[Virology diagnosis of re-emergent infections: dengue virus]

Dengue is acute viral disease transmitted to humans by Aedes mosquitoes (Ae. aegypti, Ae. albopictus). Dengue virus belongs to the family Flaviviridae, genus Flavivirus. There are four dengue virus serotypes (1-4) which are maintained endemically. The disease is endemic in tropical and subtropical areas between latitudes 35 degrees N and 35 degrees S. Infections may be asymptomatic or may produce a wide spectrum of diseases: non-specific febrile illness, dengue fever, dengue haemorrhagic fever or dengue shock syndrome. For the first time in Croatia, Ae. albopictus was registered in Zagreb in October 2004. In autumn 2005, additional records of Ae. albopictus presence were made in many places along the Adriatic coast. During 2007, two cases of imported dengue fever were reported in Croatia, after which similar imported cases appeared continually. In August 2010, the first autochthonous case of dengue fever was recorded on the peninsula Peljesac. Though Croatia is not endemic for dengue, the existence of a corresponding vector and a latent threat by imported dengue cases demand state-of-the-art and timely diagnostics. The most commonly used methods in laboratory diagnosis of dengue infections involve detection of viral RNA, antigen detection and serologic methods (detection of antibodies).