Evidence of dengue virus exposure among Iranian seafarers: a brief seroprevalence report from Southern Iran

Dengue virus (DENV) is an emerging public health concern in Iran. Frequent maritime travel between southern Iranian ports and neighboring countries with reported dengue transmission may facilitate the introduction of DENV into Iran. Therefore, this study aimed to determine the seroprevalence of DENV among Iranian seafarers. We conducted a cross-sectional serosurvey among 270 seafarers in Bushehr Province. Serum samples were tested for DENV IgM/IgG using ELISA. Travel history and demographics were collected via questionnaires. Serological testing identified 7 DENV-seropositive individuals (2.6%), including 2 IgM-positive and 5 IgG-positive participants. Seropositivity was higher among recent travelers than among past travelers (5.6% vs. 1.5%). Positive cases were detected in Bushehr (5.0%), Asaluyeh (16.7%), Genaveh (5.0%), Kangan (1.7%), and Dayyer (1.3%), whereas no seropositive cases were identified among participants employed in Deylam. Although DENV seroprevalence remained low among Iranian seafarers, evidence of both recent and past infections indicates that occupational maritime travel may contribute to DENV exposure. Given the strategic role of seafarers in cross-border movement, periodic serological surveillance of this occupational group may facilitate early detection of DENV introduction and strengthen public health preparedness in southern Iran.