Detectable viral load among HIV -1 positive pregnant women on ART (Option B +) in northern Tanzania: Baseline results from the HIVDR study

Abstract

Introduction: In Tanzania, the Ministry of Health, Community Development, Gender, Elderly and Children (MoHCDEC) has implemented the Option B+ as one of the strategies to facilitate achievement of elimination of mother to child transmission of HIV. To prevent emergence of drug resistance mutations early identification of option B+ failure is critical. The emergence of drug resistance mutation and subsequent treatment failure poses a major concern for HIV program in low- and middle-income resource settings where treatment options are limited.

Methodology: We recruited treatment naïve, treatment experienced HIV-1 positive pregnant women and those who had prophylaxis in their previous pregnancy in Kilimanjaro, northern Tanzania August 2016 to February 2017. Whole blood (2ml) for biochemistry, viral load and drug resistance testing were taken at baseline. ARV drug resistance testing was done on women with VL ≥ 1000 copies/ml. We used descriptive statistic and logistic regression to determine the strength of association between virologic outcome (virologic failure) and independent predictors.

Results: One hundred and forty eight (148) pregnant HIV-positive women were enrolled in the study with mean age of 29.82 years (SD=6.17) from August, 2016 to February, 2017. Virologic failure was demonstrated in 34 (23%) with viral load   ≥ 1,000 copies/ml. Genotyping results were available from 26 women, mutations associated with ARV resistance were detected in 23.1% (n = 6/26). Among the six women with ARV resistance mutation 4(66.7%) had high level resistance and 2(33.3%) had low level resistance. Among the 26 samples genotyped 15(58%) viruses were subtype A, while eight were subtype C (31%) and three subtypes D (11%). The most dominant drug resistance mutations against the reverse transcriptase inhibitors for the women with high level resistance were K103N, Y188L, D67N, K70R, M184V, T215F, K219EQ, and the low-level resistance was E138A. The older age was associated with virological failure compared to those who were < 20 year of age.

Conclusion: Viral load testing should be done on women who were already on antiretroviral treatment on their first antenatal visit to ensure early detection of virological failure and enable clinicians to take an appropriate course of action on their management.

Educational intervention on adherence should be targeted at an early stage to women with virological failure during pregnancy to reduce the emergence of HIV-1 drug resistance mutations.