Fluorescence versus conventional sputum smear microscopy for tuberculosis: a systematic review

Area of Science:

• Medical Diagnostics
• Microbiology
• Public Health

Background:

• Conventional sputum microscopy is the primary tuberculosis diagnostic in low- and middle-income countries.
• This method has limitations in sensitivity, particularly for HIV-co-infected patients.
• Fluorescence microscopy is standard in high-income countries, offering potential benefits but raising specificity concerns.

Purpose of the Study:

• To systematically review and summarize the diagnostic accuracy of fluorescence microscopy compared to conventional microscopy for tuberculosis.
• To quantify the sensitivity, specificity, and incremental yield of fluorescence microscopy.

Main Methods:

• Systematic review of relevant studies identified through database searches and expert consultation.
• Inclusion of 45 studies comparing fluorescence microscopy and conventional microscopy.
• Analysis focused on sensitivity, specificity, and incremental yield outcomes.

Main Results:

• Fluorescence microscopy demonstrates higher sensitivity than conventional microscopy.
• Specificity of fluorescence microscopy is comparable to conventional microscopy.
• Insufficient evidence exists to determine the utility of fluorescence microscopy in HIV-infected individuals.

Conclusions:

• Fluorescence microscopy is a more sensitive diagnostic tool for tuberculosis than conventional microscopy, with similar specificity.
• The findings provide a benchmark for evaluating the cost-effectiveness and programmatic value of fluorescence microscopy.
• Further investigation is required to establish its role in diagnosing tuberculosis in HIV-positive populations.