Prevalence, characterization and impact of hospital-acquired infections in a pulmonology department

Background: Hospital-acquired infections (HAI) can be defined as those occurring after 48 hours of hospital admission, 30 days of discharge or 30 days of an operation without prosthesis and 1 year if placement of prosthesis. They affect 1 in 10 patients admitted to hospital. Purpose: The aim of this study was to characterize, find predictors and evaluate the impact of HAI. Methods: We carried out an observational prospective study that included all patients admitted in the Pulmonology Department of a portuguese central hospital between October and December 2014. Socio-demographic variables, comorbidities, cause of admission, presence of infection and its nature (HAI or community acquired-CAI), microbiologic findings and mortality were recorded. Results: There were 235 patients included: mean age 63±1.7 years, 59.6% men. Infection prevalence was 81%: 11.1% HAI and 87.4% CAI. An aetiological agent was found in 15.3% of all infections, 52.3% of HAI, and 11% of CAI. The most frequent agents were Haemophilus influenzae and Legionella pneumophila in CAI and Staphylococcus aureus , Pseudomonas aeruginosa and Acinetobacter baumann ii in HAI. Predictors of HAI were reduced mobility (p=0.032), malnutrition (OR 5.37; p=0.047), neoplastic disease (OR 5.65; p=0.001) and immunosuppression (OR 5.65; p=0.005). Comparing with CAI HAI was associated with higher mortality (OR 4.65; p=0.032) and length of hospitalization (p=0.004). Conclusions: HAI is associated with a higher mortality and increased hospitalization duration. Risk factors for HAI such as malnutrition, immunosuppression, and presence of neoplastic disease should be evaluated at admission and infection control measures should be taken.