RESUMO
Monthly culture is usually recommended to monitor treatment of multidrug-resistant tuberculosis (MDR-TB). As mycobacterial laboratory capacity is limited in many settings, TB programs need evidence to decide whether monthly cultures are necessary compared to other approaches. We simulated three alternative monitoring strategies (culture every 2 or 3 months, and monthly smears alone) in a cohort of MDR-TB patients in Estonia, Latvia, Philippines, Russia and Peru from 2000 to 2004. This retrospective analysis illustrated that less frequent testing delays confirmation of bacteriological conversion. This would prolong intensive treatment, hospitalization and respiratory isolation, increasing cost and toxicity. After conversion, less frequent testing could delay diagnosis of possible treatment failure.
Assuntos
Antituberculosos/uso terapêutico , Técnicas Bacteriológicas , Monitoramento de Medicamentos/métodos , Farmacorresistência Bacteriana Múltipla , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adulto , Simulação por Computador , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/isolamento & purificação , Peru/epidemiologia , Filipinas/epidemiologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Escarro/microbiologia , Fatores de Tempo , Falha de Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologiaRESUMO
BACKGROUND: Multidrug-resistant tuberculosis programs in DOTS-Plus pilot sites in five countries. OBJECTIVES: To calculate sputum conversion time and its relationship to treatment outcome, document the frequency of culture reversions and examine concordance of smear and culture to assess the potential consequences of monitoring by smear microscopy alone. DESIGN: Retrospective cohort analysis of 1926 patients receiving individualized, second-line therapy. RESULTS: Among 1385 sputum culture-positive cases at baseline, 1146 (83%) experienced at least one culture conversion during treatment. Conversion, however, was not sustained in all patients: 201 (15%) experienced initial culture conversion and at least one subsequent culture reversion to positive; 1064 (77%) achieved sustained culture conversion. Median time to culture conversion was 3 months. Among 206 patients whose nal conversion occurred 7-18 months after the initiation of therapy, 71% were cured or had completed treatment. CONCLUSIONS: Prolonged treatment for patients with delayed conversion may be beneficial, as 71% of late converters still achieved cure or completed treatment. This has implications for programs with de ned end points for treatment failure. The interval between rst and nal conversion among patients whose initial con- version is not sustained raises concern with respect to the ongoing debate regarding duration of treatment and the definition of cure.