Dengue

Endothelial dysfunction leading to vascular leak is the hallmark of severe dengue. Vascular leak typically becomes clinically evident 3-6 days after the onset of illness, which is known as the critical phase. This critical phase follows the period of peak viraemia, and lasts for 24-48 hr and usually shows rapid and complete reversal, suggesting that it is likely to occur as a result of inflammatory mediators, rather than infection of the endothelium. Cytokines such as tumour necrosis factor-α, which are known to be elevated in the critical phase of dengue, are likely to be contributing factors...

BACKDROUND: Emerging infectious diseases pose threats to the general human population; including recipients of blood transfusions. Dengue is spreading rapidly to new areas and with increasing frequency of major outbreaks. Screening blood for dengue antigens in dengue-endemic countries would be costly and should, therefore, be recommended only after careful assessment of risk for infection and cost. AIM: A prospective study was conducted to establish the magnitude of the threat that dengue poses to blood safety where it is sporadic with seasonal variations, to quantify risk and to assess that whether screening is feasible and cost-effective...

Immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by low platelet count and skin-mucosal bleeding. In adults it is usually idiopathic and may have a chronic onset, while in children it is usually acute following a viral illness. Dengue has been rarely reported as a cause of ITP. We report a case of a young adult woman that presented with acute ITP following a dengue virus infection.

The pathogenesis of hematologic changes in dengue patients is not clearly understood. Consistent hematological findings include vasculopathy, thrombocytopenia, and coagulopathy. There are evidences suggesting that dengue virus causes pathophysiological changes that involve all of the consistent hematologic findings resulting in vasculopathy, reduction in platelet number as well as platelet dysfunction, and reduction of several coagulation factors. Laboratory evidences of disseminated intravascular coagulation (DIC) are also demonstrated in all degrees of severity in dengue patients...

Three-quarters of the estimated 390 million dengue virus (DENV) infections each year are clinically inapparent. People with inapparent dengue virus infections are generally considered dead-end hosts for transmission because they do not reach sufficiently high viremia levels to infect mosquitoes. Here, we show that, despite their lower average level of viremia, asymptomatic people can be infectious to mosquitoes. Moreover, at a given level of viremia, DENV-infected people with no detectable symptoms or before the onset of symptoms are significantly more infectious to mosquitoes than people with symptomatic infections...

Dengue virus (DENV), the most prevalent mosquito-borne viral diseases in humans worldwide, causes dengue fever, a mild form of the disease, as well as dengue hemorrhagic fever/dengue shock syndrome, a more severe form which can be life-threatening. The four serotypes of DENV (DENV1-4) are positive-sense, single stranded RNA virus belonging to the Flaviviridae family and are transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Together, they are estimated to cause almost 100 million symptomatic cases, 2...