How to identify tuberculosis cases in a prevalence survey

Area of Science:

• Public Health
• Infectious Diseases
• Diagnostic Medicine

Background:

• Pulmonary tuberculosis (TB) case identification in prevalence surveys presents significant challenges.
• Low prevalence rates necessitate large-scale screening, increasing the labor intensity of diagnostic methods.

Purpose of the Study:

• To evaluate different strategies for identifying pulmonary tuberculosis cases in prevalence surveys.
• To optimize diagnostic approaches considering resource limitations and desired sensitivity.

Main Methods:

• Utilized questionnaires, chest radiography (CXR), and bacteriological tests (sputum smear microscopy and culture).
• Examined four distinct strategies for applying these diagnostic methods.
• Considered scenarios with varying laboratory capacities and diagnostic tool availability.

Main Results:

• The most sensitive strategy involves applying all diagnostic methods (questionnaire, CXR, sputum smear, and culture) to all eligible individuals.
• Alternative strategies prioritize symptom enquiry and CXR for high-risk individuals, especially when laboratory capacity is limited.
• Enhanced microscopy, like fluorescence microscopy, can be used when CXR or culture is unavailable.

Conclusions:

• Optimal case definitions for TB in prevalence surveys should integrate results from symptom enquiry, CXR, and bacteriology.
• Strategic application of diagnostic methods is crucial for efficient and sensitive pulmonary TB case detection.
• Adapting strategies based on available resources and diagnostic capabilities is essential for effective TB screening programs.