Prevalence and Risk Factors of Rifampicin-Resistant Tuberculosis in Nangarhar, Afghanistan

Overview

This observational study in Nangarhar Province, Afghanistan, estimated the prevalence of rifampicin-resistant tuberculosis (RR-TB) among adults using routine Xpert MTB/RIF data and identified key risk factors through a case–control analysis. The study also characterized phenotypic resistance patterns among RR-TB cases, providing critical provincial data to inform targeted interventions.

Background

Tuberculosis remains a major global health challenge, with multidrug- and rifampin-resistant TB (MDR/RR-TB) threatening control efforts worldwide. Afghanistan, a high TB-burden country, faces additional challenges due to conflict, displacement, and health system limitations, complicating diagnosis and treatment continuity. Molecular testing like Xpert MTB/RIF has improved detection of rifampin resistance, but programmatic management of drug-resistant TB is uneven, especially at the provincial level. Understanding local prevalence and risk factors is essential for effective TB control in settings with dense living conditions and multigenerational households.

Data Highlights

Key Findings

• Facility-based prevalence of rifampicin-resistant TB was estimated using routine Xpert MTB/RIF data from three major centers.
• Previous TB treatment was identified as a significant independent risk factor for RR-TB.
• Household crowding and prolonged exposure to infectious TB cases were important determinants of rifampin resistance.
• Phenotypic drug susceptibility testing revealed additional resistance patterns among RR-TB cases, informing treatment considerations.
• Random selection of rifampin-susceptible controls frequency-matched by age and sex ensured comparability and minimized confounding.

Clinical Implications

The findings highlight the need for intensified case detection and tailored interventions targeting previously treated patients and households with high transmission risk in Nangarhar. Strengthening molecular diagnostic capacity and integrating phenotypic DST can guide appropriate treatment regimens. Addressing social determinants such as household crowding may reduce transmission of resistant TB strains.

Conclusion

This study provides essential provincial data on the prevalence and risk factors of rifampicin-resistant TB in eastern Afghanistan, supporting evidence-based strategies to improve diagnosis, treatment, and transmission control in high-burden, resource-constrained settings.

References

1. WHO Global Tuberculosis Report 2023 -- Tuberculosis burden and drug resistance
2. Kandahar DR-TB Program Experience 2023 -- Challenges in delivering drug-resistant TB care
3. Mahidol University TB Risk Factor Studies -- Questionnaire development and validation