Prevalencia e intensidad de infección por geohelmintos, caracterizando los factores socio culturales y ambientales que inciden en la infección de escolares, Paraguay, 2015 / Prevalence and intensity of geohelminths infection characterizing the socio-cultural and environmental factors that affect the infection of school children, Paraguay, 2015

Resumen Introducción: Actualmente Paraguay no cuenta con estudios de prevalencia de infección por geohelmintos transmitidos por contacto con el suelo en escolares de 6 a 12 años. Objetivo: Determinar la prevalencia e intensidad de infección por Ascaris lumbricoides, Trichuris trichiura y las uncinarias y las características socio culturalesambientales de la población afectada. Materiales y Métodos: Estudio descriptivo, de corte transversal, en tres zonas climáticas: semi tropical continental, semi tropical semi estépico y semi tropical húmedo. Se seleccionaron 1.404 escolares de 20 escuelas de ocho departamentos, de las tres zonas climáticas del país. Se analizaron exámenes coproparasitológicos in situ con el método Kato-Katz. Resultados: La prevalencia nacional de geohelmintiasis fue de 3,7% (IC95% = 2,8-4,8). Los factores de riesgo fueron el consumo de agua de pozo OR: 2,88 (IC95% = 1,64-2,07), piso de tierra en la vivienda OR: 2,56 (IC95% = 1,45-4,50) y falta de baño con arrastre de agua en los hogares OR: 2,29 (IC95% = 1,23-4,28). Conclusión: A pesar de que la prevalencia nacional de geohelmintiasis fue baja, se recomienda promocionar buenas prácticas higiénicas, el uso de calzado, y consumo de agua segura, así como diseñar intervenciones con los sectores pertinentes para mejorar el acceso al agua segura y a instalaciones mejoradas de saneamiento básico.

Introduction: Currently, Paraguay has no data on the prevalence of soil-transmitted geohelminth infection in schoolchildren aged 6 to 12 years. Aim: To determine the prevalence and intensity of infection by Ascaris lumbricoides, Trichuris trichiura and hookworms and the socio-cultural-environmental characteristics of the affected population. Methods: Descriptive, cross-sectional study, in three semi-tropical climatic zones: continental, semi steppe and humid. A total of 1,404 schoolchildren from 20 schools in eight departments were selected from the country's three climate zones. Copro-parasitological exams were analyzed in situ with the Kato-Katz method. Results: The national prevalence for geohelminthiasis was 3.73% (95% CI = 2.8-4.8). The risk factors found were consumption of well water OR: 2.88 (95% CI = 1.64-2.07), ground floor in housing OR: 2.56 (95% CI = 1.45-4.50) and lack of flushing water baths in households OR: 2.29 (95% CI = 1.23-4.28). Conclusion: Although the national prevalence of geohelminthiasis was low, it is recommended to promote good hygienic practices, use of footwear, and safe water consumption, as well as designing interventions with all relevant sectors to improve access to safe water and improved basic sanitation facilities.

Geohelmintiasis en la Argentina: Una revisión sistemática / Soil transmitted helminthiasis in Argentina: A systematic review

Con el objetivo de analizar la prevalencia y distribución de las geohelmintiasis en la Argentina e identificar las áreas de mayor riesgo, realizamos una revisión sistemática de los estudios poblacionales publicados entre 1980 y 2011, indexados en las bases MEDLINE/ PUBMED y/o LILACS. También se incluyeron los datos de prevalencia basal del Programa Nacional de Desparasitación Masiva (PNDM, 2005). Se identificaron 310 publicaciones, de las que solo 24 artículos con información sobre 26 relevamientos, realizados en 8 provincias y un total de 5495 individuos evaluados, cumplían los criterios de inclusión. La prevalencia de geohelmintiasis varió ampliamente: Ascaris lumbricoides 0-67%, uncinarias 0-90%, Trichuris trichiura 0-24.5%, Strongyloides stercoralis 0-83%. La prevalencia acumulada estimada de los 4 geohelmintos principales varió entre 0.8 y 88.6%. Los datos basales del PNDM con información de 1943 niños de 12 provincias confirman esta heterogeneidad con rangos de prevalencia acumulada entre 0 y 42.7%. Los estudios incluidos en esta revisión muestran que la distribución de geohelmintiasis en la Argentina es heterogénea, con focos de alta prevalencia (> 20%) en el noreste y noroeste del país, los que podrían beneficiarse de una estrategia de desparasitación masiva. En muchos casos esta alta prevalencia es debida a uncinarias y estrongiloidiosis, lo que debe tenerse en cuenta para definir las estrategias diagnósticas y terapéuticas para su control. Asimismo, se resalta la escasez o ausencia de datos, con información de menos de la mitad de las provincias y menos de 8000 individuos evaluados.

A systematic review of surveys performed between 1980 and 2011 (published in MEDLINE/Pubmed and/or LILACS indexed journals, available in the baseline data from a Mass Deworming National Program (MDNP, 2005) was used to identify the prevalence, distribution and detection of risk areas for soil transmitted helminth infections (STH) in Argentina. We found 310 publications in the database using the pre-defined key-words (medical subject headings) for research purposes. Only 24 articles with 26 surveillance sites in 8 provinces and a total of 5495 surveyed individuals fulfilled the inclusion criteria. Frequency rates for STH had a wide range: Ascaris lumbricoides: 0-67%, hookworms: 0-90%, Trichuris trichiura: 0-24.6 and Strongyloides stercoralis: 0-83%. The estimated combined incidence varied from 0.8% to 88.6%. Baseline surveys from the MDNP reporting on 1943 children from 12 provinces confirmed the heterogeneity, with combined STH frequency rates ranging from 0 to 42.7%. Surveys included in this review showed that the distribution of STH in Argentina is not homogeneous, with areas of high incidence (> 20%) in the northeastern and northwestern provinces where mass deworming activities would be highly beneficial. In several surveys, the high overall incidence was mostly due to hookworms and S. stercoralis, a situation to be considered when selecting diagnostic and therapeutic control strategies. The scarcity or absence of data from various provinces and the availability of less than 8000 surveyed individuals should be considered.

Prevalência e fatores associados às geo-helmintíases em crianças residentes em municípios com baixo IDH no Norte e Nordeste brasileiros / Prevalence and factors associated with geohelminth infections in children living in municipalities with low HDI in North and Northeast Brazil

Para determinar a prevalência de geo-helmintíases e identificar fatores associados a sua ocorrência, foram realizados inquéritos coprológicos em amostra de crianças entre 5 e 14 anos de idade, residentes em dez municípios brasileiros com baixo Índice de Desenvolvimento Humano. Aplicou-se questionário aos responsáveis, obtendo-se informações sócio-econômicas e ambientais e foi feita coleta de fezes. Estimaram-se prevalências de geohelmintos segundo variáveis de interesse e se avaliaram os fatores de risco mediante regressão logística multinível. Das 2.523 crianças estudadas, 36,5 por cento eram portadoras de um ou mais geohelmintos (Ascaris lumbricoides 25,1 por cento; ancilostomídeos 15,3 por cento, Trichuris trichiura 12,2 por cento). A proporção de geo-helmintíases para o conjunto na zona rural foi 45,7 por cento; na urbana, 32,2 por cento. Baixa renda familiar (OR = 1,75; 1,38-2,23), baixa escolaridade materna (OR = 1,69; 1,39-2,06), presença de lixo próximo ao domicílio (OR = 1,50; 1,22-1,84) e maior número de pessoas no domicílio (OR = 1,41; 1,17-1,71) mostraram-se associadas a tais infecções. Conclui-se que a ocorrência destas parasitoses está relacionada às condições sócio-econômicas e evidencia a importância de intervenções públicas direcionadas à melhoria das condições de vida para sua prevenção.

Stool surveys were conducted to estimate the prevalence and identify risk factors for geohelminth infections among children in ten Brazilian municipalities with low human development indices (HDI). Socioeconomic and environmental data were obtained from the children's parents or guardians, and stool samples were examined. The proportion of geohelminth infections according to target variables was calculated. Risk factors were evaluated using multilevel logistic regression. Of the 2,523 children, 36.5 percent were infected with one or more geohelminths (Ascaris lumbricoides, 25.1 percent; hookworm, 15.3 percent; Trichuris trichiura, 12.2 percent). Overall prevalence of geohelminth infections was 45.7 percent in rural areas and 32.2 percent in urban areas. Low family income (OR = 1.75; 1.38-2.23), low maternal schooling (OR = 1.69; 1.39-2.06), presence of garbage near the home (OR = 1.50; 1.22-1.84), and number of individuals in the household (OR = 1.41; 1.17-1.71) were associated with infection. In conclusion, geohelminth infections were closely related to socioeconomic conditions, thus emphasizing the importance of targeted public interventions to improve living conditions as part of sustainable prevention.

Prevalencia de parasitosis intestinales y factores asociados en un corregimiento de la Costa Atlántica Colombiana / Prevalence of intestinal parasitism and associated factors in a village on the Colombian Atlantic Coast

Objetivos Determinar la prevalencia del parasitismo intestinal e identificar los factores de riesgo asociados a estos, en el corregimiento de Loma Arena, Departamento de Bolívar, Colombia Metodología Mediante encuesta aplicada a cada grupo familiar, fueron evaluadas las condiciones socio-sanitarias y educativas de la población. Para el estudio coproparasitológico se recolectó por cada persona, dos muestras de heces obtenidas por evacuación espontánea y en dos días diferentes. El análisis de las heces se realizó mediante un examen directo en solución salina fisiológica y coloración temporal con lugol y por el método de concentración formol-éter Resultados Se encontró que el 92 por ciento de las personas estaban parasitadas, 92 por ciento de ellas con al menos un patógeno. El poliparasitismo fue muy importante (89,2 por ciento) encontrándose hasta un máximo de 7 especies por hospedador. La coinfección de protozoarios y helmintos fue frecuente (64 por ciento). Solo se encontró una frecuencia de teniosis de 0,9 por ciento. Se observó una asociación significativa entre sintomatología y presencia de parásitos (p<0,05) no así, entre síntomas y parásitos potencialmente patógenos a excepción de Trichuris trichura y dolor abdominal. El análisis estadístico no mostró asociación entre las parasitosis y los niveles educativos o hábitos higiénicos sanitarios. Conclusión La distribución uniforme de la mayoría de las parasitosis intestinales en los cinco grupos de edad evaluados, da cuenta de la exposición a las fuentes de infección en todas las etapas de la vida de los pobladores de Loma Arena.

Objectives Determining the prevalence of intestinal parasitism and identifying the associated risk factors in the village of Loma Arena, Bolivar department, Colombia. Methodology The community's sanitary and educational conditions were evaluated by using a questionnaire which was applied to each family group. Two stool samples obtained by spontaneous evacuation, on two different days, were gathered from each participating person for the coproparasitological study. The coprological test involved direct examination in saline physiological solution and temporary staining with Lugol's solution and the formol-ether concentration method. Results It was found that 92 percent of the population was parasitised, 92 percent of them with at least one pathogenic parasite. Polyparasitism was very important (89,2 percent); a maximum of 7 species per host was found. Helminth and protozoa coinfection was frequent (64 percent). There was only 0,9 percent teniosis prevalence. There was a significant association between symptomatology and parasite presence (p< 0.05), though such relationship was not seen with potentially pathogenic parasites (with the exception of Trichuris trichura and abdominal pain). The statistical analysis did not reveal any relationship between parasitism and educational level or sanitary habits. Conclusion The uniform distribution of most intestinal parasites amongst the five age-groups evaluated showed that people in Loma Arena were evenly exposed to sources of infection in all age-groups.

Seasonal fluctuations in prevalence of dog intestinal parasites in public squares of Mar del Plata city, Argentina and its risk for humans / Estacionalidad en la prevalencia de parásitos intestinales caninos en plazas públicas de Mar del Plata, Argentina, y su riesgo para la salud humana

The aim of this work is to analyze whether there is a seasonal prevalence of parasites in dog feces from public squares in Mar del Plata city, Argentina, and to evaluate the climatic conditions that promote the development of parasites and allow the transmission to people. The study was performed in 21 squares from June 2001 to May 2002. Samples were processed by the Willis technique. Differences in prevalence of parasites were examined for significance by the Chisquare test. Climatic data were obtained from the Library of the National Meteorological Service of Argentina. Total parasitic prevalence was higher in winter than in summer. The prevalence of Ancylostoma spp. was higher in the summer-autumn period. For Toxocara canis, the prevalence was higher in winter whereas for Trichuris vulpis, it was higher in winter, spring and summer. This work shows high prevalence of total parasites throughout the year. For Ancylostoma spp., summer and autumn might be the seasons with higher sanitary risk. On the other hand, T. canis could present the higher risk to people in winter and, T. vulpis, would be transmitted throughout the whole year. The seasonal variation in prevalence of dog parasites results in continuous exposure to people visiting the squares, not only Mar del Plata residents but also tourists from other regions of Argentina and the world, with at least one species of parasite with sanitary risk.

El objetivo de este trabajo es analizar la variación estacional de la prevalencia de los parásitos presentes en las heces caninas halladas en plazas públicas de la ciudad de Mar del Plata y evaluar aquellas condiciones climáticas que promueven su desarrollo y permiten su transmisión a la gente. El estudio se realizó en 21 plazas desde junio de 2001 hasta mayo de 2002. Las muestras fueron procesadas con la técnica de Willis. Se utilizó el test de c² para comparar la prevalencia de los diferentes parásitos. Los datos climáticos fueron obtenidos en la biblioteca del Servicio Meteorológico Nacional. La prevalencia total de parásitos fue considerablemente más alta en invierno que en verano. Ancylostoma spp. fue la especie prevalente en el período otoño-verano. La incidencia de Toxocara canis fue más alta en invierno que en el resto de las estaciones, y la de Trichuris vulpis fue alta en invierno, primavera y verano. Este trabajo muestra alta prevalencia de parásitos totales a lo largo de todo el año en las plazas públicas de Mar del Plata. Para Ancylostoma spp. verano y otoño podrían ser las estaciones con riesgo sanitario más alto para la gente. Por otra parte, T. canis podría presentar mayor riesgo para la gente en invierno y T. vulpis sería transmitido durante todo el año. La variación estacional en la prevalencia de los distintos parásitos caninos, con al menos una especie con riesgo sanitario, hace que la exposición para la gente que visita las plazas sea continua e involucre no sólo a la gente que vive en Mar del Plata sino también turistas de otras regiones de Argentina y el mundo.

Frecuencia de helmintiasis intestinal y su asociación con deficiencia de hierro y desnutrición en niños de la región occidente de México / Frequency of intestinal helminthiasis and its association with iron deficiency and malnutrition in children from western Mexico

Objetivo: Determinar la frecuencia de helmintiasis intestinal y su asociación con desnutrición y deficiencia de hierro. Material y métodos: Se realizó un estudio transversal analítico en el municipio de Comala, Colima, México. A todos los niños, se les determinó coproparasitoscópico seriado de tres días con la técnica de Kato-Katz. Para evaluar el grado de desnutrición; se establecieron los siguientes índices antropométricos: mediana y puntajes Z para peso/ talla, talla/edad y peso/edad. Se consideró que había deficiencia de hierro severa, moderada o leve con ferritina ≤ 12 ng/ ml, de 12 a 18 ng/mL y de 19 a 24 ng/mL respectivamente. Resultados: Se estudiaron 243 niños con una edad promedio de 65.3 ± 8.7 meses. El 60.9 % (n = 148) y el 2.5 % (n = 6) de los niños presentaron disminución de la ferritina y anemia respectivamente. El 16 % (n = 39) mostró trichuriasis, el 6.9 % (n = 17) ascariasis y el 5.3 % (n = 13) ambas. La infección por Trichuris trichiura se asoció a desmedro (OR 11.0, IC 3.9-30.8; p < 0.001) y a deficiencia de hierro con puntos de corte de < 24 ng (OR 2.0, IC 1.0-3.9, p = 0.02) y < 18 ng/dL (OR 2.2, IC 1.2-4.2, p = 0.009). La infección por ascaris no se asoció con desnutrición o deficiencia de hierro. Conclusiones: La infección de T. trichiura se asoció con desmedro y deficiencia de hierro grado leve y moderado.

OBJECTIVE: To determine intestinal helminthiasis frequency and its association with malnutrition and iron deficiency. Material and METHODS: An analytical cross-over study was carried out on children in the municipality of Comala, Colima, Mexico. Coproparasitoscopic exams in series of three using the Kato-Katz technique were performed in all children. To evaluate the degree ofmalnutrition, the following anthropometric indices were determined: means and z-scores for weight/height, height/age, weight/age. Severe, moderate and minimal iron deficiency was considered when ferritin was: < or = 12 ng/ml, 12 to 18 ng/mL and 19 to 24 ng/mL, respectively. RESULTS: 243 children were studied with an average age of 65.3+/-8.7 months. 60.9% (n = 148) of the children showed a decrease in ferritin levels and 2.5% (n = 6) had anemia. 16% (n = 39) had trichuriasis, 6.9% (n = 17) ascariasis and 5.3% (n = 13) had both parasites. Trichiura infection was associated with declining health (OR 11.0, CI 3.9-30.8; p<0.001) and with iron deficiency, with cut-off points of <24 ng (OR 2.0, CI 1.0-3.9, p = 0.02) and <18 ng/ dL (OR 2.2, CI 1.2-4.2, p= 0.009). Ascaris infection was not associated with malnutrition or iron deficiency. CONCLUSIONS: Trichiura infection was associated with declining health and slight and moderate degrees of iron deficiency.

Instruction in behavior modification can significantly alter soil-transmitted helminth (STH) re-infection following therapeutic de-worming.

Five elementary ("prototypic") schools located in five districts in central Java were selected and the children examined for helminth infections (Ascaris, Trichuris, hookworm). They were de-wormed with a course of mebendazole and provided with 6-7 months of "behavioral remediation instruction" (BRI). In other ("control") schools, children were treated with mebendazole but were not provided BRI. The objective was to determine the effectiveness of BRI in minimizing infection/re-infection following deworming. After the 6-7 month course of BRI in the prototypic schools, all the children (in both the prototypic and control schools) were re-examined for geohelminth infection. The schools in two of the five districts were omitted from further analysis because the overall prevalence of infection was low (<10%) and the infections were dominated by hookworm which are only moderately susceptible to mebendazole. Comparisons of prototypic and control schools in the other three districts provided compelling evidence that BRI was quite effective in reducing both the frequency and intensity of infection with Ascaris and Trichuris. We suggest that instructing children and adults corrects personal habits which are conducive to infection and can be an effective and safe substitute for repeated deworming, reducing the opportunity for the emergence of drug-resistant helminthes, which should prolong the time benzimidazoles may be used for treatment of geohelminth infection.

Prevalence and distribution of soil-transmitted helminthiases among Orang Asli children living in peripheral Selangor, Malaysia.

Soil-transmitted helminthiases are a public health problem in rural communities. A cross-sectional study of the prevalence and distribution of Ascaris lumbricoides, Trichuris trichiura and hookworm was conducted in 281 Orang Asli children (aborigines) aged between 2 and 15 years, from 8 Orang Asli villages in Selangor, Malaysia. All the children were infected with soil-transmitted helminthes, with 26.3% of the children infected either with A. lumbricoides, T. trichiura or hookworm and 72.6% having mixed infection. The overall prevalences of A. lumbricoides, T. trichiura and hookworm were 61.9, 98.2 and 37.0%, respectively. Approximately 19.0, 26.0 and 3.0% of the children had severe infection of ascariasis, trichuriasis and hookworm infection, respectively. The prevalences and mean egg per gram (epg) counts for A. lumbricoides and T. trichiura were not significantly dependent on age, therefore age-dependent convexity was not seen in this study. However, the results of this study reveal an age-dependent prevalence and mean epg count in children with hookworm infection. We conclude that ascariasis, trichuriasis and hookworm infection are still prevalent and therefore a public health concern in Orang Asli communities. Severe ascariasis and trichuriasis may lead to other health and medical problems.

Status of intestinal helminthic infections of borderline residents in North Korea

The present authors investigated intestinal parasitic infections among North Korean residents and refugees in China in 2003. The Kato-Katz method was applied to 236 residents and soldiers in a town on the North Korea-China border and to 46 people at a refugee camp in China. Only eggs of Ascaris and Trichuris were detected, with egg positive rates of 41.1% and 37.6%, respectively. The total egg positive rate was 55.0% and most of those who were egg positive were only lightly infected. Women of 61.2% and men of 53.1% were egg positive. The refugees from rural areas showed higher egg positive rates than those from urban areas. The present investigation confirmed high prevalence of soil-transmitted intestinal helminths in rural borderline areas of North Korea.

Intestinal helminthic infestation in children.

In this study of fecal samples from 1000 children below 6 years of age, 680 (68.0%) detected to have intestinal helminthic infection. The incidence of intestinal helminthiasis in urban group of children was 56.8% (284 out of 500 tested) while in rural group of children was 79.2% (396 out of 500 tested). Both in rural and urban population Ascaris lumbricoides was the single predominant species, whereas a combination of A. lumbricoides and Trichuris trichiura was common multiple infection. All cultures of fecal samples positive for hook worm ova revealed the prevalent species as Necator americanus in this area.

El tratamiento antihelmíntico selectivo frente al tratamiento masivo: experiencia en dos comunidades hiperendémicas / Selective vs. mass treatment with antihelminthic drugs: experience in two hyperendemic communities

OBJETIVO: Evaluar la prevalencia e intensidad de las infecciones por geohelmintos en niños de dos comunidades hiperendémicas tratadas con técnicas antihelmínticas diferentes: una con tratamiento selectivo o individual, y la otra con tratamiento masivo reiterado. MÉTODOS: La población estuvo compuesta por 909 niños de uno u otro sexo, con edades entre 2 y 13 años, que vivían en dos comunidades marginales de la ciudad: Las Lomas y El Abasto, Santa Fe, Argentina. Se realizó un trabajo prospectivo longitudinal, cuasiexperimental, de comunidades. Durante los 22 meses del estudio se llevaron a cabo 5 controles parasitológicos, evaluados desde el punto de vista cualitativo y cuantitativo, y se dispensaron tratamientos antihelmínticos después de los controles 0, 2, 3 y 4. En Las Lomas se aplicó el tratamiento selectivo a los casos con diagnóstico parasitológico positivo que integraban la muestra A (n = 55) y en El Abasto, tratamiento masivo a todos los niños, incluidos los integrantes de la muestra B (n = 50). Ambas muestras fueron escogidas para realizar los controles. RESULTADOS: Se comprobó una prevalencia e intensidad de la infección por Ascaris lumbricoides significativamente mayor en El Abasto. No se detectaron diferencias para Trichuris trichiura. Al comparar las prevalencias y cargas parasitarias de A. lumbricoides entre los controles realizados dentro de una misma comunidad (inicio y final del estudio) no se observaron diferencias significativas en la muestra A, aunque sí en la muestra B. En cuanto a T. trichiura, se detectaron diferencias significativas entre ambos controles en las dos muestras. CONCLUSIONES: Solo el tratamiento masivo y reiterado logró disminuir eficaz y significativamente la prevalencia y la carga parasitaria de A. lumbricoides durante el período estudiado

Intestinal parasites in children with diarrhea in Delhi, India.

The parasitic causes of diarrhea in children in Delhi were determined by the direct smear technique; stool specimens of 127 children were examined for intestinal parasites. In 59 cases (46.5%) intestinal helminths and protozoa were demonstrated. Ascaris lumbricoides was observed in 1 (0.8%) case, while Trichuris trichiura was the finding in 3 (2.4%). Protozoal parasites included Giardia intestinalis and Entamoeba histolytica in 14 (11%) cases each, Balantidium coli in 3 (2.4%) cases and Cryptosporidium spp in 24 (18.9%) patients. Mixed infection was not seen in any of the cases. Intestinal parasites may increase susceptibility to infection with other intestinal pathogens and therefore with the help of a simple technique, like direct fecal smear examination. rapid diagnosis can be made and specific therapy instituted.

Intestinal parasitic infection among five interior communities at upper Rejang River, Sarawak, Malaysia.

Intestinal parasitic infection among five interior communities at Bakun Valley, upper Rejang River, Sarawak, Malaysia, was investigated as part of a public health impact assessment of the proposed US$ 3 billion Bakun Hydroelectric Project. Coproparasitological examination of 355 stool samples from 7 of 16 villages representing 5 of 7 tribes in the area revealed infection rate of 41%. A higher infection rate was found among the settled Kayans (56%) than the seminomadic Penans (29%). Infection rate was high (68%) among children less than 14 years old. Trichuris trichiura accounted for more than 90% of all infections; less common were Ascaris lumbricoides, hookworms and Strongyloides stercoralis. Polyparasitism was found in 8% of the individuals surveyed with dual infection due to T. trichiura and A. lumbricoides being more common than dual infection with T. trichiura and hookworm. Women had higher infection rates (57%) than men (33%).

Prevalence and intensity of soil-transmitted helminthiasis in the city of Portoviejo (Ecuador)

We studied the stool samples of 151 school children in a district of the city of Portoviejo (Ecuador) in order to determine the prevalence and intensity of soil-transmitted helminthiasis (STH) and their relationships with anthropometric indices. The samples were analyzed with the semiquantitative Kato-Katz technique and the intensity of infections was categorized as light, moderate or high according to the thresholds set by the World Health Organization. Prevalence of soil transmitted helmintiasis was 65 percent (92 out of 141 collected samples), Ascaris lumbricoides was the most common STH (63 percent) followed by Trichuris trichiura (10 percent) and hookworm (1.4 percent). Heavy intensity infections were found in 8.5 percent of the stool samples, with T. trichiura showing higher worm burdens than A. lumbricoides. Sixteen percent of the children were below the third percentile for weight (wasted), while 27 percent were below the third percentile for height (stunted). A significant relationship was found between the worm burden and the degree of stunting. This study suggests that the periodic administration of an antihelminthic drug should be targeted to preschool and school children to allow a normal growth spurt and prevent stunting

Prevalence and intensity of infections of Ascaris lumbricoides and Trichuris trichiura and associated socio-demographic variables in four rural Honduran communities

Between January and March 1998, a cross-sectional survey was carried out in four rural communities in Honduras, Central America. We examined the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiura infections among 240 fecal specimens, and the association between selected socio-demographic variables and infection for 62 households. The overall prevalence of A. lumbricoides and T. trichiura was 45 percent (95 percent CI 39.0-51.9) and 38 percent (95 percent CI 31.8-44.4) respectively. The most intense infections for Ascaris and Trichuris were found in children aged 2-12 years old. By univariate analysis variables associated with infections of A. lumbricoides were: number of children 2-5 years old (p=0.001), level of formal education of respondents (p=0.01), reported site of defecation of children in households (p=0.02), households with children who had a recent history of diarrhea (p=0.002), and the location of households (p=0.03). Variables associated with both A. lumbricoides and T. trichiura infection included: number of children 6-14 years old (p=0.01, p=0.04, respectively), ownership of a latrine (p=0.04, p=0.03, respectively) and coinfection with either helminth (p=0.001, p=0.001, respectively). By multivariate analysis the number of children 2-5 years living in the household, (p=0.01, odds ratio (OR)=22.2), children with a recent history of diarrhea (p=0.0, OR=39.8), and infection of household members with T. trichiura (p=0.02, OR=16.0) were associated with A. lumbricoides infection. The number of children 6-14 years old in the household was associated with both A. lumbricoides and T. trichiura infection (p=0.04, p=0.01, OR=19.2, OR=5.2, respectively)

Effect of intestinal helminthiasis on nutritional status of schoolchildren.

This study was conducted in a rural agricultural area in Siniloan, Republic of the Philippines. The subjects were the school children. The nutritional status of 58 children infected with helminthiasis (Ascaris lumbricoides and Trichuris trichiura) was compared with that of 19 uninfected controls. Prevalence of Ascaris and Trichuris was 40.3% and 71.4% respectively, and 36.4% of infected children had both Ascaris and Trichuris infections. Statistically significant evidence of an adverse effect of helminthiasis on serum albumin levels was found, but no child had inadequate levels of other nutrients. Although helminthic infections increase the level of immunoglobulin E (IgE) in children endemically exposed to these parasites, there was no significant difference in the serum IgE among Ascaris or Trichuris infected groups in this study.

Prevalence of Trichuris trichiura in relation to socio-economic & behavioural determinants of exposure to infection in rural Assam.

BACKGROUND & OBJECTIVES: Stunting, anaemia, and the poor level of mental development are known to be associated with Trichuris trichiura infections. However, no information is available on the socio-environmental predictors relevant to Trichuris infection in rural communities. Whilst geohelminthic infections per se is an inevitable consequence of poor personal hygiene and household sanitation, the importance of specific factors in the epidemiology of Trichuris infection have not been formally investigated. The objective of this study was to explore, quantify and study different socio-environmental risk factors and find out their possible interaction vis-a-vis T. trichiura infection. METHODS: The study population consisted of 244 children (aged 15 yr and below) and 336 adults selected from 144 randomly selected households belonging to three villages of upper Assam. The prevalence rate ratio (PRR; = relative risk) and 95 per cent confidence interval (CI) were calculated. Univariate, multivariate analysis using Cox's proportional hazards regression assuming constant risk period and a tree-based risk factor analysis, were used. RESULTS: In the overall multivariate model, open field defaecation, large family size, and three or more children in the household were found independently associated with Trichuris infection. Gender specific analysis revealed that in females the age was also independently associated with increased risk of infection whereas in males, earth flooring was the most significant risk factor independently associated with the risk of Trichuris infection. Tree-based risk factor analysis indicated interaction between defaecating habits of people and the source of drinking water. INTERPRETATION & CONCLUSIONS: Installation of pit latrines (if not sanitary latrines) together with provision for safe drinking water and the construction of cement floors would probably reduce community prevalence of T. trichiura effectively.