PREVALENCE OF HUMAN ECHINOCOCCOSIS USING IMAGING TECHNIQUES IN YANAHUANCA, PASCO

El objetivo del estudio fue determinar la prevalencia de hidatidosis humana en nueve comunidades rurales del distrito de Yanahuanca, Pasco, empleando como técnicas de diagnóstico la ecografía abdominal y la radiografía de tórax. Además, se evaluó la asociación entre las variables edad, género y comunidad de procedencia y la presencia de pobladores positivos a quistes hidatídicos. La ecografía se realizó a 949 personas (52% de la población mayor de 5 años) y el examen radiográfico a 829 (45.6%). La prevalencia general de hidatidosis fue de 5.5% (52/949) con un intervalo de confianza al 95% de 4.1 a 7.1%. Se halló asociación estadística (p<0.05) entre edad con el resultado positivo al examen ecográfico, siendo las personas mayores de 40 años las que presentaron un mayor porcentaje. La relación de quistes hidatídicos hepáticos / pulmonares fue de 5.1. El 56% (25/45) de los quistes detectados por ecografía presentaron parcial o completa calcificación. La prevalencia obtenida es una de las más altas en Latinoamérica, posiblemente por la convivencia del poblador andino con el perro, dado su uso en el cuidado y pastoreo del ganado ovino, además de las deficientes condiciones higiénico-sanitarias, y bajos niveles socioeconómicos y culturales.The objective of this study was to determine the prevalence of human echinococcosis in nine communities of the district of Yanahuanca, Pasco, through abdominal echography and thorax radiography. In addition, the association between age, gender, and community with the disease was evaluated. Echographic examination was conducted in 949 persons (52% of the population over 5 years of age) and X ray test was performed in 829 (45.6%). The overall prevalence of human cystic echinococcosis was 5.5% (52/949) and the 95% confidence interval varied from 4.1 to 7.1%. There was statistical association (p<0.05) between age with positive results when using the ultrasound exam. The liver / lung hydatid cyst ratio was 5:1. Partial or total calcified cysts were detected by echographical examination (56%, 25/45). The prevalence of human hydatidosis in this endemic area of Peru is one of the highest in Latin America, possibly due to the close interaction with dogs, as they shepherd the flocks, plus poor sanitation and hygiene conditions in the area

Diagnosis of Cystic Echinococcosis, Central Peruvian Highlands

High prevalence was confirmed by ultrasonography, radiography, and 2 serologic tests, although usefulness of serologic testing in the field was limited

Evaluation of Oxfendazole, Praziquantel and Albendazole against Cystic Echinococcosis: A Randomized Clinical Trial in Naturally Infected Sheep

Cystic Echinococcosis (CE) is a near-cosmopolitan parasitic zoonosis that causes economic losses in many regions of the world. This parasitic infection can be regarded as an emerging or re-emerging disease causing considerable losses in livestock production. CE is produced by the larval cystic stage (hydatid) of the dog parasite Echinococcus granulosus. After infective eggs are ingested, cysts develop mainly in lungs and liver of humans and animals (sheep, cattle, pigs, horses, etc). Infected people may require surgery and/or Albendazole-based chemotherapy. In this study, we evaluated the effects of Oxfendazole alone (an antiparasitic drug used in animals), Oxfendazole plus Praziquantel, and Albendazole plus Praziquantel against hydatid cysts in sheep over 4 to 6 weeks of treatment. All of the treatments in this study were efficacious in killing the larval stages and, therefore, in minimizing the risk of a dog acquiring new infections (taenias). These treatment schemes can be added to control measures in animals and eventually could be used for the treatment of human infection. Further investigations on different schedules of monotherapy or combined chemotherapy are needed, as well as studies to evaluate the safety and efficacy of Oxfendazole in humans

OBTENCIÓN DE echinococcus GRANULOSUS EN CANINOS INFECTADOS EXPERIMENTALMENTE CON PROTOESCÓLICES DE QUISTES HIDATÍDICOS.

The objective of the present study was to experimentally reproduce the biological cycle of Echinococcus granulosus in dogs. Twelve dogs, 4-50 months old, were infected with 80,000-308,000 protoscolices recovered from lung and liver hidatyd cysts in sheep reared in the central highlands of Peru. Dogs were slaughtered 28-39 days post infection (p.i) and the small intestine was divided in three equal portions (anterior, medium, and posterior) and parasites were counted. The location of parasites in the three portions of intestine was recorded in three dogs. Eight out of 12 dogs resulted positive to the infection and the number of parasites varied from 1,299 till 65,000 per dog. Animals slaughtered on the 28th p.i day resulted negative. The preferred site for parasites was the medium portion of the small intestine. It was shown that the oral inoculation of protoscolices from sheep hydatic cysts was effective to reproduce the biological cycle of the E. granulosus in dogs.El presente estudio tuvo por objetivo reproducir experimentalmente el ciclo biológico del Echinococcus granulosus en perros. Se utilizó 12 perros (4-50 meses de edad) que fueron infectados experimentalmente con 80,000 a 308,000 protoescólices de quistes hidatídicos de pulmón e hígado de ovinos procedentes de Junín y Ayacucho. Los perros se sacrificaron 28 a 39 días post infección (p.i). El intestino delgado se dividió en tres porciones iguales (anterior, media y posterior). Los parásitos fueron separados del intestino y contados. Además, en tres perros se determinó el grado de dispersión del parásito en las tres porciones del intestino delgado. Ocho de los 12 perros se infectaron, recolectándose entre 1,299 a 65,000 parásitos adultos por perro. Los animales sacrificados el día 28 p.i resultaron negativos, mientras que ocho de los nueve perros sacrificados a partir del día 30 p.i. resultaron positivos. El sitio de mayor predilección del parásito fue la porción media del intestino delgado. Se demostró que la inoculación de protoescólices de quistes hidatídicos ovinos, vía oral, es efectiva para para reproducir el ciclo biológico del E. granulosus en perros

Performance of a sandwich antigen-detection ELISA for the diagnosis of porcine Taenia solium cysticercosis

The pig is the natural intermediate host of Taenia solium, a parasite causing significant burden of disease in both humans and pigs. Porcine cysticercosis is traditionally detected via tongue palpation and slaughterhouse meat inspection, both with limited sensitivity. Serum antibody detection has a better performance; however, it does not discriminate past from present infection. Serum antigen detection can demonstrate viable infection and gives a good estimate of parasitic load. This study evaluated a sandwich antigen-detection ELISA using monoclonal antibodies (MoAbs) 158C11 and 60H8 for the diagnosis of viable cysticercosis in pigs. Serum samples were used from 35 naturally T. solium cysticerci-infected pigs, 31 cysticercosis-negative pigs, and 22 pigs with Taenia hydatigena infection (to assess cross-reactions). Positive cysticercosis samples were subcategorized at necropsy according to parasitic burden as mild (1-10 viable cysts, n = 10), moderate (11-100 cysts, n = 5), or severe infection (more than 100 cysts, n = 20). This Ag-ELISA showed a sensitivity of 82.9% and a specificity of 96.8% when not considering cross-reactions with T. hydatigena. Hundred percentage of severely infected, 80% of moderately infected, and 50% of mildly T. solium-infected pigs tested positive. Twenty of 22 pigs with only T. hydatigena infections were positive, with 13 reaching saturating levels in the ELISA. The Ag-ELISA revealed the presence of live cysts and is, thus, a fairly reliable test to monitor experimental infection, response to treatment, and follow-up in animal models of cysticercosis. It should, however, be carefully interpreted when used in regions where T. hydatigena is endemic in pigs

Diagnosis of Cystic Echinococcosis, Central Peruvian Highlands

We evaluated prevalence of cystic echinococcosis (CE) in a central Peruvian Highland district by using 4 diagnostic methods: ultrasonography for 949 persons, radiography for 829, and 2 serologic tests for 929 (2 immunoblot formats using bovine hydatid cyst fluid [IBCF] and recombinant EpC1 glutathione S-transferase [rEpC1-GST] antigens). For the IBCF and rEpC1-GST testing, prevalence of liver and pulmonary CE was 4.7% and 1.1% and seropositivity was 8.9% and 19.7%, respectively. Frequency of seropositive results for IBCF and rEpC1-GST testing was 35.7% and 16.7% (all hepatic cysts), 47.1% and 29.4% (hepatic calcifications excluded), and 22.2% and 33.3% (lung cysts), respectively. Weak immune response against lung cysts, calcified cysts, small cysts, and cysts in sites other than lung and liver might explain the poor performance of the serodiagnostic tests. We confirm that CE is highly endemic to Peru and emphasize the limited performance of available serologic assays in the field