Subsets of Cytokines and Chemokines from DENV-4-Infected Patients Could Regulate the Endothelial Integrity of Cultured Microvascular Endothelial Cells.

Introduction: It is a consensus that inflammatory mediators produced by immune cells contribute to changes in endothelial permeability in dengue. We propose to relate inflammatory mediators seen in dengue patients with the in vitro alteration of endothelial cells (ECs) cultured with serum from these patients. Methods: Patients with mild (DF) to moderate and severe dengue (DFWS/Sev) were selected. ELISA quantified inflammatory mediators. Expression of adhesion molecules and CD147 were evaluated in the ECs cultured with the patient's serum by flow cytometry. We assessed endothelial permeability by measuring transendothelial electrical resistance in cocultures of ECs with patient serum. Results: Dengue infection led to an increase in inflammatory mediators-the IL-10 distinguished DF from DFWS/Sev. There were no changes in CD31, CD54, and CD106 but decreased CD147 expression in ECs. DFWS/Sev sera induced a greater difference in endothelial permeability than DF sera. Correlation statistical test indicated that low IL-10 and IFN-γ and high CCL5 maintain the integrity of ECs in DF patients. In contrast, increased TNF, IFN-γ, CXCL8, and CCL2 maintain EC integrity in DFWS/Sev patients. Conclusions: Our preliminary data suggest that a subset of inflammatory mediators may be related to the maintenance or loss of endothelial integrity, reflecting the clinical prognosis.

Different Profiles of Cytokines, Chemokines and Coagulation Mediators Associated with Severity in Brazilian Patients Infected with Dengue Virus.

The incidence of dengue in Latin America has increased dramatically during the last decade. Understanding the pathogenic mechanisms in dengue is crucial for the identification of biomarkers for the triage of patients. We aimed to characterize the profile of cytokines (IFN-γ, TNF-α, IL-1ß, IL-6, IL-18 and IL-10), chemokines (CXCL8/IL-8, CCL2/MCP-1 and CXCL10/IP-10) and coagulation mediators (Fibrinogen, D-dimer, Tissue factor-TF, Tissue factor pathway inhibitor-TFPI and Thrombomodulin) during the dengue-4 epidemic in Brazil. Laboratory-confirmed dengue cases had higher levels of TNF-α (p < 0.001), IL-6 (p = 0.005), IL-10 (p < 0.001), IL-18 (p = 0.001), CXCL8/IL-8 (p < 0.001), CCL2/MCP-1 (p < 0.001), CXCL10/IP-10 (p = 0.001), fibrinogen (p = 0.037), D-dimer (p = 0.01) and TFPI (p = 0.042) and lower levels of TF (p = 0.042) compared to healthy controls. A principal component analysis (PCA) distinguished between two profiles of mediators of inflammation and coagulation: protective (TNF-α, IL-1ß and CXCL8/IL-8) and pathological (IL-6, TF and TFPI). Lastly, multivariate logistic regression analysis identified high aspartate aminotransferase-to-platelet ratio index (APRI) as independent risk factors associated with severity (adjusted OR: 1.33; 95% CI 1.03-1.71; p = 0.027), the area under the receiver operating characteristics curve (AUC) was 0.775 (95% CI 0.681-0.869) and an optimal cutoff value was 1.4 (sensitivity: 76%; specificity: 79%), so it could be a useful marker for the triage of patients attending primary care centers.

West Nile Virus in Brazil.

Background: West Nile virus (WNV) was first sequenced in Brazil in 2019, when it was isolated from a horse in the Espírito Santo state. Despite multiple studies reporting serological evidence suggestive of past circulation since 2004, WNV remains a low priority for surveillance and public health, such that much is still unknown about its genomic diversity, evolution, and transmission in the country. Methods: A combination of diagnostic assays, nanopore sequencing, phylogenetic inference, and epidemiological modeling are here used to provide a holistic overview of what is known about WNV in Brazil. Results: We report new genetic evidence of WNV circulation in southern (Minas Gerais, São Paulo) and northeastern (Piauí) states isolated from equine red blood cells. A novel, climate-informed theoretical perspective of the potential transmission of WNV across the country highlights the state of Piauí as particularly relevant for WNV epidemiology in Brazil, although it does not reject possible circulation in other states. Conclusion: Our output demonstrates the scarceness of existing data, and that although there is sufficient evidence for the circulation and persistence of the virus, much is still unknown on its local evolution, epidemiology, and activity. We advocate for a shift to active surveillance, to ensure adequate preparedness for future epidemics with spill-over potential to humans.

Plasma lipidome profiling of newborns with antenatal exposure to Zika virus.

The 2015-2016 Zika virus (ZIKV) outbreak in Brazil was remarkably linked to the incidence of microcephaly and other deleterious clinical manifestations, including eye abnormalities, in newborns. It is known that ZIKV targets the placenta, triggering an inflammatory profile that may cause placental insufficiency. Transplacental lipid transport is delicately regulated during pregnancy and deficiency on the delivery of lipids such as arachidonic and docosahexaenoic acids may lead to deficits in both brain and retina during fetal development. Here, plasma lipidome profiles of ZIKV exposed microcephalic and normocephalic newborns were compared to non-infected controls. Our results reveal major alterations in circulating lipids from both ZIKV exposed newborns with and without microcephaly relative to controls. In newborns with microcephaly, the plasma concentrations of hydroxyoctadecadienoic acid (HODE), primarily as 13-HODE isomer, derived from linoleic acid were higher as compared to normocephalic ZIKV exposed newborns and controls. Total HODE concentrations were also positively associated with levels of other oxidized lipids and several circulating free fatty acids in newborns, indicating a possible plasma lipidome signature of microcephaly. Moreover, higher concentrations of lysophosphatidylcholine in ZIKV exposed normocephalic newborns relative to controls suggest a potential disruption of polyunsaturated fatty acids transport across the blood-brain barrier of fetuses. The latter data is particularly important given the neurocognitive and neurodevelopmental abnormalities observed in follow-up studies involving children with antenatal ZIKV exposure, but normocephalic at birth. Taken together, our data reveal that plasma lipidome alterations associated with antenatal exposure to ZIKV could contribute to identification and monitoring of the wide spectrum of clinical phenotypes at birth and further, during childhood.

DENV-1 Genotype V in Brazil: Spatiotemporal dispersion pattern reveals continuous co-circulation of distinct lineages until 2016.

In Brazil, DENV-1 introduced in the 80's, remained the prevalent serotype from 2012 to 2016. After its re-emergence in the country in 2009, the co-circulation of different viral lineages was identified, however, its transmission dynamics afterwards, was not fully characterized. In this study, we performed the continuous molecular surveillance after the reemergence period (2012 to 2016), covering the 30 years of circulation of DENV-1 in Brazil. Phylogenetic analysis allowed confirmation of the continued presence of genotype V, as well as three distinct co-circulating lineages. The molecular characterization of the E gene presented two new amino acid substitutions previously unidentified in the country. Phylogeographic analysis has shown that a large flow of migrations has occurred between Brazil and Argentina in the last 10 years.

Analysis of Clinical and Laboratory Alterations Related to Dengue Case Severity: Comparison between Serotypes 2 and 4 in Brazil.

The increase in severe dengue (SD) cases has caused great impact on public health and has concerned authorities of countries where the disease is endemic and epidemics reach high proportions. The recognition of progression signs of this severe disease during the initial febrile phase can be difficult, since the symptoms are often indistinguishable from other febrile diseases. The aim of this study was to evaluate the clinical manifestations and laboratory findings in patients from two dengue outbreaks and their association with the disease. The study was conducted in patients (n = 153) with signs and symptoms consistent with dengue occurred during two distinct epidemics, 2010 and 2013, in the city of Campos dos Goytacazes, Rio de Janeiro, Brazil. According to the 2009 World Health Organization criteria, patients were classified as dengue without warning signs ([DwoWS] 60.6%, 57/94), dengue with warning signs ([DwWS] 30.9%, 29/94), and SD (4.25%, 4/94). Patients with DwWS/SD presented lower platelet and leukocyte counts and higher transaminase levels when compared with the DwoWS ones. Interestingly, patients from the epidemic of 2010 caused by dengue virus 2 (DENV-2) had lower platelet counts than patients of the 2013 epidemic caused by DENV-4. Furthermore, plasma leakage, gastrointestinal bleeding, and pleural effusion, hallmarks for a more severe disease, were also more frequently observed in those cases. Although previous studies may have extensively reported the wide range of the clinical aspects of dengue, the characterization of DENV-4 is desirable considering the burden of the disease during epidemics, especially for the health units and hospitals performing patient's management.

Evaluation of a generic RT-nested-PCR for detection of flaviviruses in suspected fatal cases of dengue infection, Rio de Janeiro, Brazil.

Flaviviruses are significant causes of disease worldwide and can be classified serologically into several antigenic complexes. The purpose of the present study was to evaluate the effectiveness of a generic RT-nested-PCR for detection of flavivirus during a dengue outbreak in Brazil in 2008. A total of 105 serum samples were collected from patients with fatal outcome and examined by generic RT-PCR, conventional RT-PCR, and IgM serology. The generic RT-PCR confirmed 19 of 105 (18%) cases. Conventional RT-PCR performed on 105 serum samples detected 45 (42.8%) dengue virus infections. The IgM serology confirmed 44 of 102 (43.1%) cases. The infecting serotype was identified by generic RT-PCR in 19 cases (18 DENV-2 and 1 DENV-3) and by conventional RT-PCR in 45 cases (40 DENV-2 and 5 DENV-3). In addition, we analyzed the performance of the generic and conventional RT-PCRs and IgM serology on serum samples stratified by the day of onset of symptoms. Our results indicate that different methods should be included in flavivirus surveillance programs, including virological and serological approaches.