Eritema nudoso asociado a parasitismo por Ascaris lumbricoides. Presentación de caso / Nudose erythema associated to Ascaris lumbricoides parasitism: Cases presentation

Introducción: El Eritema nudoso es una paniculitis, de relativa frecuencia, que se expresa como manifestación de trastornos internos de gran envergadura, como las enfermedades del tejido conectivo, las enfermedades infecciosas y el cáncer. Es por ello, que los pacientes que lo presenten, deben ser estudiados cuidadosamente en busca de la causa. Objetivo: Presentar un caso clínico de Eritema nudoso resaltando el diagnóstico de la causa parasitaria y su tratamiento. Presentación de Caso: Se muestra el caso de una paciente femenina de 29 años, de raza blanca, residente en un municipio rural (Jatibonico), profesora de escuela primaria, sin antecedentes patológicos, quien acude a consulta por eritema elevado muy doloroso en la superficie anterior de ambos miembros inferiores, malestar general y artralgias. Se le diagnosticó clínicamente un eritema nudoso, y durante varios meses se realizaron complementarios para establecer la posible causa; se encontró solo un parasitismo intestinal por Ascaris lumbricoides. Recibió tratamiento médico con antiparasitarios, y desapareció el eritema. Conclusiones: El diagnóstico clínico certero, más la búsqueda constante de la causa del eritema nudoso y el tratamiento del parasitismo encontrado, llevaron a la solución del problema de la paciente. El eritema nudoso siempre debe ser estudiado por la posibilidad de ser un síndrome reactivo a procesos grave(AU)

Introduction: Nudose erythema is a panniculitis, of relative frequency, that it is expressed like a manifestation of internal disorders of great significance, like the illnesses of the connective tissue, the infectious diseases and the cancer. So the patients that show it, must be studied carefully in search of the cause. Objective: To Present a nudose erythema clinic case highlighting the diagnose of parasitical cause. Cases presentation: Is show the case of a white female patient, 29 years old, resident at rural municipality (Jatibonico), elementary school teacher, without pathological past health history, that assist at the consult for nodular due to a high very painful erythema on the anticus surface of both inferior members, general discomfort and arthralgia. Was clinically diagnosed a nudose erythema, and during several months were performed complementary to establish the possible cause, finding only an intestinal parasitism for Ascaris lumbricoides. He received medical treatment with antiparasitcs, disappearing the erythema. Conclusions: The accurate diagnostic, furthermore, a constantly cause searching of the cause of the nudose erythema plus the treatment of parasitism found, solve the patients problem. Nudose erythema always must be studied due to the possibility to be a reactive syndrome of seriously ill process(AU)

Eliminación de estadios juveniles de Ascaris lumbricoides (Linneo, 1758) por via oral: Reporte de un caso y algunas consideraciones epidemiológicas / Elimination of juvenile stages of Ascaris lumbricoides (Linnaeus, 1758) by mouth: Report of a case and some epidemiological considerations

Ascariosis is a parasitic disease caused by Ascaris lumbricoides, a large geohelmint endemic in our country. At present, ascariosis is a rare infection in Chile. We present a case of an adult, resident of the Villa Alemana municipality, Valparaiso Region, who spontaneously expelled two juvenile nematodes by mouth. We review the manifestations produced by the larval and adult stages of this parasite including their diagnosis, treatment, and epidemiological considerations.

La ascariosis es una parasitosis provocada por Ascaris lumbricoides, el geo-helminto de mayor tamaño que afecta al ser humano en nuestro país. En Chile, la ascariosis es una infección poco frecuente en la actualidad. Se presenta el caso de un adulto residente en la comuna de Villa Alemana, Región de Valparaíso, que eliminó en forma espontánea dos ejemplares del nemátodo en estado juvenil por vía oral. Se revisan las manifestaciones producidas por este parásito en la fase larvaria y adulta, el diagnóstico, el tratamiento y algunas consideraciones epidemiológicas.

Áscaris lumbricoides en el corazón de una gestante / Presence of Ascaris lumbricoides in the heart of a pregnant woman

El áscaris es el nematodo de mayor tamaño que parasita al hombre; es un helminto dioico (sexos separados). Su prevalencia se debe fundamentalmente a la contaminación fecal del suelo y a la capacidad de supervivencia de los huevos. Los adultos de áscaris lumbricoides se localizan en el intestino delgado, aunque algunas veces puede haber migraciones erráticas de parásitos adultos a lugares como el hígado, peritoneo, riñones, etc. Describir la forma de presentación del parasitismo intestinal por áscaris lumbricoides en una embarazada, actualizar e informar sobre el parasitismo intestinal, mostrar la experiencia en el manejo de un caso de difícil diagnóstico y transmitir conocimientos, contribuir a la docencia médica, son los objetivos de esta presentación. Se realizó una revisión bibliográfica sobre el parasitismo intestinal, específicamente del áscaris lumbricoides partiendo de la existencia de un caso obstétrico portadora de manifestaciones cardiovasculares importantes y de difícil manejo, por lo que se revisó exhaustivamente la historia clínica de dicha paciente en los 2 hospitales en los cuales estuvo ingresada. Paciente portadora de una gestación de 12 sem que acude con manifestaciones respiratorias y cardiovasculares, la primera impresión diagnóstica fue de una miocarditis o miocardiopatías, después de concluir estudios pertinentes se concluye como portadora de áscaris lumbricoides en corazón derecho y además se complica con un tromboembolismo pulmonar. A pesar de ser infrecuente en nuestros días, debemos pensar en el parasitismo como una explicación a ciertas sintomatologías de extraña presentación clínica

The ascaris is the higher nematode to parasitizes the man; it is dioecious helminths (having separate sexes). Its prevalence is due mainly to soil fecal contamination and to survival ability of eggs. The adult Ascaris lumbricoides are located in the small bowel, although some times may be erratic migrations of adult parasites to places like the liver, peritoneum, kidneys, etc. The aim of present paper is to describe the presentation way of intestinal parasitism by Ascaris lumbricoides in a pregnant woman, to update and to inform on the intestinal parasitism, to show the experience in the management of a case of difficult diagnosis and to transmit the knowledges, and to contribute to medical teaching. A bibliographic review on the intestinal parasitism was made, specifically of Ascaris lumbricoides from the existence of a obstetric case carrier of significant cardiovascular manifestations and of a difficult management, thus we made an exhaustive review of medical record of this patient in the two hospitals where she was admitted. A patient with 12 weeks pregnancy to come to consultation due to respiratory and cardiovascular manifestations, the first diagnostic impression was a myocarditis or myocardiopathies. After conclude the pertinent studies she is classified as a Ascaris lumbricoides carrier in right heart and that also it is complicated with a pulmonary thromboembolism. Despite this condition is infrequent nowadays, we must to think about the parasitism like an explanation for some symptomatology of a rare clinical presentation

MONRATE: A descriptive tool for calculation and prediction of re-infection of Ascaris lumbricoides (Ascaridida: Ascarididae)

The study presents an interactive descriptive tool (MONRATE) for calculating and predicting reinfection rates and time of Ascaris lumbricoides following mass chemotherapy. The implementation was based on the theoretical equation published by Hayashi in 1977, for time-prevalence: Y=G [1-(1-X)N-R] as modified by Jong-Yil in 1983. Using the Psuedo-Code of the MONRATE tool, the calculated monthly reinfection rates (X) for the LGAs are (names are locations in Nigeria in a region predominately populated by the Yoruba speaking tribes of Nigeria whose traditional occupations are agriculture and commerce): Ewekoro (1.6 %), Odeda (2.3 %), Ado-odo/Otta (2.3 %), Ogun Waterside (3.8 %) and Obafemi/Owode (4.2 %). The mathematical mean of ‘X’ values in the study areas for Ogun State was 2.84. The calculated reinfection time (N months) for the LGAs are varied such as Ado-odo/Otta (12.7), Ogun Waterside (21.8), Obafemi/Owode (22.92), Odeda (25.45), and Ewekoro (25.9). The mean value for N in Ogun State was 21.75. The results obtained from MONRATE were compared with those obtained using the mathematical equation and found to be the same. Rev. Biol. Trop. 55 (3-4): 755-760. Epub 2007 December, 28.

Se presenta una herramienta descriptiva e interactiva (MONRATE) para calcular y predecir las tasas y tiempo de reinfección con Ascaris lumbricoides tras un tratamiento de quimioterapia. Nos basamos en la ecuación propuesta por Hayashi en 1977 para el tiempo de prevalencia: Y=G [1- (1-X)N-R], según la modificó Jong-Yil en 1983. Utilizando el código Psuedo de la herramienta de MONRATE, las tasas de reinfección mensuales (X) para varios sitios de Nigeria, África, son: Ewekoro (1.6 %), Odeda (2.3 %), Ado-odo/Otta (2.3 %), Ogun Waterside (3.8 %) y Obafemi/ Owode (4.2 %). El promedio matemático de los valores de "X" en el área de estudio del Estado de Ogun fue 2.84. El tiempo de reinfección calculado (N meses) para LGAs es variado: Ado-odo/Otta (12.7), Ogun Waterside (21.8), Obafemi/Owode (22.92), Odeda (25.45) y Ewekoro (25.9). El valor promedio para N en el Estado de Ogun fue 21.75. Los resultados del programa MONRATE son iguales a los producidos por la ecuación.

Cure and reinfection patterns of geohelminthic infections after treatment in communities inhabiting the tropical rainforest of Assam, India.

Mass de-worming targeted at socio-economically poor communities can be considered as an option for communities living in the tropical forests of Assam who do not have access to safe drinking water and proper sanitation, and consequently have a higher risk of suffering from geohelminthic infection and associated morbidity. A random sample of 265 subjects was included in this study (134 males and 131 females). The chemotherapeutic regimen followed was a single dose of albendazole 400 mg. Stools samples were collected in 10% formol-saline for detection of infection before treatment. Post-treatment stool samples were collected 10 to 14 days after treatment to determine the cure rate. Stool samples were again collected 3 to 6 months post-treatment to study the rate of reinfection. Multiple logistic regression was used to find possible associations between age, sex and treatment failure. The chi-square test was used wherever appropriate. The cure rates for Ascaris lumbricoides, Trichuris trichiura and hookworms were 70.8%, 68.7% and 93.0%, respectively. Logistic regression revealed that age was associated with treatment failure in A. lumbricoides infection. Re-infection rates after 3 months of successful treatment were 19.6% for A. lumbricoides, 30.9% for T. trichiura and 11.3% for hookworms. Six months post-treatment, the prevalence of re-infection was highest with T. trichiura (43.6%); followed by A. lumbricoides (35.3%). The rate of reinfection with hookworms was lower (11.3%) six months post-treatment. The rates of re-infection with A. lumbricoides and T. trichiura was higher in children below 15 years of age, compared with adults. Hookworm reinfection was higher in the adult age group (15 to 39 years). The rates of new infection in previously uninfected subjects were lower compared with the rates for re-infection.

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

Six-monthly de-worming in infants to study effects on growth.

OBJECTIVE: The study was conducted to assess the effectiveness of six monthly albendazole (ABZ) for improving the weight and height of preschool children when initiated at 0.5-1 year of age in populations with a high transmission rate of intestinal roundworm, Ascaris lumbricoides. It was a cluster randomized trial in the urban slums of Lucknow, North India. METHODS: Control children received 2 ml (1 ml to infants) of Vitamin A every six month whereas those in the ABZ areas received, in addition, 400 mg of ABZ suspension (Zentel, SKB) every six month. Sixty-three and sixty-one slum areas were randomized to albendazole (ABZ) or to control groups, respectively. Children aged 0.5-1 year were recruited in April 1996 and followed up for 1.5 years. Of 1022 children recruited from control and 988 from ABZ areas, the loss to follow-up at 1.5 year was 15.6% and 14.6% respectively. Mean (+/- SE) weight gain in Kg in control versus ABZ areas was 3.04 (0.03) versus 3.22 (0.03), (p = 0.01). RESULTS: After controlling for the presence of weight-for age z-score < -2.00 at enrollment in the ordinary least square's regression model, the extra weight gain in 1.5 years in those who received ABZ plus vitamin A was 0.13 Kg (95% CI: 0.004 to 0.26 Kg., p value = 0.043) when compared to those who received only vitamin A; underweight children at enrollment benefiting more than the normal ones. CONCLUSION: It was concluded that there was an improvement in weight with six monthly ABZ over 1.5 years. However, a much larger trial would be needed to determine whether there is any net effect of improvement in weight on under five mortality rate.

Tratamento da estrongiloidíase humana e outras parasitoses intestinais com dose única de ivermectina / Treatment of human strongyloidiasis and other intestinal parasitosis with a single dose of ivermectin

Os autores trataram 70 pacientes portadores de estrongiloidíase, ascaríase, tricuríase e ancilostomíase com dose única de ivermectina (200 ug/kg). A cura parasitológica obtida foi de 95 porcento para estrongiloidíase, de 100 poecento para ascaríase e tricuríase e de 60 porcento para ancilostomíase. As reaçöes adversas foram observadas em 3 porcento dos pacientes - cefaléia, náuseas e vômitos.(au)

Successful eradication of Ascaris lumbricoides and hookworm infection after three repeated doses of albendazole.

Three repeated orally doses of albendazole 400 mg in 6 weekly intervals were evaluated in Thai hill-tribe students who had at least one kind of soil-transmitted helminths (i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura). Stool examination and parasite egg count were performed using Beaver's standard direct smear method and Kato-Katz's cellophane thick smear method prior to treatment and then 1 month after the first, second and third dose of drug administrations. A single dose of albendazole was very effective against A. lumbricoides and hookworm infections, with cure rates of 98.68 per cent and 92.16 per cent, respectively. The second and third dosages eradicated A. lumbricoides and hookworm infections, respectively. Conversely, the first to third cure rates for T. trichiura infection were relatively low, being 37.76-58.16 per cent. Three repeated doses of albendazole proved to be beneficial in eradication of A. lumbricoides and hookworm infections, and decreased the prevalence of T. trichiura infected cases. For eradication of T. trichiura infection, further regimen and period of drug administration is required.

Antihelmínticos como factor de riesgo en la obstrucción intestinal por ascaris lumbricoides en niños / Anthelmintics as a risk factor of intestinal obstruction by ascaris lumbricoides in children

In a retrospective study the authors analyzed the clinical records of 199 children ages one month to 16 years hospitalized, with the diagnosis of intestinal ascariasis, in the Instituto Nacional de Pediatría of México from 1984 to 1999. The purpose of the study was to evaluate the use of anthelmintics drugs as a risk factor of intestinal obstruction by A. lumbricoides. Two groups were made for the study: group A (n=66) of children who presented intestinal obstruction, group B (n=133) children with no complications. A comparative analysis of clinical data of both groups was made by means of chi square with Yates correction and a stratified analysis by means of chi square. Possible confusing elements were overcrowding, age and the use of antiparasitic drugs. The calculus of risk factors for intestinal obstruction by A. lumbricoides was done by means of contingency tables of 2 x 2 and odds ratio with an IC of 95 percent. The significant risk factors were included in a model of logistic regression with an impact variable consting in the presence or absence of intestinal obstruction in order to establish a multivariate model of predictive risk at level of significance of p<0,05

Uso de nitazoxanida contra helmintiasis y protozoos múltiples en niños / Nitrazoxanide use against multiple helminthiasis and protozoan in children

Objetivo. Analizar, evaluar y comprobar la eficacia de nitazoxanida contra helmintiasis y protozoos múltiples en niños de 0 a 15 años de edad. Diseño. Estudio clínico y clínico-biológico, prospectivo. Población. Cincuenta niños de ambos sexos. Metodología. Todos los pacientes durante los meses de mayo a junio de 1999, fueron evaluados clínicamente y por laboratorio químico biológico, antes y después del tratamiento establecido, según dosificación establecida en estudios previos de 15 mg/kg/día, dividido en dos dósis por 3 días seguidos. Resultados. Al primer examen coprobiológico, la ascariasis resulta ser la de mayor incidencia (76 por ciento), respecto a las otras infestaciones parasitarias que sólo representaron el 2 por ciento cada una. Al examen final se comprobó que la incidencia bajó al 10 por ciento y las otras infestaciones desaparecieron totalmente. Conclusiones. La nitazoxanida es efectiva en el tratamiento de pacientes multiparasitados

Quantitative assessment of Ascaris lumbricoides infection in school children from a slum in Visakhapatnam, south India.

An epidemiological study was conducted on 217 school children aged between 7-13 years, from Relliveedhi a slum in Visakhapatnam, Andhra Pradesh, south India, during August 1993 to August 1994. The children belonged to a socioeconomically backward community-parental occupation being fishing or waged labor. Intensity and prevalence estimations for Ascaris lumbricoides were done indirectly by formalin-ethyl-acetate sedimentation technic and directly by worm expulsions following albendazole administration at a single oral dose of 400 mg/child. Prevalence rate was 73% while the intensity of infection ranged between low to moderate. Boys had severe infection than girls due to their outdoor activities and behavioral habits. Nine year old children had the highest prevalence rates. Mean Ascaris worm intensity was 2.2 (+/-1.91) with an over-dispersed distribution of the parasite in the host population. Reinfection study over a period of nine month showed that the prevalence rates exceeded the pre-intervention level but the intensity of infection was very low. Dual species intensity correlation between Ascaris and Trichuris was consistently strong.

O papel do estado nutricional na reinfecçäo pós-tratamento antiparasitário em crianças residentes no município de Santa Isabel, SP / The role of nutritional status in helminthic infections in school children living in Santa Isabel, Säo Paulo, Brazil

Avalia o papel do estudo nutricional na infecçäo ou reinfecçäo por parasitas intestinais após tratamento quimioterápico em crianças de 1 a 10 anos de idade, através de estudo epidemiológico longitudinal (coorte prospectiva) com acompanhamento bimensal da populaçäo alvo pelo período de 1 ano. Analisa em 3 bairros com características semi-urbanas do Município de Santa Isabel: Jardim Novo Éden, Jardim das Acácias e Jardim Eldorado, iniciando em outubro de 1997, com 759 crianças estudadas. Foram aplicados questionários sobre a saúde da criança, tomada de medidas de peso e altura, recolhidas 3 amostras de fezes. Após o resultado do primeiro exame de fezes todas as crianças receberam tratamento com Panfugan (mebendazol) com reforço após 15 dias e comprovaçäo da cura através de novo exame protoparasitológico. As crianças que apresentaram positividade para Giardia lamblia e Entamoeba histolytica receberam Secnidal (secnidazol). Em uma sub-amostra da populaçäo estudada foram preenchidos questöes sobre as condiçöes sócio-econômica e cultural das famílias, e ainda foi aplicado o Recordatório 24 horas para conhecermos o consumo alimentar das crianças. Os métodos utilizados na identificaçäo dos ovos e larvas dos parasitas foram: Hoffman e col., Rugai e col., Faust e col. e para a contagem de ovos utiliza o método de Kato-Katz. Para avaliar o perfil nutricional das crianças, utiliza o padräo de referência do National Center Health Statistics (NCHS) e os "scores" de desvio padräo (Zscores) para os índices de peso para altura (WHZ) e altura para idade (HAZ). As análises estatísticas univariadas foram realizadas por meio do teste do qui-quadrado, e para as análises de "sobrevida", o modelo de riscos proporcionais de Cox, e os resultados indicam que as crianças desnutridas säo mais susceptíveis a infecçäo e reinfecçäo por helmintos

Ascariasis, trichuriasis, and growth of schoolchildren in Northeastern Peninsular Malaysia.

A study to determine the effect of antihelminthic treatment on growth and nutritional status was undertaken on 103 children in the second grade of primary school, 71 of whom were found to be infected with Ascaris lumbricoides or Trichuris trichiura. The median Ascaris and Trichuris intensities in the infected group were 19,600 (range; 0-488,000) and 2,800 (range; 0-84,600) eggs per gram of feces respectively. Forty-three children harbored both types of worm. Fourteen weeks after two 400 mg doses of albendazole were administered to infected children, the increases in weight, height, weight for age, height for age and weight for height were significantly higher among infected children than controls who were uninfected at baseline. The observed gains were independent of sex and socioeconomic status. Decrease in log transformed Trichuris intensity correlated with increases in weight (r=0.24; p=0.02) and weight for age (r=0.20; p=0.06) but decrease in Ascaris intensity did not correlate with increases in any of the anthropometric parameters. The results suggest that antihelminthic treatment has beneficial short-term effects on growth and nutritional status of a modest magnitude among early primary schoolchildren in the area.

Efficacy of single dose albendazole on the prevalence and intensity of infection of soil-transmitted helminths in Orang Asli children in Malaysia.

The efficacy of a single-dose 400 mg albendazole to treat Ascaris, Trichuris and hookworm infection was studied in Orang Asli community. Kato-Katz examination was performed on fecal samples which were collected before treatment, 1 and 4 months after treatment. A total of 123 children were involved in all three surveys. The cure rate of Ascaris infection was 97.4% and the egg reduction after treatment was 99.9%. The cure rate for hookworm infection was 93.1% with 96.6% egg reduction. Although the cure rate was low in Trichuris infection (5.5%), egg reduction was more evident (49.1%). The reinfection rate at 4 months after treatment was 54.5%, 3.6% and 10.3% for Ascaris, Trichuris and hookworm infection, respectively. Within 4 months after treatment almost one-fifth children with Ascaris and hookworm infection reached pre-treatment intensity infection. In Trichuris infection, however more than half of the children reached their pre-treatment intensity infection at 4 months after treatment. Findings suggest that 4-monthly targeted periodic treatment with 400 mg single-dose albendazole in highly endemic areas can have a significant impact on intensity infection of Ascaris and hookworm, but not on Trichuris infection.

Abscesos hepáticos por áscaris lumbricoides / Hepatic abscesses by ascaris lumbricoides

Se describen dos niños con absceso hepático por áscaris lumbricoides: una niña de 14 meses de edad, quien se internó por síndrome febril prolongado y un varón de 20 meses, quien ingresó por distensión abdominal, fiebre y eliminación de áscaris en materia fecal. Se promovió búsqueda de la localización abdominal extraintestinal de los niños parasitados por áscaris con síndrome febril. La ultrasonografía fue el método de gran utilidad

Minimum effective doses of mebendazole in treatment of soil-transmitted helminths.

Three hundred and fifteen primary school children infected with soil-transmitted helminths were divided into 5 groups. Three groups were treated with 25, 50 and 75 mg mebendazole (MBZ) single dose. One group was given MBZ conventional dose of 100 mg twice daily for 3 days and another group was given albendazole (ABZ) standard dose of 400 mg single dose. Every trial lower MBZ dose 75 mg, 50 mg and 25 mg regimen were highly effective against Ascaris lumbricoides but only moderately effective against Trichuris trichiura and Necator americanus.

Comparative trials using albendazole and mebendazole in the treatment of soil-transmitted helminths in schoolchildren on Penang, Malaysia.

Trials using albendazole and mebendazole, as single 400 mg dose treatments, against soil-transmitted helminths, were carried out in 7-9 and 10-12 years-old schoolchildren living in urban and rural environments in Penang, Malaysia. Both drugs were equally effective in treating trichuriasis and ascariasis in both age groups and environments. However, mebendazole is not so effective in the treatment for hookworms when compared to albendazole. It is suggested that albendazole should be considered the drug of choice for mass chemotherapy for Penang.