Management of TB/HIV Coinfection - TB and HIV: Overview

Authors: Gavin J. Churchyard, MBBCh, MMed, FCP, PhD; Christopher J. Hoffmann, MD, MPH, MS
Editor In Chief: Richard E. Chaisson, MD (More Info)

Last Reviewed: July 8, 2016 (What's New)

Credit Information

inPractice® Africa’s Continuing Education Unit (CEU) provider, the South African Medical Association, offers physicians 3 CPD points on a 70% pass rate for completing this individual module. Nonphysicians who successfully complete the module will receive a participation certificate. To learn more on CPD credits and participation certificates, click here.

Introduction

The escalating and severe tuberculosis (TB) epidemic threatens the success of HIV care in southern Africa. Individuals infected with HIV are at markedly increased risk for both acquiring and dying from TB infection, a risk that has been well established since early in the HIV epidemic. However, despite the combination of high levels of awareness among most clinicians and the availability of standardised screening and treatment algorithms in southern Africa, TB disease persists as the leading cause of death among HIV-infected patients (Table 1).[Rana 2000; Cohen 2010; Ansari 2002] Indeed, although TB disease is commonly diagnosed in HIV clinics, the burden of undiagnosed disease remains high: Approximately 7% to 33% of patients eligible for antiretroviral therapy (ART) have undiagnosed TB disease at the time of ART evaluation.[Hanifa 2012; Lawn 2006; Moore 2007]

Table 1. TB Among HIV-Infected Individuals in Southern Africa

Patient Characteristics and Outcomes

Range, %

ART initiators who have TB infection[Hanifa 2012; Lawn 2006; Moore 2007]

7-33

ART initiators with unsuspected TB infection after pre-ART evaluation[Hanifa 2012; Lawn 2006; Lawn 2010]

4-20

Deaths attributable to TB infection among HIV-infected persons[Rana 2000; Cohen 2010; Ansari 2002; Glynn 2010]

25-60

TB-related deaths in which TB infection was unrecognised before death[Wong 2012; Martinson 2007]

30-50

Unfortunately, outside of study settings in which sputum and blood cultures are obtained from all HIV-infected patients, only a fraction of individuals with active TB disease are diagnosed at ART initiation.[Hanifa 2012; Lawn 2006; Moore 2007] Many who remain undiagnosed develop severe disease or die before treatment is initiated.[Wong 2012; Omar 2015] Even experienced and competent clinicians working in tertiary settings all too often fail to diagnose TB disease while a patient is still alive, only learning the cause of the patient’s illness at postmortem evaluation.[Wong 2012] This need not be. To reduce TB mortality and control the TB epidemic, increased diagnosis and successful treatment of TB is essential. However, knowing when to suspect TB can be challenging due to the highly varied manifestations of disease in individuals with HIV infection. Because timely diagnosis can lead to cure of TB disease and restoration of health, reducing TB-related mortality depends on overcoming diagnostic challenges and assuring timely treatment initiation and successful completion of treatment. This may require initiation of presumptive TB treatment without laboratory confirmation (“clinically diagnosed TB”) in clinical situations consistent with TB disease, especially among HIV-infected individuals.

For more information from inPractice on the diagnosis of TB, click here.

Identifying and treating the many HIV-infected individuals who do not present with classic symptoms of TB disease requires both knowledge of atypical presentations of TB disease and confidence in applying that knowledge or laboratory testing for TB regardless of symptoms among categories of HIV-infected persons at highest risk for TB. This chapter provides an overview of TB epidemiology, clinically relevant biology, the natural history of TB, and signs and symptoms that may suggest TB disease. The information in this and subsequent chapters is intended to improve clinicians’ confidence in identifying and treating TB infection among HIV-infected individuals so that they can make earlier diagnoses of TB disease and can, in turn, provide optimal management of TB disease.