Toxocariosis en diferentes poblaciones infantiles vulnerables de la Argentina / Toxocariosis in different vulnerable groups of children in Argentina

La toxocariosis humana es una parasitosis de amplia distribución en el mundo. Se estudiaron 857 muestras de sangre de poblaciones vulnerables de distintas edades. Todas las muestras fueron analizadas mediante el test de ELISA: 346 correspondieron a habitantes de zonas urbanas; 258 eran de niños de entre 0 y 20 años, y 88 eran donantes de sangre; de las 356 muestras estudiadas de poblaciones rurales, 326 correspondieron a niños; los 30 restantes, a adultos de la misma zona; también se analizó una población aborigen de 130 niños y 25 adultos. Entre los niños de zonas urbanas la prevalencia fue de 28.3% y de 46.6% en los adultos. En la zona rural la prevalencia en niños fue de 59.2%, y en los adultos, de 53.3%; en la población aborigen la prevalencia alcanzó el 78.5% en niños y el 80.0% en los adultos. Estos valores son altos y tienen relación con el nivel de educación y con el medio ambiente. El suero de los dadores fue estudiado con dos equipos comerciales, y al compararlos ofrecieron resultados con mayor positividad. Se muestra que la toxocariosis es una infección endémica, que afecta a los niños y tiene alto impacto en la población con déficit educacional. Se discuten los informes internacionales, el diagnóstico y los mecanismos de transmisión. Los resultados justifican que esta parasitosis sea considerada un problema de salud pública...

Infección chagásica en niños de cuatro distritos de riesgo de la provincia de Santa Fe / Chagas' infection in children of four districts at risk in Santa Fe province / Infecgáo chagasica em changas de quatro distritos de risco da provincia de Santa Fe

El objetivo del presente estudio fue investigar infección chagásica en niños de 1 a 15 años que residen en zona de riesgo vectorial o con antecedentes migratorios en la provincia de Santa Fe, estimar la/s vía/s más probable/s de infección y comparar la prevalencia con trabajos anteriores. Se realizó un estudio seroepidemiológico en escuelas de los Distritos Garabato, Fortín Olmos y Gato Colorado y la escuela de la comunidad Com Caia del Departamento La Capital. A los seropositivos se les realizó una encuesta para determinar las probables vías de infección. Se comparó la prevalencia actual con la del último control de cada distrito. No se hallaron seropositivos en Com Caia (prevalencia 0%, 0/130). La prevalencia en Garabato fue 1,0% (6/604), Fortín Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Disminuyó respecto de los últimos estudios: Garabato 11,2% (año 2000), Fortín Olmos 14,6% (2004), Gato Colorado 6,3% (2006). La vía de infección que se sospecha más frecuente es la congènita, seguida por la vectorial. Se concluye que, a pesar de la disminución de la prevalencia, se deben continuar las acciones de control, principalmente por vías vectorial y congènita.

The aim of the present study was to diagnose Chagas infection in children 1 to 15 years of age living in a risk area or with migrant background in Santa Fe province, to estimate the most probable way of infection and to compare the prevalence with previous works. A seroepidemiological study was conducted in schools in the districts Garabato, Fortin Olmos and Gato Colorado and the community Com Caia in La Capital Department. An inquiry was conducted in positive patients to determine the most probable way of infection. The current prevalence was compared with the last control in each district. No seropositive were found in Com Caia (prevalence 0%, 0/130). In Garabato the prevalence was 1.0% (6/604), Fortin Olmos 1.9% (13/688), Gato Colorado 3.0% (12/399). It decreased in comparison with the latest study: Garabato 11.2% (2000), Fortin Olmos 14.6% (2004), Gato Colorado 6.3% (2006). The most suspected way of infection was congenital, followed by vector one. We conclude that, although the prevalence decreased, it must be continued mainly vector and congenital controls actions.

O objetivo deste estudo foi investigar a infecgáo chagásica em criangas de 1 a 15 anos que moram em zona de risco vetorial ou com antecedentes de migragáo na provincia de Santa Fe, estimar a/as via/s mais provável/veis de infecgáo e comparar prevalencia com trabalhos anteriores. Foi realizado um estudo soroepidemiológico em escolas nos distritos Garabato, Fortin Olmos e Gato Colorado e na escola da comunidade Com Caia no departamento La Capital. Os soropositivos foram entrevistados para determinar as prováveis vias da infecgáo. A prevalencia atual foi comparada com a do último controle em cada distrito. Náo foram encontrados soropositivos em Com Caia (prevalencia 0%, 0/130). A prevalencia em Garabato foi 1,0% (6/604), Fortin Olmos 1,9% (13/688), Gato Colorado 3,0% (12/399). Diminuiu a respeito dos últimos estudos: Garabato 11,2% (ano 2000), Fortin Olmos 14,6% (2004), Gato Colorado 6,3% (2006). A via de infecgáo que se suspeita como sendo a mais frequente é a congenita, seguida pela vetorial. Concluise que, apesar da diminuigáo da prevalencia, devem continuar sendo realizadas agoes de controle, principalmente por vias vetorial e congenita.

Infección chagásica en estudiantes universitarios de Santa Fe (Argentina) / Chagas' infection in universitary students of Santa Fe (Argentina)

La tripanosomiasis americana se transmite por picadura de triatominos hematófagos (principalmente), o por vía connatal o transfusional. Generalmente es asintomática en fase aguda y en fase crónica puede evolucionar a trastornos cardíacos (más comunes) o digestivos. El tratamiento etiológico es más efectivo en casos agudos y en menores de 15 años con infección crónica. Nuestro objetivo fue determinar: a) si existen infectados jóvenes que perdieron su oportunidad de tratamiento por superar la edad cuando fueron diagnosticados y b) probable vía de infección. Se estudiaron 14374 ingresantes a universidades de Santa Fe entre marzo de 2004 y julio de 2008. Se realizó serología para Chagas y encuesta sobre datos relacionados con las posibles vías de transmisión. Se identificaron 20 infectados chagásicos, 80% menores de 25 años. En 4 la transmisión probablemente fue congénita, 3 transfusionaly 3 vectorial. En 10 no se pudo determinar. Concluimos que, de haberse realizado análisis para Chagas al ingreso escolar, estos jóvenes infectados chagásicos podrían haber recibido el tratamiento tripanocida en el momento oportuno. En ellos es importante tener en cuenta todas las vías de transmisión.

Evaluación de ELISA F29 como marcador de eficacia del tratamiento etiológico en la enfermedad de Chagas / Assessment of ELISA F29 as a marker of etiological treatment efficacy for Chagas disease

A transversal study was performed on sera from chronic chagas ic patients treated with nifurtimox (Nx) or benznidazole (Bz), in order to evaluate the Trypanosoma cruzi flagellar calcium-binding protein (F29) as a marker for therapeutic effectiveness. An ELISA was used with these F29 recombinant antigen, and its relation to conventional serology (CS) and parasitological and clinical evolution was analysed. Sera from 118 patients with retrospective, serological, parasitological and clinical information was available, were analyzed. Patients were grouped into: A) 30 treated patients whose CS became negative after treatment; B) 34 treated patients whose CS remained positive; C) 54 untreated patients. A double-blind trial was conducted simultaneously in all serum samples, by means ofCS (indirect hemagglutination, direct agglutination and indirect immunofluorescence) and ELISA F29. The ELISA F29 test was non reactive in: 100 percent of group A, 82.4 percent of group B and 13 percent> of group C. The infected patients who presented electrocardiographic alterations compatible with chronic chagasic myocardiopathy (n = 11) were reactive for ELISA F29. All patients whose parasitological studies (xenodiagnosis and/or strout method) were positive presented a high reactivity to the ELISA F29 test. The correlation between ELISA F29 and CS was statistically significant (p < 005) in the treated group whose CS was non reactive (group A) and the untreated group (group C). As opposed to this, in the group of treated patients whose CS remained positive (group B), the ELISA F29 test was reactive only in a 17.6 percent>. These results suggest that the fast and user-friendly ELISA F29 test could be useful to monitor changes after trypanocidal treatment.

La proteína flagelar F29 es una proteína ligadora de calcio del Trypanosoma cruzi. En el presente trabajo se realizó un estudio transversal en sueros de pacientes con infección crónica por T. cruzi tratados con nifurtimox (Nx) o benznidazol (Bz) y no tratados, para evaluar el antígeno F29 como marcador de eficacia terapéutica. Se utilizó un ensayo inmuno-enzimático con la proteína recombinante F29 (ELISA F29) y se analizó su relación con la serología convencional (SC) y la evolución parasitológica y clínica en esos pacientes. Se estudiaron 118 sueros de pacientes que formaban parte de una cohorte, de los cuales se disponía de información retrospectiva, serológica, parasitológica y clínica. Los pacientes se dividieron en 3 grupos: A) 30 tratados negativizaron SC post-tratamiento; B) 34 tratados permanecieron con SC reactiva; C) 54 no tratados. Las muestras de suero se procesaron a doble ciego en forma simultánea mediante serología convencional (hemoaglutinación indirecta, aglutinación directa e inmunofluorescencia indirecta) y ELISA F29. El test ELISA F29 resultó no reactivo en: 100 por ciento del grupo A, 82,4 por ciento del grupo B y 13 por ciento del grupo C. Los infectados con alteraciones electrocardiográficas compatibles con miocardiopatía chagásica crónica (n = 11) fueron reactivos al ELISA F29. Los pacientes en quienes los estudios parasitológicos (xenodiagnóstico y/o strout) fueron (+) presentaron elevada reactividad al ELISA F29. La correlación entre ELISA F29 y SC en los pacientes tratados con SC no reactiva (grupo A) y no tratados (grupo C), fue significativa (p < 0,05). En cambio, en pacientes tratados que mantuvieron la SC reactiva (grupo B) el test de ELISA F29 fue reactivo sólo en 17,6 por ciento. Estos resultados sugieren que el test ELISA F29, rápido y sencillo, podría ser útil para monitorear cambios post-tratamiento tripanocida.

Trypanocide treatment among adults with chronic Chagas disease living in Santa Fe city (Argentina), over a mean follow-up of 21 years: parasitological, serological and clinical evolution

The efficacy of treatment with nifurtimox and/or benznidazole among adults with chronic Chagas disease with no previous electrocardiographic disturbances was evaluated over a mean follow-up of 21 years, by means of conventional serology, xenodiagnosis, clinical examination, electrocardiograms and chest X-ray. One hundred and eleven patients, between 17 and 46 years old, were studied: 54 underwent treatment (nifurtimox 27, benznidazole 27) and 57 remained untreated (control group). Xenodiagnosis was performed on 65 percent of them: 36/38 of the treated and 9/34 of the untreated patients had previous positive xenodiagnosis. Post-treatment, 133 xenodiagnoses were performed on 41 patients, all resulting negative. In the control group, 29 xenodiagnoses were performed on 14 patients; 2 resulted positive. Sera stored during the follow-up were simultaneously analyzed through conventional serology tests (IHA; DA-2ME; IIF). The serological evolution in the treated group was: a) 37 percent underwent negative seroconversion (nifurtimox 11, benznidazole 9); b) 27.8 percent decreased titers (nifurtimox 9, benznidazole 6), 9 showed inconclusive final serology (nifurtimox 7, benznidazole 2); c) 35.2 percent remained positive with constant titers (nifurtimox 7; benznidazole 12). The control group conserved the initial antibody levels during the follow-up. In the clinical evolution, 2/54 (3.7 percent) of the treated and 9/57 (15.8 percent) of the untreated patients showed electrocardiographic disturbances attributable to Chagas myocardiopathy, with a statistically relevant difference (p<0.05). Treatment caused deparasitation in at least 37 percent of the chronically infected adults and a protective effect on their clinical evolution.

Avaliamos a eficácia do nifurtimox e/ou benznidazol, durante 21 anos em média, em adultos chagásicos crônicos sem alterações eletrocardiográficas iniciais, mediante sorologia convencional, xenodiagnóstico, exames clínicos, eletrocardiográficos e radiografia do tórax. Estudamos 111 pacientes (17 a 46 anos): 54 foram tratados (27 com nifurtimox e 27 com benznidazol) e 57 formaram o grupo controle. Foram submetidos ao xenodiagnóstico 65 por cento dos pacientes estudados: 36/38 tratados e 9/34 do grupo controle com xenodiagnóstico positivo prévio. Após tratamento, foram realizados 133 xenodiagnósticos em 41 pacientes, sendo todos negativos. Foram realizados 29 xenodiagnósticos em 14 pacientes do grupo controle, 2 foram positivos. A sorologia convencional foi realizada em soros estocados durante o seguimento. Evolução sorológica. Grupo tratado: a) 37 por cento negativaram (nifurtimox 11, benznidazol 9); b) 27,8 por cento diminuíram a titulação (nifurtimox 9, benznidazol 6), 9 deles apresentaram sorologia final discordante (nifurtimox 7, benznidazol 2; c) 35,2 por cento permaneceram positivos com titulação constante (nifurtimox 7, benznidazol 12). Grupo controle: conservou os níveis iniciais de anticorpos durante o seguimento. Evolução clínica: 2/54 (3,7 por cento) pacientes tratados e 9/57 não tratados apresentaram alterações eletrocardiográficas atribuíveis a miocardiopatia chagásica. Diferenças estatisticamente significantes (p<0,05). O tratamento produziu efeito de combate ao parasita em pelo menos 37 por cento dos infetados crônicos adultos e efeito protetor na evolução clínica.

Evolutive behavior towards cardiomyopathy of treated (nifurtimox or benznidazole) and untreated chronic chagasic patients

The aim of this work was to compare the evolution of chronic chagasic untreated patients (UTPs) with that of benznidazole or nifurtimox-treated patients (TPs). A longitudinal study from a low endemic area (Santa Fe city, Argentina) was performed during an average period of 14 years. Serological and parasitological analyses with clinical exams, ECG and X-chest ray were carried out. At the onset, 19/198 infected patients showed chagasic cardiomyopathy (CrChM) while 179 were asymptomatic. In this latter group the frequency of CrChM during the follow-up was lower in TPs compared with UTPs (3.2 per cent vs 7 per cent). Within the CrChM group, 2/5 TPs showed aggravated myopathy whereas this happened in 9/14 UTPs. Comparing the clinical evolution of all patients, 5.9 per cent of TPs and 13 per cent of UTPs had unfavourable evolution, but the difference is not statistically relevant. Serological titers were assessed by IIF. Titers equal to or lower than 1/64 were obtained in 86 per cent of the TPs, but only in 38 per cent of UTPs. The differences were statistically significant (geometric mean: 49.36 vs. 98.2). Antiparasitic assessment of the drugs (xenodiagnosis) proved to be effective. The low sensitivity in chronic chagasic patients must be born in mind. Despite treated patients showed a better clinical evolution and lower antibody levels than untreated ones, it is necessary to carry on doing research in order to improve therapeutic guidelines, according to the risk/benefit equation and based on scientific and ethical principles.

Chagas congénito en la ciudad de Santa Fé. Diagnóstico y tratamiento / Congenital Chagas disease in the city of Santa Fé. Diagnosis and treatment

We studied 6123 pregnant women and their 341 newborn (NB), from Santa Fe city, by the following serological tests for chagasic infection: Direct Agglutination with and without 2-mercaptoethanol, Indirect Hemagglutination and Indirect Immunofluorescence test, and by identification of parasites by Fresh drops, Strout and/or by Xenodiagnosis. The prevalence of seropositivity found in pregnant women was of 14.62 with a 73 of migratory history. The parasitological studies yielded 9/341 incidence of transplacentary infection. Clinical examinations were made in the infected newborn (NB). They were treated with Benznidazol or Nifurtimox, and post-treatment evolution was evaluated. We registered connatal infection in twin-brothers. Brothers/sisters (siblings) of infected NB were also studied. Some of them were seropositive and the others seronegative. Results here obtained show that this way of transmission is important, and should be considered even in low endemicity areas. The parasitological assays proved to be decisive for the NB infection diagnosis (Table 1). The serological assays enabled us to follow the non-infected NB up to their negativization. A 6 month follow-up is recommended. It is impossible to define only one clinical outline because both symptomatic and asymptomatic infected NB may be found with gestational age at term and pre-term and when born with a weight above or below 2000 g. We obtained parasitological and serological negativization in all cases. The chagasic pregnant woman does not necessarily transmit the infection to all her descendents. Only 2.64 are infected. It is possible to systematize the diagnosis without extra resources beyond the usual ones.