Retention and viral suppression among patients on ART before and after the implementation of the HIV “Treat All” guidelines in Zimbabwe

In 2015, the World Health Organization recommended “Treat All”, i.e. antiretroviral therapy (ART) for all people living with HIV regardless of clinical or immunological status. This recommendation was informed by several clinical trials, which showed improved outcomes across the cascade of care, resulting in population-level viral suppression and decreased HIV incidence and mortality. Since then, the policy has been adopted by most low- and middle-income countries, including those in Sub-Saharan Africa (SSA). There has been a paucity of evidence on the real-world effects of ”Treat All” on treatment outcomes for different patient subgroups since “Treat All” was scaled up. The programmatic procedures, uptake of HIV care services, treatment outcomes, as well as whether the patient mix shifted in favour of previously underserved subgroups were unknown. This PhD used several methodologies to investigate the effects of “Treat All” on the patient mix, retention and viral suppression on ART and subgroups at risk of attrition and viral non-suppression in Zimbabwe and SSA. The PhD thesis also describes strategies that need to be implemented to enhance control of the HIV epidemic. We found no significant difference in attrition at one year ART before and after “Treat All in a systematic review of implementation studies conducted in SSA. However, our own retrospective study showed an increase in attrition after “Treat All”. In addition, males (vs females), adolescents and young adults (vs adults), pregnant and breastfeeding women (vs non-pregnant and non-breastfeeding women), and patients with advanced HIV disease (WHO Stage III & IV; vs patients in WHO Stage I and II) were at risk of attrition. One study conducted in Zimbabwe showed that VL suppression was higher during the “Treat All” years. Males (vs females), children, adolescents and young adults (vs adults), patients with advanced HIV disease (vs WHO Stage I and II) and those with suboptimal adherence (vs optimal adherence) were at a higher risk of VL non-suppression. In Zimbabwe, there were substantial within-country variations in HIV prevalence, HIV testing coverage, HIV testing yield, linkage to ART and ART coverage. Therefore we call for precision public health , i.e. tailoring interventions to the yet uncovered needs of specific subgroups and situations, to enhance epidemic control.