Epidemiology and Research Division, National Tuberculosis Institute, Bangalore, Karnataka, India.
PLoS One. 2012;7(8):e42625. doi: 10.1371/journal.pone.0042625. Epub 2012 Aug 15.
We conducted a survey to estimate point prevalence of bacteriologically positive pulmonary TB (PTB) in a rural area in South India, implementing TB program DOTS strategy since 2002.
Survey was conducted among persons ≥ 15 years of age in fifteen clusters selected by simple random sampling; each consisting of 5-12 villages. Persons having symptoms suggestive of PTB or history of anti-TB treatment (ATT) were eligible for sputum examination by smear microscopy for Acid Fast Bacilli and culture for Mycobacterium tuberculosis; two sputum samples were collected from each eligible person. Persons with one or both sputum specimen positive on microscopy and/or culture were labeled suffering from PTB. Prevalence was estimated after imputing missing values to correct for bias introduced by incompleteness of data. In six clusters, registered persons were also screened by X-ray chest. Persons with any abnormal shadow on X-ray were eligible for sputum examination in addition to those with symptoms and ATT. Multiplication factor calculated as ratio of prevalence while using both screening tools to prevalence using symptoms screening alone was applied to entire study population to estimate prevalence corrected for non-screening by X-ray.
Of 71,874 residents ≥ 15 years of age, 63,362 (88.2%) were screened for symptoms and ATT. Of them, 5120 (8.1%) - 4681 (7.4%) with symptoms and an additional 439 (0.7%) with ATT were eligible for sputum examination. Spot specimen were collected from 4850 (94.7%) and early morning sputum specimens from 4719 (92.2%). Using symptom screening alone, prevalence of smear, culture and bacteriologically positive PTB in persons ≥ 15 years of age was 83 (CI: 57-109), 152 (CI: 108-197) and 196 (CI :145-246) per 100,000 population respectively. Prevalence corrected for non-screening by X-ray was 108 (CI: 82-134), 198 (CI: 153-243) and 254 (CI: 204-301) respectively.
Observed prevalence suggests further strengthening of TB control program.
我们在印度南部的一个农村地区进行了一项调查，以估计自 2002 年以来实施结核病规划 DOTS 战略以来，经细菌学证实的肺结核（PTB）的现患率。
在通过简单随机抽样选择的 15 个群集中，对年龄≥15 岁的人群进行了调查；每个群集由 5-12 个村庄组成。有疑似肺结核症状或有抗结核治疗（ATT）史的人有资格进行痰检，用抗酸杆菌涂片显微镜检查和培养结核分枝杆菌；对每个符合条件的人采集两份痰样。对一份或两份痰标本显微镜检查和/或培养阳性的人被标记为患有肺结核。通过对数据缺失值进行插补，以纠正数据不完整带来的偏差，来估计现患率。在 6 个群集中，还对登记在册的人进行了 X 射线胸片筛查。X 射线胸片有任何异常阴影的人，除了有症状和 ATT 的人外，还可进行痰检。使用两种筛查工具的现患率与仅使用症状筛查的现患率之比作为倍增系数，应用于整个研究人群，以估计 X 射线筛查未检出的现患率。
在≥15 岁的 71874 名居民中，有 63362 人（88.2%）接受了症状和 ATT 筛查。其中，有 5120 人（8.1%）-4681 人（7.4%）有症状，另外 439 人（0.7%）有 ATT，他们有资格进行痰检。从 4850 人（94.7%）采集了点样标本，从 4719 人（92.2%）采集了清晨痰标本。仅使用症状筛查，≥15 岁人群中痰涂片、培养和细菌学阳性肺结核的现患率分别为 83（95%置信区间：57-109）、152（95%置信区间：108-197）和 196（95%置信区间：145-246）/100000 人。经 X 射线筛查未检出的校正现患率分别为 108（95%置信区间：82-134）、198（95%置信区间：153-243）和 254（95%置信区间：204-301）。
观察到的现患率表明需要进一步加强结核病控制规划。
