Sub-national TB prevalence surveys in India, 2006-2012: Results of uniformly conducted data analysis.

SETTING: Community based tuberculosis (TB) prevalence surveys in ten sites across India during 2006-2012. OBJECTIVE: To re-analyze data of recent sub-national surveys using uniform statistical methods and obtain a pooled national level estimate of prevalence of TB. METHODS: Individuals ≥15 years old were screened by interview for symptoms suggestive of Pulmonary TB (PTB) and history of anti-TB treatment; additional screening by chest radiography was undertaken in five sites. Two sputum specimens were examined by smear and culture among Screen-positives. Prevalence in each site was estimated after imputing missing values to correct for bias introduced by incompleteness of data. In five sites, prevalence was corrected for non-screening by radiography. Pooled prevalence of bacteriologically positive PTB was estimated using Random Effects Model after excluding data from one site. Overall prevalence of TB (all ages, all types) was estimated by adjusting for extra-pulmonary TB and Pediatric TB. RESULTS: Of 769290 individuals registered, 715989 were screened by interview and 294532 also by radiography. Sputum specimen were examined from 50 852 individuals. Estimated prevalence of smear positive, culture positive and bacteriologically positive PTB varied between 108.4-428.1, 147.9-429.8 and 170.8-528.4 per 100000 populations in different sites. Pooled estimate of prevalence of bacteriologically positive PTB was 350.0 (260.7, 439.0). Overall prevalence of TB was estimated at 300.7 (223.7-377.5) in 2009, the mid-year of surveys. Prevalence was significantly higher in rural compared to urban areas. CONCLUSION: TB burden continues to be high in India suggesting further strengthening of TB control activities.

Prevalence of pulmonary tuberculosis in Wardha district of Maharashtra, Central India.

A house based survey was conducted during 2007-2009 in a representative sample of population in Wardha district implementing Directly Observed Treatment Short Course strategy for tuberculosis (TB) control since 2001. The objective was to estimate prevalence of bacillary pulmonary TB (PTB) in individuals aged 15 years or above, and to estimate trends in prevalence when compared to a previous survey carried out in mid 1980's. Two sputum samples (one spot, one early morning) collected from individuals having symptoms suggestive of PTB, history of previous anti-TB treatment (ATT) or abnormal pulmonary shadow on Mass Miniature Radiography (MMR) consistent with possibly or probably active tuberculosis were subjected to Ziehl-Neelsen microscopy and culture on Lowenstein-Jensen medium. Of 55,096 individuals registered into the survey, 50,332 (91.4%) were screened by interview for symptoms and history of ATT and/or by MMR. Of them, 4805 were eligible for sputum collection; both specimens were collected in 4285 (89.2%) and only one specimen in 27 (0.6%). A total of 86 bacillary cases were detected during the survey. Prevalence of bacillary PTB was estimated at 188.7 (140.3-236.9) per 100,000 populations. There was a decline of 61% in the prevalence of PTB over a period of 22 years.