Dugom otok investigation reveals spread of dengue virus

An epidemiological investigation on the Croatian island of Dugom otok has revealed the silent spread of the dengue virus. The investigation was triggered after a German tourist returned home in May 2024 with fever and a rash, subsequently being diagnosed with dengue in Germany.

Following reports from Munich, the Zadar County Institute of Public Health conducted field research, collecting blood samples from 30 residents in areas including Veli Rat, Verunić, Solin, and Božave. The results confirmed that the tourist's infection was not an isolated incident. Eight of the 30 individuals tested showed antibodies against the virus, indicating recent or past infection. Under European Centre for Disease Prevention and Control (ECDC) criteria, one resident was classified as a confirmed case due to seroconversion, while five others were identified as probable cases due to the presence of IgM antibodies.

Health experts warn that warmer summers are creating favorable conditions for the spread of dengue and chikungunya. These viruses are transmitted by the Asian tiger mosquito, an invasive species first recorded in Croatia in 2004. Unlike native mosquitoes, the tiger mosquito is active during the day, posing a continuous risk to residents and tourists.