First Molecular Characterization of Trichostrongylus colubriformis Infection in Rural Patients from Chile.

PURPOSE: The aim was to characterize the infection by Trichostrongylus spp. in patients from Chile using a combination of molecular detection techniques and phylogenetic analysis relating the findings to clinical and epidemiological reports of the patients METHODS: Strongylid eggs were detected in seven patients by coproparasitological techniques. From each sample a fragment of the ITS-2 ribosomal gene was amplified by PCR, sequenced and analyzed by the Neighbor-Joining method. RESULTS: All the sequences and phylogenetic clusters corresponded to T. colubriformis. Two samples presented a single nucleotide polymorphism showing two possible haplotypes. Six patients presented gastrointestinal symptoms. All of them lived on farms and used sheep manure as fertilizer. CONCLUSION: T. colubriformis was the strongylid involved in the infections of these Chilean patients associated with the presence of livestock and agricultural practices that favor infection by this type of nematode.

Oestrus ovis infection of grazing sheep during summer in southern Chile

Oestrus ovis is a botfly whose larvae cause nasal myiasis, an environmental-dependent disease in small ruminants, generating acute and chronic injuries in the cranial cavities of sheep. Chile is a country of the southernmost worldwide distribution of this parasite, and there is few information about. Whence, the objective of this study was to approximate the epidemiological situation of O. ovis infection in Chilean sheep. From December 2009 to March 2010, a total of 87 samples were obtained by necropsy for skull inspection. The larvae were collected, and microscopically identified. The prevalence in the sampled sheep was 60.9%. From those that were infected, 85.7% (18/21) of sheep were 1 to 3 years old, constituting the stratum with the highest prevalence. The difference of infection in females and males was not significant. The high risk of infection seems to be dependent upon the environmental conditions of this southern region, especially during summer when the first larval stage (L1) could be found as the evidence. Therefore, the disease should be considered as a significant problem for this kind of livestock production.

Viability and fertility of human hepatic hydatid cysts.

INTRODUCTION: The adequate treatment for hydatidosis requires a knowledge of certain aspects related to the survival of infectious agents, especially protoscoleces. The aim of this study is to evaluate the viability of protoscoleces in human hepatic hydatid cysts in order to determine the prevalence of their fertility and to study the association with variables typical of the host and of the parasite. MATERIALS: A cross-sectional study was done in biological material (the fluid from human hepatic hydatid cysts). The viability criteria used were: ovoid form, invaginated scolices and intact calcareous corpuscles, the presence of vibrating movements, and the absence of "vital" staining. The cysts were grouped as univesicular cysts (UVC), multivesicular cysts (MVC) and abscessed cysts (LAHO). Fertility was defined as living protoscoleces in relation to the total number of protoscoleces. Descriptive statistics were for the calculation of the prevalence of fertility, analytical statistics for the comparison of groups, and a multivariate analysis for the examination of the association between cyst fertility and clinical variables. RESULTS: A total of 163 cysts with a median diameter of 15 cm were studied in this way. Of these lesions, 79 (48.5%) were UVC, 54 (33.1%) MVC, and 30 (18.4%) LAHO. On 99 occasions (60.7%), macroscopic communication was evident in the bile duct, and a prevalence of general fertility of 57.1% (94.4% for MVC, 53.2% for UVC, and 0% for LAHO, with a value of P<0.001). Association with location, type, and diameter of the cyst, and presence of biliary communications was verified by applying a bivariate analysis, and association between fertility and the variables of the type of the cyst and the existence of biliary communications was verified employing a multivariate analysis (P values of 0.004 and <0.001, respectively). CONCLUSIONS: The prevalence of fertility found was low. The main prevalence of fertility was observed in MVCs. Fertility is associated with the type of cyst and the presence of biliary communications.

Enteroparasitosis en población ribereña del lago Villarrica, Chile / Enteroparasitosis in Villarrica lake riverside population, Chile

El estudio demostró que las enteroparasitosis siguen costituyendo un problema de salud en el ecosistema lacustre investigado, siendo sus causas preferentemente de orden educativo, socioeconómico y de saneamiento ambiental. Se puede inferir que una comunidad directa o indirectamente afectada por factores epidemiológicos predisponentes (clima, calidad de suelos, limitación o ausencia de vías de dispersión de formas infectantes en el ambiente), mediante medidas de control adecuadas e información sanitaria preventiva, podría neutralizar el fenómeno del parasitismo intestinal con relativa buenas expectativas de éxito haciendo participar activamente a la comunidad

Blastocystosis en pacientes sintomáticos del hospital regional de Temuco, Chile / Blastocystosis in symptomatic patients at the regional hospital of Temuco, Chile

Se comprobó la persistenci de altos indices de enteroparásitos en general y de B. homisis en particular. La frecuencia global de B. homisis como agente único en individuos sintomáticos, supera el promedio descrito en otros estudios de distintas zonas de nuestro país y términos de infecciones mixtas o asociadas, un tercio de las infecciones por G. intestinalis y casi la mitad de las causadas por E. histolytica coexistían con el nuevo agente protozoario. Lo anterior debiera ser justamente valorado desde un punto de vista clínico, terapéutico y epidemiológico, dado que aún se discuten los mecanismos patogénicos de esta entidad (Sheehan y col., 1966). Por último, deseamos enfatizar que el laboratorio debe acompañar el hallazgo de B. homisis de un informe cuantitativo de la carga parasitaria, considerando las recomendaciones que estiman que un número superior a cinco formas de este protozoario por campo microscópico (40x) costituirían una carga suficiente para producir cuadros clínicamente sintomáticos y que en ausencia de otros patógenos, en clínica se deben abordar terapéuticamente los casos (Zierdt, 1983)