Secondary dengue virus infections during the 2009 outbreak in Buenos Aires

Abstract

We detected a high percentage of secondary DENV infections in a non-endemic area; this finding might correspond to socio-demographic characteristics of the group under study or indicate a previous cryptic DENV circulation causing inapparent infections.

Dengue Virus 1 Outbreak in Buenos Aires, Argentina, 2016

“…Our continuous work in DENV diagnosis, surveillance, and research enabled us to characterize the serologic status of the population of Buenos Aires in 2009. We found that an unusually high percentage of the population had secondary DENV infections in what was considered at the time a nonendemic area; therefore, we proposed that cryptic DENV circulation causing inapparent infections might be affecting this area ( 9 ). We also described the phylogenetic and phylogeographic characteristics of the first DENV-1 outbreak in 2009; the circulating virus clustered in a monophyletic group within genotype V, which is the most predominant DENV-1 genotype in the Americas ( 10 ).…”

Validation and Application of a Commercial Quantitative Real-Time Reverse Transcriptase-PCR Assay in Investigation of a Large Dengue Virus Outbreak in Southern Taiwan

“…Consistent with this conclusion, Hernandez et al (2013) [ 40 ] previously demonstrated that while dengue IgM antibody-negative patients exhibit significantly higher VLs than IgM-positive patients, the presence of IgM does not correlate with NS1 antigen clearance. Recently, Tittarelli et al (2016)[ 13 ] found no significant differences in VL between patients with primary and secondary infections. In this study, 26 of the 34 specimens in the NS1/IgM/IgG/VL (+/-/+/+) category (76.4%) had VLs of 10 3 –10 6 copies/mL, indicating the presence of a suspected secondary infection group with medium VLs among the patients examined during this outbreak.…”

“…Specifically, an IgM/IgG ratio > 1.7 is indicative of primary infection in certain enzyme-linked immunosorbent assays (ELISA). Meanwhile, patients with secondary infections are characterized as having IgM/IgG ratios < 1.7 or as testing IgG-positive 2 days after onset of illness [ 12 , 13 ]. Therefore, NS1 antigen, nucleic acid, and antibody (IgM, IgG) screening tests are optimal for dengue diagnosis.…”

Brote epidémico de dengue en la Ciudad de Buenos Aires, 2016: características clínicas y hematológicas de la infección en una población pediátrica

“…Las técnicas para el diagnóstico virológico utilizadas han sido descritas en estudios previos. 1,5 Para la clasificación de dengue, dengue con signos de alarma y dengue grave, se utilizaron las definiciones establecidas por la guía del Ministerio de Salud de la Nación Argentina y la Organización Mundial de la Salud. 2,9,10 Se consideró dengue con signos de alarma la presencia de uno o más de los siguientes: dolor abdominal intenso y sostenido; vómitos persistentes; derrame seroso (en el peritoneo, la pleura o el pericardio) detectado por clínica, por laboratorio (hipoalbuminemia) o por imágenes (ecografía de abdomen o radiografía de tórax); sangrado de mucosas; cambio en el estado mental del paciente (somnolencia o irritabilidad); hepatomegalia mayor de 2 cm; incremento brusco del hematocrito concomitante con rápida disminución del recuento de plaquetas.…”

“…[1][2][3] En las áreas no endémicas, los casos podrían subvalorarse, debido a que sus manifestaciones clínicas podrían confundirse con otras enfermedades. 4,5 En el mundo, se producen, por año, 390 millones de infecciones por DENV, de las cuales alrededor del 25 % se manifiestan clínicamente. 6 En América, solo Canadá y Uruguay aún no han reportado casos autóctonos.…”