Abstract :Background and Objectives: Community-Acquired Pneumonia (CAP) is a leading cause of
hospitalization and death worldwide. Knowledge of local pathogens guides antimicrobial treatment,
however the etiology of CAP in Western Australia has not been well studied. We hypothesized that
Streptococcus pneumonia, Chlamydia pneumonia, Mycoplasma pneumonia and respiratory viruses
would be common pathogens detected in patients hospitalized with CAP. We further hypothesized
that the pneumococcal vaccination would impact upon rates of Streptococcus pneumonia detection.
Methods: A retrospective analysis of two hospital medical record databases identified all patients 18
years or older admitted with CAP in 2015. Patients with recent hospitalization, significant immune
suppression, chronic respiratory disease or active cancer were excluded. All investigations ordered
during admission were reviewed.
Results: 184 patients met the necessary criteria with radiographic evidence and clinical features of
CAP. Mean age was 66 years (range, 20-96), 19 patients required admission to intensive care and 3
patients died. There were 75 pathogens detected in 55 patients (30%). The most common pathogens
detected were influenza virus (7%), Streptococcus pneumonia (7%) and Haemophilus influenza (7%).
Only one of seven ‘high-risk’ patients with isolated Streptococcus pneumonia was appropriately
vaccinated.
Conclusions: Causative agents were not detected in the majority of patients. Bacteria were most
frequently detected, however influenza virus was the most common single pathogen detected. There
were missed opportunities in administering pneumococcal vaccinations in the community. We
believe a prospective study ensuring consistent and updated diagnostic protocols is overdue.