Can tuberculosis case finding among health-care seeking adults be improved? Observations from Bissau.

SETTING

The Bandim Health Project study area in Bissau, Guinea-Bissau.

OBJECTIVE

To assess the potential usefulness of predictors (elsewhere applied) and clinical scores (TBscore and TBscore II) based on signs and symptoms typical of tuberculosis (TB) in case finding.

DESIGN

Observational prospective cohort study of patients with signs and symptoms suggestive of pulmonary TB (PTB) from 2010 to 2012.

RESULTS

We included 1089 PTB suspects with a mean age of 34 years (95%CI 33-35); human immunodeficiency virus (HIV) prevalence was 15.1%. PTB was diagnosed in 107 suspects (76.4% sputum smear-positive, 25.2% HIV-infected). Cough > 2 weeks had the highest diagnostic ability (area under the receiver operating characteristic curve [AUC] 0.66, 95%CI 0.62-0.71), while TBscore < 3 best excluded PTB (negative likelihood ratio [LR-] 0.3) when HIV status was not known. TBscore II ≥ 3 had the highest diagnostic ability in HIV-infected PTB suspects (AUC 0.62, 95%CI 0.53-0.72), while the absence of self-reported weight loss best excluded PTB (LR- 0.2). Cough > 2 weeks as a trigger for smear microscopy missed 32.1% of smear-positive PTB cases.

CONCLUSION

Case finding could be improved by screening symptomatic adults for cough and/or weight loss using TBscore II as the trigger for smear microscopy. To suspect PTB only in patients with cough > 2 weeks (non-HIV-infected) or with current cough, fever, weight loss or night sweats (HIV-infected) was not effective in patients whose HIV status was unknown at first visit.