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Effect of Maternal HAART on Postnatal HIV-1 Transmission after Cessation of Extended Infant Antiretroviral Prophylaxis
T Taha1, J Kumwenda2, S Cole3, D Hoover4, G Kafulafula2, Q Li1, M Thigpen5, M Glenn Fowler6, N Kumwenda1, and Lynne Mofenson*7
1Johns Hopkins Univ Bloomberg Sch of Publ Hlth, Baltimore, MD, US; 2Univ of Malawi Coll of Med, Blantyre; 3Univ of North Carolina at Chapel Hill, US; 4Rutgers Univ, Piscataway, NJ, US; 5CDC, Atlanta, GA, US; 6Johns Hopkins Med Insts, Baltimore, MD, US; and 7Natl Inst of Child Hlth and Human Devt, NIH, Bethesda, MD, US
Background: The PEPI-Malawi trial showed that infant
daily ARV prophylaxis from birth to age 14 weeks can reduce breast-feeding postnatal
HIV infection by >65%. Maternal HAART can potentially prevent postnatal HIV infection.
We assessed the effect of maternal HAART provided by existing government
program first-line regimen of nevirapine (NVP) + stavudine (4dT) + lamivudine (3TC)
on postnatal HIV infection between 14 weeks and 24 months after cessation of
infant prophylaxis in the PEPI study. The trial was conducted between April 2004
and December 2007; HAART did not become available in Malawi until 2006.
Methods: Breast-feeding HIV-uninfected infants were randomized
at birth to receive: single-dose NVP + 1 week of zidovudine (ZDV) (control); control
plus extended daily NVP to age 14 weeks; or control plus extended daily NVP+ZDV
to age 14 weeks. CD4 cell count was obtained at delivery, 14 weeks and 6, 12, 18,
and 24 months. Maternal CD4 count exposure categories were: HAART-eligible,
untreated (CD4 <250 cells/μL but no HAART), HAART-eligible, treated
(CD4 <250 and received HAART), and HAART-ineligible (CD4 ≥250). Incident
infant HIV infection after cessation of prophylaxis by maternal HAART category and
hazard ratios from proportional hazards models were calculated.
Results: Of 2318 HIV-uninfected infants at 14 weeks,
130 (5.6%) acquired HIV infection during follow-up; 323 women (13.9%)
received HAART. The table shows postnatal HIV transmission rates between 14
weeks and 24 months and the association with maternal HAART use. After
adjusting for infant prophylaxis, HAART-eligible, treated women had
significantly reduced HIV infection risk versus HAART-eligible, untreated women
(adjusted hazard ratio [AHR] = 0.21; 95%CI 0.09 to 0.48). Likewise, being
HAART-ineligible was associated with a significantly lower risk of infant HIV
infection versus being HAART-eligible but untreated (AHR 0.35; 95%CI 0.25 to 0.50).
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Overall, N = 2318
|
[n/N]
Transmission Rate per 100 person-years (95%CI)
|
Adjusted Rate Ratio
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95% confidence interval
|
|
HAART-eligible, untreated
|
[52/494.4]
10.5 (7.86 to 13.79)
|
1
|
—
|
|
HAART-eligible, treated
|
[6/288.1]
2.1 (0.76 to 4.53)
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0.21
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0.09 to 0.48
|
|
HAART-ineligible
|
[72/1067.9]
3.7 (2.86 to 4.61)
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0.35
|
0.25 to 0.50
|
|
Total
|
[130/2750.4]
4.7 (3.95 to 5.61)
|
—
|
—
|
Conclusions: Breast-feeding HAART-eligible women
should start ART early for their own health and to reduce postnatal HIV
transmission to their infants. Whether maternal HAART or continuation of infant
prophylaxis can safely be recommended for HAART-ineligible women remains
unknown.
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