Aliyu Gambo, El-Kamary Samer S, Abimiku Alash'le, Hungerford Laura, Obasanya Joshua, Blattner William
Health and Human Services, Federal Capital Territory, Abuja, Nigeria.
BMC Infect Dis. 2014 Dec 13;14:675. doi: 10.1186/s12879-014-0675-0.
Chest-x-ray is routinely used in the diagnosis of smear negative tuberculosis (TB). This study assesses the incremental cost per true positive test of a point-of-care digital chest-x-ray, in the diagnosis of pulmonary mycobacterial infections among HIV patients with presumed tuberculosis undetected by smear microscopy.
Consecutive patients with clinical suspicion of pulmonary tuberculosis were serially tested for Human immunodeficiency virus (HIV), their sputum examined for Acid Fast Bacilli then cultured in broth and solid media. Cultures characterized as tuberculous (M.tb) and non-tuberculous (NTM) mycobacteria by Hain assays were used as gold standards. A chest-x-ray was classified as: (1) consistent for TB, (2) not consistent for TB and (3) no pathology.
Of the 1391 suspected cases enrolled, complete data were available for 952 (68%): 753/952 (79%) had negative smear tests while 150/753 (20%) had cultures positive for TB. Of those, 82/150 (55%) had chest-x-ray signs consistent with TB and 29/82 (35%) were positive for HIV. Within the co-infected, 9/29 (31%) had NTM infections. Among all suspects, the cost per positive case detected using smear microscopy test was $52.84; the overall incremental cost per positive case using chest-x-ray in smear negatives was $23.42, and in smear negative, HIV positive patients the cost was $15.77.
Point-of-care chest-x-ray is a cost-effective diagnostic tool for smear negative HIV positive patients with pulmonary mycobacterial infection.
胸部X线检查常用于涂片阴性肺结核（TB）的诊断。本研究评估了即时检验数字胸部X线检查在诊断涂片显微镜检查未发现的疑似肺结核HIV患者肺部分枝杆菌感染中，每例真阳性检测的增量成本。
对临床怀疑患有肺结核的连续患者进行人类免疫缺陷病毒（HIV）系列检测，检查其痰液中的抗酸杆菌，然后在肉汤和固体培养基中培养。通过海恩检测鉴定为结核分枝杆菌（M.tb）和非结核分枝杆菌（NTM）的培养物用作金标准。胸部X线检查分为：（1）符合肺结核，（2）不符合肺结核，（3）无病变。
在纳入的1391例疑似病例中，952例（68%）有完整数据：952例中的753例（79%）涂片检查阴性，而753例中的150例（20%）结核培养阳性。其中，82/150例（55%）胸部X线征象符合肺结核，82例中的29例（35%）HIV检测阳性。在合并感染患者中，9/29例（31%）为非结核分枝杆菌感染。在所有疑似患者中，使用涂片显微镜检查检测到的每例阳性病例成本为52.84美元；涂片阴性患者使用胸部X线检查的每例阳性病例总体增量成本为23.42美元，涂片阴性且HIV阳性患者的成本为15.77美元。
即时检验胸部X线检查是诊断涂片阴性且HIV阳性的肺部分枝杆菌感染患者的一种具有成本效益的诊断工具。
