The Effect of Long-Term HAART on the Incidence of Tuberculosis Among People Living with HIV in Addis Ababa, Ethiopia: A Matched Nested Case–Control Study

Abstract

Background

The introduction of antiretroviral therapy (ART) significantly decreases the incidence of tuberculosis (TB) in people living with human immunodeficiency virus (PLWHIV). However, a considerable proportion is still co-infected with TB after ART initiation. Thus, this study aimed to assess the effect of long-term HAART on the incidence of TB among PLWHIV in Addis Ababa, Ethiopia.

Methods

A matched nested case–control study was conducted among PLWHIV who were enrolled in ART clinics in Addis Ababa, Ethiopia from 2013 up to 2018. Cases were HIV-TB co-infected individuals who were taking antiretroviral treatment, while controls were PLWHIV without TB who were taking antiretroviral treatment. The cases and controls are matched exactly in age and sex. Data were entered in Epi Info version 7.1 and analyzed using SPSS version 20. Bi-variable and multivariable conditional logistic regression were employed along with 95% CI. A P-value <0.05 in the multivariable analysis was considered statistically significant.

Results

Fifty-seven cases were compared with 114 controls. Accordingly, previous TB history (X²; 13.790, P < 0.001), baseline functional status (X²; 9.120, P = 0.010), baseline WHO clinical stage (X²; 10.083, P = 0.001), baseline hemoglobin value (X²; 6.985, P = 0.008), baseline body mass index (X²; 3.873, P = 0.049), isoniazid preventive treatment (X²; 8.047, P = 0.005), baseline CD4 value (X²; 12.741, P < 0.001) and length of stay on ART (X²; 53.359, P < 0.001) were associated with developing TB. Length of stay on ART was found to be the statistically significant determinant of TB infection after ART initiation (aOR = 5.925, 95% CI = 2.649–13.250).

Conclusion

Advanced clinical stages at the baseline, previous TB history, and not taking IPT were associated with TB infection. The long-term ART exposure significantly decreases tuberculosis incidence in PLWHIV. Thus, retaining PLWHIV on ART would be important to decrease the incidence of TB in this group of individuals.

Keywords:

• HAART
• tuberculosis
• long-term ART
• matched nested case–control study

Acknowledgments

We would like to thank St. Paul’s Hospital Millennium Medical College, Addis Ababa City Administration Health Bureau, and St. Peter Specialized Hospital for their permission to conduct the study. Our gratitude goes to the staff of each health facility and the data collectors.

Abbreviations

ART, Antiretroviral Therapy; BMI, Body Mass Index; Hgb, Hemoglobin; HAART, Highly Active Antiretroviral Therapy; HIV, Human Immunodeficiency Virus; IPT, Isoniazid Preventive Treatment; MDR-TB, Multi Drug Resistant; PLWHIV, People living with Human Immunodeficiency Virus; TB, Tuberculosis; WHO, World Health Organization.

Data Sharing Statement

The data is available upon request with the corresponding author.

Ethics Approval and Consent to Participate

The study obtained ethical clearance from St. Paul’s Hospital Millennium Medical College, Addis Ababa City Administration Health Bureau, and St. Peter Specialized Hospital. Since it is a study based on a review of patient registries, consent was not applicable. Besides, any patient identifier was not used in the entire process to keep confidentiality.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors have declared that no competing interests exist in this work.