Seroprevalence and viral DNA assessment of HSV-1 and HSV-2 infections among 0–90 years old population in Hamadan, Iran

Background This study estimated the seroprevalence of HSV-1 and HSV-2 infections in a diverse population and examined the association of antibody index with age, gender, and the presence of viral DNA in peripheral blood.Methods The study included 510 participants (172 males, 338 females). Serum antibody levels were measured by ELISA, and viral DNA was quantified by real-time PCR.Results No HSV-1/2 DNA was detected. Overall seropositivity was 73.9% (76.04% in females, 69.7% in males), slightly above the global baseline, with no significant gender difference (p = 0.1361). Seroprevalence increased significantly with age, from 20% in those under 10 years to 100% in those aged 81–90 years. Antibody index was significantly associated with age (p < 0.001). Infants under 6 months showed markedly higher antibody levels, likely due to maternal antibody transfer.Conclusions The high seroprevalence and its significant age-related increase reflect cumulative lifetime exposure and widespread infection. The absence of detectable HSV-1/2 DNA in peripheral blood is consistent with viral latency and the limited sensitivity of serum-based molecular detection in asymptomatic individuals. Serological markers primarily indicate past exposure rather than active viremia, underscoring the importance of combining serological and molecular approaches for accurate epidemiological interpretation.