The effect of maternal viral load on the risk of perinatal transmission of HIV-1. New York City Perinatal HIV Transmission Collaborative Study Group.
OBJECTIVE
To determine the effect of maternal viral load at delivery on the risk of perinatal transmission of HIV-1.


METHODS
A nested case-control study within a prospectively followed cohort of HIV-1-infected pregnant women and their infants.


METHODS
The multicenter New York City Perinatal HIV Transmission Collaborative Study.


METHODS
Fifty-one women who gave birth to HIV-1 infected infants were frequency-matched within CD4+ cell count quintiles with 54 non-transmitting mothers.


METHODS
Maternal quantity of HIV-1 viral RNA was assayed in plasma obtained near delivery using the nucleic acid sequence-based amplification assay system.


RESULTS
Viral RNA was detected in 73 (70%) out of 105 women and the median viral load was 16,000 RNA copies/ml in transmitters and 6,600 in non-transmitters (P < 0.01). When adjusted for maternal CD4+ count near delivery, women with measurable viral load were nearly sixfold more likely to transmit HIV-1 than women with viral load below detection [adjusted odds ratio (AOR), 5.8; 95% confidence interval (CI), 2.2 15.5]. The odds ratio for perinatal transmission of log10 viral load, adjusted for CD4 count was 2.7 (95% CI, 1.5-5.1). When stratified by the stage of HIV-1 disease, the only group with significant association between log10 viral load and transmission were AIDS-free women with CD4+ count > 500 x 10(6)/l (AOR, 9.1; 95% CI, 2.6-31.5).


CONCLUSIONS
High maternal viral load increases the likelihood of perinatal transmission of HIV-1 in women without AIDS and advanced immunosuppression. HIV-1 infected pregnant women without advanced disease, shown by others to have the lowest risk of perinatal transmission, may benefit the most from efforts to identify and decrease viral load at delivery.
Thea
D M
DM
Medical and Health Research Association, New York, New York, USA.
Steketee
R W
RW
Pliner
V
V
Bornschlegel
K
K
Brown
T
T
Orloff
S
S
Matheson
P B
PB
Abrams
E J
EJ
Bamji
M
M
Lambert
G
G
Schoenbaum
E A
EA
Thomas
P A
PA
Heagarty
M
M
Kalish
M L
ML
D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000635:transmission* / Q000821:virology*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood / Q000821:virology*; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D012307:Risk Factors; D019562:Viral Load
D012367:RNA, Viral