Fatal granulomatous amoebic encephalitis due to free-living amoebae in two boys in two different hospitals in Lima, Perú.

Granulomatous amoebic encephalitis caused by free-living amoebae is a rare condition that is difficult to diagnose and hard to treat, generally being fatal. Anti-amoebic treatment is often delayed because clinical signs and symptoms may hide the probable causing agent misleading the appropriate diagnostic test. There are four genera of free-living amoeba associated with human infection, Naegleria, Acanthamoeba sp., Balamuthia and Sappinia. Two boys were admitted with diagnosis of acute encephalitis. The history of having been in contact with swimming pools and rivers, supports the suspicion of an infection due to free-living amoebae. In both cases a brain biopsy was done, the histology confirmed granulomatous amoebic encephalitis with the presence of amoebic trophozoites.

Efecto del sacrificio de perros vagabundos en el control de la rabia canina / Effect of free-roaming dogs culling on the control of canine rabies

RESUMEN En la ciudad de Arequipa, Perú, se han detectado perros con rabia desde marzo de 2015, señal de la reintroducción del virus de la rabia (VR) en esta zona previamente declarada libre de esta enfermedad. La alta densidad de perros vagabundos ha sido considerada una de las causas de la continua transmisión del VR en el brote de la ciudad de Arequipa, alentando el sacrificio de perros como medida de salud pública. Sin embargo, la efectividad de esta medida de control no ha sido evaluada. El objetivo de esta revisión fue determinar la efectividad del sacrificio de perros vagabundos como medida de control de la rabia urbana. Se realizó la búsqueda de artículos sobre control de rabia canina o urbana en las bases de datos de Medline, Scopus y LILACS. Se incluyeron estudios originales y revisiones que hayan evaluado algún efecto del sacrificio de perros en la transmisión del VR. Veinte de 21 artículos concluyen que el sacrificio de perros vagabundos es inefectivo en reducir la trasmisión del VR e, incluso, puede tener consecuencias imprevistas que empeoren el problema. En conclusión, la evidencia disponible indica que sacrificar perros vagabundos no es efectivo para controlar la rabia urbana. Además, las diversas consecuencias negativas del sacrificio de los perros vagabundos reportadas en otras partes del mundo sugieren que el sistema de rabia urbana es altamente complejo y todos sus componentes deben ser tomados en cuenta durante la implementación de actividades de control.

ABSTRACT In the Peruvian city of Arequipa, rabid dogs have been detected since March 2015, signaling the reintroduction of the rabies virus (RV) in this previously officially-declared rabies free zone. High dog density is considered one of the causes for the continuous transmission of the RV in the outbreak in the city of Arequipa, which seemingly lends support to the culling of dogs as a public health measure. However, the effectiveness of culling free-roaming dogs to control urban rabies has not been evaluated. Objective to determine the effectiveness of free-roaming dog culling as a control measure of urban rabies. Source of data: We searched for articles on dog rabies control or urban rabies control in the databases of PubMed, Scopus and LILACS. The characteristics and results of the documents obtained were recorded. Eligibility criteria: We included original studies and reviews that have evaluated an effect of culling dogs in the transmission of RV. Data collection and evaluation: One of the authors (RCN) screened the articles found in the search based on their titles and abstracts. The data and results of the articles selected for full reading were evaluated by at least two authors. Results: 21 articles were eligible for full reading. 20 of 21 articles conclude that free-roaming dog culling is ineffective in reducing the transmission of RV and may even have unintended consequences that worsen the problem. We believe that the available evidence indicates that the sacrifice of free-roaming dogs is not effective to control urban rabies. In addition, the various negative consequences of free-roaming dog culling reported in other parts of the world suggest that the system of urban rabies is highly complex and all its components must be taken into account during the implementation of control activities.

Urbanización de la enfermedad de chagas en el Perú: experiencias en su prevención y control / Urbanization of chagas disease in Peru: experiences in prevention and control

En el Perú, la enfermedad de Chagas tiene importancia epidemiológica en tres macrorregiones, una de ellas es la macrorregión sur conformada por los departamentos de Arequipa, Moquegua y Tacna. En 1965 se realizó un control exitoso mediante rociamiento domiciliario de insecticidas, sin embargo, la persistencia del vector hizo necesario un segundo plan de control que se implementó en el 2000 y que siguió los lineamientos del Plan CONAL, basado en la eliminación del Triatoma infestans y el tamizaje en los bancos de sangre. Este plan fue exitoso en Tacna y Moquegua por lo que estos departamentos fueron considerados libres de transmisión vectorial por la Organización Panamericana de la Salud. Similar situación no se ha logrado en el departamento de Arequipa por la presencia, entre otros factores, de la migración rural a la ciudad, constituyéndose la urbanización de la enfermedad de Chagas como un nuevo escenario epidemiológico que necesita conocerse.

In Peru, Chagas disease has an epidemiological significance in three macro-regions, one of them is the southern macro-region formed by the departments of Arequipa, Moquegua and Tacna. In 1965 a successful control was performed by house spraying insecticides, however, the persistence of the vector made it necessary for a second control plan that was implemented in 2000 and followed the guidelines of CONAL Plan, based on the elimination of Triatoma infestans and screening in blood banks.This plan was successful in Tacna and Moquegua, therefore these departments were considered free of vectorial transmission by the Pan American Health Organization. A ssimilar situation has not been achieved in the department of Arequipa because of the presence, among other factors, of rural migration to the city, in this way the urbanization of Chagas disease is a new epidemiological scenario of which we need to know more.

Temporal differences in blood meal detection from the midguts of Triatoma infestans / Diferencias temporales en la detección de fuentes de alimentación en el contenido intestinal de Triatoma infestans

We used genus/species specific PCRs to determine the temporal persistence of host DNA in Triatoma infestans experimentally fed on blood from six common vertebrate species: humans, domestic dogs, guinea pigs, chickens, mice, and pigs. Twenty third or fourth instar nymphs per animal group were allowed to feed to engorgement, followed by fasting-maintenance in the insectary. At 7, 14, 21, or 28 days post-feeding, the midgut contents from five triatomines per group were tested with the respective PCR assay. DNA from all vertebrate species was detected in at least four of five study nymphs at seven and 14 days post-feeding. DNA of humans, domestic dogs, guinea pigs, pigs, and chickens were more successfully detected (80-100%) through day 21, and less successfully (20-100%) at day 28. Findings demonstrate that species-specific PCRs can consistently identify feeding sources of T. infestans within two weeks, a biologically relevant time interval.

Se utilizó pruebas PCR género o especie específicas para determinar la persistencia temporal de ADN del hospedero en el contenido intestinal de Triatoma infestans que fueron alimentados experimentalmente con sangre de seis vertebrados muy frecuentemente asociados a enfermedad de Chagas: humano, perro, cobayo, pollo, ratón, y cerdo. Se emplearon 20 ninfas de tercer y cuarto estadio por cada especie de hospedero. Fueron alimentados a saciedad y mantenidas en el insectario sin alimentación posterior. Se obtuvo el contenido intestinal de cinco triatominos por cada grupo a los 7, 14, 21 y 28 días post - alimentación, que fueron evaluados con los respectivos PCRs específicos. El ADN de todos los vertebrados fue detectado en al menos 4 de 5 ninfas evaluadas a los 7 y 14 días post - alimentación. El ADN de humano, perro, cobayo, cerdo y pollo fue detectado exitosamente (80-100%) hasta el día 21 y con menos éxito (20-100%) en el día 28. Estos resultados demuestran que PCRs específicos para cada especie de hospedero pueden identificar consistentemente la fuente de alimentación de T. infestans dentro de las dos semanas post - alimentación, siendo un intervalo de tiempo biológicamente relevante.

Echinococcus granulosus genotypes circulating in alpacas (Lama pacos) and pigs (Sus scrofa) from an endemic region in Peru.

The identification of the genotypes of Echinococcus granulosus present in livestock and wild animals within regions endemic for cystic echinococcosis (CE) is epidemiologically important. Individual strains display different biological characteristics that contribute to outbreaks of CE and that must be taken into account in the design of intervention programs. In this study, samples of hydatid cysts due to E. granulosus were collected from alpacas (4) in Puno and pigs (8) in Ayacucho in Peru, an endemic region for CE. Polymerase chain reaction amplification and DNA sequencing of specific regions of the mitochondrial cytochrome C oxidase subunit 1 and NADH dehydrogenase subunit 1 genes confirmed the presence of a strain common to sheep, the G1 genotype, in alpacas. Two different strains of E. granulosus were identified in pigs: the G1 and the G7 genotypes. This is the first report of the G1 genotype of E. granulosus in alpacas in endemic regions of CE in Peru.

Echinococcus granulosus genotypes circulating in alpacas (Lama pacos) and pigs (Sus scrofa) from an endemic region in Peru

The identification of the genotypes of Echinococcus granulosus present in livestock and wild animals within regions endemic for cystic echinococcosis (CE) is epidemiologically important. Individual strains display different biological characteristics that contribute to outbreaks of CE and that must be taken into account in the design of intervention programs. In this study, samples of hydatid cysts due to E. granulosus were collected from alpacas (4) in Puno and pigs (8) in Ayacucho in Peru, an endemic region for CE. Polymerase chain reaction amplification and DNA sequencing of specific regions of the mitochondrial cytochrome C oxidase subunit 1 and NADH dehydrogenase subunit 1 genes confirmed the presence of a strain common to sheep, the G1 genotype, in alpacas. Two different strains of E. granulosus were identified in pigs: the G1 and the G7 genotypes. This is the first report of the G1 genotype of E. granulosus in alpacas in endemic regions of CE in Peru.

A field trial of alternative targeted screening strategies for Chagas disease in Arequipa, Peru.

BACKGROUND: Chagas disease is endemic in the rural areas of southern Peru and a growing urban problem in the regional capital of Arequipa, population ∼860,000. It is unclear how to implement cost-effective screening programs across a large urban and periurban environment. METHODS: We compared four alternative screening strategies in 18 periurban communities, testing individuals in houses with 1) infected vectors; 2) high vector densities; 3) low vector densities; and 4) no vectors. Vector data were obtained from routine Ministry of Health insecticide application campaigns. We performed ring case detection (radius of 15 m) around seropositive individuals, and collected data on costs of implementation for each strategy. RESULTS: Infection was detected in 21 of 923 (2.28%) participants. Cases had lived more time on average in rural places than non-cases (7.20 years versus 3.31 years, respectively). Significant risk factors on univariate logistic regression for infection were age (OR 1.02; p = 0.041), time lived in a rural location (OR 1.04; p = 0.022), and time lived in an infested area (OR 1.04; p = 0.008). No multivariate model with these variables fit the data better than a simple model including only the time lived in an area with triatomine bugs. There was no significant difference in prevalence across the screening strategies; however a self-assessment of disease risk may have biased participation, inflating prevalence among residents of houses where no infestation was detected. Testing houses with infected-vectors was least expensive. Ring case detection yielded four secondary cases in only one community, possibly due to vector-borne transmission in this community, apparently absent in the others. CONCLUSIONS: Targeted screening for urban Chagas disease is promising in areas with ongoing vector-borne transmission; however, these pockets of epidemic transmission remain difficult to detect a priori. The flexibility to adapt to the epidemiology that emerges during screening is key to an efficient case detection intervention. In heterogeneous urban environments, self-assessments of risk and simple residence history questionnaires may be useful to identify those at highest risk for Chagas disease to guide diagnostic efforts.

Parasitosis en niños en edad escolar: relación con el grado de nutrición y aprendizaje / Parasites in schoolage children: relationship with the degree of nutrition and learning

OBJETIVO: Conocer la prevalencia e infección por enteroparásitos, así como determinar el estado nutricional de una población escolar infantil aparentemente sana de la Institución Educativa Nacional ôKarol Wojtylaõ, del distrito de San Juan de Lurigancho, Lima-Perú. MATERIAL Y MÉTODO: 05 niños, de ambos sexos, entre 6 y 12 años de primer a sexto grado de primaria. Las muestras fueron analizadas utilizando la técnica de sedimentación espontánea (TSET) y el método de Graham. RESULTADOS: En el 44.4 % (91/205) se realizó el examen parasitológico. La prevalencia de enteroparásitos fue 61.50% (56/91), hallando Enterobius vermicularis (14.30%), Hymenolepis nana (8.80%), Blastocystis hominis (38.50%), y Giardia lamblia (13.20%) y no patógenos como Entamoeba coli (17.60%). CONCLUSIONES: Existe una alta prevalencia de parasitosis en la población escolar analizada, la que estuvo relacionada con el nivel sociocultural y económico. No se observó relación directa entre presencia de parásitos y deficiencia en el aprendizaje, ni con desnutrición.

OBJECTIVES: To determine the prevalence and degree of infection by intestinal parasites and to determine the nutritional status of apparently healthy infant school population that attends the National Educational Institution ôKarol Wojtylaõ in the district of San Juan de Lurigancho, Lima, Peru. MATERIAL AND METHODS: 205 children, both female and male between 6 and 12 years belonging to the sections of first through sixth grade. We used the spontaneous sedimentation technique (TSET) and the method of Graham. RESULTS: 44.4% (91/205) were made parasitological examination. The prevalence of intestinal parasites was 61.50% (56/91), finding the presence of Enterobius vermicularis (14.30%), Hymenolepis nana (8.80%), Blastocystis hominis (38.50%) and Giardia lamblia (13.20%) and pathogens such as Entamoeba coli (17.60%). CONCLUSIONS: There is a high prevalence of parasitosis in the school population tested, which is related to sociocultural and economic level of the settlers did not observe a direct relationship between the presence of parasites and poor learning. There was no relation between the presence of parasites and malnutrition.

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.

Molecular characterization of Echinococcus granulosus from Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene.

Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosus worldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.

Molecular characterization of Echinococcus granulosusfrom Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene

Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosusworldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.

Aspectos entomológicos de la enfermedad de chagas en Huallaga y Picota, San Martín, Perú / Entomological aspects of chagas disease in Huallaga and Picota, San Martin, Peru

Introducción: Existe escasa información y no actualizada sobre la presencia de triatominos en el departamento de San Martín, zona amazónica de nuestro país, y es importante actualizarla, ya que hay reportes recientes de casos de enfermedad de Chagas procedentes de la amazonía peruana cuyos vectores serían triatominos silvestres. Objetivos: Conocer la distribución geográfica de triatominos hematófagos en Huallaga y Picota, San Martín, Perú. Determinar los índices entomológicos, sus hábitos alimenticios y caracterizar los tripanosomatídeos que portan. Diseño: Investigación descriptiva observacional. Lugar: Red de Salud Huallaga y Picota, Laboratorio Regional de la Región de Salud San Martín. Laboratorios del Instituto Nacional de Salud. Participantes: Viviendas de 6 distritos de las provincia de Huallaga y 9 de Picota, del Departamento de San Martín. Intervenciones: La búsqueda de triatominos fue en 3 362 viviendas de áreas periurbanas y rurales. Mediante la prueba de precipitina, se determinó la fuente de alimentación. Se aisló tripanosomatídeos mediante infección en ratones Balb/C e inoculación en medio agar sangre, y por PCR se caracterizó el genoma por amplificación del espaciador intergénico del gen miniexón. Principales medidas de resultados: Determinar si Huallaga y Picota, San Martín, Perú, son zonas de riesgo de enfermedad de Chagas. Resultados: En 46 viviendas, de 3 362 muestreadas se capturó 53 triatominos adultos pertenecientes a Rhodnius pictipes (56,6 por ciento), Panstrongylus geniculatus (41,5 por ciento) y Eratyrus mucronatus (1,9 por ciento). Se reporta P. geniculatus por primera vez para las dos provincias. Los índices de infestación para ambas provincias fueron 1,4 por ciento y 3,8 por ciento, respectivamente, y corresponden al índice de infección natural; mientras que el índice de dispersión fue 30,1 por ciento. En R. pictipes se identificó cinco fuentes de alimentación (pollo, humano, perro, cobayo y gato) y en P. geniculatus un perfil alimentario mixto: perro/gato/pollo. Los Trypanosoma spp. aislados de R. pictipes, procedente de Sacanche (Huallaga), corresponden a TCI (350 pb); resultado similar se obtuvo en los 10 clones de este aislamiento. Conclusiones: Los resultados nos indican que, en las localidades estudiadas, R. pictipes y P. geniculatus estarían pasando por un proceso de domiciliación y que en las localidades de Huallaga R. pictipes sería el principal vector de Trypanosoma cruzi TC1; por lo que, dichas localidades estarían consideradas como zonas de riesgo de enfermedad de Chagas.

Introduction: There is little and not recent information on the presence of triatomine bugs in San Martin department, Amazon area of our country where Chagas disease has been reported by wild triatomine insects as vectors. Objectives: To determine the geographic distribution of hematophagous triatomine insects in Huallaga and Picota provinces, San Martin department, Peru. To determine the domiciliary infestation by triatomine vectors indexes, trypano-triatomine infection as well as their dispersion. To determine the insects feeding source and to genetically characterize the tripanosomatidae they carry. Design: Observational and descriptive study. Setting: Health and Laboratories region networks. National Institute of Health laboratories. Participants: Houses from 6 districts of Huallaga province and 9 from Picota province (San Martin department). Interventions: Triatomine insectÆs collection was carried out in 3 362 homes located in semi-urban and rural zones accounting for 30 per cent of the total area of studied provinces. Feeding preferences were assessed by a precipitin test using specific antibodies against guinea pig, dog, cat, chicken and human beings sera. Trypanosomes were isolated by inoculation of stool samples from infected insects in Balb/c mice and using axenic culture media. Genetic characterization was done by PCR amplification of the genome by gene intergenic spacer of the miniexon. Main outcome measures: To assess if Huallaga and Picota, San Martin, Peru, are Chagas disease risk areas. Results: In 46 of the 3 368 homes visited, 53 triatomine adults were collected belonging to the species Rhodnius pictipes (56,6 per cent), Panstrongylus geniculatus (41,5 per cent) and Eratyrus mucronatus (1,9 per cent). For the first time, P. geniculatus was reported in both provinces included in the study. Domiciliary infestation index was 1,4 per cent, trypano-triatomine infection index was 3,8 per cent and dispersion index was 30,1 per cent. For R. pictipes 5 sources of food were identified (chicken, human, dog, guinea pig and cat) and for P. geniculatus, a mix feed: dog, cat and chicken. Trypanosoma spp. isolates of R. pictipes from Sacanche (Huallaga) belonged to T. cruzi TCI (350 pb); similar result was obtained in 10 clones studied. Conclusions: Results indicate that R. pictipes and P. geniculatus are undergoing colonization of the regions included in this study. Within the province of Huallaga, R. pictipes is the predominant vector of T. cruzi; therefore these locations must be considered high risk areas for Chagas disease.

[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.

Breve reseña histórica de la enfermedad de Chagas, a cien años de su descubrimiento y situación actual en el Perú: [revisión] / Short review of Chagas disease history after a century of its descovery and the current situation in Peru: [review]

Se presenta un resumen sobre el descubrimiento de la enfermedad de Chagas y datos actuales de la situación epidemiológica y clínica de la enfermedad en el Perú. El hallazgo de Trypanosoma cruzi en la sangre de una niña en 1909, el aislamiento del agente etiológico en animales de experimentación y el hallazgo del parásito en el intestino de un triatomino, convierte a Carlos Chagas en el descubridor de la enfermedad, que hoy, con justicia, el mundo científico lareconoce como la enfermedad de Chagas. Ocho años después del descubrimiento de Carlos Chagas, Edmundo Escomel, médico arequipeño, reporta la presencia de Triatoma infestans en los valles del departamento de Arequipa y dos años después el primer caso de enfermedad de Chagas en un paciente de Madre de Dios. En el Perú se ha descrito 19 especies de triatominos y como el reservorio más importante el cobayo. Las áreas endémicas más importantes son elsur, norte, nororiente y existen algunos focos de transmisión activa en la cuenca amazónica. Tacna logró la certificaciónde la eliminación de la transmisión vectorial y se espera que otras áreas con T. infestans puedan lograrlo en el futuro.

This paper is a short review of the discovery of Chagas disease and the current information of the epidemiological and clinical aspects of the disease observed in Peru. With the discovery of Trypanosoma cruzi in the blood of a child in 1909, the isolation of the etiologic agent in experimental animals and the finding of similar parasites in the intestinal content oftriatomines, Carlos Chagas determined the parasiteÆs life cycle and, clinical symptoms of this new entity designated as Chagas disease. Eight years after Dr Carlos Chagas discovery (1917), Dr. Edmundo Escomel born in Arequipa, reported the presence of Triatoma infestans in the valleys of Arequipa department and after two years the first human case of Chagas disease from Madre de Dios. In Peru, have been described 19 species of triatomines, and several studies show guinea pig ôcuyõ as the most important reservoir of the parasite. The endemic areas are present in the south, north and northeast, mainly the Amazonian area. Recently, Tacna has been declared free of vectorial transmission and we hope others parts of the country could receive similar certification.

Evaluación de una prueba de aglutinación de látex para el diagnóstico serológico de la equinococosis quística / Evaluation of agglutination latex test for serologic diagnosis of cystic echinococcosis

Se evaluó una prueba de aglutinación de látex estandarizada para el diagnóstico serológico de la echinococosis quística. Se utilizó partículas de látex de 0,25 um de diámetro, las cuales fueron sensibilizadas con antígeno total de líquido liofilizado de quiste hidatídico de ovino. Se usaron 80 sueros, 40 de pacientes operados por enfermedad hidatídica confirmada patología,20 de pacientes con otras enfermedades parasitarias como cisticercosis, fasciolosis, toxoplasmosis, teniosis, enfermedad de chagas y malaria y 20 de personas sanas. Se encontró que de los 40 sueros de pacientes con hidatidosis uno dio resultado negativo y de los 40 sueros de pacientes o personas sin hidatidosis cuatro dieron resultados positivo obteniéndose una sensibilidad de 97,5 por ciento, una especificidad de 90,0 por ciento, un valor predictivo positivo de 90,7 por ciento y negativo de 97,3 por ciento, siendo la concordancia encontrada al evaluar la repetibilidad y reproducibilidad del 100 por ciento en laboratorios de zonas endémicas. Se recomienda el uso de esta prueba para el descarte de hidatidosis en regiones endémicas del país, así como prueba de tamizaje en estudios epidemiológicos.

We evaluated a latex agglutination test standardized for serological diagnosis of cystic echinococcosis. We used latexparticles of 0.25 um in diameter, which were sensitized with antigen lyophilized total of hydatid cyst fluid of sheep. Weused 80 serum samples, 40 patients operated on pathology confirmed hydatid disease, 20 patients with other parasitic diseases such as cysticercosis, fascioliasis, toxoplasmosis, taeniosis, Chagas disease and malaria, and 20 healthy people. It was found that of 40 serum samples from patients with hydatidosis was negative and one of the 40 serum samples from hydatidosis patients or people with no positive results four gave a sensitivity of 97.5 por ciento, specificity of 90.0 por ciento, predictive value 90.7 por ciento positive and negative 97.3 por ciento, with the agreement found to evaluate the repeatability and reproducibility of 100 por ciento in laboratories in endemic areas. We recommend the use of this test for the diagnosis of hydatiddisease in endemic regions of Peru, also as a screening test in epidemiological studies.

Fuentes de alimentación de panstrongylus herreri (hemiptera: Triatominae) capturados en utcubamba, amazonas - perú / Food sources of panstrongylus herreri (hemiptera: triatominae) collected in utcubamba, Amazonas - Peru

Objetivo. Identificar las fuentes de alimentación de Panstrongylus herreri, procedente del distrito de Cajaruro, provincia de Utcubamba, departamento de Amazonas. Materiales y métodos. El estudio se realizó en dos etapas: primera, se estandarizó la prueba de precipitina usando como antígenos sueros sanguíneos de: humano, perro, gato, cobayo y pollo, y anticuerpos específicos obtenidos por inoculaciónde los antígenos en conejos. Se alimentaron ninfas de Triatoma infestans del IV y V estadio criadas en laboratorio con sangre de perro,cobayo, pollo y humano para luego determinar la sensibilidad y especificidad de la prueba. Segunda, se aplicó la prueba de precipitina a 102ejemplares de P. herreri domiciliarios, procedentes de la zona de estudio. Resultados. Se obtuvo títulos de anticuerpos desde 1:10 000 a1:30 000. La especificidad de la prueba fue 100 por ciento para todos los intervalos de tiempo evaluados; mientras, que la sensibilidad varió de 70 a 100 por ciento. De los 102 P. herreri, en 93 ejemplares se detectó contenido intestinal y se encontró la fuente alimenticia en 77 de ellos, la sangre de cobayo (36,3 por ciento) fue la principal fuente de alimentación, seguido de humano (18,2 por ciento) y pollo (14,3 por ciento). El índice de infección tripano-triatomíno fue 62,4 por ciento. Conclusiones. La prueba de precipitina mostró mejor especificidad que sensibilidad. En las áreas de estudio, la fuente principal de alimentación de P. herreri es la sangre de cobayo, seguido del humano y pollo. El elevado índice de infección a Trypanosoma sp. relacionado con la fuente de alimentación por cobayo, nos indicaría que es el principal reservorio.

Objective. To identify the food sources of Panstrongylus herreri from district of Cajaruro, province of Utcubamba, department of Amazonas. Material and methods. The study was performed in two steps: in the first, a precipitin test was standardized using as antigen, blood sera from human being, dog, cat, guinea pig and chicken and the specific antibodies obtained by inoculation of the antigens in rabbits. Nymphs of Triatoma infestans (IV and V instars)maintained in the laboratory were fed on dog, cat, guinea pig, and human being to determine the sensitivity and the specificity of the precipitin test. In the second step, 102 P. herreri specimens collected from houses of the two villageswere submitted to the standardized precipitin test. Results. The developed test permitted good titles of antibodies in the range from 1:10 000 to 1:30 000. The specificity was 100 per cent and the sensitivity was 70 per cent to 100 per cent. Of the 102 P. herreri specimens were detected intestinal content in 93 and found the food source in 77 of them, the blood of guinea pig (36.3 per cent) was the main source of food, followed by human (18.2 per cent) and chicken (14.3 per cent).The Trypano-triatomine index was 62.4 per cent. Conclusions. The precipitin test showed better specificity than sensitivity. In this study sites, the main food source of P. herreri was guinea pig follow by the human being and chicken. The high rate of insects carrying Trypanosoma sp. was related to the insects fed on guinea pig pointing it out as reservoir of the parasite.

Características morfométricas, genéticas, alimenticias y vectoriales de Panstrongylus herreri procedentes de Jaén (Cajamarca) y Cajaruro Amazonas), Perú / Morphometric, genetic, FEEDING and vectorial characteristics of Panstrongylus herreri from Jaén (Cajamarca) and Cajaruro (Amazonas), Peru

Objetivo. Comparar las características morfológicas, alimenticias y genéticas de dos poblaciones de Panstrongylusherreri, de los distritos de Jaén (Cajamarca) y Cajaruro (Amazonas). Materiales y métodos. Se colectó especímenes adultos de P. herreri, 42 (Jaén) y 68 (Cajaruro). Se utilizó la morfometría geométrica para evaluar el dimorfismo sexual de tamaño y conformación. El perfil genómico se realizó por amplificación del espaciador interno transcrito del ADNr(ITS-2). La amplificación del espaciador intergénico del gen mini-exón, permitió la caracterización molecular de lostrypanosomas aislados. Se utilizó la prueba de precipitina para conocer las fuentes de alimentación de los vectores y así poder asociarlos a posibles reservorios del parásito. Resultados. El análisis morfométrico demostró que el dimorfismo sexual de tamaño fue similar (p > 0,05); no ocurrió lo mismo con el dimorfismo de la conformación; asimismo no se encontró diferencias de tamaño al comparar por separado hembras y machos de Jaén y Cajaruro. Por ITS-2, se evaluó cinco especímenes de cada distrito, en ellos se observó una banda de 960 pb aproximadamente. Sólo en Cajaruro se encontraron triatominos parasitados, que fue caracterizado como Trypanosoma cruzi TCI (350 pb). Se identificó al cobayo como la fuente de alimento más frecuente. Conclusiones. Ambas poblaciones de P. herreri por morfometría geométrica e ITS-2, no evidenció diferencias, indicando que se trataría de una misma población y por consiguiente de la misma procedencia. La sangre de cobayo fue la más frecuente fuente de alimento, pudiendo ser el principal reservorio para la enfermedad de Chagas en esta zona del Perú.

Objective. To compare the morphology, feeding and the genetic profile of specimens of Panstrongylus herreri from districts of Jaen (Cajamarca) and Cajaruro (Amazonas). Material and methods. Adult specimens of P. herreri were collected, 42 from Jaen and 68 from Cajaruro. Geometric morphometrics was used to evaluate the sexual differences in size and form. The genetic profile was done using the PCR amplification, second internal transcribed spacer (ITS-2) of theribosomal ADN. The molecular characterization of the isolated trypanosomes was made by the amplification the parasite. We used the precipitin test for identification the feeding sources and thus be able to associate them with the potential reservoir of the parasite. Results. The morphometric analyses showed no difference (p > 0,05) in sex between the insects from both departments, but there was difference in the form between females. The genetic profile showed by ITS-2 similar bands of 960 pb in both groups (five insects) from Jaen and Cajaruro. The trypanosoma isolated from P. herreri (only in Cajaruro) was identify as Trypanosoma cruzi TCI (350 pb). Guinea pig blood was the main source of food for the insects. Conclusions. P. herreri from both localities no showed important differences under geometric morphometry and genetic studies. These results indicate the same population with similar origin. The guinea pig blood was the main source of food of P. herrei, may be the principal reservoir for the Chagas disease from this Peruvian area.