Extrapulmonary tuberculosis: a potential source of laboratory-acquired infection

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Laboratory Safety

Background:

• Extrapulmonary tuberculosis (TB) presents diagnostic challenges in routine bacteriology laboratories.
• Processing TB-suspect specimens requires stringent safety measures to protect laboratory staff.
• The study addresses the safety implications of handling extrapulmonary TB specimens in a non-specialized setting.

Purpose of the Study:

• To evaluate the safety risks associated with processing extrapulmonary tuberculosis specimens in a routine bacteriology laboratory.
• To assess the proportion of high-risk specimens handled outside of designated protective areas.
• To provide recommendations for improving specimen handling safety.

Main Methods:

• A three-year retrospective study analyzing 112 patients and 162 risk-assessed specimens.
• Categorization of specimens processed outside B1 protective areas.
• Analysis of specimen types (sputum, pus, urine) and their bacterial load.

Main Results:

• 162 specimens were processed outside the B1 protective area.
• 51 specimens were estimated to be heavily positive for TB.
• Pus and urine accounted for 50% of non-TB investigation specimens, highlighting processing challenges.

Conclusions:

• Handling extrapulmonary TB specimens requires careful risk assessment.
• Current safety protocols may be insufficient for the volume of potentially infectious specimens.
• Clear indication of high-risk specimens on request forms is recommended to enhance laboratory safety.