Symptom-Based Active Tuberculosis Screening in Two Nigerian Correctional Facilities: A Cross-Sectional Study

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Clinical Diagnostics

Background:

• Tuberculosis (TB) poses a significant health threat in Nigerian correctional facilities, with prevalence rates up to ten times higher than the general population.
• Traditional passive TB case detection methods often fail to identify asymptomatic infections, necessitating improved screening strategies.

Purpose of the Study:

• To evaluate a systematic active case-finding (ACF) strategy employing symptom-based screening and GeneXpert MTB/RIF testing in two Nigerian correctional facilities.
• To determine the effectiveness of ACF in enhancing TB diagnosis within a high-prevalence correctional setting.

Main Methods:

• A total of 2,244 inmates were screened for TB symptoms between April and September 2021.
• Presumptive TB cases provided sputum for GeneXpert analysis, with interventions including outreach screening, cell-to-cell searches, and contact tracing.
• Data were analyzed to calculate detection rates per 100,000 inmates and overall positivity yield.

Main Results:

• The study identified 45 confirmed TB cases, yielding an estimated prevalence of 0.5% (489 per 100,000 inmates), more than double the national average.
• The overall TB positivity rate among presumptive inmates was 7%, with point prevalence in Lagos and Ogun states at 500 and 458 per 100,000, respectively.
• All detected TB cases were rifampicin-sensitive, with no drug-resistant strains identified.

Conclusions:

• Symptom-based GeneXpert screening is an effective method for active case-finding in correctional facilities, substantially improving upon passive detection rates.
• Systematic ACF, including universal entry screening and regular facility-wide checks, is crucial for early TB diagnosis and treatment initiation in high-risk environments.
• Recommendations include institutionalizing routine ACF, integrating rapid molecular testing, and considering digital radiography for enhanced TB control in correctional settings.