Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by the SFTS virus, posing significant public health challenges in East Asia. This study aimed to evaluate the seroprevalence of SFTS on Jeju Island, Korea, and to identify the demographic and geographic factors influencing exposure to the virus. A total of 1001 serum samples collected from healthy individuals between 2009 and 2016 were analyzed using a double-antigen enzyme-linked immunosorbent assay. The overall seroprevalence was 1.7%, with slightly higher rates observed in females (2.06%) than in males (1.29%); however, this difference was not statistically significant. Seroprevalence increased with age, peaking at 2.50% in individuals over aged 60 and over. Regional analysis revealed elevated seroprevalence in the eastern coastal areas (4.41%), which was attributed to population density and environmental factors favoring human–tick interactions. These findings suggest that population distribution and land use patterns, rather than altitude alone, significantly affect the exposure of SFTS on Jeju Island. Targeted tick control strategies and public health interventions that focus on high-risk regions and demographics could mitigate SFTS transmission. This study provides valuable insights into the epidemiological characteristics of SFTS and emphasizes the importance of tailored preventive measures in endemic regions.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne disease with a high mortality rate. While research has focused on high-risk rural populations and healthy individuals in endemic regions, such as Jeju Island, data on patients with underlying chronic diseases remain limited. This study aimed to evaluate the seroprevalence of SFTS virus (SFTSV) in patients with various chronic diseases across the Republic of Korea. Serum samples (n = 2948) collected from 10 regional biobanks between 2009 and 2019 were analyzed using a double-antigen sandwich enzyme-linked immunosorbent assay. The overall seroprevalence was 1.22% (36/2948). Seropositivity was significantly higher in males (1.73%) than in females (0.73%, p = 0.013) and increased with age (p = 0.001), peaking at 2.73% in individuals aged 70–79. Geographically, the highest rates were in Gyeongbuk (3.03%), Jeonnam (2.40%), and Gangwon (1.83%). Multivariable logistic regression showed older age (adjusted odds ratio 1.47 per 10-year increase, 95% confidence interval: 1.12–1.97) as the strongest independent predictor of seropositivity. Patients with hepatobiliary/pancreatic cancer (3.16%) and prostate cancer (2.50%) exhibited higher seroprevalence than those in other disease groups. SFTSV exposure is non-negligible among those with chronic diseases, particularly older males in rural provinces. Public health strategies should specifically address these vulnerable populations.

Background/Objectives: Research on the relationship between small-area-level deprivation and cancer survival, particularly for colorectal cancer (CRC), is lacking. Therefore, we investigated the relationship among small area-level deprivation, individual-level factors, and CRC survival using data from the Busan Regional Cancer Registry. Methods: We analyzed 34,999 patients with CRC from the Busan Regional Cancer Registry from 2003 to 2020. The primary outcome was CRC mortality. The explanatory variables at the individual level included age, gender, cancer stage, and year of diagnosis, whereas the Deprivation Index (DI) was used at the regional level. We conducted a multilevel survival analysis with frailty to assess the impact of individual- and area-level factors on survival probabilities. Results: In the multilevel survival model, each unit increase in the DI at the area level was associated with a 6.6% decrease in survival probability. When applying Model 2 and deriving regional estimates using the empirical Bayesian estimation method, the graph of the DI (x-axis) against survival probability (y-axis) showed that the slope of the regional DI for the 3-year and 5-year survival probabilities increased compared with the 1-year rate across all stages of the disease. Additionally, the slopes were steeper for the distant stage than for the local or regional stages. Conclusions: Small-area level deprivation negatively affects CRC survival, especially in distant-stage patients and those with longer disease duration.

Kim A, et al. J Korean Med Sci. 2019 May;34(18):e138. https://doi.org/10.3346/jkms.2019.34.e138