Dengue is the most important and widely distributed arthropod-borne viral disease affecting humans. The number of dengue virus infections has steadily grown and more than 100 countries survey dengue incidence every year. Due to the lack of an approved antiviral treatment or licensed preventative vaccine, accurate and opportune diagnosis is commended for efficient dengue epidemiological surveillance, to propose control measures in order to curtail outbreaks timely and treat patients satisfactorily. In this review, the basis, application and indications for different diagnostic tests are described, and their advantages and limitations considered. At the end of this piece, we speculate what the future may hold for the diagnosis of dengue infections.
KeywordsThe four serotypes of dengue virus (DENV 1-4) may equally be the cause of dengue infection in humans. DENV is a member of the Flaviviridae family, genus Flavivirus and is transmitted by the bite of female mosquitoes of the Aedes genus, mainly Aedes aegypti; an anthropophilic arthropod extensively distributed [1,2]. The viral genome is constituted by a single RNA strand of positive polarity of approximately 11 kb. It encodes three structural proteins: the envelope (E), pre-membrane/membrane (prM/M) and capsid (C) proteins; and seven nonstructural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5), which are implicated in viral translation, replication and modulation of the host immune response [2,3]. Dengue prevails in 128 countries and it is estimated that more than 2.5 billion people (two fifths of the world's population) are at risk of DENV infection [1,2]. Every year over 50 million DENV infections occur, causing more than 500,000 severe cases of dengue and resulting in at least 125,000 fatalities. The enormous increase in dengue prevalence observed in the last decades is multifactorial in nature. Unplanned and uncontrolled urbanization caused by the global population growth is associated with the deterioration in water supply quality and poor sewer and waste management systems availability. These conditions are ideal for the domestic propagation of the vector and a hallmark for the most recent epidemic outbreaks observed in tropical regions of the world such as Southeast Asia and South America. In addition, the modern trade globalization facilitates the introduction of the vector and all DENV serotypes to previously uninfected populated centers [1,4,5], where a highly dense susceptible population may be at risk. In this way, over the last decades DENV infection has become a global menace not only for tropical regions of the world, where the vector thrives, but also for temperate zones starting to be colonized by Aedes mosquitoes. The annual cost of dengue disease is estimated at US$135 million in Asiatic countries alone [6].