AEGiS-13IAC: Determinants of HIV RNA in newborn nasal/oral secretions and association with risk for perinatal HIV transmission.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

Determinants of HIV RNA in newborn nasal/oral secretions and association with risk for perinatal HIV transmission.

Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. MoOrC241)

Chuachoowong R, Bhadrakom C, Siriwasin W, Shaffer N, Wanprapar N, Chotpitayasunondh T, Young NL, Mock PA, Simonds RJ
R. Chuachoowong, Dept Microbiology Siriraj Hospital, 2 Prannok Road, Bangkok Noi, Bangkok 10700, Thailand, Tel.: +662 419 70 69, Fax: +662 418 41 48, E-mail: sircc@mahidol.ac.th

BACKGROUND: The mechanism by which interventions such as zidovudine (ZDV) or cesarean section (C-S) delivery reduce perinatal transmission risk are not fully known.

METHODS: In a randomized, placebo-controlled trial of short antenatal ZDV (36 weeks' gestation until delivery) in Bangkok, we used a bulb syringe to collect nasal and oral secretions (NOS) at delivery from 368 infants born to HIV-infected mothers. We measured HIV RNA levels in NOS, cervicovaginal secretions from the mothers at 38 weeks' gestation, and maternal plasma at delivery using the Roche Amplicor HIV-1 Monitor (v.1.5) quantitative RNA assay (level of detection 400 copies/mL). We considered infants who tested DNA PCR-positive at any time as infected (Inf), and who tested PCR-negative at 2 months as uninfected (Uninf).

RESULTS: NOS HIV RNA levels were more associated with levels in cervicovaginal secretions (r = .32, p > .01) than with levels in maternal plasma (r = .23, p > .05). 34% of infants with detectable HIV but only 7% of those with undetectable HIV were infected (RR = 5.0, p > .001). As shown in table below, the percents of specimens with detectable HIV RNA also were associated with mode of delivery, and treatment group (p > .01 for each comparison). Only 1 of 27 (4%) children in the ZDV group born by C-S had detectable HIV RNA, compared with 72 of 169 (43%) of children in the placebo group born vaginally. Total Uninf Inf C-S Vaginal ZDV Placebo Number 368 306 52 49 319 177 191 Number with detectable RNA 105 69 35 6 99 28 77 Detection rate (%) 29 23 67 12 31 16 40

CONCLUSIONS: Newborns with HIV RNA detectable in NOS were more likely to be infected with HIV. HIV was less detectable in NOS if the child was born by C-S and if the child's mother took ZDV. Our findings may help explain why these interventions reduce transmission risk.

Keywords: AEGIS, HIV Infections, Zidovudine, HIV-1, HIV Seropositivity, RNA, Viral, RNA, Delivery, Obstetric, HIV-1 Reverse Transcriptase, Polymerase Chain Reaction, Vagina, Infant, Newborn, Human, Female, Pregnancy, Child, Infant, transmission, surgery
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MoOrC241