Asymptomatic SARS coronavirus infection among healthcare workers, Singapore.

We conducted a study among healthcare workers (HCWs) exposed to patients with severe acute respiratory syndrome (SARS) before infection control measures were instituted. Of all exposed HCWs, 7.5% had asymptomatic SARS-positive cases. Asymptomatic SARS was associated with lower SARS antibody titers and higher use of masks when compared to pneumonic SARS.

Characteristics of patients with delayed diagnosis of infectious pulmonary tuberculosis.

OBJECTIVE: The aim of this study was to identify patient and disease characteristics associated with delayed diagnosis of infectious pulmonary tuberculosis (TB). METHODOLOGY: A retrospective analysis of 375 adult patients with culture-positive pulmonary TB and cough, treated at the Singapore Tuberculosis Control Unit (TBCU) in 2000, was carried out using data extracted from the TB notification registry and clinical records of the TBCU. Demographic, social, clinical and disease characteristics of patients with reported cough of duration less than, and exceeding, the median duration for the study population were compared. RESULTS: The median duration of cough reported at TB notification was 4 weeks (range, 1-156 weeks). By multivariate analysis, patients with cough > 4 weeks were more likely to be < 65 years old (adjusted odds ratio (OR), 1.8; 95% CI, 1.1-2.9; P = 0.02), of Chinese ethnicity (adjusted OR, 2.0; 95% CI, 1.2-3; P = 0.004), more likely to be sputum acid-fast bacilli smear-positive (adjusted OR, 1.7; 95% CI, 1.1-2.7; P = 0.016), and to have weight loss (adjusted OR, 2.6; 95% CI, 1.7-4; P < 0.01). CONCLUSION: Further studies are needed to identify the possible reasons for delayed diagnosis of TB among those < 65 years old, in the Chinese population in Singapore.