Multi-morbidities Associated with Tuberculosis in South Africa: A Systematic Review of the Literature

Background: The concept of multi-morbidity is typically defined as the concurrent existence of more than one infectious and/or chronic condition in one person. We conducted a systematic review to quantify and describe the extent of multi-morbidities associated with tuberculosis (TB) in South Africa. Methods: This systematic review and meta-analysis were developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA). Searches were conducted in PubMed inclusive of MEDLINE using a combination of keywords ‘Tuberculosis’, ‘HIV’, ‘Diabetes’, as well as other non-communicable disease-related terms. Only studies providing data for South Africa and those published in English from January 2013 to December 2019 were included. Results: A total of 1772 publications were reviewed, of which 81 (4.6%) were identified for full-text review. Of these, 17 (21%) publications, representing 23,839 study participants with at least one multi-morbidity, were included in the final analysis. Human Immunodeficiency Virus (HIV) was the most commonly occurring co-morbidity reported (16/17 publications; 94.1%), followed by diabetes (6/17; 35.3%), smoking (4/17; 23.5%) and alcohol consumption (2/17; 11.8%). Pooled prevalence estimates for co-morbidities were 65% [95% confidence interval (CI): 59–70%], 6% [95% CI: 4–10%], 27% [95% CI: 8–51%] and 73% [95% CI: 70–77%], respectively. Conclusions: HIV is the most common co-morbidity associated with TB in South Africa. However, other prevalent conditions and patient characteristics known to be strongly associated with TB were not consistently reported. Having a holistic understanding of TB and its associated multi-morbidities is critical to prevent further disease development and to manage patients with existing multi-morbidities more effectively.