Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Jan 17;19(1):62.
doi: 10.1186/s12879-019-3696-x.

Effect of isoniazid preventive therapy on tuberculosis incidence and associated risk factors among HIV infected adults in Tanzania: a retrospective cohort study

Amon Sabasaba  1 , Henry Mwambi  2   3 , Geoffrey Somi  4 , Angella Ramadhani  4 , Michael J Mahande  2
Affiliations

Effect of isoniazid preventive therapy on tuberculosis incidence and associated risk factors among HIV infected adults in Tanzania: a retrospective cohort study

Amon Sabasaba et al. BMC Infect Dis. .

Abstract

Background: Tuberculosis (TB) continues to be the leading cause of morbidity and mortality among human immunodeficiency virus (HIV) infected individuals in Sub Saharan Africa including Tanzania. Provision of isoniazid preventive therapy (IPT) is one of the public health interventions to reduce the burden of TB among HIV infected persons. However there is limited information about the influence of IPT on TB incidence in Tanzania. This study aimed at ascertaining the effect of IPT on TB incidence and to determine risk factors for TB among HIV positive adults in Dar es Salaam region.

Methods: A retrospective cohort study was conducted using secondary data of HIV positive adults receiving care and treatment services in Dar es Salaam region from 2011 to 2014. TB incidence rate among HIV positive adults on IPT was compared to those who were not on IPT during the follow up period. Risk factors for incident TB were estimated using multivariate Cox proportional hazards regression model.

Results: A total of 68,378 HIV positive adults were studied. The median follow up time was 3.4 (IQR = 1.9-3.8) years for patients who ever received IPT and 1.3 (IQR = 0.3-1.3) years among those who never received IPT. A total of 3124 TB cases occurred during 114,926 total person-years of follow up. The overall TB incidence rate was 2.7/100 person-years (95%CI; 2.6-2.8). Patients on IPT had 48% lower TB incidence rate compared to patients who were not on IPT (IRR = 0.52, 95%CI; 0.46-0.59). Factors associated with higher risk for incident TB included; being male (aHR = 1.8, 95% CI; 1.6-2.0), WHO stage III (aHR = 2.7, 95% CI; 2.3-3.3) and IV (aHR = 2.4, 95% CI; 1.9-3.1),being underweight (aHR = 1.7, 95% CI; 1.5-1.9) while overweight (aHR = 0.7, 95% CI; 0.6-0.8), obese (aHR = 0.5, 95% CI; 0.4-0.7), having baseline CD4 cell count between 200 and 350 cells/μl (aHR = 0.7, 95% CI; 0.6-0.8) and CD4 count above 350 cells/μl (aHR = 0.5, 95% CI; 0.4-0.6) were associated with lower risk of developing TB.

Conclusion: Isoniazid preventive therapy (IPT) has shown to be effective in reducing TB incidence among HIV infected adults in Dar es Salaam. More efforts are needed to increase the provision and coverage of IPT.

Keywords: Dar es salaam; Isoniazid preventive therapy; TB incidence; Tanzania.

PubMed Disclaimer

Conflict of interest statement

Ethics approval and consent to participate

Ethical approval was obtained from the Kilimanjaro Christian Medical University College (KCMUCo). The need for informed consent was deemed unnecessary since we used secondary data which did not have any identifier and it was unlinked from the database. Permission to use CTC data was sought from the MOHCDGEC through the National Aids Control Program (NACP).

Consent for publication

The permission to publish the data was obtained from the NACP after being fully informed about the objectives and findings of the study.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Flow chart showing the recruitment of the study population
Fig. 2
Fig. 2
Kaplan-Meir probability of TB-free survival by IPT status
See this image and copyright information in PMC

References

    1. Dean GL, Edwards SG, Ives NJ, Matthews G, Fox EF, Navaratne L, et al. Treatment of tuberculosis in HIV-infected persons in the era of highly active antiretroviral therapy. AIDS. 2002;16(1):75–83 10.1097/00002030-200201040-00010PMID:11741165. - PubMed
    1. World Health Organization. Global tuberculosis report 2015: World Health Organization; 2015.
    1. Worodria W, Massinga-Loembe M, Mayanja-Kizza H, Namaganda J, Kambugu A, Manabe YC, Kestens L, Colebunders R. Antiretroviral treatment-associated tuberculosis in a prospective cohort of HIV-infected patients starting ART. Clin Dev Immunol 2010 Dec;2011. - PMC - PubMed
    1. Sharma SK, Mohan A, Kadhiravan T. HIV-TB co-infection: epidemiology, diagnosis & management Indian J Med Res 2005;121(4):550–567. PMID:15817963. - PubMed
    1. World Health Organization . InWHO policy on collaborative TB/HIV activities: guidelines for national programmes and other stakeholders. 2012. WHO policy on collaborative TB/HIV activities: guidelines for national programmes and other stakeholders. - PubMed

MeSH terms