Molecular epidemiology of dengue fever cases imported into Romania between 2008 and 2013

Abstract

Background: Dengue fever is the commonest arthropod-borne infection worldwide. In recent years, rapid growth in global air travel has resulted in a considerable increase in the incidence of imported cases. In Romania it is now the second most frequent cause for hospitalization (after malaria) in patients arriving from tropical regions.

Methods: Serological and molecular diagnostics were applied to samples obtained between 2008 and 2013 from travelers with suspected dengue. Molecular typing was performed by RT-PCR followed by sequencing of the E-NS1 junction.

Results: Twelve of 37 suspected cases were confirmed and three remained probable. The infections were acquired in endemic regions in Asia, Africa and in Europe (Madeira Island). Dengue virus nucleic acid was detected and sequenced in nine cases. Phylogenetic analysis indicated that the viruses were of genotypes I and V of serotype 1, cosmopolitan genotype of serotype 2 and genotypes I and III of serotype 3.

Conclusions: Romanian tourists traveling to dengue-endemic countries are at risk of acquiring dengue infection. Appropriate prevention measures prior to travel and upon return should be taken, particularly as the dengue secondary vector Aedes albopictus is now established in Bucharest.

Keywords: DNA sequencing; Dengue viruses; Mosquito-borne infection; Phylogenetic analysis; RT-PCR.