Dengue fever and severe dengue in Barbados, 2008–2016

Analysis of the temporal, seasonal and demographic distribution of dengue virus (DENV) infections in Barbados was conducted using national surveillance data from a total of 3994 confirmed dengue cases. D

Zika virus infection induces elevation of tissue factor production and apoptosis on human umbilical vein endothelial cells

Zika virus (ZIKV) infection is typically characterized by a mild disease presenting with fever, maculopapular rash, headache, fatigue, myalgia, and arthralgia. A recent animal study found that ZIKV-infected pregnant Ifnar-/-mice developed vascular damage in the placenta and reduced amount of fetal capillaries. Moreover, ZIKV infection causes segmental thrombosis in the umbilical cord of pregnant rhesus macaques. Furthermore, several case reports suggest that ZIKV infection cause coagulation disorders. These results suggest that ZIKV could cause an alteration in the host hemostatic response, however, the mechanism has not been investigated thus far. This paper aims to determine whether ZIKV infection on HUVECs induces apoptosis and elevation of tissue factor (TF) that leads to activation of secondary hemostasis. We infected HUVECs with two ZIKV strains and performed virus titration, immunostaining, and flow cytometry to confirm and quantify infection. We measured TF concentrations with flow cytometry and performed thrombin generation test (TGT) as a functional assay to assess secondary hemostasis. Furthermore, we determined the amount of cell death using flow cytometry. We also performed enzyme-linked immunosorbent assay (ELISA) to determine interleukin (IL)-6 and IL-8 production and conducted blocking experiments to associate these cytokines with TF expression. Both ZIKV strains infected and replicated to high titers in HUVECs. We found that infection induced elevation of TF expressions. We also showed that increased TF expression led to shortened TGT time. Moreover, the data revealed that infection induced apoptosis. In addition, there was a significant increase of IL-6 and IL-8 production in infected cells. Here we provide in vitro evidence that infection of HUVECs with ZIKV induces apoptosis and elevation of TF expression that leads to activation of secondary hemostasis

Time since Onset of Disease and Individual Clinical Markers Associate with Transcriptional Changes in Uncomplicated Dengue

Dengue virus (DENV) infection causes viral haemorrhagic fever that is characterized by extensive activation of the immune system. The aim of this study is to investigate the kinetics of the transcriptome signature changes during the course of disease and the association of genes in these signatures with clinical parameters. Sequential whole blood samples from DENV infected patients in Jakarta were profiled using affymetrix microarrays, which were analysed using principal component analysis, limma, gene set analysis, and weighted gene co-expression network analysis. We show that time since onset of disease, but not diagnosis, has a large impact on the blood transcriptome of patients with non-severe dengue. Clinical diagnosis (according to the WHO classification) does not associate with differential gene expression. Network analysis however, indicated that the clinical markers platelet count, fibrinogen, albumin, IV fluid distributed per day and liver enzymes SGOT and SGPT strongly correlate with gene modules that are enriched for genes involved in the immune response. Overall, we see a shift in the transcriptome from immunity and inflammation to repair and recovery during the course of a DENV infection. Time since onset of disease associates with the shift in transcriptome signatures from immunity and inflammation to cell cycle and repair mechanisms in patients with non-severe dengue. The strong association of time with blood transcriptome changes hampers both the discovery as well as the potential application of biomarkers in dengue. However, we identified gene expression modules that associate with key clinica

Hyperferritinemia is a potential marker of chronic chikungunya: A retrospective study on the Island of Curaçao during the 2014–2015 outbreak

Background Recently Chikungunya virus (CHIKV) outbreaks have been reported in the Carribean. There is no data regarding the outbreak in Curaçao. In addition, to date there is no biomarker that could be used to predict chronic infection. Objectives To characterize the first CHIKV outbreak in Curaçao and to identify potential biomarkers for chronic infection. Study design A serological test and quantitative polymerase chain reaction (qPCR) were used on samples collected in Curaçao to confirm infection. Subsequently, six samples with high viral load were selected for phylogenetic analysis. Furthermore we investigated the association of macrophage-related biomarkers during CHIKV infection with chronic arthralgia/arthritis. Results 116 patients in Curacao were diagnosed with CHIKV infection based on ELISA and 77% were tested positive for CHIKV by qPCR. Phylogenetic analysis showed that an Asian genotype was the cause of the outbreak. Elevated levels of ferritin and CRP were significantly associated with viraemia. In addition, elevated ferritin levels were significantly associated with chronic arthralgia. Conclusions The results showed that the presence of an Asian genotype of CHIKV in Curaçao for the first time. Moreover, we found an association between ferritin levels with chronic arthralgia

Time since Onset of Disease and Individual Clinical Markers Associate with Transcriptional Changes in Uncomplicated Dengue

<div><p>Background</p><p>Dengue virus (DENV) infection causes viral haemorrhagic fever that is characterized by extensive activation of the immune system. The aim of this study is to investigate the kinetics of the transcriptome signature changes during the course of disease and the association of genes in these signatures with clinical parameters.</p><p>Methodology/Principle Findings</p><p>Sequential whole blood samples from DENV infected patients in Jakarta were profiled using affymetrix microarrays, which were analysed using principal component analysis, limma, gene set analysis, and weighted gene co-expression network analysis. We show that time since onset of disease, but not diagnosis, has a large impact on the blood transcriptome of patients with non-severe dengue. Clinical diagnosis (according to the WHO classification) does not associate with differential gene expression. Network analysis however, indicated that the clinical markers platelet count, fibrinogen, albumin, IV fluid distributed per day and liver enzymes SGOT and SGPT strongly correlate with gene modules that are enriched for genes involved in the immune response. Overall, we see a shift in the transcriptome from immunity and inflammation to repair and recovery during the course of a DENV infection.</p><p>Conclusions/Significance</p><p>Time since onset of disease associates with the shift in transcriptome signatures from immunity and inflammation to cell cycle and repair mechanisms in patients with non-severe dengue. The strong association of time with blood transcriptome changes hampers both the discovery as well as the potential application of biomarkers in dengue. However, we identified gene expression modules that associate with key clinical parameters of dengue that reflect the systemic activity of disease during the course of infection. The expression level of these gene modules may support earlier detection of disease progression as well as clinical management of dengue.</p></div

Principle component analysis of all transcriptome snapshots in this study.

<p>Icons and colours indicate type and sampling stage of the samples. Timing of samples range from day 0 to day 6 of admission. The day 0 samples have the lightest colour and the day 6 samples the darkest. All probesets were included for this analysis.</p

Differential gene expression analysis.

<p>Venn diagrams show the overlap between different sets of differentially expressed genes. FDR <0.05, all differentially expressed genes are at least 2-fold up- or down-regulated.</p

Characteristics of studies profiling whole blood of DENV infected patients.

<p>Characteristics of studies profiling whole blood of DENV infected patients.</p

Gene set analysis of dengue signatures.

<p>The interferon pathway (left panel) is upregulated in the early stages of dengue, but not later. Segment plots indicate the significance of enrichment of particular Reactome gene sets and pathways. The longer the segment, the larger the enrichment. All segments longer than the grey segment are significant.</p

Dengue co-expression network analysis.

<p>Significant correlations between gene modules (y-axis) and clinical parameters (x-axis) are depicted in a red-to-green colour scale. Upper number is pearson correlation coefficient, lower number the level of significance (p-value). All gene modules are annotated with gene enrichment categories; clinical parameters are grouped by symptom type.</p