ELISA performs well for the diagnosis of lung CHD and adds an easily reproducible diagnostic assay to the existing diagnostic tools.

Human and canine echinococcosis infection in informal, unlicensed abattoirs in Lima, Peru.

Echinococcus granulosus infections are a major public health problem in livestock-raising regions around the world. The life cycle of this tapeworm is sustained between dogs (definitive host, canine echinococcosis), and herbivores (intermediary host, cystic hydatid disease). Humans may also develop cystic hydatid disease. Echinococcosis is endemic in rural areas of Peru; nevertheless, its presence or the extension of the problem in urban areas is basically unknown. Migration into Lima, an 8-million habitant's metropolis, creates peripheral areas where animals brought from endemic areas are slaughtered without veterinary supervision. We identified eight informal, unlicensed abattoirs in a peripheral district of Lima and performed a cross-sectional study in to assess the prevalence of canine echinococcosis, evaluated by coproELISA followed by PCR evaluation and arecoline purge. Eight of 22 dogs (36%) were positive to coproELISA, and four (18%) were confirmed to be infected with E. granulosus tapeworms either by PCR or direct observation (purge). Later evaluation of the human population living in these abattoirs using abdominal ultrasound, chest X-rays and serology, found 3 out of 32 (9.3%) subjects with echinococcal cysts in the liver (two viable, one calcified), one of whom had also lung involvement and a strongly positive antibody response. Autochthonous transmission of E. granulosus is present in Lima. Informal, unlicensed abattoirs may be sources of infection to neighbouring people in this urban environment.

Economic impact of cystic echinococcosis in peru.

BACKGROUND: Cystic echinococcosis (CE) constitutes an important public health problem in Peru. However, no studies have attempted to estimate the monetary and non-monetary impact of CE in Peruvian society. METHODS: We used official and published sources of epidemiological and economic information to estimate direct and indirect costs associated with livestock production losses and human disease in addition to surgical CE-associated disability adjusted life years (DALYs) lost. FINDINGS: The total estimated cost of human CE in Peru was U.S.$2,420,348 (95% CI:1,118,384-4,812,722) per year. Total estimated livestock-associated costs due to CE ranged from U.S.$196,681 (95% CI:141,641-251,629) if only direct losses (i.e., cattle and sheep liver destruction) were taken into consideration to U.S.$3,846,754 (95% CI:2,676,181-4,911,383) if additional production losses (liver condemnation, decreased carcass weight, wool losses, decreased milk production) were accounted for. An estimated 1,139 (95% CI: 861-1,489) DALYs were also lost due to surgical cases of CE. CONCLUSIONS: This preliminary and conservative assessment of the socio-economic impact of CE on Peru, which is based largely on official sources of information, very likely underestimates the true extent of the problem. Nevertheless, these estimates illustrate the negative economic impact of CE in Peru.

[Household factors associated with the presence of human hydatid disease in three rural communities of Junin, Peru]. / Factores domiciliarios asociados con la presencia de hidatidosis humana en tres comunidades rurales de Junín, Perú.

INTRODUCTION: Hydatid disease, a zoonosis caused by the larval stage of the parasite Echinococcus granulosus, is a public health problem at national level, especially in those regions dedicated to raising livestock. By now, there are many factors, at individual level, that have been associated to the infection by E. granulosus; nevertheless there is not any previous report that explore the association between household characteristics and the presence of the disease among household members. OBJECTIVE: To explore the association between household characteristics and the presence of hydatid disease among household members. MATERIAL AND METHODS: We performed a cross-sectional study in the households of 3 rural communities located in Junín, we evaluated the association between household characteristics and the presence of hydatid disease by multiple logistic regression (MLR). RESULTS: From 417 evaluated households, 56 (13%) of them had at least one positive case among its members. Multivariate analysis showed that households with three or more members, located in the community with the lowest quintile of poverty, that reported raising livestock, and with evaluation coverage greater than 25% were more likely to have at least one positive case among its members. CONCLUSION: The observed characteristics be taken into account in the preliminary definition of high-risk subgroups, optimizing the use of resources and improving the effectiveness of screening programs.

Absence of brain involvement and factors related to positive serology in a prospective series of 61 cases with pulmonary hydatid disease.

A prospective series of 65 patients with surgically confirmed lung cystic hydatid disease was evaluated in terms of their radiologic characteristics, serologic response, and presence of cysts in other organs. Cysts were mostly single and located in lower lung lobes. Liver compromise was found in 34% of the patients. Despite a systematic search, no patient showed brain cysts in this series. Twelve patients had previous hydatid disease: six in the liver and eight in the lung (two had involvement of both organs in the past). Serology using bovine cyst fluid in an immunoblot assay was 85% sensitive. Serologic response was not associated with number or cyst or compromise of other organs but was clearly associated to the presence of at least one complicated cyst. Cyst status in terms of complications should be described to allow appropriate assessment of serologic evaluations.

Human hydatid disease in Peru is basically restricted to Echinococcus granulosus genotype G1.

A molecular PCR study using DNA from 21 hydatid cysts was performed to determine which strain type is responsible for human infection in Peru. The mitochondrial cytochrome c oxidase subunit 1 (CO1) gene was amplified in 20 out of 21 samples, revealing that all but 1 sample (19/20, 95%) belonged to the common sheep strain (G1). The remaining samples belonged to the camel strain (G6). The G1 genotype was most frequently found in human cases of cystic hydatid disease (CHD) in Peru. Local control measures should focus primarily on decreasing dog and sheep infection rather than intermediate reservoirs.

Factores domiciliarios asociados con la presencia de hidatidosis humana en tres comunidades rurales de Junín, Perú / Household factors associated with the presence of human hydatid disease in three rural communities of Junin, Peru

Introducción. La hidatidosis, zoonosis producida por el estadio larvario de la taenia Echinococcus granulosus, es un problema de salud pública a nivel nacional, en especial en aquellas regiones dedicadas a la crianza de ganado. A la fecha, se han descrito factores, a nivel individual, asociados con la infección por E. granulosus; sin embargo, no se encontró reporte previo que explore la asociación entre características de la vivienda y la presencia de esta enfermedad en alguno de sus miembros. Objetivos. Explorar la asociación entre las características de la vivienda y la presencia de hidatidosis entre las personas que la habitan. Materiales y métodos. Se realizó un estudio transversal en viviendas de tres comunidades rurales de Junín. Se evaluó el grado de asociación entre las características de la vivienda y la presencia de hidatidosis en el hogar mediante un análisis de regresión logística múltiple (RLM). Resultados. De un total de 417 viviendas evaluadas, 56 (13 por ciento) de ellas tenían al menos un caso positivo entre sus miembros; luego del análisis de RLM se observó que aquellas viviendas con más de tres miembros, localizadas en la comunidad con quintil de pobreza más bajo, que refirieron crianza de animales, y con una cobertura de evaluación mayor al 25 por ciento presentaron una mayor probabilidad de tener al menos un caso de positivo entre sus miembros. Conclusión. Las características observadas deben ser tomadas en cuenta para la determinación preliminar de subgrupos de alto riesgo, optimizando así el uso de los recursos y mejorando la eficacia de los programas de despistaje.

Introduction. Hydatid disease, a zoonosis caused by the larval stage of the parasite Echinococcus granulosus, is a public health problem at national level, especially in those regions dedicated to raising livestock. By now, there are many factors, at individual level, that have been associated to the infection by E. granulosus; nevertheless there is not any previous report that explore the association between household characteristics and the presence of the disease among household members. Objective. To explore the association between household characteristics and the presence of hydatid disease among household members. Material and methods. We performed a cross-sectional study in the households of 3 rural communities located in Junín, we evaluated the association between household characteristics and the presence of hydatid disease by multiple logistic regression (MLR). Results. From 417 evaluated households, 56 (13 percent) of them had at least one positive case among its members. Multivariate analysis showed that households with three or more members, located in the community with the lowest quintile of poverty, that reported raising livestock, and with evaluation coverage greater than 25 percent were more likely to have at least one positive case among its members. Conclusion. The observed characteristics be taken into account in the preliminary definition of high-risk subgroups, optimizing the use of resources and improving the effectiveness of screening programs.