[Dengue shock syndrome: decoding the pathophysiology].

Considered as major human arbovirosis, dengue occurs in several clinical forms. Some forms can lead to fatal complications such as dengue shock syndrome. This hypovolemic shock cannot be predicted and specific curative treatments are still lacking, and thus management of patients with dengue is difficult.

Genome-wide expression profiling deciphers host responses altered during dengue shock syndrome and reveals the role of innate immunity in severe dengue.

Background: Deciphering host responses contributing to dengue shock syndrome (DSS), the life-threatening form of acute viral dengue infections, is required to improve both the differential prognosis and the treatments provided to DSS patients, a challenge for clinicians.

Methodology/principal Findings: Based on a prospective study, we analyzed the genome-wide expression profiles of whole blood cells from 48 matched Cambodian children: 19 progressed to DSS while 16 and 13 presented respectively classical dengue fever (DF) or dengue hemorrhagic fever grades I/II (DHF). Using multi-way analysis of variance (ANOVA) and adjustment of p-values to control the False Discovery Rate (FDR<10%), we identified a signature of 2959 genes differentiating DSS patients from both DF and DHF, and showed a strong association of this DSS-gene signature with the dengue disease phenotype.

[Rift Valley fever virus: evolution in progress].

Several viruses now circulating in tropical zones around the globe are potential threats for ever-increasing human populations even in temperate zones that have long remained unaffected. The mechanisms underlying transport and transmission, which can be enhanced by human activity, can be even stronger in zones where factors needed to support development of these viruses, i.e.

West Nile virus in Europe and Africa: still minor pathogen, or potential threat to public health?

Until 1999 the West Nile virus had been reported only in the "Old world" and particularly in Europe, Africa, Middle East and Asia where it was responsible only for sporadic or size-and-time-limited outbreaks in humans and equines. The sudden and unexpected emergence of WN in New York in 1999, followed by a rapid and huge extension to the whole North America in less than four years, made health authorities aware of the potential of previously forgotten viruses to become a threat to public health. The present review will focus on the epidemiology of West Nile virus in Europe and Africa during the last five decades.

[Activated eosinophils: techniques to characterize them].

The deleterious role thought to be played by eosinophils in many situations is linked to their ability to secrete various inflammatory substances, mainly toxic proteins and lipid mediators, in body tissue. This ability is a particular feature of activated eosinophils, which have undergone numerous metabolic, functional, and phenotypic changes from their resting state. Characterizing the properties of these activated cells is an essential step in improving our understanding of their contributions to local inflammatory response, as both regulatory and effector cells.