[Incidence, bacterial spectrum and predictive risk factors for stent associated respiratory tract infection]

To evaluate the incidence, bacterial spectrum and predictive risk factors for stent associated respiratory tract infection (SARTI).

A prospective nested case-control study was conducted to evaluate the incidence of SARTI and the predictive risk factors for SARTI. Respiratory symptoms, sputum bacterial culture, electronic bronchoscopy investigation, bacterial culture obtained from protective bronchoscopic brushing, and chest radiographs were evaluated before and after stent implantation.

(1) Between January, 2011 and March, 2015, a total of 103 patients were included. The incidence of SARTI was 27.2% (28/103). (2) The incidence of SARTI was similar in subgroups with different stent types (metal stent or silicon stent) and different stent shapes (straight, L or Y shape). (3)Staphylococcus aureus (50.0%, 14/28) and Pseudomonas aeruginosa (35.7%, 10/28) were the dominant pathogens. The infection of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans occurred 7 (4-60) days, 53 (15-67) days and 63 (28-90) days after stent implantation, respectively. (4) Binary logistical regression model analysis showed that female gender(OR=0.178, P=0.011) and age below 50 years (OR=3.91, P=0.036) were favorable predictive risk factors for SARTI.

SARTI occurs in a quarter of the patients. Staphylococcus aureus and Pseudomonas aeruginosa are the dominant pathogens. Female gender and younger age are favorable predictive factors for SARTI.