Abstract
Tuberculosis (TB) remains the leading cause of morbidity and mortality among people living with HIV (PLHIV) in high-burden countries like Tanzania. Despite national and global guidelines recommending routine TB screening at every clinical encounter, missed and delayed TB case notifications persist, suggesting gaps in screening practices. This study evaluated the implementation fidelity of the TB screening algorithm and associated factors within routine HIV care in public health facilities in Geita, Tanzania. A facility-based cross-sectional study was conducted, involving the extraction of data from 423 client treatment records and observation of 423 screening sessions. Simple random and systematic sampling methods were employed to select the records and sessions, respectively. Descriptive and inferential analyses were performed using Excel and Stata. Modified Poisson regression with robust variance was used to estimate prevalence ratios (PRs) to determine factors associated with two binary outcomes: (1) consistent TB screening over 12-month period, and (2) correct utilization of the screening tool. TB screening was documented in 82.8% of clinical encounters. Overall, 70.7% of clients were screened at every encounter, and 75.4% screened at their most recent visit. Laboratory investigations were recorded in 94% of presumptive cases, with all confirmed TB cases initiated on treatment. Additionally, 80.6% of eligible clients were initiated on TB preventive therapy (TPT). The WHO Four-Symptom Screening (W4SS) was widely used (98.8%), and the tool was correctly administered in 62% of the sessions observed. Factors associated with inconsistent screening included age 40-49 years [Adjusted Prevalence Ratio (aPR) = 0.82; p = 0.046], age ≥50 years (aPR = 0.76; p = 0.025), suppressed viral load (aPR = 0.63; p < 0.001), monthly drug refill model (aPR = 0.55; p = 0.006), refill by treatment supporter (aPR = 0.09; p < 0.001), being traced back from a lost to follow up (aPR = 1.38; p = 0.019), and absence of prior TB (aPR = 0.81; p = 0.001). The correct use of the W4SS tool was less likely at PMTCT clinics (aPR = 0.55; p < 0.001). Although TB screening is widely integrated into HIV care, fidelity to the screening algorithm remains suboptimal in the initial stages of symptom screening. The completion of the algorithm cascade was well-implemented. Fidelity at earlier stages of the algorithm, such as the consistent and correct use of the W4SS, should be enhanced by strengthening provider capacity and routine monitoring to improve adherence to the protocol.