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

The concept of multi-morbidity is typically defined as the concurrent existence of more than one infectious and/ or chronic condition in one person. The study was conducted through a systematic review to quantify and describe the extent of multi-morbidities associated with tuberculosis (TB) in SA.

Abstract

South Africa is one of the six countries accounting for 60% of the global Tuberculosis (TB) burden, with an estimated incidence of 615 cases per 100,000 people in 2019. In addition to the country’s TB epidemic is an accompanying Human Immunodeficiency Virus (HIV) epidemic with approximately 7.5 million people living with the virus in 2018. In addition, a third epidemic, that of non-communicable diseases (NCDs), has emerged more recently in South Africa. Several medical conditions are risk factors for TB; commonly, these include HIV, diabetes mellitus and malnutrition.

Links between TB and smoking, alcohol abuse, chronic lung disease, cancer and immunosuppressive diseases/illness are also well recognised.Other demographic and socio-economic risk factors such as an unhealthy lifestyle and living in poverty are commonly associated with TB as well as TB co-infection with both communicable diseases and NCDs.

As such, co-existing communicable diseases and NCDs may increase the risk and/or effect of the other. Subsequently, those already living with a communicable disease such as TB and/or HIV are more likely to develop co-morbidities with NCDs.

Understanding these patterns is imperative not only to gain an accurate understanding of disease burden in the country but also to facilitate an integrated health-care approach that could support efficient resource use, higher quality of care and potentially better treatment outcomes.

Why

These latter improvements are particularly important in the context of high disease-burden, resource-limited settings, like South Africa. It is crucial to quantify the extent of multi-morbidities associated with TB and to which demographics, socio-economic and clinical characteristics, treatment outcomes and patient management models have been reported among patients infected with TB and at least one other co-morbid condition.

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.

The paper included human studies with both children and/ or adults with the simultaneous presence of two or more infectious and/or chronic conditions, where active TB disease was one of the conditions listed. Patients diagnosed with or on treatment for drug-sensitive (DS-TB), drug-resistant (DR-TB), pulmonary (PTB) or extra-pulmonary TB (EPTB) were considered to have active TB disease.

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 (94.1%), followed by diabetes (35.3%), smoking ( 23.5%) and alcohol consumption (11.8%). Pooled prevalence estimates for co-morbidities were 65%

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 managing patients with existing multi-morbidities more effectively.

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