Back HIV Populations Pregnancy & MTCT ICAAC 2011: Lopinavir/ritonavir Reduces Mother-to-Child HIV Transmission during Supplemental Breastfeeding

ICAAC 2011: Lopinavir/ritonavir Reduces Mother-to-Child HIV Transmission during Supplemental Breastfeeding

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HIV positive mothers who use a lopinavir/ritonavir (Kaletra or Alluvia) antiretroviral regimen can reduce the risk of transmitting the virus to their infants during extended supplemental breastfeeding, supporting recent World Health organization (WHO) guidelines.

As presented at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2011) this week in Chicago, Mark Sullivan from the University of Toronto and colleagues looked at rates of mother-to-child HIV transmission in the Aluvia study in Zambia.

WHO recommendations for infant feeding by HIV positive mothers in developing countries were recently changed to encourage exclusive breastfeeding for the first 6 months, followed by supplemented or partial breastfeeding for the remainder of the first year, the researchers noted as background.

Prior studies have shown that maternal use of antiretroviral drugs during pregnancy and early exclusive breastfeeding can dramatically lower transmission rates. Some research has found that mixed feeding of breast milk, formula, and solid foods is riskier than exclusive breastfeeding in the absence of treatment. However, the safety of extended supplemented breastfeeding when mothers are on antiretroviral therapy (ART) has not been well studied.

This analysis included 225 HIV positive women in Zambia. They generally had well-preserved immune function with a mean CD4 T-cell count of 353 cells/mm3 -- just above the current WHO threshold for initiating ART for the mother's health.

All participants received a combination antiretroviral regimen consisting of zidovudine (AZT; Retrovir), lamivudine (3TC; Epivir), and 400/100 mg lopinavir/ritonavir twice-daily for 12 months post-partum while breastfeeding.

Results

  • At the time of this preliminary analysis, participating women had delivered 230 live-born infants and 9 babies were still-born.
  • 4 infants tested (2.1%) were PCR positive for HIV by 6 weeks post-partum, suggesting infection during gestation, delivery, or early breastfeeding.
  • 1 out of 93 infants (1.1%) with 12-month PCR test results was found to have acquired HIV between 6 weeks and 12 months post-partum.
  • An additional 1 infant (2.0%) with later test results acquired HIV after 12 months.
  • The mothers who transmitted HIV between 6 weeks and 12 months or later reported suboptimal treatment adherence or discontinuation of therapy.

Based on these findings, the researchers concluded, "Maternal [lopinavir/ritonavir] based HAART appears to be effective in [prevention of mother-to-child transmission] both during periods of exclusive and then supplemented breastfeeding."

"This is the first study to demonstrate this finding, and thus support the new WHO guidelines," they added.

Investigator affiliations: University of Zambia, Lusaka, Zambia; University of Ottawa, Ottawa, Canada; Health Canada, Ottawa, Canada; Abbott Laboratories, Chicago, IL; University of Toronto, Toronto, Canada; Johns Hopkins University, Baltimore, MD.

9/23/11

Reference

M Ngoma, A Raha, W Mutale, M Sullivan, et al. Preliminary Results of HIV Transmission Rates Using a Lopinavir/ritonavir (LPV/r, Aluvia) based regimen and the New WHO Breast Feeding Guidelines for PMTCT of HIV. 51st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2011). Chicago, September 17-20, 2011. Abstract H1-1153.