Prevalencia de Giardia lamblia por ecorregiones en preescolares y escolares peruanos: Propuesta de estratificación de riesgo

Introducción. La giardiasis es ocasionada por el protozoario intestinal Giardia lamblia, su transmisión tiene variabilidad geográfica y a pesar de ser muy frecuente, no existe una herramienta de estratificación de riesgo para priorizar las intervenciones. Objetivo. Estimar la prevalencia de G. lamblia en preescolares y escolares peruanos por ecorregiones entre 1990 a 2018. Métodos. A partir de un metaanálisis previo, se realizó un subanálisis por ecorregiones de la prevalencia de G. lamblia en 26 estudios en preescolares y escolares peruanos entre 1990 a 2018. Se extrajeron los datos por distrito y utilizando Google Earth fueron clasificados en ecorregiones. La heterogeneidad fue analizada mediante la prueba de Q de Cochrane y el sesgo de publicación mediante el método de Egger con StatsDirect versión 3.2.7. Se utilizó el método de riesgo absoluto para estratificar la prevalencia a nivel de distrito y se definió 4 estratos en base a los percentiles o arbitrariamente. Resultados. Se identificaron 43 datos de prevalencia a nivel de distrito que incluyeron 7606 participantes. Las prevalencias combinadas más altas por el método de efectos aleatorios de G. lamblia fueron de 47,0% intervalo de confianza (IC) 95%: 40,0 -54,0) en el desierto del Pacífico; 27,9% (IC95%: 22,8 - 33,2) en selva baja y 26,9% (IC95%: 22,5 -31,5) en la Puna. Conclusiones. De cada 100 preescolares y escolares que viven en las ecorregiones del desierto del Pacífico, selva baja y Puna, 47, 28 y 27 menores de edad, respectivamente, están infectados con G. lamblia. Asimismo, se propone 4 estratos de riesgo en función de la prevalencia: esporádico (0 a <1%), hipoendémico (1 a <25%), mesoendémico (≥ 25 a <50%) e hiperendémico (≥50%).

Introduction. Giardiasis is caused by an intestinal protozoan, Giardia lamblia. Despite its high prevalence and geographical transmission variability, there is no risk stratification tool available to prioritize interventions. Objective. To estimate the prevalence of G. lamblia in Peruvian preschoolers and schoolchildren by ecoregion from 1990 to 2018. Methods. Based on a previous meta-analysis, we conducted a G. lamblia prevalence sub-analysis by ecoregions from data of 26 studies in Peruvian preschoolers and school-aged children between 1990 and 2018. The data was extracted by district, a classification by ecoregions was made through Google Earth. Heterogeneity was analyzed using Cochrane Q test and publication bias applying the Egger method with StatsDirect version 3.2.7. The absolute risk method was performed to stratify the prevalence at district level, and 4 strata were defined based on percentiles or arbitrarily. Results. Forty-three district-level prevalence data was estimated, including 7,606 participants. The highest pooled prevalences by the random effects method of G. lamblia were 47.0% (95% CI: 40.0-54.0) in the Pacific desert, 27.9% (95% CI: 22.8-33.2) in the lowland forest and 26.9% (95% CI 22.5-31.5) in the Puna. Conclusions. Of every 100 preschoolers and school-aged children living in the Pacific desert, lowland forest, and in the Puna ecoregions, 47, 28, and 27 minors are infected with G. lamblia, respectively. Likewise, 4 risk strata are proposed based on prevalence: sporadic (0 to <1%), hypoendemic (1 to <25%), mesoendemic (≥25 to <50%) and hyperendemic (≥50%).

Strongyloides stercoralis hyperinfection syndrome: a deeper understanding of a neglected disease.

Strongyloides stercoralis hyperinfection syndrome (SHS) is a life-threatening condition that warrants early detection and management. We describe the pathogenesis, organ-specific clinical manifestations, and risk factors associated to this condition. A comprehensive review of the literature was conducted in PubMed, LILACS, EBSCO and SciELO by using the keywords: "hyperinfection syndrome"; "Strongyloides stercoralis"; "disseminated strongyloidiasis"; "systemic strongyloidiasis", "pathogenesis" and "pathophysiology". Relevant articles on this topic were evaluated and included by consensus. Also, a secondary search of the literature was performed. Articles in English and Spanish language were included. SHS has been described in tropical and sub-tropical regions. However, there is growing evidence of cases detected in developed countries favored by increasing migration and the advance in immunosuppressive therapies for oncologic and inflammatory diseases. SHS is characterized by massive multiplication of larvae, typically in immunocompromised hosts. Clinical manifestations vary according to the organ involved and include diarrhea, intestinal bleeding, alveolar hemorrhages, heart failure, jaundice, bacteremia among others. Despite advances in the understanding of this condition, fatality rates are near 90%. Clinicians should consider SHS in the differential diagnosis of acutely ill patients with multiple organ damage and epidemiological risk factors. Adverse outcomes are common, especially with delayed anti-parasitic treatment.

Occurrence and molecular characterization of Giardia duodenalis cysts and Cryptosporidium oocysts in raw water samples from the Rímac River, Peru.

Giardia and Cryptosporidium are potentially pathogenic protozoa which are ubiquitous in ambient surface water. The present study included 60 samples of surface water from three sampling sites from the Rímac River, Lima and Callao, Peru, to detect the occurrence of Giardia spp. and Cryptosporidium spp. and to perform molecular characterization of specimens found. Water samples were concentrated using the membrane filtration technique, and following elution, cysts and oocysts were visualized by direct immunofluorescence assay (IFA). For molecular characterization, tpi and bg gene fragments and 18S rRNA were amplified by nested PCR for Giardia and Cryptosporidium, respectively, followed by sequencing and phylogenetic analysis. Giardia cysts were found in 93.3% of the analyzed samples, whereas Cryptosporidium oocysts were detected in 15%. The positivity of the Giardia cysts was 86.6% (n = 26) in 2014, while Cryptosporidium oocysts were not detected. In 2015, both protozoa were found in raw water samples, with all 30 samples collected positive for Giardia cysts (100.0%) and 9 positive for Cryptosporidium oocysts (30.0%). Oocysts were detected in 20.0% of water samples from sites 1 (mean 5.25 oocysts/L) and 2 (mean 52.3 oocysts/L), while at site 3, oocysts were detected in 50.0% of raw water samples (mean 193.6 oocysts/L). The presence of Giardia duodenalis assemblage A was confirmed in several samples by the phylogenetic positioning of the bg and tpi genes, and the sub-assemblage AII was predominant (8/9). Sequencing for Cryptosporidium resulted in profiles compatible with Cryptosporidium hominis, Cryptosporidium meleagridis, and Cryptosporidium baileyi. This is the first time that the presence of G. duodenalis assemblage A/sub-assemblage AII and Cryptosporidium species has been reported in surface water samples in Peru. These Cryptosporidium species and the Giardia duodenalis assemblage are associated with human disease which highlights the potential risk to public health and the need to increase environmental monitoring measures to protect this water body.

Association of Fasciola hepatica Infection with Liver Fibrosis, Cirrhosis, and Cancer: A Systematic Review.

BACKGROUND: Fascioliasis has been sporadically associated with chronic liver disease on previous studies. In order to describe the current evidence, we carried out a systematic review to assess the association between fascioliasis with liver fibrosis, cirrhosis and cancer. METHODOLOGY AND PRINCIPAL FINDINGS: A systematic search of electronic databases (PubMed, LILACS, Scopus, Embase, Cochrane, and Scielo) was conducted from June to July 2015 and yielded 1,557 published studies. Among 21 studies that met inclusion and exclusion criteria, 12 studies explored the association of F. hepatica with liver fibrosis, 4 with liver cirrhosis, and 5 with cancer. Globally these studies suggested the ability of F. hepatica to promote liver fibrosis and cirrhosis. The role of F. hepatica in cancer is unknown. Given the heterogeneity of the studies, a meta-analysis could not be performed. CONCLUSIONS: Future high-quality studies are needed to determine the role of F. hepatica on the development of liver fibrosis, liver cirrhosis, and cancer in humans.

Fracaso de dosis única de triclabendazole para el tratamiento de fasciolosis humana / Failure of single-dose triclabendazole in the therapy of human fasciolasis

La fasciolosis humana es prevalente en zonas ganaderas del Perú. La única droga efectiva para tratar a la infección por Fasciola hepatica en la práctica clínica es el triclabendazole (TCBZ). Sin embargo, se ha reportado recientemente resistencia de la F. hepatica al TCBZ en Perú tanto en humanos como en animales. Este problema ya se sospechaba anteriormente en vista que una dosis única de triclabendazole no curaba (eliminación de huevos de Fasciola en heces) en algunos pacientes. Aquí reportamos 11 de 12 casos humanos infectados por F. hepatica que no respondieron a dosis única de TCBZ 10 mg/kg vía oral. En vista de estos resultados observados en la práctica clínica, recomendamos considerar por lo menos dos dosis de TCBZ para los infectados. Creemos que el tratamiento de fasciolosis se ha convertido en un problema emergente desde el punto de vista farmacológico. Se necesitan nuevos regímenes de terapia o drogas contra F. hepática

Human fascioliasis is prevalent in cattle raising areas in Peru. The only effective drug against Fasciola hepatica infections in clinical practice is triclabendazole (TCBZ). However, the occurrence of TCBZ-resistant F. hepatica both in humans and animals has recently been reported in Peru. This issue was previously suspected, due to treatment failure (presence of Fasciola eggs after treatment) in some patients receiving a single dose of TCBZ. Here, we report 11 of 12 human cases infected by F. hepatica who did not respond to TCBZ administered in a single 10 mg/Kg oral dose. Given these results observed in clinical practice, we recommend the use of at least two doses of TCBZ for human fascioliasis. Nowadays, the treatment for fascioliasis has become an emergent problem from the pharmacological point of view. New therapies against Fasciola are urgently needed

Síndrome de intestino irritable y parasitosis intestinal: una visión desde Sud-América / Irritable bowel syndrome and intestinal parasites: a view from South America

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder of uncertain etiology. Several studies have proposed the possible role of intestinal parasites in the pathogenesis of IBS. We aimed to summarize the epidemiological studies that describe a possible link between intestinal parasites and IBS, with special interest in endemic areas for intestinal parasitism such as South America. A comprehensive review of the literature was conducted by using the keywords: irritable bowel syndrome, intestinal parasites, protozoan infection, soil-transmitted helminths and South America. Giardia lamblia may cause IBS symptoms that can persist several years after effective treatment. Dientamoeba fragilis can cause IBS-like symptoms, but low sensitive parasitological techniques may fail to detect it. Entamoeba histolytica can cause a chronic non-dysenteric colitis, but several studies have failed to find an association with IBS. The role of Blastocystis hominis in IBS remains controversial. In addition, epidemiological studies evaluating the effect of soil-transmitted helminths in IBS are scant. Symptoms elicited by intestinal parasites may resemble to those in IBS, especially in endemic areas such as South America, where both the prevalence of IBS and intestinal parasitism are high. Whether these organisms are the cause or contributing factors in IBS remains a subject of study. Routine parasitological examination of stools in individuals who full-fit the criteria for IBS should be included upon initial assessment in endemic countries...

El Síndrome de intestino irritable (SII) es un desorden gastrointestinal funcional de etiología incierta. Muchos estudios han propuesto que los parásitos intestinales pueden tener un rol en la patogénesis del SII. Se sintetizó estudios epidemiológicos que describen una relación posible entre el parasitismo intestinal y el SII, con especial interés en aquellos estudios que fueron realizados en zonas endémicas para dichos organismos. Se realizó una revisión extensa de la literatura por medio de las siguientes palabras clave: síndrome de intestino irritable; parásitos intestinales; protozoarios; helmintos y Sud-América. Giardia lamblia puede causar síntomas similares al SII que pueden persistir por muchos años, después de tratamiento efectivo. Dientamoeba fragilis puede causar un cuadro similar al SII, pero al emplearse técnicas de baja sensibilidad, se puede fallar en detectar su presencia. Entamoeba histolytica puede causar un cuadro de colitis no disentérica, pero varios estudios no han podido encontrar una relacion con el SII. El rol del Blastocystis hominis en el SII sigue siendo controversial. Adicionalmente, los estudios epidemiológicos evaluando el efecto de los helmintos en el SII son escazos. Los parásitos intestinales pueden causar síntomas que pueden parecerse a los que se encuentran en pacientes con SII. Ésta observación merece especial atención en regiones como Sud-América, donde las prevalencias del SII y del parasitismo intestinal han sido estimadas como altas. Si es que éstos organismos son la causa o un factor contributor en el SII, aún es materia de estudio. En la evaluación inicial de un probable caso de SII, los estudios parasitológicos pueden ser necesarios, especialmente en áreas endémicas...

Efficacy and tolerability of two single-day regimens of triclabendazole for fascioliasis in Peruvian children

The therapeutic scheme of triclabendazole (TCBZ), the recommended anthelmintic against Fasciola hepatica , involves 10mg/kg of body weight administered in a single dose; however, clinical trials in children are scarce. We evaluated the efficacy and tolerability of 2 schemes of TCBZ.

Field evaluation of a coproantigen detection test for fascioliasis diagnosis and surveillance in human hyperendemic areas of Andean countries.

BACKGROUND: Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in a few countries. Two hyperendemic areas were chosen: Huacullani, Northern Altiplano, Bolivia, representing the Altiplanic transmission pattern with high prevalences and intensities; Cajamarca valley, Peru, representing the valley pattern with high prevalences but low intensities. Coprological sample collection, transport and study procedures were analyzed to improve individual diagnosis and subsequent treatments and surveillance activities. Therefore, a coproantigen-detection technique (MM3-COPRO ELISA) was evaluated, using classical techniques for egg detection for comparison. METHODOLOGY AND FINDINGS: A total of 436 and 362 stool samples from schoolchildren of Huacullani and Cajamarca, respectively, were used. Positive samples from Huacullani were 24.77% using the MM3-COPRO technique, and 21.56% using Kato-Katz. Positive samples from Cajamarca were 11.05% using MM3-COPRO, and 5.24% using rapid sedimentation and Kato-Katz. In Huacullani, using Kato-Katz as gold standard, sensitivity and specificity were 94.68% and 98.48%, respectively, and using Kato-Katz and COPRO-ELISA test together, they were 95.68% and 100%. In Cajamarca, using rapid sedimentation and Kato-Katz together, results were 94.73% and 93.58%, and using rapid sedimentation, Kato-Katz and copro-ELISA together, they were 97.56% and 100%, respectively. There was no correlation between coproantigen detection by optical density (OD) and infection intensity by eggs per gram of feces (epg) in Cajamarca low burden cases (<400 epg), nor in Huacullani high burden cases (≥ 400 epg), although there was in Huacullani low burden cases (<400 epg). Six cases of egg emission appeared negative by MM3-COPRO, including one with a high egg count (1248 epg). CONCLUSIONS: The coproantigen-detection test allows for high sensitivity and specificity, fast large mass screening capacity, detection in the chronic phase, early detection of treatment failure or reinfection in post-treated subjects, and usefulness in surveillance programs. However, this technique falls short when evaluating the fluke burden on its own.

Highly effective and inexpensive parasitological technique for diagnosis of intestinal parasites in developing countries: spontaneous sedimentation technique in tube.

Millions of low-income people in the world are affected by intestinal parasites. Inexpensive, simple, and effective techniques for diagnosis are necessary. The spontaneous sedimentation technique in tube (SSTT), for application in poor healthcare settings and under field-work conditions, was described 25 years ago in Peru by Tello. The advantages of the SSTT are its ability to detect the majority of intestinal parasites, including eggs, larvae, cysts, and trophozoites, and its low cost.

Mechanisms of liver fibrosis associated with experimental Fasciola hepatica infection: roles of Fas2 proteinase and hepatic stellate cell activation.

We have evaluated the possible mechanisms of liver fibrosis caused by Fasciola hepatica in an animal model and in culture using immortalized human stellate cells. Liver biopsies of F. hepatica-infected rats were performed at wk 8 and 16. Serum-starved LX-2 cells, a human stellate cell line, were exposed to increasing concentrations of Fas2 antigen. The expression of key fibrosis-related genes was evaluated by qRT-PCR. There was a significant correlation between fibrogenic gene expression and both intensity and duration of infection. LX-2 cells exposed to Fas2 showed progressively increased expression of mRNAs for Collagen I, alpha-smooth muscle-actin, platelet-derived growth factor beta receptor, and tissue inhibitor of metalloproteinase II; inhibition of Fas2 cysteine proteinase activity by E-64 abrogated these increases, suggesting that the protease activity of Fas2 is involved in fibrogenic stimulation. In summary, F. hepatica infection is associated with up-regulation of mRNAs associated with hepatic fibrogenesis in vivo and in activated hepatic stellate cells.

Fasciolosis humana y animal en el Perú: impacto en la economía de las zonas endémicas / Human and animal fascioliasis in Peru: impact in the economy of endemic zones

Fasciola hepatica es el agente etiológico de la fasciolosis en el Perú. La fasciolosis es un problema de salud pública por la alta prevalencia de la infección humana, especialmente niños y un problema veterinario de importancia por las altas tasas de infección del ganado en la mayoría de regiones del País. La fasciolosis es endémica en la sierra y la costa, y esporádica en la región amazónica. La infección humana se reporta en 18 regiones y la animal en 21 de las 24 regiones del Perú. La transmisión humana ocurre en poblaciones andinas rurales dedicadas a la agricultura, pero hay un creciente número de casos en ciudades. Diferentes situaciones epidemiológicas de la infección humana se presentan: i) Regiones con casos no autóctonos, donde la infección es por consumo de vegetales contaminados traídos de zonas endémicas; ii) Regiones con poblados hipo- y mesoendémicos, transmisión local y prevalencia < 10 por ciento; y iii) Regiones con poblados hiperendémicos, transmisión local y prevalencia ≥ 10 por ciento. El parásito infecta a vacunos, ovinos, equinos, caprinos, porcinos, camélidos, cobayos y conejos. La pérdida ganadera anual por la fasciolosis es no menor de US$ 50 millones, estimada por la prevalencia de la infección y los decomisos de hígados de vacunos en mataderos. Es difícil estimar el impacto económico de la fasciolosis humana por su estatus de enfermedad desatendida, lo cierto es que la fasciolosis es endémica, y en algunos casos hiperendémica, en las regiones más pobres de nuestro país, donde la situación debe ser reconocida como una emergencia de salud pública.

Fasciola hepatica is the causative agent of fasciolosis in Peru; the disease is an important public health problem by the high prevalence of the human infection affecting mainly children and a major veterinary problem by the high rates of infected livestock. The human disease is endemic in the Sierra and the Coast but sporadic in the Amazonia, and reported in 18 Departments, while the animal infection in 21 of 24 Departments of Peru. Transmission occurs in Andean rural populations engaged in agriculture, but recently an increasing number of people became infected in the cities. The epidemiological situation in Peru includes i) Departments with non-autochtonous cases, where infection occurs by consumption of contaminated vegetables brought from endemic areas or infection is acquired by visit to endemic areas; ii) Departments with hypoendemic and mesoendemic villages, where transmission occurs by ingest of contaminated vegetables and prevalence ≤10 percent; and iii) Departments with hyper-endemic villages with human prevalence >10 percent, with an intense transmission by consumption of contaminated vegetables. The disease affects bovine, sheep, goat, swine, equine, South American camelids, rabbits and guinea pigs. The negative impact of fasciolosis in the livestock economy is not lesser than US$ 50 million per year, estimation based on the prevalence and the number of condemned livers in the abattoirs. It is difficult to estimate the economic impact of this infection in the human health due to its status of neglected disease, but fasciolosis is hyper-endemic in the poorest Andean areas of Peru where the situation has to be recognized as a public health emergency.

Características clínicas y epidemiológicas de la dermatitis de contacto de manos en una clínica médica de la ciudad de Lima, enero 2004 - diciembre 2008 / Clinical and epidemiological characteristics of hand contact dermatitis at a clinic in Lima, January 2004 - December 2008

Objetivos: determinar las características clínicas y epidemiológicas de los pacientes con dermatitis de contacto en manos diagnosticada en una clínica médica de Lima, así como determinar los alérgenos más frecuentes y relevantes en el grupo de pacientes con dermatitis de contacto alérgica. Material y métodos: estudio descriptivo de serie de casos. Se revisaron las fichas clínicas y resultados de pruebas de parche epicutáneo de pacientes atendidos por dermatitis de contacto entre los meses de enero del 2004 y diciembre del 2008 en la clínica médica Cayetano Heredia de la ciudad de Lima. Se recogió información demográfica, clínica y relacionada a la prueba del parche epicutáneo. Resultados: se observó un total de 118 pacientes de 32,5 +/- 15.8 años, 70.3% de sexo femenino, 87.3% presentaban dermatitis de contacto alérgica. Ser ama de casa y estudiante universitario fueron las ocupaciones más frecuentes (22.0% cada una). La media del tiempo de enfermedad fue de 56.8 +/- 7.5 meses, 78% de casos tenían un tiempo de enfermedad mayor a seis meses. El prurito fue el síntoma más frecuente (75.4%), la localización más común fue las palmas (87.3%) y la historia de alergias el antecedente personal más reportado (31.1%). Las sustancias de contacto más frecuentes fueron los detergentes, perfumes y cosméticos. Los cinco alérgenos más frecuentes con la prueba de parche y clínicamente relevantes fueron el sulfato de níquel (61% y 58% respectivamente), dicromato potásico (41.7% y 40.8%), cloruro de cobalto (34% y 33%), mezcla de fragancias a 18% (12.6% y 8.7%) y mezcla de fragancias al 14% (10.7% y 7.8%). Conclusiones: la dermatitis de contacto alérgica fue la forma más frecuente de dermatitis de manos en este estudio. Los alérgenos más relevantes fueron sulfato de níquel...

Objective: to determine the clinical epidemiological characteristics of patients with hand contact dermatitis diagnosed in a clinic in Lima, and to identify the most common and relevant allergens in a group of patients with allergic contact dermatitis. Methods: descriptive case series study. We reviewed clinical charts and results of epicutaneous patch test from patients seen by contact dermatitis between January 2004 and December 2008, at Cayetano Heredia Clinic in Lima. We collected demographic and clinical information and also information related to epicutaneous patch test. Results: we obtained a total of 118 patients with hands contact dermatitis with a media of 32.5 +/- 15.8 years of age, 70.3% were female, and 87.3% had allergic dermatitis. Being a housewife and a college student were the most frequent occupations (22.0% each). The mean disease duration was 56.8 +/- 7.5 months, 78% of cases had disease duration longer than six months. Pruritus was the most common symptom (75.4%). the most common location was the palms (87.3%) and history of allergies most reported personal history (31.1%). The most frequent contact substances were detergents, perfumes and cosmetics. The five most common allergens to the patch test and clinically relevant were nickel sulphate (61% and 58% respectively), potassium dichromate (41.7% and 40.8%), cobalt chloride (34% and 33%), mixed fragrances at 8% (12.6% and 8.7%) and fragrance mix at 14% (10.7% and 7.8%). Conclusions: allergic contact dermatitis was the most common type of hand dermatitis in this study. The most relevant allergens were nickel sulfate, potassium dichromate and cobalt chloride. The most frequent contact substances were detergents, perfumes and cosmetics.

Técnica de sedimentación en tubo de alta sensibilidad para el diagnóstico de 305 parásitos intestinales / Spontaneous sedimentation in tube technique (SSTT) for diagnosis of intestinal parasites

OBJETIVO. El objetivo de este estudio fue medir la eficacia diagnóstica de la técnica de sedimentación espontánea en tubo descrita por Tello (TSET), en comparación con el examen directo y otras técnicas de concentración, cuando se usa para determinar la prevalenciade enteroparasitosis en trabajos de campo y laboratorio en zonas rurales de la sierra y selvas peruanas.METODOS. Se realizó un estudio prospectivo (2000 û 2004) donde se incluyeron 1 802 muestrasde heces de diversas zonas del Perú: Iquitos (N=74), Puno (N=399), Junín (N=1241), Lima (N=88). RESULTADOS. La TSET presentó mayor sensibilidad para la detección de helmintos y protozoarios en comparación con las otras técnicas convencionales empleadas simultáneamente (P<0.000). Aunque no se debe prescindir de otras técnicas coprológicas, como Baermann para diagnóstico de Strongyloides stercoralis y la Técnica de Sedimentación Rápida de Lumbreras (TSR) para Fasciola hepatica, la TSET contribuye a un diagnóstico eficaz y oportuno de las enteroparasitosis. CONCLUSIONES. Debido a su bajo costo, fácil ejecución y adaptabilidad en la realización,tanto en el trabajo dentro de laboratorios como en los trabajos de campo, se constituye en un hecho de necesidad urgente su implementación en los laboratorios de áreas rurales, asícomo la capacitación del personal de salud encargado del diagnóstico, como un primer paso en la lucha contra la parasitosis intestinal en el Perú.

OBJECTIVE. The objective of this study was to evaluate the diagnostic efficacy of the Spontaneous Sedimentation in Tube Technique (SSTT) described by Tello, in comparison with thedirect smear and other concentration techniques, when it is used to determine the prevalence of intestinal parasites in field and laboratory studies in rural areas of the Andean Region. METHODS. A prospective study (2000 û 2004) was carried out including 1 802 fecal samplesfrom several areas around Peru: Iquitos (N=74), Puno (N=399), Junín (N=1241), Lima (N=88). RESULTS. SSTT showed more sensitivity to detect helminthes and protozoa in comparisonto other conventional techniques carried out simultaneously (P;0.000). Although Baermann Technique and LumbreraÆs Rapid Sedimentation Technique are crucial for Strongyloides larvae and Fasciola eggs detection, respectively; SSTT contributes to an effective andtimely diagnosis of the intestinal parasites. CONCLUSIONS. Due to its low cost, easy reproducibility and adaptability both in the laboratoryand field work, it should be mandatory and urgent its implementation in laboratories from rural areas, as well as training of the staff involved in the diagnosis, as first step in the fightagainst intestinal parasites in Peru.

Update on hepatobiliary flukes: fascioliasis, opisthorchiasis and clonorchiasis.

PURPOSE OF REVIEW: Hepatobiliary flukes--Fasciola, Opisthorchis, Clonorchis- are a major public health problem in east Asia, east Europe, Africa and Latin America. The present review focuses on current knowledge of clinical, diagnostic and treatment aspects caused by hepatobiliary flukes that can be applied to current protocols in endemic areas. RECENT FINDINGS: Specific risk factors and geographic areas for these flukes have been heavily reported recently, with millions of people infected worldwide. Human cases in nonendemic areas, related to immigration and the international food trade (i.e. raw vegetables and fish), have also been reported. Diagnostic imaging changes include track-like lesions that are a characteristic feature of acute fascioliasis on computed tomography scanning of the liver. Newly available diagnostic serological tests may detect early infection and, therefore, help reduce severe clinical complications such as recurrent cholangitis, cholecystitis, hepatic tumours, cysts, calcification, cholelithiasis, pancreatitis, most importantly, cholangiocarcinoma related to Opisthorchis viverrini and possibly Clonorchis sinensis, and liver fibrosis associated with Fasciola hepatica infections. Highly effective antiparasitic treatment is available for all flukes. SUMMARY: There is a better understanding of risk factors, clinical manifestations and complications, novel diagnosis tests and effective treatment, which together should help reduce the morbidity and mortality of these infections.

Strongyloides hyperinfection syndrome: an emerging global infectious disease.

The hyperinfection syndrome (HS) caused by Strongyloides stercoralis has a high mortality rate (15% to 87%). A variety of risk factors and predisposing conditions have been described, including new immunosuppressive therapies; HTLV-1 infection; cadaveric transplantation; immune reconstitution syndrome; haematological malignancies (especially lymphoma); tuberculosis; malnutrition secondary to chronic Strongyloides diarrhoea; international travel and immigration. Inhibition of Th2 cell-mediated, humoral or mucosal immunity is associated with HS. HS is more frequently seen in HTLV-1 than HIV patients. In AIDS, there is an increase in Th2 cytokines, while in HTLV-1 infection there is a decrease in the Th2 response, leading to an increased risk of autoinfection. Corticosteroid use remains the most frequent risk factor for HS. A number of ELISAs are useful for diagnosis and post-treatment evaluation. Once diagnosed, the disease may be managed effectively with anthelminthic drugs, including ivermectin. HS causes diverse symptoms and signs, with unusual manifestations leading to misdiagnosis and medical errors related to healthcare providers' lack of familiarity with the condition. HS is an example of an emerging tropical infection migrating to developed countries and requiring greater clinician awareness.

Natural history, clinicoradiologic correlates, and response to triclabendazole in acute massive fascioliasis.

Fascioliasis is highly endemic in the Andean region of South America. Newer serological assays have improved our ability to diagnose acute fascioliasis. The diagnosis was established by Fasciola hepatica serology (Fas2-ELISA or Western blot) in 10 patients. Identifiable exposure included ingestion of watercress (N = 8), alfalfa juice (N = 5), and lettuce (N = 1). Computed tomography of the abdomen showed hepatomegaly (N = 9), track-like hypodense lesions with subcapsular location (N = 8), and subcapsular hematoma (N = 2). Radiologic sequelae included cyst calcifications detectable at least 3 years after treatment. Stool examinations were negative for F. hepatica eggs; serology was positive (Arc II [N = 2], Fas2-ELISA [N = 6], Western blot [N = 2]). The syndrome of eosinophilia, fever, and right upper quadrant pain, elevated transaminases without jaundice, hypodense liver lesions on CT, and an appropriate exposure history suggests acute fascioliasis. Fascioliasis is specifically treatable with a single dose of triclabendazole.

Frequent HTLV-1 infection in the offspring of Peruvian women with HTLV-1-associated myelopathy/tropical spastic paraparesis or strongyloidiasis

OBJECTIVES: To describe the frequency of HTLV-1 infection among offspring of mothers who had presented with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), strongyloidiasis, or asymptomatic HTLV-1 infection, and to identify factors associated with HTLV-1 infection. METHODS: In a descriptive study, records were reviewed of HTLV-1-positive women and their offspring who had been tested for HTLV infection at a public hospital in Lima, Peru, from 1989 to 2003. Sons and daughters of women who had presented with strongyloidiasis, HAM/TSP, or asymptomatic infection were eligible for this study. RESULTS: Three hundred seventy subjects were included: 279 were the offspring of 104 mothers presenting with HAM/TSP, 58 were the offspring of 22 mothers with strongyloidiasis, and 33 were the offspring of 26 asymptomatic mothers. Mean age of the offspring at the time of testing was 26 years (standard deviation 12). Nineteen percent of the offspring tested positive for HTLV-1: 6 percent (2/33) of those with asymptomatic mothers, 19 percent (52/279) among the offspring of mothers with HAM/TSP, and 31 percent (18/58) among the offspring of mothers presenting with strongyloidiasis On multiple logistic regression analysis, three factors were significantly associated with HTLV-1: (a) duration of breast-feeding (odds ratio [OR] = 15.1; [4.2-54.1] for 12 to 24 months versus less than 6 months breast-feeding); (b) clinical condition of the mother (OR = 8.3 [1.0-65.3] for HAM/TSP and OR = 11.5 [1.4-98.4] for strongyloidiasis in comparison with offspring of asymptomatic mothers); and (c) transfusion history (OR = 5.5 [2.0-15.2]). CONCLUSIONS: In addition to known risk factors for HTLV-1 transmission (duration of breast-feeding and history of blood transfusion), maternal HAM/TSP and strongyloidiasis were associated with seropositivity among offspring of HTLV-1-infected mothers.

OBJETIVOS: Describir la frecuencia de la infección por HTLV-1 en los hijos e hijas de madres diagnosticadas con mielopatía/paraparesia espástica tropical asociada con el HTLV-1 (M/PET-HTLV-1), estrongiloidiasis o infección asintomática por HTLV-1, e identificar los factores asociados con la infección por HTLV-1. MÉTODOS: Para este estudio descriptivo se revisaron los registros de mujeres positivas a HTLV-1 y de sus hijos evaluados con pruebas para la infección por HTLV en un hospital público de Lima, Perú, entre 1989 y 2003. Eran elegibles para este estudio los hijos y las hijas de las mujeres que se presentaron con estrongiloidiasis, M/PET-HTLV-1 o infección asintomática. RESULTADOS: En el estudio participaron 370 personas: 279 hijos de 104 madres con M/PET-HTLV-1, 58 hijos de 22 madres con estrongiloidiasis y 33 hijos de 26 madres asintomáticas. La edad promedio de los participantes en el momento de su prueba para HTLV era de 26 años (desviación estándar: 12 años). De las personas estudiadas, 19 por ciento resultaron positivas a la infección por HTLV-1: 6 por ciento (2/33) de los hijos de madres asintomáticas, 19 por ciento (52/279) de los hijos de madres con M/PET-HTLV-1 y 31 por ciento (18/58) de los hijos de madres con estrongiloidiasis. Según el análisis de regresión logística múltiple, tres factores se asociaron significativamente con la infección por HTLV-1: a) duración de la lactancia materna por 12_24 meses (razón de posibilidades [odds ratio, OR] = 15,1; intervalo de confianza de 95 por ciento [IC95 por ciento]: 4,2 a 54,1, frente a la lactancia materna por menos de 6 meses); b) que la madre presentara M/PET-HTLV-1 o estrongiloidiasis (OR = 8,3; IC95 por ciento: 1,0 a 65,3 y OR = 11,5; IC95 por ciento: 1,4 a 98,4, respectivamente, en comparación con los hijos de madres asintomáticas); y c) los antecedentes de haber recibido una transfusión sanguínea (OR = 5,5; IC95 por ciento: 2,0 a 15,2). CONCLUSIONES: Además de los factores...

Evaluation of Fas2-ELISA for the serological detection of Fasciola hepatica infection in humans.

The performance of Fas2-ELISA for the diagnosis of Fasciola hepatica infection in children living in areas of high endemicity for fascioliasis in the Peruvian Andes is analyzed. Fas2-ELISA is based on the detection of circulating IgG antibodies elicited in infected individuals against a F. hepatica antigen termed Fas2. The study was conducted in three Andean localities, Huertas-Julcan in Junin, Asillo in Puno, and Cajamarca, with a total population of 634 children in an age range 1 to 16 years old. Child fascioliasis prevalence was 21.1% in Huertas-Julcan, 25.4% in Asillo, and 24% in Cajamarca, estimated by coprological inspection. The seroprevalence of F. hepatica infection, determined by Fas2-ELISA, was 27.8% in Huertas-Julcan, 44.6% in Asillo, and 29.1% in Cajamarca. The overall sensitivity of Fas2-ELISA was 92.4%, the specificity 83.6%, and the negative predictive value 97.2%. No association between OD(450) Fas2-ELISA and infection intensity measured by egg counting was observed. Results show that Fas2-ELISA is a highly sensitive immunodiagnostic test for the detection of F. hepatica infection in children living in human fascioliasis endemic areas.

Zonas hiperendémicas y mesoendémicas de la infección por fasciola hepática aledañas a la ciudad de Lima: una enfermedad emergente? / Hyperendemic and mesoendemic zones of the infection by hepatic fasciola bordering to the city of Lima: an emergent disease?

Introducción: La infección causada por F. hepática es endémica en el Perú con un creciente número de áreas endémicas, el reporte de estas es esencial para conocer el impacto de la infección en la población. Objetivo: Reportar la tasa de prevalencia de fasciolosis en zonas donde previamente no se habían detectado casos humanos. Material y métodos: Se estudiaron 3 distritos alrededor de la ciudad de Lima: La Chaqui, provincia de Canta; San Lorenzo de Quinti y San Miguel de Sangallaya, provincia de Huarochirí, pertenecientes al departamento de Lima. Se incluyó a niños y adultos jóvenes (menores de 25 años). Cada muestra de heces se analizó mediante la Técnica de Sedimentación Rápida de Lumbreras. Resultados: La prevalencia global por métodos coprológicos en los tres distritos fue 8.6 por ciento (n=291); 3.9 por ciento (n=102) en La Chaqui, 26.9 por ciento (n=27) en San Miguel de Sangallaya, y 8.6 por ciento (n=163) en San Lorenzo de Quinti. Conclusión: La infección por F. hepática infection es un problema de Salud Pública en pueblos alrededor de la ciudad de Lima. Por lo tanto, las medidas de control y prevención, a parte de ser dirigidas a pobladores autóctono, deben tomar en cuenta grupos de alto riesgo como viajeros frecuentes y personas con regímenes dietéticos basados en vegetales crudos.

Introduction: The infection caused by F. hepatica is endemic in Perú with anincreasing number of endemic areas, the reporting of them is essential to know the impact of the infection in the population. OBJECTIVE: To report the prevalence rate of fascioliasis in areas where it had not been detected human cases previously. MATERIAL AND METHODS: Three districts in Lima department were studied; La Chaqui,province of Canta; San Lorenzo of Quinti and San Miguel of Sangallaya, province of Huarochirí. It included children and young adults (less than 25 years old). One stool sample by person was collected and processed by means of the Rapid Sedimentation Technique described by Lumbreras. RESULTS: Overall, the prevalence rate in the three districts was 8.6 per cent (n=291); 3.9 per cent (n=102) in La Chaqui, 26.9 per cent (n=27) in San Miguel of Sangallaya, and 8.6 per cent (n=163) inSan Lorenzo of Quinti. CONCLUSION: F. hepatica infection is a Health Public problem in populations surrounding Lima city. Therefore, control and prevention measurements, besides being addressed to authoctonus people, should also take into account high-risk groups such as frequent travelers to endemic areas and people with dietetic programs based on raw vegetables.

Preliminary antigenic characterisation of an adult worm vomit preparation of Fasciola hepatica by infected human sera

Fascioliasis is an emerging/re-emerging vector-borne disease with the widest known distribution. Approximately 17 million people are infected around the world, being the Andean region the most affected area. There is an important necessity to develop sensitive and specific diagnostic tools to treat patients early and to avoid complications. In this paper we evaluated the immune response of infected humans against two antigenic preparations: the total soluble extract (FhTSE) and the adult worm vomit (FhAWV) in order to identify antigenic fractions specific for Fasciola hepatica. Both preparations were processed by SDS-PAGE and Western blot with human sera with fascioliasis (F), other parasitosis and healthy individuals. In the immunoblot of FhTSE, sera F recognised 16 bands with MW between eight and 110 kDa, from which those of 8, 9, 10, 38, 45 and 57 kDa were specific. In the preparation FhAWV, sera F recognised nine bands with MW from eight to 85 kDa, from which those of 8, 12, 15 and 24 kDa were specific. Some bands of cross-reaction were evident with sera from patients with other parasitoses, more frequent with the FhTSE. Bands within the MW mentioned, particularly that of eight kDa, have been shown to be specific by others, and deserve additional characterisation for their potential use in immunodiagnosis.

Fasciolíase é uma doença emergente/re-emergente transmitida por vetores com a distribuição sabidamente mais ampla. Existem aproximadamente 17 milhões de pessoas infectadas em todo mundo, sendo a região andina a área mais afetada. Há uma necessidade importante para desenvolver ferramentas diagnósticas sensíveis e específicas para tratar cedo os pacientes e para evitar complicações. Neste trabalho avaliamos a resposta imune de seres humanos infectados comparando a duas preparações antigênicas: o extrato solúvel total (FhTSE) e o vômito (FhAWV) do verme adulto a fim de identificar as frações antigênicas específicas para Fasciola hepatica. Ambas as preparações foram processadas por SDS-PAGE e Western blot com os soros humanos de portadores de fasciolíase (F), outras parasitoses e indivíduos saudáveis. No immunoblot de FhTSE, os soros F reconheceram 16 faixas com PM entre 8 e 110 kDa, das quais as de 8, 9, 10, 38, 45 e 57 kDa foram específicas. Na preparação de FhAWV, os soros F reconheceram 9 faixas com PM entre 8 e 85 kDa, das quais as de 8, 12, 15 e 24 kDa foram específicas. Algumas faixas com reação cruzada foram evidentes com os soros dos pacientes com outras parasitoses, mais freqüentes com o FhTSE. As faixas dentro do PM mencionado, particularmente aquela de 8 kDa, mostraram ser específicas por outros autores, e merecem a caracterização adicional para seu uso potencial no diagnóstico imunológico.