Surveillance of tuberculosis by means of tuberculosis surveys

This document provides technical guidance on the use of tuberculin surveys for tuberculosis surveillance and epidemiological assessment. It reviews the principles underlying tuberculin testing, including the interpretation of reaction patterns, the distinction between specific and non-specific sensitivity, and the influence of BCG vaccination and environmental mycobacteria on test results. The paper discusses the epidemiological value of tuberculin surveys for estimating tuberculosis infection prevalence, particularly in children, and examines methodological issues affecting comparability and reliability of results. It also describes the characteristics and use of different tuberculin products and outlines procedures for administration, reading and interpretation of tests.

Detailed operational guidance is presented for the planning and implementation of tuberculin surveys, including sampling design, stratification, cluster selection, field organization, recording procedures and statistical analysis. The document emphasizes the importance of representative sampling, standardized techniques and confidence intervals in surveillance activities intended to monitor changes in infection prevalence over time. Appendices provide methodological explanations concerning precision, sample size determination, cluster sampling and comparison of prevalence estimates.