Of symptomatic cases, only a small minority (<5%) are severe, known as dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) 1. Nevertheless, virus-intrinsic virulence factors, which are not discussed in this Review, can participate in both pathogenesis and vascular leakage through multiple mechanisms and have been reviewed elsewhere 9.Ī | Asymptomatic cases account for the majority of yearly dengue virus (DENV) infections. These findings indicate that vascular pathologies are likely to be primarily immune-mediated.
NITRO PDF EDITOR KICKASS SKIN
Although DENV has been shown to be able to infect endothelial cells in vitro 5, studies failed to identify wide-spread endothelial cell infection after fatal dengue 6, 7, and, furthermore, DENV was not detected in skin lesions distal to the site of virus infection in humans 8. In some cases, as fever progresses, skin rashes and cutaneous bleeding manifestations may occur, such as petechiae and ecchymosis. Mild cases, called dengue fever, are self-resolving.
After a mosquito bite, the incubation period is between 4 and 7 days before common flu-like symptoms arise, such as fever, nausea, muscle and joint pain and headache (Fig. When short-term cross-protection wanes, patients with secondary DENV infections are at higher risk of severe disease 4.Ĭlinically, dengue is defined as a febrile illness, but asymptomatic infections also occur and, on the basis of modelling of transmission dynamics, are estimated to constitute the majority of infections 1 (Fig. They are also cross-reactive however, prior infection provides protection against all 4 serotypes for only 2–3 months, after which protection is serotype-specific 3. Immune memory responses are neutralizing and largely protective to viruses of the same serotype upon re-exposure.
Humans can acquire symptomatic DENV infection more than once in a lifetime owing to the circulation of four antigenically distinct serotypes, DENV1–DENV4, which makes combating this disease complex.
NITRO PDF EDITOR KICKASS PLUS
The three structural proteins (capsid, E and prM/M) plus seven non-structural proteins are transcribed and translated during viral replication 2, making them accessible to antigen-processing pathways within the cell, and the genome is synthesized through a double-stranded RNA intermediate. The DENV particle consists of a single-stranded positive-sense RNA enclosed within a capsid that is surrounded by an envelope containing the proteins E and prM/M. Several other important human pathogens such as West Nile virus (WNV), Japanese encephalitis virus (JEV), yellow fever virus (YFV) and the recently re-emerged Zika virus (ZIKV) are closely related flaviviruses 2. It is caused by dengue virus (DENV), which belongs to the family of Flaviviridae in the genus Flavivirus. Dengue is a viral illness that is spread primarily by Aedes mosquitoes and infects ~390 million people each year worldwide 1.
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