HIV-free survival among breastfed infants born to HIV-positive women in northern Uganda: a facility-based retrospective study.

Abstract

Background: Without interventions, the risk of mother-to-child transmission of HIV is 25% during pregnancy, labour and delivery with an additional risk of 5-20% during the breastfeeding, leading to an overall risk of 45%. The effectiveness of interventions towards prevention of mother-to-child transmission of HIV in any setting is measured by its HIV-free survival rate. We carried out a study to determine the HIV-free survival among breastfed infants enrolled by 2 months of age in a resource-poor setting. Methods: We conducted a cross-sectional survey of early infant diagnosis registers at two tertiary facilities in northern Uganda and retrospectively reviewed records of exposed infants enrolled from 2014 to 2016. We used simple random sampling and analyzed data using SPSS v16 software package. The chi-square and Student t-tests were used to compare factors among HIV-free survivors (HIV-uninfected and alive at 18 months) and those who became HIV-infected or died. Multivariate analysis using logistic regression was used to determine the factors that were independently associated with HIV-free survival. Odds ratios with 95% confidence interval were used to measure the strength of association between the outcome and predictor variables. P-value <0.05 was considered for statistical significanceResults: The mean age at enrolment of the 317 infants was 1.57 (SD 0.23), majority of whom were males 55.5% (176/317). All except two infants were initiated on Nevirapine prophylaxis. Less than one third, 29.3% (93/317) of the infants were exclusively breastfed for at least 6 months, while the breastfeeding status of 30 infants could not be ascertained. The overall HIV-free survival rate in the current study was 94.6% (300/317), while 2.5% (8/317) were HIV-infected and 2.8% (9/317) died. Gender and treatment facility were the factors independently significantly associated with HIV-free survival. Conclusions: Our study estimates that the HIV-free survival rate in the study setting for breastfed infants enrolled by 2 months of age was 94.6%, below the WHO goal of >95% HIV-free rate in breastfeeding population for virtual elimination of HIV. A further prospective study would be necessary to assess a more accurate HIV-free survival rate given the limitations of retrospective data.