Syphilis in HIV-infected mothers and infants: results from the NICHD/HPTN 040 study.

Background—Untreated syphilis during pregnancy is associated with spontaneous abortion, stillbirth, prematurity and infant mortality. Syphilis may facilitate HIV transmission, which is especially concerning in low and middle income countries where both diseases are common. Methods—We performed an analysis of data available from NICHD/HPTN 040 (P1043), a study focused on the prevention of intrapartum HIV transmission to 1684 infants born to 1664 untreated HIV-infected women. The present analysis evaluates risk factors and outcomes associated with a syphilis diagnosis in this cohort of HIV-infected women and their infants. Results—Approximately 10% (n=171) of women enrolled had serological evidence of syphilis without adequate treatment documented and 1.4% (n=24) infants were dually HIV and syphilis infected. Multivariate logistic analysis showed that compared to HIV-infected women, co-infected women were significantly more likely to self-identify as non-white (AOR 2.5, 95% CI 1.5-4.2), to consume alcohol during pregnancy (AOR 1.5, 95% CI 1.1-2.1) and to transmit HIV to their infants (AOR 2.1, 95% CI 1.3-3.4), with 88% of HIV infections being acquired in-utero. As compared to HIV infected or HIV exposed infants, co-infected infants were significantly more likely to be born to mothers with VDRL titers ≥1:16 (AOR 3, 95% CI 1.1-8.2) and higher viral loads (AOR 1.5 95% CI 1.1-1.9). Of 6 newborns with symptomatic syphilis, 2 expired shortly after birth, and 2 were HIV-infected. Conclusion—Syphilis continues to be a common co-infection in HIV-infected women and can facilitate in utero transmission of HIV to infants. Most infants are asymptomatic at birth, but those with symptoms have high mortality rates.