Avidity of Antibodies against HSV-2 and Risk to Neonatal Transmission among Mexican Pregnant Women

Objective. To determine HSV-2 seroprevalence, risk factors, and antibody avidity among a sample of Mexican pregnant women. Material and Methods. The avidity test was standardized with different urea concentrations and incubation times; the cut-off point was calculated to determine the low avidity (early infection). IgG antibodies against HSV-2 were detected from pregnant and postpartum women from Morelos, Mexico, and the avidity test was performed to positive samples. Multivariate regression logistic analysis was employed to evaluate demographic and sexual behavior characteristics associated with HSV-2 infection. Results. HSV-2 seroprevalence among Mexican women analyzed was 14.5% (333/2300), demographic factors (location of General Hospital, age, education level, and civil status), and risky sexual behaviors (STI self-report and number of sexual partners during last year) were associated with HSV-2 infection. Seventeen women were detected with low avidity antibodies (early infection) with a cut-off point of 66.1%. Conclusions. HSV-2 infection was common among this group of women from Mexico; the avidity test detected women with recent infections, and these women were more likely to transmit HSV-2 to their neonates. Neonatal herpes has no epidemiological surveillance, the disease could be overlooked, and so more studies are needed to estimate the magnitude of neonatal infection. 1. Introduction Herpes Simplex Virus (HSV) belongs to Herpesviridae family and has four basic structures: core with DNA double strand, icosahedral capsid, tegument, and lipidic envelope, and also HSV presents two basic properties, latency and neurovirulence. HSV-1 can cause oral lesions, and HSV-2 is the principal agent of genital herpes and could cause recurrent ulcers but is asymptomatic in 80% of cases [1, 2]. Genital herpes is a frequent infection during pregnancy, one-fifth of women have antibodies against HSV-2 [3], one-tenth of pregnant women infected with HSV-2 have genital viral shedding [4], and finally, 5% of women with genital viral shedding could transmit the infection to their neonates [5]. USA reported a neonatal herpes incidence of 31.25 for 100,000 newborns in Washington [5] and 13.3/100,000 in New York [6]. Vertical transmission leading to neonatal herpes virus infection may occur at vaginal delivery, which can cause congenital anomalies. Forty-five percent of neonatal herpes cause the localized form in mouth, eyes, or skin; 30% of cases arise nervous system infections, with lethargy, convulsions, and loss of appetite, with or without skin lesions; the