Colebunders R, Bastian I
Department of Microbiology, Institute of Tropical Medicine, Antwerp, Belgium.
Int J Tuberc Lung Dis. 2000 Feb;4(2):97-107.
Recommendations on the management of smear-negative pulmonary tuberculosis (TB) are still based on the behaviour of this disease in populations unaffected by the human immunodeficiency virus (HIV). Studies prior to the HIV epidemic estimated that there were 1.22 cases of smear-negative and extra-pulmonary TB for each smear-positive case. Patients with smear-negative pulmonary TB were found to be less infectious and to have a lower mortality, but a significant proportion (50%-71%) progressed to active disease justifying treatment. Moreover, a wide variety of regimens also proved effective in the treatment of smear-negative disease in HIV-negative patients. The advent of HIV has changed many of these parameters. Countries affected by both HIV and TB have experienced a disproportionate increase in smear-negative disease. While apparently remaining less infectious than smear-positive cases, HIV-positive patients with smear-negative pulmonary TB are generally more immunocompromised, have more adverse drug reactions, and suffer higher mortality rates on treatment. Clinical decision-making has also been complicated because HIV co-infection broadens the differential diagnoses of smear-negative pulmonary TB to include diseases such as Pneumocystis carinii pneumonia (PCP), pulmonary Kaposi's sarcoma, and Gram-negative bacteraemia. Our approach to smear-negative pulmonary TB must therefore adapt to these changed parameters. Management algorithms based on several features (clinical symptoms, response to antibiotic trials, smear investigations, and chest radiography) have been developed to improve case detection. These algorithms must be validated in each locale because their performance will vary depending on numerous local factors such as the regional prevalence of PCP. Alternative methods of specimen collection, such as sputum induction, and processing must be evaluated. National tuberculosis programmes should also consider extending the use of rifampicin-based short-course chemotherapy (SCC) to new patients with smear-negative disease. This latter intervention, and the much-needed establishment of additional microscopy and culture facilities, will depend on increased financial and technical support from the international community.
关于涂片阴性肺结核（TB）管理的建议仍基于该疾病在未感染人类免疫缺陷病毒（HIV）人群中的表现。HIV流行之前的研究估计，每例涂片阳性病例对应1.22例涂片阴性和肺外结核病例。涂片阴性肺结核患者的传染性较低，死亡率也较低，但相当一部分（50%-71%）会进展为活动性疾病，因此需要治疗。此外，多种治疗方案在治疗HIV阴性患者的涂片阴性疾病方面也被证明是有效的。HIV的出现改变了许多这些参数。同时受到HIV和TB影响的国家涂片阴性疾病的增长比例过高。虽然涂片阴性肺结核的HIV阳性患者显然比涂片阳性病例传染性低，但他们通常免疫功能更差，药物不良反应更多，治疗期间死亡率更高。由于HIV合并感染扩大了涂片阴性肺结核的鉴别诊断范围，包括卡氏肺孢子虫肺炎（PCP）、肺卡波西肉瘤和革兰氏阴性菌血症等疾病，临床决策也变得复杂。因此，我们对涂片阴性肺结核的处理方法必须适应这些变化了的参数。基于多种特征（临床症状、对抗生素试验的反应、涂片检查和胸部X线摄影）制定了管理算法，以提高病例检测率。这些算法必须在每个地区进行验证，因为其性能会因许多当地因素而有所不同，例如PCP的地区患病率。必须评估替代标本采集方法，如诱导痰采集及处理。国家结核病规划还应考虑将基于利福平的短程化疗（SCC）扩大应用于涂片阴性疾病的新患者。后一项干预措施以及急需建立的更多显微镜检查和培养设施，将取决于国际社会增加的财政和技术支持。
