Positivity of anti-Zika virus (ZIKV) antibodies among patients undergoing ART in São Paulo State, Brazil (2016-2024): a retrospective record analysis.

OBJECTIVES: To evaluate the presence of anti-ZIKV IgM and IgG antibodies in couples undergoing Assisted Reproduction Techniques (ART) and to examine reported ZIKV infections among women of reproductive age in São Paulo state. METHODS: A retrospective cohort analysis was performed using medical records of ART patients consecutively tested for ZIKV between March 2016 and June 2024 at a private ART center. Testing involved a rapid immunochromatographic assay, with positive results confirmed by PCR. According to ANVISA regulations, anti-ZIKV IgG testing was required from 2016 to 2022, while both IgG and IgM testing became mandatory from 2022 to 2024. Additionally, ZIKV notification data from DATASUS for metropolitan cities near the ART center were collected and compared with positivity rates observed in the cohort. RESULTS: Anti-ZIKV IgM positivity was 0.18% (1/569 female patients; 95% CI ≈ 0.00-0.98%), while anti-ZIKV IgG positivity was 2.1% (2/96 tested; 95% CI ≈ 0.25-7.32%), indicating limited prior exposure. DATASUS data showed a significant decline in ZIKV cases in São Paulo state, from 10,455 cases in 2016 to 228 in 2024. In cities surrounding the ART clinic, reported cases decreased from 73 to 1 during the same period. Among women of reproductive age, 42 cases were reported in 2016 and none in 2024. DISCUSSION: Conducting widespread population testing creates logistical and financial challenges. In this ART group, ZIKV positivity was rare (<1%), with about 2% showing signs of previous exposure, and most patients came from regions with low rates of ZIKV-related microcephaly. CONCLUSION: Positivity for anti-ZIKV was low among patients on ART.