Enhanced tuberculosis identification through 1-month follow-up of smear-negative tuberculosis suspects.

SETTING: Bandim Health Project, Bissau, Guinea-Bissau. OBJECTIVE: To conduct tuberculosis (TB) screening among former TB suspects in whom TB had been ruled out on initial consultation and therefore assumed to be TB-negative (aTBneg). DESIGN: In a cohort follow-up study, 'aTBneg suspects' were screened for symptoms from 1 month after the initial negative sputum smear examination. Symptomatic individuals were referred for clinical re-examination and human immunodeficiency virus (HIV) testing. RESULTS: Among 428 TB suspects presenting over a 10-month period in 2007, 80% (343) were smear-negative. Of these, 21 were subsequently diagnosed with smear-negative TB. Of the remaining 322 aTBneg patients, 212 were followed up and symptoms were examined ≥1 month after initial examination. Among followed up patients, 89 (42%) were still symptomatic: five were diagnosed with TB on the basis of repeated sputum smears and chest X-ray. Of 44 symptomatic patients, 39% (n = 17) were HIV-infected. Thirteen (4%) of the 322 aTBneg suspects died before follow-up. CONCLUSION: A large proportion of aTBneg patients remained symptomatic after 1 month. Several TB cases had initially not been diagnosed, and HIV infection was highly prevalent. aTBneg suspects have a high mortality rate and need increased attention from both TB and HIV programmes.

DC-SIGN (CD209), pentraxin 3 and vitamin D receptor gene variants associate with pulmonary tuberculosis risk in West Africans.

We investigated the role of DC-SIGN (CD209), long pentraxin 3 (PTX3) and vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in susceptibility to pulmonary tuberculosis (TB) in 321 TB cases and 347 healthy controls from Guinea-Bissau. Five additional, functionally relevant SNPs within toll-like receptors (TLRs) 2, 4 and 9 were typed but found, when polymorphic, not to affect host vulnerability to pulmonary TB. We did not replicate an association between SNPs in the DC-SIGN promoter and TB. However, we found that two polymorphisms, one in DC-SIGN and one in VDR, were associated in a nonadditive model with disease risk when analyzed in combination with ethnicity (P=0.03 for DC-SIGN and P=0.003 for VDR). In addition, PTX3 haplotype frequencies significantly differed in cases compared to controls and a protective effect was found in association with a specific haplotype (OR 0.78, 95% CI 0.63-0.98). Our findings support previous data showing that VDR SNPs modulate the risk for TB in West Africans and suggest that variation within DC-SIGN and PTX3 also affect the disease outcome.