Seroprevalence of Toxoplasma gondii infection among pregnant women in the first trimester in China

Toxoplasma gondii (T. gondii), a zoonotic parasite, significantly affects human health. Pregnant women infected with T. gondii are at risk of congenital anomalies or fetal death. Seroepidemiological surveys of toxoplasmosis can help develop control measures. This study measured the seroprevalence of anti-T. gondii antibodies among Chinese pregnant women in the first trimester of pregnancy in 13 districts of Hangzhou, eastern China. The overall seroprevalence of anti-T. gondii antibodies was 3.6 % (95 % confidence interval [CI]: 2.8-4.6 %). Anti-Toxoplasma IgG and IgM positivity was 3.5 % (95 % CI: 2.7-4.4 %) and 0.1 % (95 % CI: 0-0.3 %), and one pregnant woman tested positive for IgG and IgM. Seropositivity increased significantly from 3.4 % (95 % CI: 2.4-4.9 %) in 2013 and 2.3 % (95 % CI: 1.3-3.8 %) in 2015 to 7.2 % (95 % CI: 4.6-10.9 %) in 2023 (P = 0.001). There was regional heterogeneity in seroprevalence. Seroprevalence was highest in Qiantang District (11.1 %, 95 % CI: 0.6-49.3 %) and lowest in Tonglu District (0). Overall seroprevalence was higher in the age group 41-49 years (10.7 %, 95 % CI: 2.8-29.4 %) than in the age group 18-40 years (3.0-4.3 %). Thus, health education and promotion should target the age group 41-49 years.