Tracking Progress Toward Elimination of Mother to Child Transmission of HIV in Zambia: Findings from the Early Infant Diagnosis of HIV Program (2009-2017)

Abstract

Background: We carried out analyses of early infant testing results at Livingstone Central Hospital in Zambia to assess time of testing, linkages to care and availability of test results for clinical decision making.

Methods: We abstracted data from registers of HIV-exposed infants who had dried blood spots cards (DBS) collected for DNA-PCR from January 2009 to December 2017. Only those tested from 2014 to 2017 had additional data which were used to estimate risk factors for mother-to-child HIV transmission using logistic regression models.

Results: DBS were collected from 2630 children. The proportion of HIV-positive tests decreased from 21% in 2009 to 2% in 2016 and 2017. Median turnaround time for results was 9 weeks (IQR: 5, 15) for HIV-negative, 7 weeks (IQR: 5, 13) for HIV-positive children. Only 2% of infants whose mothers took antiretroviral therapy (ART) were HIV positive, while 18% of infants whose mothers took short course antiretroviral drugs (ARVs) were infected. Infants of mothers who did not take ARVs had 9 times the odds of an HIV positive test (OR = 8.9, 95% CI: 3.6, 22.6). Infants of mothers who received short course ARVs were 40% less likely to get an HIV test within the first 2 months of life (OR = 0.6, 95% CI: 0.4, 0.9) compared to infants of mothers who received ART. Only 52% had a third test at median age 52 weeks (IQR: 50, 54).

Conclusions: Long turnaround time for test results and low retention in care after the initial HIV test were critical challenges to clinical decision making.

Keywords: HIV; early infant diagnosis; effectiveness of PMTCT; elimination; mother-to-child-transmission of HIV; risk factors.