Assessment of the Immune Response to Coxiella burnetii in Rural Areas of the Thessaly Region Following the Daniel Floods

Background: In September 2023, Storm Daniel triggered catastrophic flooding across Thessaly, in central Greece, leading to the deaths of approximately 483,476 animals and heightening concerns about zoonotic diseases, particularly Q fever caused by Coxiella burnetii. Sofades, a municipality in the Karditsa region that is severely impacted by the floods, emerged as a critical area for evaluating the risk of zoonotic disease transmission. This study aimed to determine the seroprevalence status of Coxiella burnetii Phase 1 IgA antibodies among residents in the rural area of Sofades after the Daniel floods. Methods: Serum samples were obtained from a convenient sample of residents with livestock exposure between 1 March and 31 March 2024. Enzyme-linked immunosorbent assay (ELISA) was used to detect Coxiella burnetii Phase 1 IgA antibodies. Descriptive analyses summarized demographic data, and logistic regression was employed to examine the association between gender, age, and positive ELISA results. Results: The overall seroprevalence was 16.66%. Males had a significantly higher positivity rate (28.57%) than females (6.25%). Seropositivity was more frequent among individuals aged 41–80 years, with peak prevalence observed in the 61–80 age group. Conclusions: This cross-sectional study offers a snapshot of Coxiella burnetii exposure in a high-risk rural population post-flood. The slightly higher seroprevalence in Sofades (16.66%) compared to Karditsa (16.1%) suggests limited influence of environmental factors on transmission. Despite limitations in causal inference, the findings highlight the need for enhanced surveillance and targeted public health measures. Longitudinal studies are needed to assess the long-term impact of environmental disasters on Q fever dynamics.