Naslov
Molecular characterization of the first autochthonous Dengue virus cases in Croatia

Autori
Kurolt, Ivan-Christian ; Betica Radić, Ljiljana ; Đaković Rode, Oktavija ; Merdić, Enrih ; Markotić, Alemka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
20TH ENIVD / 3RD ENIVD - CLRN MEETING

Mjesto i datum
Antalya, Turska, 12.05.2011. - 14.05.2011

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Dengue virus; autochthonous cases; Croatia; Phylogeny

Sažetak
In 2004 the first larvae of Aedes albopictus were discovered in Croatia. During the following years the species spread and established all over the country. The first imported Dengue (DENV) infection was confirmed in Dubrovnik in August 2007 in a Spanish tourist after returning from a six month journey to India. So far, five imported cases have been reported. However, no autochthonous DENV cases have been reported in Croatia until 2010. The first autochthonous case in Croatia, a 33-year-old women, with fever, headache, myalgia, leukopenia, thrombocytopenia and elevated liver transaminases, appeared in August 11th, 2010, but the diagnosis was not established at that time. On October 22nd, the 54-year-old mother of the previously hospitalized patient was hospitalized with similar symptoms including papular rash. About two weeks before, ECDC informed us about a German patient with confirmed DENV infection after he returned from Croatia. It appeared that the German patient spent his holiday at the same village at the Croatian coast on the Peljesac peninsula where both female Croatian patients lived. A retrospective analysis confirmed DENV infection in two female Croatian patients. RNA was isolated using phenol-chloroform extraction and nested reverse transcription PCR (RT-PCR) was used for virus detection. For phylogenetic analyses the 306 bp nested RT-PCR product from the E-NS1 gene junction was sequenced on an ABI PRISM® 3100-Avant Genetic Analyzer (Applied Biosystems, Carlsbad, California, USA) using dye-termination. The sequenced fragment of the viral genome was identical in the two Croatian patients. It showed 99% similarity with the first imported case from 2007 from Anantapur, India. Both sequences exhibited the most homology to strains circulating in Sri Lanka. Phylogenetic analyses revealed these sequences as Genotype V within serotype 1. They clustered with full-length genome sequences that have been isolated in Thailand, Singapore and Brunei. In addition, we screened 100 blood samples from regular blood donors from the region (81 males and 19 females) for the presence of IgG antibodies, using ELISA (Focus Diagnostics, Cypress, California, USA). Additionally, 97 sera from patients with fever of unknown origin hospitalized at the General Hospital in Dubrovnik were tested as well. No specific DENV IgG antibodies have been detected among them. Even though it was late October, and the daily temperature dropped significantly we organized trapping of Aedes albopictus. Using CDC traps and dry ice, 20 mosquitoes were trapped. The mosquitoes were pooled and RNA was isolated using phenol-chloroform extraction. The pools have been tested with the nested RT-PCR. No viral RNA was detected. This is the first evidence of the autochthonous DENV infections in Croatia in a small isolated endemic niche. Strong public-health measures are necessary to monitor and prevent possible spread of DENV in other parts of Croatia.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Kliničke medicinske znanosti, Javno zdravstvo i zdravstvena zaštita

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