Tuberculosis preventive treatment in people living with HIV—Is the glass half empty or half full?
Authors: Olivia Oxlade, Hannah Rochon, Jonathon R. Campbell, Dick Menzies
Journal: PLoS Medicine (2021)

The most recent World Health Organization Global Tuberculosis (TB) Report suggests that 50% of people living with HIV (PLHIV) newly enrolled in HIV care initiated tuberculosis preventive treatment (TPT) in 2019 [1].TPT is an essential intervention to prevent TB disease among people infected with Mycobacterium tuberculosis-some 25% of the world's population [2].Without TPT, it is estimated that up to 10% of individuals will progress to TB disease.Among PLHIV, the prognosis is worse.Of the approximately 1.4 million annual deaths from TB, 200,000 occur among PLHIV [1], who experience TB at rates more than 30 times [3] higher than people living without HIV.In 2018, governments at the United Nations High-Level Meeting (UNHLM) on TB committed to rapid expansion of testing for TB infection and provision of TPT [4].The goal was the provision of TPT to at least 24 million household contacts of people with TB disease and 6 million PLHIV between 2018 and 2022.However, by the end of 2019, fewer than half a million household contacts had initiated TPT, well short of the pace needed to achieve the 5-year target [1].On the other hand, approximately 5.3 million PLHIV have initiated TPT in the past 2 years [1], with particularly dramatic increases in countries supported by the President's Emergency Plan for AIDS Relief (PEPFARAU : PleasenotethatPEPFARhasbeendefinedasPresident 0 sEmergen ) [5].Globally, among PLHIV entering HIV care programs, TPT initiation rose from 36% in 2017 to 49% in 2018 and 50% in 2019 [6,7].To provide insight into scaling up TPT for PLHIV, it is important to consider each of the many steps involved in the "cascade of care" for TPT.A previous systematic review of studies in several populations receiving TPT concluded that nearly 70% of all people who may benefit from TPT were lost to follow-up at cascade of care steps prior to treatment initiation [8].To maximize the impact of TPT for TB prevention among PLHIV, the full TPT cascade of care must be assessed to identify problems and develop targeted solutions addressing barriers at each step.Until now, these data had not been synthesized for PLHIV.In order to address important research gaps related to TPT in PLHIV such as this one, we are now presenting a Collection in PLOS Medicine on TPT in PLHIV.In the first paper in this Collection, Bastos and colleagues performed a systematic review and meta-analysis of the TPT cascade of care in 71 cohorts with a total of 94,011 PLHIV [9].AU : Anabbreviationlisthasbeencompiled This analysis highlights key steps in the cascade where substantial attrition occurs and identifies individual-level and programmatic barriers and facilitators at each step.In stratified analyses, they found that losses during the TPT cascade were not different in high-income compared to low-or middleincome settings, nor were losses greater in centers performing tests for TB infection (tuberculin skin test [TST] or interferon gamma release assay [IGRA]) prior to TPT initiation.