A comprehensive seroepidemiology of dengue and chikungunya arboviruses in Iran, 2020–2023

Dengue virus (DENV) and Chikungunya virus (CHIKV) are the most common arthropod-borne viruses (Arboviruses) globally. So far, no autochthonous cases of DENV and CHIKV infections have been reported in Iran. Nevertheless, due to the recent identification of Aedes aegypti in the south and Aedes albopictus in the north of Iran, the country is at a serious risk of local outbreaks of these infections. Between 2020 and 2023, a comprehensive cross-sectional study was conducted to explore the anti-DENV and CHIKV IgG antibodies in the general populations of both southern and northern regions of Iran using ELISA. A total of 11,192 participants were included, of whom 2.3% (256 individuals) and 0.1% (11 cases) were DENV seropositive and CHIK seropositive, respectively. Across the eight examined provinces, Sistan and Baluchestan province displayed the highest prevalence of dengue seropositive cases (6.80%) (P < 0.001). Samples collected in 2022 demonstrated a notably higher seropositive rate of 5.5% (P < 0.001). Interestingly, all 11 CHIKV seropositive cases were from Sistan and Baluchestan province. The seroprevalence of DENV was notably higher in southern regions, particularly in Sistan and Baluchestan province and CHIKV seropositive cases were exclusively found in Sistan and Baluchestan province. This study furnishes crucial insights into the seroepidemiology of DENV and CHIKV in Iran, which in conjunction with the presence of Ae. aegypti in the south and Ae. albopictus in the north of Iran, emphasizes the requirement of improving integrated surveillance and control systems in the whole of the country, especially in the south of Iran.