The goals of this research are to understand adherence and retention in care for multi-and extensively drug-resistant tuberculosis (M/XDR-TB) patients using a mixed methods approach.

Tuberculosis (TB) remains the leading cause of morbidity and mortality worldwide among people living with HIV. Globally, incidence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB), the most drug-resistant forms of TB, has approximately doubled over the past fifteen years. Nowhere has this increased incidence generated more concern than in South Africa where interactions between TB and generalized HIV epidemics are causing 'explosive' TB incidence and case-fatality threatening to undermine the progress reached with antiretroviral therapy (ART).

Medication adherence, a key predictor of outcomes in multi-and extensively drug-resistant tuberculosis (M/XDR-TB) and HIV treatment, is understudied in high burden TB/HIV settings. Patient losses during transitions in the care continuum are frequent, increase mortality and limit control of the linked epidemics. Demands of M/XDR-TB HIV treatment are severe including extraordinary pill burden, severe adverse effects, lengthy treatment, isolation and stigma with few parallels in modern medicine.

This is a prospective observational cohort study for patients newly diagnosed with M/XDR-TB initiating treatment. A mixed method approach will be employed to address the complex research questions of distilling determinants of barriers and facilitators to both TB medications and ART; this study will employ complementary qualitative and quantitative methodologies for assessing differential adherence to TB medications and ART.

A sub-set of patients and health care workers will be approached for participation in focus group discussions.

Inclusion Criteria:

1. Age ≥ 18 years

2. Mycobacterium Tuberculosis (MTB) culture positive with at least isoniazid and rifampicin resistance OR

   Molecular drug susceptibility test confirming resistance to at least isoniazid and rifampicin OR

   Polymerase chain reaction test (GeneXpert MTB/RIF) result showing MTB positive and RIF resistance. Patients enrolled with only a GeneXpert MTB/RIF result will be withdrawn if their subsequent susceptibility test or molecular drug susceptibility test reveals rifampicin monoresistance.

3. Initiating treatment for M/XDR-TB which includes at least 2 new medications

4. Have capacity for informed consent

5. HIV Positive Patients: on antiretroviral therapy (ART) or initiating ART within the following 4 weeks as per clinician recommendation

Exclusion Criteria:

1. Pregnancy
2. Prisoners
3. Discretion of the Investigator of Record or clinician

Adult patients with newly diagnosed active pulmonary multi- and extremely-drug resistance tuberculosis (M/XDR-TB) (≥ 18 years old), admitted for routine care at King DinuZulu Hospital in Durban, South Africa will be approached for enrollment. Only patients with capacity for consent will be included in the study. Healthcare workers will be approached for participation in focus group discussions.