Respiratory etiological surveillance among quarantined patients with suspected lower respiratory tract infection at a medical center in southern Taiwan during COVID-19 pandemic.

BACKGROUND: A comprehensive study of respiratory pathogens was conducted in an area with a low prevalence of COVID-19 among the adults quarantined at a tertiary hospital. METHODS: From March to May 2020, 201 patients suspected lower respiratory tract infection (LRTI) were surveyed for etiologies by multiplex polymerase chain reaction (PCR: FilmArray TM Respiratory Panel) test combination with cultural method, viral antigen detection and serologic surveys. RESULTS: Total 201 patients tested with FilmArray TM Respiratory Panel were enrolled, of which 68.2% had sputum bacterial culture, 86.1% had pneumococcus and Legionella urine antigen test. Their median age was 72.0 year-old with multiple comorbidities, and 11.4% were nursing home residents. Bacteria accounted for 59.7% of identified pathogens. Atypical pathogens were identified in 31.3% of total pathogens, of which viruses accounted for 23.9%. In comparison to patients with bacterial infection, patients with atypical pathogens were younger (median= 77.2 vs 67.1, years, P = 0.017) and had shorter length of hospital (8.0 vs 4.5, days, P = 0.007). CONCLUSIONS: Patients with LRTI caused by atypical pathogens was indistinguishable from those with bacterial pathogens by clinical manifestations or biomarkers. Multiplex PCR providing rapid diagnosis of atypical pathogens enhance patient care and decision making when rate of sputum culture sampling was low in quarantine ward during pandemic.

Reduction of cooking oil fume exposure following an engineering intervention in Chinese restaurants.

BACKGROUND: A new engineering intervention measure, an embracing air curtain device (EACD), was used to increase the capture efficiency of cooker hoods and reduce cooking oil fume (COF) exposure in Chinese restaurants. METHODS: An EACD was installed in six Chinese restaurants where the cooks complained of COF exposure. Before- and after-installation measurements were taken to compare changes in particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) in kitchen air, and changes in levels of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA). The association between PM and PAHs in air and 8-OHdG and MDA in urine was evaluated by linear mixed-effects regression analysis. RESULTS: Results showed that geometric mean kitchen air levels of PM(10), PM(2.5), PM(1.0) and total particulate PAHs were significantly reduced after the EACDs were introduced. Urinary levels of 8-OHdG and MDA in cooks were also significantly lower after EACD instalment. PM(2.5), PM(1.0) and benzo(a)pyrene (BaP) levels were positively associated with urinary 8-OHdG levels after adjusting for key personal covariates. Urinary MDA levels in cooks were also positively associated with BaP levels after adjusting for key personal covariates. CONCLUSION: This study demonstrates that the EACD is effective for reducing COF and oxidative stress levels in cooks working in Chinese kitchens.

Removal of bioaerosols by the combination of a photocatalytic filter and negative air ions.

This study focused on the investigation of the effectiveness of negative air ionization (NAI), photocatalytic oxidation (PCO), and the combination of NAI and PCO on the removal of aerosolized Escherichia coli, Candida famata, and λ vir phage under different relative humidity. The experiments were conducted with a stainless steel reactor equipped with a negative air ion generator, a photocatalytic filter, and two ultraviolet lamps with 365 nm wavelength. The removal efficiency ( η ) , defined as one minus the ratio of the outlet concentration to the inlet concentration of the appropriate bioaerosol, was used to evaluate the effectiveness of the removal methods. The combination of NAI and PCO was the most efficient removal method for aerosolized E. coli ( η = 0.304 ± 0.06 - 0.364 ± 0.008 ) , C. famata ( η = 0.433 ± 0.08 - 0.598 ± 0.047 ) , and λ vir phage ( η = 0.689 ± 0.02 - 0.903 ± 0.06 ) . In this removal method, the contributions of NAI were higher than those of PCO for the removal of E. coli and C. famata; for the removal of λ virus phage the contributions of NAI and PCO were comparable NAI was the least efficient removal method for bioaerosols, and the removal efficiencies are: η = 0.175 ± 0.04 - 0.245 ± 0.03 for E. coli; η = 0.216 ± 0.007 - 0.297 ± 0.044 for C. famata; and η = 0.299 ± 0.12 - 0.384 ± 0.02 for λ vir phage.