Intensified tuberculosis case finding among HIV-infected persons using a WHO symptom screen and Xpert(®) MTB/RIF

Area of Science:

• Infectious Diseases
• Public Health
• Clinical Diagnostics

Background:

• The World Health Organization (WHO) recommends active tuberculosis (TB) case-finding among people living with HIV (PLHIV) in high-burden settings.
• HIV clinics in high-burden areas face challenges in effectively identifying TB cases.

Purpose of the Study:

• To evaluate the effectiveness of combining a WHO-recommended symptom screen with the Xpert MTB/RIF test for enhanced TB case finding among PLHIV.
• To assess the diagnostic performance of symptom screening and smear microscopy in PLHIV.

Main Methods:

• A cross-sectional study was conducted in an HIV clinic in Addis Ababa, Ethiopia.
• PLHIV were screened for TB using a WHO-recommended symptom-based algorithm.
• Individuals with a positive symptom screen underwent diagnostic testing, including smear microscopy, culture, and Xpert MTB/RIF.

Main Results:

• Of 828 PLHIV, 39% had a positive symptom screen, with unscheduled clinic visits, low CD4 counts, and prior TB history as predictors.
• Active pulmonary TB was diagnosed in 6% of those with a positive symptom screen.
• Smear microscopy demonstrated poor sensitivity (30%) for TB detection compared to culture and Xpert.

Conclusions:

• A positive symptom screen is frequent among PLHIV, leading to a significant laboratory workload.
• Smear microscopy is not sensitive enough for diagnosing active TB disease in this population.
• Intensified TB case finding among PLHIV in high-burden areas requires substantial resources due to the high rate of positive symptom screens.