First Colombian multicentric newborn screening for congenital toxoplasmosis.

AIMS: To determine the incidence of congenital toxoplasmosis in Colombian newborns from 19 hospital or maternal child health services from seven different cities of five natural geographic regions (Caribbean, Central, Andean, Amazonia and Eastern). MATERIALS AND METHODS: We collected 15,333 samples from umbilical cord blood between the period of March 2009 to May 2010 in 19 different hospitals and maternal-child health services from seven different cities. We applied an IgM ELISA assay (Vircell, Spain) to determine the frequency of IgM anti Toxoplasma. The results in blood cord samples were confirmed either by western blot and repeated ELISA IgM assay. In a sub-sample of 1,613 children that were negative by the anti-Toxoplasma IgM assay, the frequency of specific anti-Toxoplasma IgA by the ISAGA assay was determined. All children with positive samples by IgM, IgA, clinical diagnosis or treatment during pregnancy were recalled for confirmatory tests after day 10 of life. RESULTS: 61 positive samples for specific IgM (0.39%) and 9 positives for IgA (0.5%) were found. 143 questionnaires were positive for a clinical diagnosis or treatment for toxoplasmosis during pregnancy. 109 out of the 218 children that had some of the criteria for postnatal confirmatory tests were followed. Congenital toxoplasmosis infection was confirmed in 15 children: 7 were symptomatic, and three of them died before the first month of life (20% of lethality). A significant correlation was found between a high incidence of markers for congenital toxoplasmosis and higher mean annual rainfall for the city. CONCLUSIONS: Incidence for congenital toxoplasmosis is significantly different between hospitals or maternal child health services from different cities in Colombia. Mean annual rainfall was correlated with incidence of congenital toxoplasmosis.

Validación de pruebas ELISA IgM anti-Toxoplasma para uso en programas de tamización en recién nacidos / Validation of anti-Toxoplasma IgM ELISA tests in newborn screening programs

Objetivos. Evaluar y determinar el punto de corte para la detección de IgM anti-Toxoplasma por el método ELISA, en muestras de sangre de cordónumbilical, mediante dos ensayos comerciales diferentes, y correlacionar los resultados obtenidos con el diagnóstico de toxoplasmosis congénitarealizado por seguimiento serológico y los datos clínicos. Métodos. Se evaluó la prueba IgM anti-Toxoplasma ELISA de Vircell®, frente a los resultados por Western blot e IgM ELISA de Labsystems®. Seestudiaron 105 muestras de cordón umbilical de niños colombianos, obtenidas de seis ciudades diferentes por Western blot y seguimiento clínico yserológico en aquellos positivos. Se obtuvo una curva receptor-operador (ROC) para la prueba ELISA IgM anti-Toxoplasma de Vircell® y de Labsystems®. Se analizó la concordancia entre pruebas en 105 sueros obtenidos de cordón umbilical. Resultados. El mejor desempeño para la prueba Vircell® fue con un punto de corte de índice 8 y la prueba de Labsystems® con un punto de cortede 16 inmunounidades enzimáticas. Frente al Western blot, la prueba Vircell® tuvo una sensibilidad de 100 % (IC 95%; 71,8-100) y una especificidadde 78 % (IC 95%; 69-85,7), la prueba Labsystems® tuvo una sensibilidad de 100 % (IC95%; 71,8-100) y una especificidad de 100 % (IC95%; 96-100). Laconcordancia entre ambas pruebas (Labsystems® y Vircell®) fue de 80 %, con un índice kappa de 0,45. Conclusiones. Un punto de corte de un índice 8 para la prueba ELISA IgM anti-Toxoplasma de Vircell® y un punto de corte de 16 inmunounidadesenzimáticas por Labsystems®, permiten identificar infecciones congénitas en sangre de cordón umbilical en niños colombianos.

Objectives: To evaluate and validate the detection of anti-Toxoplasma IgM ELISA in umbilical cord blood by means of two different commercialassays and to correlate the results with the diagnosis of congenital infection in children by serological follow up and clinical data. Materials and methods: We evaluated the commercial anti-Toxoplasma IgM ELISA kitÔ from Vircell (Granada, Spain) compared to the results of Toxoplasma IgM Western blotÔ (LDbio, Lyon, France) and IgM ELISA testÔ from Labsystems (Finland). We obtained the receptor-operator curve (ROC) for the IgMELISA assay form Vircell and Labsystems. We studied 105 umbilical cord blood serum samples from Colombian children from six different cities by Westernblot, and clinical and serological follow up for positive cases. The kappa agreement index was determined for the 105 sera obtained from umbilical cords. Results: The Vircell assay showed a better performance with a cut-off index of 8 against a 16 for Labsystems for enzyme immunounits (EUI). Whenthe results were evaluated against the Western blot assay, the Vircell IgM assay had a sensitivity of 100% (IC95%: 71.8-100) and a specificity of 78%(IC95%: 69-85.7), the IgM assay from Labsystems had a sensitivity of 100% (IC95%; 71.8-100) and a specificity of 100% (IC95%; 96-100). Agreement between both tests (Labsystems and Vircell) was 80% and had a kappa index of 0.45. Conclusions: A cut-off point of 8 for the anti-Toxoplasma IgM ELISA assay from Vircell and 16 EIU for the Labsystems assay allow the identificationof congenital infections in umbilical cord blood samples from Colombian children.

Prevalencia de infección por VIH/SIDA en hombres que tienen sexo con hombres en Bucaramanga, Colombia / Prevalence of infection by HIV/AIDS in men who have sex with men in Bucaramanga, Colombia

Introducción: La infección por VIH/SIDA continúa siendo un reto para la salud pública en términos de su prevención y control. El objetivo del estudio fue determinar la prevalencia de VIH/SIDA en el grupo de hombres que tienen sexo con hombres y los factores comportamentales que favorecen su transmisión. Materiales y métodos: Estudio descriptivo trasversal con muestreo no probabilístico en sitios de encuentro frecuentados por esta población y en la cárcel. Se aplicó una encuesta estructurada y se realizó toma de muestra sanguínea anónima ligada por códigos para el diagnóstico de infección por VIH. Resultados: Se encuestaron 336 hombres en 9 sitios con un promedio de 27,6 +/- 8,4 años. El 92,4% tenía estudios de secundaria o superiores, el 6% declaró vivir con pareja femenina y el 19,9% con pareja masculina estable. El 54,6% refirió que nunca o solo de forma ocasional utiliza preservativo con sus parejas sexuales. El 43% de los encuestados se había realizado prueba para VIH/SIDA y de éstos el 20,1% (29 hombres) ya tenían diagnóstico confirmatorio. Entre los 150 hombres tamizados se diagnosticaron 8 nuevos casos obteniendo una prevalencia general de 11,01%. Conclusiones: Los hallazgos indican que la epidemia en el municipio corresponde a una de tipo concentrada. Aunque actualmente se recomiendan estrategias de prevención dirigidas a población general, en el municipio se recomienda continuar actividades específicas en este grupo de población que aún presenta conductas de riesgo para la trasmisión del VIH.

Introduction: Prevention and control of infection by HIV/AIDS is a challenge to public health. The aim of the study was to determine the prevalence of HIV/AIDS in men who have sex with men and the behavioral factors related with transmission in Bucaramanga, Colombia. Materials and Methods: Transversal descriptive serological survey with non probabilistic sampling in meeting and reclusion places. A structured interview and serum sample linked by codes was applied. Results: 336 men with 27.6 +/- 8.4 age mean were studied in nine places. A 92.4% had secondary or upper education level. 6% were living with a female partner and 19.9% with a male partner. The 54.6% reported that never or occasionally used condom with their partners. The 43% of men had been tested for HIV and 20.1% of them (29 men) were already diagnosed as serum positive. Amongst 150 men screened, 8 new cases were diagnosed reaching 11.01% prevalence in general. Conclusions: Results show there is a concentrated epidemic HIV in Bucaramanga. In spite prevention strategies for general population currently carried out, it is recommended to continue specific strategies for this population group to control risk behavior in the HIV transmission.