Assessment of contextual factors shaping delivery and uptake of isoniazid preventive therapy among people living with HIV in Dar es salaam, Tanzania

BACKGROUND: Tuberculosis has remained a leading cause of death among people living with HIV (PLHIV) globally. Isoniazid preventive therapy (IPT) is the recommended strategy by the World Health Organization to prevent TB disease and related deaths among PLHIV. However, delivery and uptake of IPT has remained suboptimal particularly in countries where HIV and TB are endemic such as Tanzania. This study sought to assess contextual factors that shape delivery and uptake of IPT in Dar es Salaam region, Tanzania. METHODOLOGY: We employed a qualitative case study design comprising of in-depth interviews with people living with HIV (n = 17), as well as key informant interviews with clinicians (n = 7) and health administrators (n = 7). We used thematic data analysis approach and reporting of the results was guided by the Consolidated Framework for Implementation Research (CFIR). RESULTS: Characteristics of IPT such as aligning the therapy to individual patient schedules and its relatively low cost facilitated its delivery and uptake. On the contrary, perceived adverse side effects negatively affected the delivery and uptake of IPT. Characteristics of individuals delivering the therapy including their knowledge, good attitudes, and commitment to meeting set targets facilitated the delivery and uptake of IPT. The process of IPT delivery comprised collective planning and collaboration among various facilities which facilitated its delivery and uptake. Organisational characteristics including communication among units and supportive leadership facilitated the delivery and uptake of IPT. External system factors including HIV stigma, negative cultural and religious values, limited funding as well as shortage of skilled healthcare workers presented as barriers to the delivery and uptake of IPT. CONCLUSION: The factors influencing the delivery and uptake of IPT among people living with HIV are multifaceted and exist at different levels of the health system. Therefore, it is imperative that IPT program implementers and policy makers adopt multilevel approaches that address the identified barriers and leverage the facilitators in delivery and uptake of IPT at both community and health system levels. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-022-07867-5.