Scielo RSS <![CDATA[Revista Panamericana de Salud Pública]]> http://www.scielosp.org/rss.php?pid=1020-498920000011&lang=en vol. 8 num. 6 lang. en <![CDATA[SciELO Logo]]> http://www.scielosp.org/img/en/fbpelogp.gif http://www.scielosp.org <![CDATA[<B>Cryptosporidiosis in the Andean region of Colombia</B>: <B>seroprevalence and antigen recognition</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100001&lng=en&nrm=iso&tlng=en El objetivo de este estudio fue investigar, por primera vez, la seroprevalencia de la criptosporidiosis en habitantes urbanos y rurales de distintos departamentos de la región andina de Colombia. Se estudió también el reconocimiento de antígenos de Cryptosporidium parvum por los sueros. Entre junio de 1996 y octubre de 1998 se recogieron 1 778 muestras séricas de personas seleccionadas mediante un muestreo "de conveniencia". La detección de anticuerpos (IgM, IgA e IgG) anti-C. parvum se realizó mediante la técnica de ELISA y el reconocimiento de antígenos, por una técnica de inmunoelectrotransferencia. Se halló una prevalencia de 83,3%, mientras que los porcentajes de anticuerpos fueron 72,2% de IgM; 27,7% de IgA y 27,6% de IgG. Los porcentajes de seropositividad más altos se obtuvieron en mujeres, menores de 30 años de edad y personas de procedencia rural. Se observó que la seroprevalencia de IgM disminuye a medida que aumenta la edad, mientras que las de IgG e IgA aumentan al par que la edad. Estos tres isotipos reconocieron con mayor frecuencia los antígenos de 51 a 69 kDa, que pueden considerarse inmunodominantes. Se destacó la inmunorreactividad de IgM e IgA a fracciones proteínicas de 12 a 14 kDa y de 42 a 48 kDa, respectivamente, lo que podría indicar exposición al parásito. Estos resultados parecen indicar que la criptosporidiosis es endémica en esa región de Colombia, por lo que es posible atribuir muchos casos de síndrome diarreico a C. parvum.<hr/>The objective of this study was to investigate, for the first time, the seroprevalence of cryptosporidiosis among urban and rural inhabitants in several departments of the Andean region of Colombia. The antigen recognition of Cryptosporidium parvum was also studied with sera. Between June 1996 and October 1998 1 778 serum samples were collected from people selected through convenience sampling. The detection of anti-C. parvum antibodies (IgM, IgA, and IgG) was carried out with enzyme-linked immunosorbent assay, and antigen recognition was done with immunoblotting. A prevalence of 83.3% was found, and the antibody percentages were 72.2% for IgM, 27.7% for IgA, and 27.6% for IgG. Higher seropositivity percentages were found among women, persons less than 30 years old, and residents of rural areas. IgM seroprevalence decreased with age, while IgG and IgA seroprevalences increased with age. These three immunoglobulin isotypes most frequently recognized the antigens from 51 to 69 kDa, which can be considered immunodominant. Of note was the immunoreactivity of IgM and IgA to protein fractions from 12 to 14 kDa and from 42 to 48 kDa, respectively, which could indicate exposure to the parasite. These results indicate that cryptosporidiosis is endemic in the Andean region of Colombia, and that it is possible to attribute many cases of diarrheal syndrome to C. parvum. <![CDATA[<b>Nutritional status of children under 5 years of age in three hurricane-affected areas of Honduras</b>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100002&lng=en&nrm=iso&tlng=en Hurricanes and other natural disasters can produce crop destruction, population displacement, infrastructure damage, and long-term public health consequences that include increased malnutrition among the affected populations. This paper presents the results of anthropometric measurements taken of 295 children under 5 years of age from three regions of Honduras that were affected by Hurricane Mitch, a major storm that struck Central America in the fall of 1998. The children in our study were sampled in three shelters in the capital city of Tegucigalpa; in the resettlement zone of Nueva Choluteca, Choluteca; and in the small urban area of Catacamas, Olancho. Our data indicated that, in comparison to the period before the hurricane, there was an elevated prevalence of wasting in all three of the study areas, and that there were also high levels of underweight in the Tegucigalpa and Nueva Choluteca study areas. There were statistically significant differences between the mean values of malnutrition indicators for Catacamas and those for the Tegucigalpa and Nueva Choluteca settlements. These differences suggest that resettled families were confronting a nutritional crisis in July and August of 1999, some 9 months after the hurricane struck.<hr/>Los huracanes y otros desastres naturales pueden destruir cosechas, desplazar a poblaciones enteras, causar daños infraestructurales y acarrear consecuencias a largo plazo para la salud pública, entre ellas un aumento de la desnutrición en las poblaciones afectadas. Este trabajo presenta los resultados de las mediciones antropométricas de 295 niños menores de 5 años de tres zonas de Honduras que fueron azotadas por el huracán Mitch, tempestad que azotó Centroamérica en el otoño de 1998. Los niños que participaron en nuestro estudio provinieron de tres alojamientos provisionales, uno en la capital del país, Tegucigalpa; otro en la zona de asentamiento para refugiados de Nueva Choluteca, Choluteca; y otro en la pequeña zona urbana de Catacamas, Olancho. Según indican nuestros datos, en comparación con el período anterior al huracán, la frecuencia de emaciación en las tres zonas fue alta, como también lo fue la de peso subnormal en las zonas de estudio de Tegucigalpa y Nueva Choluteca. Hubo diferencias estadísticamente significativas entre los valores promedio de los indicadores de desnutrición en Catacamas y los de los asentamientos de Tegucigalpa y Nueva Choluteca. Estas diferencias indican que las familias desplazadas enfrentaban una crisis nutricional en julio y agosto de 1999, alrededor de 9 meses después de la llegada del huracán. <![CDATA[<b>Evaluation of the effectiveness of a new vaccine against human leptospirosis among groups at risk</b>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100003&lng=en&nrm=iso&tlng=en Se realizó un estudio de cohorte prospectivo cuasi experimental que incluyó a los grupos en riesgo de enfermar de leptospirosis en la provincia de Holguín para evaluar la efectividad de la vacuna contra la leptospirosis humana. Se incluyeron 118 018 personas de 15 a 65 años que presentaban un riesgo permanente o temporal de contraer la enfermedad; de estas, 101 137 fueron inmunizadas con dos dosis de 0,5 mL por vía intramuscular profunda en el músculo deltoides del brazo no dominante, con un intervalo de 6 semanas, constituyendo la cohorte de vacunados, mientras que 16 881 personas no inmunizadas pasaron a integrar la cohorte de no vacunados. A los 21 días de aplicada la segunda dosis, el universo de estudio (previamente censado en un registro de modelo) fue seguido por el sistema local de vigilancia epidemiológica con el objetivo de detectar la enfermedad. El criterio de caso sospechoso y confirmado se conservó durante todo el período de estudio. En el presente trabajo se exponen los resultados al año de haber comenzado el período de vigilancia epidemiológica. La efectividad calculada fue de 97%. Se estima que se logró prevenir 8 de cada 10 casos que se hubieran presentado en esta provincia de no haberse realizado la vacunación. También se midió la reactogenicidad de la vacuna en una submuestra de 1 500 voluntarios de 15 a 65 años de edad. La sintomatología observada fue baja, siendo el dolor ligero en el sitio de la inyección el síntoma más referido (25%). Los resultados del estudio aportan elementos que prueban la utilidad de la nueva vacuna para la prevención de la leptospirosis en personas expuestas al riesgo, por lo que en este grupo se recomienda su aplicación.<hr/>In order to evaluate the effectiveness of a new vaccine against human leptospirosis, a prospective cohort study was done with persons in the Cuban province of Holguín who were at risk of becoming ill with leptospirosis. The study included 118 018 persons from 15 to 65 years old who were considered to face either permanent or temporary risk. The vaccinated cohort consisted of 101 137 persons. They received two vaccine doses, 6 weeks apart, of 0.50 mL via deep intramuscular injection into the deltoid muscle of the nondominant arm. The unvaccinated cohort consisted of 16 881 persons. Epidemiological surveillance began 21 days after the application of the second vaccine dose and continued for 1 year. The same criteria for suspected and confirmed cases were maintained throughout the study period. At the end of the surveillance period effectiveness was calculated as being higher than 97%. It is estimated that the vaccination program prevented eight out of ten cases that would have otherwise occurred. Vaccine reactogenicity was also measured in a subsample of 1 500 persons between 15 and 65 years old. The observed symptomatology was low. Slight pain at the injection site was the most frequent symptom (25%). The results of the study indicate the usefulness of the vaccine for disease prevention among people at risk, and its use is thus recommended. <![CDATA[<b>History, effects, and mechanisms of action of ecstasy (3,4-methylenedioxymethamphetamine)</b>: <b>a literature review</b>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100004&lng=en&nrm=iso&tlng=en A presente revisão enfoca a 3-4 metilenodioximetanfetamina, droga ilegal conhecida como "êxtase". O êxtase foi introduzido no Brasil em 1994. Embora faltem dados sobre a epidemiologia e sobre os padrões de uso do êxtase no Brasil, há indicações de que o consumo seja, até o momento, restrito a jovens da classe alta ou média-alta e desconhecido para a maioria da população, inclusive para profissionais da saúde. Contudo, é possível que ocorra uma popularização dessa droga no Brasil, seguindo a tendência norte-americana e européia. A facilidade de consumo do êxtase -- em forma de pílulas -- pode ser um fator importante para sua popularização. O êxtase tem reputação de não apresentar perigo físico; contudo, há inúmeros relatos de reações adversas e mortes relacionadas à sua ingestão. Além disso, sabe-se que nem todos os comprimidos consumidos como êxtase necessariamente contém metilenodioximetanfetamina. Diante da ausência de controle farmacêutico, nenhum consumidor sabe exatamente o que está ingerindo. Assim, embora os efeitos do êxtase sejam percebidos como predominantemente positivos pelos usuários, a droga é potencialmente perigosa. Por essa razão, são necessárias intervenções de caráter primário e secundário para prevenir o uso de êxtase e a ocorrência de reações adversas. Para serem efetivas, tais ações devem levar em conta as características da população consumidora e seu padrão de consumo. Também é fundamental a capacitação de profissionais de saúde para intervenções médicas de emergência em casos de intoxicação e complicações resultantes do uso da droga.<hr/>This review focuses on 3,4-methylenedioxymethamphetamine, an illegal drug known as "ecstasy." Ecstasy was introduced in Brazil in 1994. Data are lacking on the epidemiology and usage pattern of the drug in Brazil. However, there is evidence that until now the use of ecstasy has been limited to middle-class or upper-middle-class youth, so that most people, including health care professionals, are unfamiliar with the drug. However, ecstasy may be becoming more popular in Brazil, following a pattern seen in North America and Europe. Possibly contributing to the drug's popularity is the fact that ecstasy is sold as a pill and is thus extremely easy to use. Ecstasy has a reputation for not being physically dangerous; however, there are many reports of adverse reactions associated with the drug. In addition, it is known that not all pills sold as ecstasy actually contain methylenedioxymethamphetamine. Since there is no quality control for the pills' contents, users never know exactly what they are taking. Thus, although users may perceive the effects of the drug as mostly positive, ecstasy is potentially dangerous. Primary and secondary interventions are needed to prevent the use of ecstasy and the occurrence of adverse reactions. To be effective, these measures must take into consideration the characteristics of the user population and the usage patterns. It is also essential to prepare health professionals for emergency medical interventions in cases of intoxication and complications resulting from the use of ecstasy. <![CDATA[<B>The use of socioeconomic factors in mapping tuberculosis risk areas in a city of northeastern Brazil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100005&lng=en&nrm=iso&tlng=en In Brazil the challenge of meeting the needs of those living in deprived areas has generated discussions on replacing the existing approach to epidemiological surveillance with an integrated public health surveillance system. This new approach would supplant the traditional focus on high-risk individuals with a method for identifying high-risk populations and the areas where these persons live. Given the magnitude of the problem that tuberculosis (TB) poses for Brazil, we chose that disease as an example of how such a new, integrated public health surveillance system could be constructed. We integrated data from several sources with geographic information to create an indicator of tuberculosis risk for Olinda, a city in the Brazilian state of Pernambuco. In order to stratify the urban space in Olinda and to check for an association between the resulting TB risk gradient and the mean incidence of the disease between 1991 and 1996, we applied two different methods: 1) a "social deprivation index" and 2) principal component analysis followed by cluster analysis. Our results showed an association between social deprivation and the occurrence of TB. The results also highlighted priority groups and areas requiring intervention. We recommend follow-up that would include treating acid-fast bacilli smear-positive pulmonary TB cases, tracing of these persons' contacts, and monitoring of multidrug-resistant cases, all in coordination with local health services.<hr/>En Brasil, el reto de satisfacer las necesidades de los residentes en zonas pobres ha generado discusiones sobre la sustitución del actual abordaje de la vigilancia epidemiológica por un sistema integrado de vigilancia de la salud pública. Este nuevo abordaje debería sustituir el tradicional enfoque en los individuos de alto riesgo por un método destinado a identificar las poblaciones de alto riesgo y las zonas en las que viven. Dada la magnitud del problema de la tuberculosis en Brasil, elegimos esta enfermedad como un ejemplo de cómo se podría concebir este nuevo sistema integrado de vigilancia de la salud pública. Se reunieron los datos de varias fuentes y la información geográfica para crear un indicador del riesgo de tuberculosis en Olinda, ciudad del estado de Pernambuco. Con el fin de estratificar el espacio urbano de Olinda y de buscar una asociación entre el gradiente del riesgo de tuberculosis y la incidencia media de la enfermedad entre 1991 y 1996, se aplicaron dos métodos diferentes: 1) un "índice social de pobreza", y 2) un análisis de componentes principales seguido de un análisis por grupos. Los resultados obtenidos revelaron una asociación entre la pobreza y la aparición de la tuberculosis y también señalaron grupos y zonas prioritarias que requerían intervención. Se recomienda un seguimiento que debería incluir el tratamiento de los casos de tuberculosis pulmonar con baciloscopia positiva, la identificación de los contactos de estos individuos y el control de los casos resistentes a múltiples fármacos, todo ello en coordinación con los servicios de salud locales. <![CDATA[<b><i>Trypanosoma cruzi</i> antibody detection in eight rural communities of Somoto, Nicaragua, through indirect ELISA and indirect immunofluorescence in blood samples collected on filter paper</b>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100006&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>Posible efecto protector de <I>Helicobacter pylori</I> contra la diarrea infantil</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100007&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>El consumo de calcio y fibra en la dieta y el riesgo de sufrir pólipos intestinales</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100008&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>Relación entre salud materna e intervalo entre embarazos</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100009&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>¿Es beneficiosa la dosis de refuerzo de la vacuna contra <I>Haemophilus influenzae</I>?</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100010&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>Mecanismos de inhibición de la respuesta inmunitaria por algunos agentes patógenos</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100011&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>Estado deplorable de la higiene en el mundo</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100012&lng=en&nrm=iso&tlng=en Se estandarizó un inmunoensayo enzimático en fase sólida (ELISA) para estudiar la presencia de anticuerpos contra Trypanosoma cruzi en personas asintomáticas que viven en un área endémica de enfermedad de Chagas en Nicaragua. El ensayo fue estandarizado para el análisis de muestras de sangre colectadas en papel de filtro como método simple de transporte de muestras de sangre. Se realizó un estudio previo en el que se estudiaron por ELISA 18 muestras de suero total y 18 eluidos de sangre de pacientes con enfermedad de Chagas crónica, 30 muestras de suero y 30 eluidos de sangre de personas sanas que se utilizaron como controles negativos y 14 muestras de suero y 14 eluidos de sangre de pacientes con leishmaniasis cutánea o visceral que se utilizaron para los estudios de reacciones cruzadas. Tanto con el suero total como con los eluidos de sangre, la prueba de ELISA proporcionó una sensibilidad de 100% y una especificidad de 90%; solo se observaron reacciones cruzadas con las muestras de pacientes con leishmaniasis visceral. El estudio poblacional incluyó a ocho comunidades rurales de Somoto, Nicaragua. Mediante un muestreo al azar se colectaron muestras de sangre en papel de filtro a 2 434 personas (1 335 del sexo masculino y 1 099 del sexo femenino) de las comunidades de Aguas Calientes, La Manzana, Los Canales, Santa Rosa, Las Playas, El Brocal, Santa Isabel y Santa Teresa. Las muestras fueron estudiadas por ELISA e inmunofluorescencia indirecta (IFI) encontrándose un total de 260 seropositivos por ELISA (10,7%), 207 de los cuales fueron también positivos por IFI (8,5%). La mayoría de los sueros seropositivos correspondieron a personas del sexo femenino con ambas técnicas, pero la diferencia entre hombres y mujeres no fue estadísticamente significativa. Los resultados obtenidos con ambas técnicas mostraron una excelente concordancia. Con respecto a la edad se observó una curva ascendente, con 5,4% de seropositivos por ELISA en individuos de 0-10 años y 42,7% en mayores de 50 años. La vasta mayoría de los individuos analizados fueron asintomáticos.<hr/>We standardized a solid-phase enzyme-linked immunosorbent assay (ELISA) in order to study the presence of Trypanosoma cruzi antibodies in asymptomatic persons who live in an area of Nicaragua endemic for Chagas' disease. The test was standardized to analyze filter-paper blood samples, which are easy to transport. In the first phase of our investigation, ELISA was used to study 18 samples of total serum and 18 eluates of blood from patients with chronic Chagas' disease; 30 samples of serum and 30 eluates of blood from healthy people, used as negative controls; and 14 samples of serum and 14 eluates of blood from patients with cutaneous or visceral leishmaniasis, which were used to study cross-reactions. Both with the total-serum and the blood-eluate samples, the ELISA test provided 100% sensitivity and 90% specificity. Cross-reactions in the patient samples were observed only with visceral leishmaniasis. The second phase of our investigation was a population study that included eight rural communities in the area of Somoto, Nicaragua. Through random sampling, filter-paper blood samples were collected from 2 434 people (1 335 men and 1 099 women) from the communities of Aguas Calientes, El Brocal, La Manzana, Las Playas, Los Canales, Santa Isabel, Santa Rosa, and Santa Teresa. Studied by ELISA and by indirect immunofluorescence (IIF), the samples included 260 found seropositive by ELISA (10.7%), of which 207 were positive according to IIF (8.5%). With both techniques, the majority of seropositives were among women, but the difference between men and women was not statistically significant. There was a high level of agreement between the results obtained with the two techniques. There was an upward trend with age, with 5.4% of those found seropositive by ELISA being persons 10 years of age or younger and 42.7% of those found seropositive being older than 50. The vast majority of the individuals analyzed were asymptomatic. <![CDATA[<B>HIV and AIDS in the Americas</B>: <B>an epidemic with many faces</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100013&lng=en&nrm=iso&tlng=en This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the Latin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janeiro from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are usually considered of low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV. <![CDATA[<B>El progreso en la salud de la población. Informe anual del director, 2000</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100014&lng=en&nrm=iso&tlng=en This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the Latin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janeiro from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are usually considered of low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV. <![CDATA[<B>Pido la palabra. El médico, periodista y su circunstancia. Microensayos y otros escritos</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100015&lng=en&nrm=iso&tlng=en This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the Latin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janeiro from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are usually considered of low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV. <![CDATA[<B>La salud en el contexto de la nueva salud pública</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100016&lng=en&nrm=iso&tlng=en This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the Latin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janeiro from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are usually considered of low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV. <![CDATA[<B>La salud en la América Latina. De la reforma para unos a la reforma para todos</B>]]> http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S1020-49892000001100017&lng=en&nrm=iso&tlng=en This document presents data that was analyzed at a joint meeting of the Monitoring the AIDS Pandemic Network and the Latin America and Caribbean Epidemiological Network for HIV/AIDS, held in Rio de Janeiro from 4 to 5 November 2000, along with the final recommendations of that meeting. The report focuses on the diversity of the global HIV/AIDS pandemic, a diversity that is particularly evident in Latin America and the Caribbean. After providing an overall perspective on the epidemic in the Americas, the report describes the epidemic in different areas of the Americas: the Andean Subregion, Brazil, the Caribbean, Central America, Mexico, the Southern Cone, and North America. The problem of infections associated with HIV/AIDS is also addressed, especially tuberculosis, as well as other sexually transmitted infections. Also analyzed are achievements and challenges in preventing HIV infection, both in groups that are usually considered of low risk (heterosexual adults) and those of high risk (men who have sex with men, intravenous drug users, young people, and marginalized populations). Other aspects analyzed are efforts to improve HIV surveillance, new antiretroviral agents and their impact, and the prevention of vertical transmission of HIV.