Effect of the COVID-19 pandemic on drug-resistant tuberculosis treatment outcomes at a national referral hospital in Sierra Leone, 2017 to 2022: A retrospective cohort study

Sierra Leone is one of the 30 high TB burden countries in the world, with an incidence rate in 2023 of 273 per 100,000 population. Despite progress in case notification and treatment coverage, around 5,000 cases of TB in Sierra Leone are missing each year. The COVID-19 pandemic has further compounded these challenges. We highlight its effect on drug-resistant TB treatment outcomes. We conducted a retrospective cohort study of drug-resistant TB cases using national data from January 2017 to December 2022. Data was analyzed using STATA. Descriptive analysis summarized demographic, clinical characteristics and treatment outcomes. Logistic regression examined the association between time-period and outcomes, adjusting for age, gender, nutritional status, HIV status and regimen. Of 701 patients, 383 (54.6%) were registered pre-COVID-19, 228 (32.5%) during, and 92 (13.1%) post-COVID-19. Pre-treatment TB cases reduced from 359 (92.5%) in the pre-COVID-19 period to 80 (30.9%) in the COVID-19 period. New treatment cases increased from 29 (7.5%) to 159 (61.4%) during COVID-19. Treatment completion decreased from 74.7% pre-COVID-19 to 63.3% during and 68.5% post-COVID-19). Malnourished patients had higher odds of success (aOR: 1.482, 95% CI: 1.007-2.183), while those on short regimen had lower odds (aOR: 0.51, 95% CI: 0.321-0.810). We observed a decline in drug-resistant TB treatment success rate during COVID-19, which was primarily influenced by concurrent shifts in treatment protocols and underlying secular trends. The pandemic itself did not emerge as an independent determinant of poor treatment outcomes, highlighting the resilience of the TB care system. Nonetheless, the pandemic had significant indirect consequences, including worsening rates of malnutrition and HIV co-infection. These trends point to deeper systemic vulnerabilities, such as weak social protection mechanisms, increased food insecurity, and disruptions in HIV service delivery, all of which contributed to delay in diagnosis and compromised treatment adherence.