Sensitive and Stable Molecular Detection of Dengue, Chikungunya, and Zika Viruses from Dried Blood Spots.

Standard molecular detection of many pathogens, in particular RNA viruses, requires appropriate handling in the field for preserving the quality of the sample until processing. This could be challenging in remote tropical areas. Dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) are RNA viruses, prominent among the causes of fever in the tropics. We aimed to test the stability of arboviral RNA in contrived dried blood spots prepared on Whatman 903 Protein saver cards as a means of sample collection and storage. We were able to detect DENV, CHIKV, and ZIKV by real-time RT-PCR up to 180 days after card inoculation with stable Ct values across the study period. Our study supports dried blood spots (DBS) on protein saver cards as a platform for stable detection of arboviral RNA of sufficient quality to be used in diagnostic RT-PCR assays and next generation sequencing.

Seroprevalencia de anticuerpos anti-Toxoplasma gondii en mujeres menores de 18 años de una localidad de Colombia / Seroprevalence of anti-Toxoplasma gondii antibodies in women under 18 years old from a locality of Colombia

Resumen OBJETIVO: Determinar la seroprevalencia de Toxoplasma gondii en mujeres menores de 18 años de dos instituciones educativas de un municipio de Colombia. MATERIALES Y MÉTODOS: Estudio de prevalencia, transversal, efectuado en 2016 en mujeres de dos colegios de Dosquebradas, Colombia, aprobado por los comités de ética de las instituciones participantes. Criterios de inclusión: ser menores de 18 años, firmar el consentimiento informado y responder las preguntas de una encuesta de datos demográficos. Criterios de exclusión: tener más de 18 años y haber tenido embarazos previos. Las muestras se analizaron contra anticuerpos IgM, IgG e IgG de avidez con antígenos recombinantes para Toxoplasma gondii altamente purificados con la prueba recomLine, con desarrollo de Western blot mikrogen Diagnostik. Para definir el momento infeccioso se determinó la avidez anti-IgG contra antígenos p30, MAG1, GRA1 y rSAG1 en muestras positivas para IgG total. La prueba se realizó e interpretó de acuerdo con las instrucciones del fabricante. RESULTADOS: Se estudiaron 80 pacientes con edad media de 15 años: 4 resultaron con IgM anti-Toxoplasma gondii, infección menor de 3 meses; 28 IgG anti-Toxoplasma gondii, con infección mayor a 3 meses y 17 IgG de avidez con infección superior a 6 meses. La prevalencia fue de 61.3%. CONCLUSIÓN: La seroprevalencia global de anticuerpos anti-toxoplasma encontrada fue de 61.3%, lo que pone de manifiesto que la toxoplasmosis es una enfermedad en la que debe pensarse para diagnosticarla y tratarla oportunamente.

Abstract OBJECTIVE: To determinate seroprevalence of Toxoplasma gondii in the female population of the municipality of Dosquebradas. MATERIALS AND METHODS: Cross-sectional prevalence study in reproductive age female of two school of the from a locality of Dosquebradas, Colombia, during 2016, was approved by the ethics committees of the participating institutions. The study volunteers signed the consent and completed the survey with demographic data, excluding women older than 18 years, and having had previous pregnancies. The samples were analyzed against IgM, IgG and avid IgG antibodies using highly purified recombinant antigens for Toxoplasma gondii using RecomLine test with development of Western blot mikrogen DIAGNOSTIK. To define the infectious moment, anti-IgG avidity against antigens p30, MAG1, GRA1 and rSAG1 were determined in samples positive for total IgG. The test was performed and interpreted according to the manufacturer's instructions. RESULTS: 80 patients were studied with average age of 15 years, 4 presented IgM anti-Toxoplasma gondii, infection less than 3 months; 28 IgG anti-Toxoplasma gondii, with infection greater than 3 months and 17 IgG of avidity with infection greater than 6 months, representing a prevalence of 61.3%. CONCLUSIONS: The global seroprevalence of anti-toxoplasma antibodies was 61.3%, which shows that toxoplasmosis is a disease in which it must be thought to diagnose and treat it in a timely manner.