Impact of Option B+ Combination Antiretroviral Therapy on Mother-to-Child Transmission of HIV-1, Maternal and Infant Virologic Responses to Combination Antiretroviral Therapy, and Maternal and Infant Mortality Rates: A 24-Month Prospective Follow-Up Study at a Primary Health Care Clinic, in Harare, Zimbabwe

We conducted a 24-month prospective follow-up study, at a primary health care clinic in Harare, Zimbabwe, to determine cumulative mother-to-child transmission of HIV-1 (MTCT) rate and the contributions of intrauterine (IU), intrapartum (IP), and postpartum (PP) to MTCT, as well as maternal and infant mortality rates in the era of Option B⁺ combination antiretroviral therapy (cART). Plasma for viral load (VL) quantitation was obtained from 475 mothers enrolled into the study. VL was quantified at enrolment and every 6 months thereafter up to 24 months using the Cepheid GeneXpert HIV-1 Quantitative test. Dried blood spots were collected from 453 infants at birth, 4–6 weeks, 3 months, and every 3 months thereafter up to 24 months. HIV-1 infant diagnosis was conducted using the Cepheid GeneXpert HIV-1 Qualitative test. Absolute, cumulative MTCT rates and mortality rate were calculated. Seven mothers (1.55%) transmitted HIV-1 infection to their infants by 24 months. Four infants (0.88%; 95% CI 0.26–2.33%), one infant (0.22%; 95% CI 0–1.4%), and two infants (0.44%; 95% CI 0.01–1.7%) were infected IU, IP, and PP, respectively. By 24 months, 88.94% of the mothers and 80% of the infants had undetectable VL. The maternal and infant mortality rates were 0.21% and 1.78%, respectively. In the first 24 months of life, IU transmission is the major route of MTCT. The cumulative MTCT rate of 1.55% and low maternal and infant mortality rates of 0.21% and 1.78%, respectively, contribute to growing evidence that Option B⁺ cART not only drastically reduces MTCT but also maternal and infant mortality.

Mother-to-child transmission of HIV-1 and infant mortality in the first six months of life, in the era of Option B Plus combination antiretroviral therapy

OBJECTIVES

The aim of this study was to determine the contributions of intrauterine (IU), intrapartum (IP), and postpartum (PP) transmission to mother-to-child transmission of HIV-1 (MTCT) and infant mortality in the first 6 months of life, in the era of Option B Plus combination antiretroviral therapy.

METHODS

Plasma for virus load (VL) quantitation was obtained from 451 women enrolled into the study. VL was quantified using the Cepheid GeneXpert HIV-1 quantitative test. Dried blood spots were collected from 453 infants at birth, 4-6 weeks, 3 months, and 6 months. HIV-1 infant diagnosis was conducted using the Cepheid GeneXpert HIV-1 qualitative test. Absolute and cumulative MTCT rates, and the mortality rate by 6 months were calculated.

RESULTS

Seven mothers (1.55%) had transmitted HIV-1 infection to their infants by 6 months. Four infants (0.88%, 95% confidence interval (CI) 0.26-2.33%) were infected IU, one infant (0.22%, 95% CI 0-1.4%) was infected IP, and two infants (0.44%, 95% CI 0.01-1.7%) were infected PP. The infant mortality rate was 0.88% (95% CI 0.26-2.33%).

CONCLUSIONS

In the first 6 months of life, in the era of Option B Plus combination antiretroviral therapy, IU transmission is the major route of MTCT. The cumulative MTCT rate of 1.55% in a breastfeeding population contributes to growing evidence that complete elimination of MTCT is possible.