Etiology of community-acquired pneumonia and prevalence of comorbidities in elderly patient population

Objective.

To investigate the mortality rate, comorbidity prevalence, and etiology of community-acquired pneumonia (CAP) in elderly patient population.

Materials and Methods.

Hospitalized elderly patients with CAP were distributed into the following age groups: 65–74 years (group I), 75–84 years (group II) and 85–94 years (group III). The patients’ medical records were used for determining comorbidities and mortality rate. In order to determine etiology of CAP, sputum or BAL samples were collected. A total of 171 isolates were identified using MALDI-TOF MS.

Results.

The mortality rates were 27.1%, 31.5% and 45.7% in age groups I, II, III, respectively. The most common concomitant diseases in all age groups were arterial hypertension (47.4%, 54.6%, and 62.8% for groups I, II, and III, respectively), chronic heart failure (45.7%, 50.9%, and 60.0%, respectively), and coronary heart disease (15.2%, 25.9%, and 24.3%, respectively). The most frequently isolated bacteria by age group were the following: group I – non-fermenting Gram-negative bacteria (NFGNB) (7.4%), Enterobacterales (6.6%), S. aureus (6.6%); group II – Enterobacterales (13.9%), S. aureus (5.6%), Enterococcus spp. (5.6%), NFGNB (2.8%); group III – NFGNB (15.4%), S. aureus (7.7%), Enterococcus spp. (7.7%), Enerobacterales (7.7%).

Conclusions.

The mortality rates in elderly patients with CAP were high and varied from 27.1% in 65–74 years old patients to 45.7% in 85–94 years old patients. The most common comorbidities in all age groups were arterial hypertension (up to 62.8%), chronic heart failure (up to 60%), and coronary heart disease (up to 25.9%). The main pathogens causing CAP in elderly patient population were Enterobacterales and non-fermenting Gram-negative bacteria.