Treatment delivery and monitoring

Close collaboration among clinicians, health-care institutions and public health programs involved in the diagnosis and treatment of patients with HIV infection and TB is necessary in order to integrate care and improve patient outcomes. A specialist or specialists with appropriate expertise should supervise the management of all patients with HIV-TB co-infection in Australia. Hospital admission is not mandatory and depends on clinical indications. The treatment delivery model varies between jurisdictions in Australia but is either a community-based or ambulatory model of care. A patient-centred approach with treatment support that mitigates barriers to adherence such as patient education, social support, provision of transport and addressing any comorbidities (e.g. substance dependence, mental illness) is recommended by WHO.  This approach can include directly observed therapy (DOT), or video observed therapy (VOT), although a meta-analysis demonstrated that DOT is not significantly better than self-administered therapy (SAT) in preventing failure, relapse or acquired drug resistance.

Patients should be monitored closely, in order to ensure they are making the appropriate response to treatment with minimal drug-related toxicity. Patients should have monthly clinical review, biochemical (liver and kidney function tests) and microbiological investigations. Patients with pulmonary TB should have monthly sputum smears and cultures performed (especially in patients with MDR-TB) to document culture conversion on therapy (defined as two consecutive negative cultures). Sputum cultures typically convert to negative between 2 and 4 months, although may be delayed in extensive or cavitary disease. Failure of conversion or clinical improvement should prompt evaluation (adherence, drug-drug interactions, alternative diagnoses) and drug-resistance testing. Therapeutic drug monitoring in patients being treated for HIV infection and TB has a potential role because of the individual pharmacokinetic variability and risk of drug-drug interactions in this patient population. It is available in some Australian laboratories and is having an increasing role, although not recommended as standard of care in guidelines. 55

Adequate infection control measures (personal, administrative, environmental) should be implemented in health facilitates where patients with TB are admitted and ambulatory points where treatment is received. Nosocomial outbreaks of TB have been documented in Australia. It is unknown when patients are non-infectious after the initiation of anti-tuberculosis treatment; however, evidence suggests that a marked reduction in infectiousness occurs rapidly after the onset of effective therapy. There is a statutory requirement to notify all cases of TB (including patients started on empirical anti-tuberculosis therapy) to public health authorities. Investigation and management of contacts of the index case is carried out by the state TB services.

Prognosis 

If active TB and HIV infection are untreated in a patient with co-infection, the outcome is almost universally fatal. Patients with HIV-TB co-infection respond well to anti-tuberculosis treatment and have similar culture conversion and treatment completion rates compared to HIV-negative TB patients. However, the case fatality rate is higher despite cART. The degree of immunodeficiency is the most important predictor of survival in HIV patients with TB.In high TB burden settings, cART reduces the mortality risk by 64-95% in patients with HIV-TB co-infection.