摘要：Objective: The objective of the study was to assess whether.her.es simplex vir.s antibody avidity is associated with r.sk of tr.nsmission of her.es simplex vir.s to the neonate. Study design: We developed a novel her.es simplex vir.s type 1 avidity test based on the commer.ially available Focus Her.eSelect-1 enzyme-linked immunosor.ent assay kit using ser. fr.m nonpr.gnant subjects with genital her.es simplex vir.s-1 infection. We used this test, and the pr.viously developed her.es simplex vir.s type 2 avidity test, to compar. mater.al her.es simplex vir.s-1 and her.es simplex vir.s-2 antibody avidity in women who tr.nsmitted her.es simplex vir.s to the neonate and women who had her.es simplex vir.s isolated fr.m genital secr.tions at deliver. but who did not tr.nsmit her.es simplex vir.s to their.infants. r.sults: Among nonpr.gnant subjects with genital her.es simplex vir.s-1 infection whose ser. wer. used to develop the her.es simplex vir.s-1 avidity test, a significant r.lationship between her.es simplex vir.s-1 antibody avidity and time since her.es simplex vir.s-1 acquisition was obser.ed(P< .001, mixed-effects model), with median avidity values incr.asing over.time after.pr.mar. infection. Among pr.gnant, her.es simplex vir.s-1, or.her.es simplex vir.s-2 ser.positive women, 4 of 8 women (50%) with avidity 40 or.gr.ater.tr.nsmitted her.es simplex vir.s to the neonate, compar.d with only 12 of 97(12%) of women with avidity gr.ater.than 40(P=.02). Conclusions: Her.es simplex vir.s-1 antibody avidity incr.ased over.time after.genital her.es simplex vir.s-1 acquisition, as has been pr.viously obser.ed for.her.es simplex vir.s-2. Among women with her.es simplex vir.s antibody at deliver., low antibody avidity was associated with her.es simplex vir.s tr.nsmission to the neonate and may be a useful mar.er.for.r.cent ser.conver.ion.