Multiple drug resistant tuberculosis: aetiology, diagnosis and outcome.

Tuberculosis is an increasing problem worldwide both in terms of disease burden and resistance to conventional antibiotic therapy. Studies of outbreaks involving resistant strains have highlighted the need for both improved infection control and the rapid provision of accurate susceptibility data. Each patient should undergo a risk assessment for possible resistance and those in whom risk factors exist should be investigated by means of rapid molecular techniques or other phenotypic methods, so that appropriate management can be instituted with minimal delay. The ultimate outcome will vary according to whether the patient is immunosuppressed, the time taken to make a diagnosis, the severity of disease as well as the degree of resistance. The prognosis can be improved when adequate antibiotic therapy is started as soon as resistance is suspected. Adjuncts to conventional treatment, such as surgery and perhaps immunotherapy may be considered when response to antimicrobial chemotherapy has been suboptimal.