Longitudinal adherence to antiretroviral drugs for preventing mother-to-child transmission of HIV in Zambia.

Sumiyo Okawa,Shinsuke Miyano,Gardner Syakantu,Charles Yekha Msiska,Kenichi Komada,Mable Chirwa,Naoko Ishikawa,Junko Yasuoka,Masamine Jimba,Henry Kapyata

doi:10.1186/s12884-015-0697-7

Abstract

BackgroundAdherence to antiretroviral (ARV) drugs is essential for eliminating new pediatric infections of human immunodeficiency virus (HIV). Since the Zambian government revised the national guidelines based on option A (i.e., maternal zidovudine and infant ARV prophylaxis) of the World Health Organization’s 2010 guidelines, no studies have assessed adherence to ARVs during pregnancy up to the postpartum period. This study aimed to examine adherence to ARVs and identify the associated risk factors.MethodsA prospective cohort study was conducted in the Chongwe district from June 2011 to January 2014. Self-reported adherence to ARVs was examined during pregnancy and at one week, six weeks, and 24 weeks postpartum among 321 HIV-positive women. The probability of remaining adherent to ARVs was estimated using the Kaplan-Meier method, and the risk factors for non-adherence were identified using the Cox proportional hazard regressions—treating loss to follow-up as non-adherence. The statuses of HIV in HIV-exposed infants were assessed in January 2014.ResultsDuring the study period, 326 infants were born to HIV-positive women, 262 (80.4 %) underwent HIV testing, and 11 (3.4 %) had their HIV infection detected at the time that they had the latest HIV testing as of January 2014. The ARV adherence rate was 82.5 % during pregnancy, 84.2 % at one week postpartum, 81.5 % at six weeks postpartum, and 70.5 % at 24 weeks postpartum. The probability of remaining adherent to ARVs was 0.61 at day 50, 0.35 at day 100, 0.18 at day 200, and 0.06 at day 300. Attending a referral health center (HC) was a risk factor for non-adherence compared with attending rural HCs that provided HIV care/treatment (adjusted hazard ratio [aHR] 0.71, 95 % confidence interval [CI] 0.57–0.88) and those that did not provide HIV care/treatment (aHR 0.58, 95 % CI 0.46–0.74). A new diagnosis of HIV infection compared to a known HIV-positive status before pregnancy was another risk factor for non-adherence (aHR 1.24, 95 % CI 1.03–1.50).ConclusionsMaintaining adherence to ARVs through pregnancy to the postpartum period remains a crucial challenge in Zambia. To maximize the treatment benefits, adherence to ARVs and retention in care should be improved at all health facilities.

Highlights

Adherence to antiretroviral (ARV) drugs is essential for eliminating new pediatric infections of human immunodeficiency virus (HIV)
In 2013, about 240,000 children were newly infected with HIV, with the majority of pediatric HIV infections being attributed to mother-to-child transmission [1]
This study included the western part of the district as the study site where the Chongwe referral health center (HC) and 19 rural HCs are operated

Summary

Introduction

Adherence to antiretroviral (ARV) drugs is essential for eliminating new pediatric infections of human immunodeficiency virus (HIV). In an attempt to eliminate new pediatric HIV infections, the World Health Organization (WHO) revised the guidelines for preventing mother-to-child transmission of HIV (PMTCT) in 2010 [2]. In option B, pregnant women receive triple ARV prophylaxis from 14 weeks of pregnancy to the end of the breastfeeding period, while their infants receive NVP for the first four to six weeks. In both options, lifelong antiretroviral therapy (ART) is recommended for all women with a CD4 cell count ≤350 cells/mm or those in the WHO clinical stage 3 or 4. In option B+, all women initiate lifelong triple ARVs regardless of their WHO clinical stage or CD4 cell count [3]

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