Dengue type 4 in Rio de Janeiro, Brazil: case characterization following its introduction in an endemic region

Abstract

BackgroundDue to the populations’ susceptibility, DENV-4 introduction in 2010 led to the occurrence of explosive epidemics in the following years in Brazil. In 2011, DENV-4 was identified in Rio de Janeiro (RJ) and it was prevalent in 2012 and 2013. Here, we aimed to characterize clinical, epidemiological and laboratorial aspects of DENV-4 cases after this serotype introduction in an endemic scenario.MethodsDengue suspected cases (n = 3727) were received and analyzed from January 2011 to December 2013, during outbreaks occurred in RJ, Brazil. Samples were submitted to virological, serological and molecular methods for case confirmation. DENV-4 cases (n = 705) were characterized according to the type of infection, disease severity and, viremia levels and NS1 antigenemia were accessed. Representative strains were partial sequenced for genotyping.ResultsDENV-4 was identified in 44.2% (705/1593) of dengue positive cases, virus isolated in 48.7% of the cases. Anti-DENV IgM was detected in 39.4% of the cases, however an increased detection was observed in cases with ≥4 days of symptoms (57.0%). NS1 antigen was identified in 41.5% of DENV-4 cases however, after immune complexes dissociation, the detection significantly increased (87.6%). Females were more affected than males, so did children aged 11–15 years old. Primary cases were more frequently observed than secondary ones and most of them were classified as dengue. No differences on NS1 antigenemia and viraemia within the groups were observed. Despite the higher frequency of severe disease on individuals >65 years old, no differences were observed among the groups and type of infection. However, DENV-4 fatal cases were more frequent on secondary infections (57.1%). DENV-4 Genotype II was identified with a probable origin from Venezuela and Colombia.ConclusionsIt has been shown that laboratorial diagnosis is still a reliable tool for the disease surveillance, detecting and confirming emerging epidemics. Despite the occurrence of secondary infections, most DENV-4 cases presented a mild disease. As RJ is endemic for dengue, high rates of secondary infections would be expected. Despite the existence of two genotypes, only Genotype II was identified in our study.

Renal Injury in DENV-4 Fatal Cases: Viremia, Immune Response and Cytokine Profile

“…In 2012, DENV-4 was prevalent and detected in 63% of the cases reported in Brazil [7]. Despite the highest notification in 2013 (1,452,289 cases), DENV-4 circulation was associated with mild cases [8,9], but severe and fatal cases due to DENV-4 were also reported [10]. Although there has been no definitive association of the different DENV serotypes within the clinical course of the disease, it has been suggested that DENV-2 and DENV-3 are more frequently associated with severe disease [11].…”

Arbovirus Surveillance near the Mexico–U.S. Border: Isolation and Sequence Analysis of Chikungunya Virus from Patients with Dengue-like Symptoms in Reynosa, Tamaulipas

“…Other studies have also shown that most patients clinically diagnosed with dengue do not have laboratory-confirmed DENV infections. 13,14 Overall, 126 patients were diagnosed with laboratory-confirmed DF and eight patients were diagnosed with laboratory-confirmed DHF. Sera from select patients (N = 34) were further tested by qRT-PCR for CHIKV RNA, including 20 patients with laboratoryconfirmed DF and four patients with laboratory-confirmed DHF.…”

Neurological complications associated with emerging viruses in Brazil

“…From 1997 to 2017, 1593 cases of GBS were reported in the state of Rio de Janeiro (annual average, 60 cases). Analysis of monthly GBS cases determined that there were significant increases in GBS from 1 month to the next for 3 years (Farrington test P <0.001): in 2009 (n=115 cases) contemporaneous with the introduction of H1N1; in 2013 (n=85), which coincided with an epidemic of dengue virus type 4; and in 2015 with the arrival of Zika virus (n=326) (Fig. ).…”