Management of TB/HIV Coinfection - Diagnosing TB

Authors: Colleen Hanrahan, PhD; Mark Nicol, MD; Wendy Susan Stevens, MD
Editor in Chief: Ian M. Sanne, MBBCH, FCP(SA) (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.

Background: A Global and South African Perspective on TB in the Context of HIV Coinfection

Overview

The World Health Organisation (WHO) 2015 Global Report[WHO Global TB 2015] estimated that there were 9.6 million new tuberculosis (TB) cases and 1.2 million deaths due to TB worldwide in 2014, of which 33% of TB deaths occurred in HIV-positive individuals. In 2014 in South Africa, TB incidence was 834 per 100,000 people and TB mortality was 44 per 100,000 people; this translates to 450,000 new cases and 24,000 deaths.[WHO Global TB 2015; WHO TB Fact Sheet ZA 2016] The incidence rate among HIV-positive individuals was 509 per 100,000 in 2014,[WHO TB Fact Sheet ZA 2016] which shows that the South African TB epidemic is fuelled by the concurrent HIV epidemic. South Africa has the largest burden of HIV-infected individuals worldwide (6.8 million in 2014). In 2014, WHO estimated that 61% of new TB cases in South Africa were coinfected with HIV.[WHO Global TB 2015] Tuberculosis is the leading killer of HIV-positive people worldwide and South Africa is no exception.[WHO TB Fact Sheet 2016]

For more information from inPractice on the trends in HIV and TB infection in South Africa, click here.

The Contributions of Drug-Resistant Tuberculosis

Added to this pandemic is the emergence of drug-resistant strains of Mycobacterium tuberculosis. South Africa is ranked as a high-burden country for multidrug-resistant tuberculosis (MDR-TB), which is resistance to both isoniazid and rifampicin, 2 of the most potent first-line anti-TB drugs. In 2014, 18,734 laboratory-confirmed cases of MDR-TB were reported in South Africa, representing 1.8% of all newly identified TB cases and 6.7% of all retreatment cases.[WHO Global TB 2015] This is likely an underestimate of the true level. HIV coinfection is common among South African patients with MDR-TB. A national cohort in 2011 found that 38% of patients with MDR-TB were infected with HIV.[Farley 2011] Mortality among HIV-infected individuals with MDR-TB is known to be high. In the national cohort of patients with MDR-TB, HIV-infected patients had twice the mortality risk of HIV-uninfected patients.[Farley 2011]

It remains unclear, however, whether HIV infection is a risk factor for MDR-TB.[Suchindran 2009] As high HIV rates drive the TB epidemic in South Africa, the dramatic increase in the TB caseload can overwhelm the TB control program, exacerbating the problem of MDR-TB.[Wells 2007] South Africa was the site of the first documented outbreak of extensively drug-resistant TB (resistant to all first- and second-line drugs), in which HIV coinfection was present in 100% of those tested, and mortality was 98%.[Gandhi 2006] Results from the first national TB drug-resistance survey in more than a decade will be presented in 2016 and should provide an updated understanding of the prevalence of MDR-TB in South Africa.

For more information from inPractice on drug-resistant TB, please click here.