Temporal, Spatial and Seasonal Patterns of Parvovirus B19 Seroepidemiology in Childbearing-Aged Women in Croatia, 2015-2024.

Parvovirus B19 (B19V) infection during pregnancy represents a significant clinical concern due to its potential impact on the fetus and pregnancy outcome. We analyzed temporal, spatial, and seasonal B19V seroepidemiology in childbearing-aged and pregnant women in Croatia over 10 years (2015-2024). A total of 976 women who underwent routine TORCH screening were included. The overall B19V IgG and IgM seroprevalence was 63.7 and 8.7%, respectively, with significant temporal differences (IgG 36.8-72.3%, IgM 1.3-18.4). Significant differences in the IgG seropositivity were observed among age groups, from 42.3% in the 16-20 group to 72.7% in the 36-40 group. Spatial analysis showed no significant differences in the IgG or IgM seroprevalence between regions (City of Zagreb/Northern Croatia, Pannonian and Adriatic Croatia) and settlements (urban, suburban/rural). Additionally, seropositivity did not differ significantly in relation to obstetric history. In a logistic regression model, age was a significant predictor for IgG seroprevalence, with each additional year of age associated with increased odds of IgG seropositivity. Year, region, and settlement type were not significant predictors, indicating no evidence of temporal trends, regional differences, or differences between urban and rural settings after adjusting for age. Year of sampling, age, and region were significant predictors for IgM positivity. Acute infections were most common from March to July (61.2%) and December (9.4%), with regional variations in seasonal prevalence patterns. Given that screening in pregnancy is not routinely recommended, the high susceptibility to B19V observed in Croatia supports targeted serologic testing in women with clinical symptoms, known exposure, or occupational risk.