Care for community-acquired pneumonia and emerging pneumococcal serotypes

Pneumonia is a common condition that frequently leads to hospitalization. In hospitalized adults Streptococcus pneumoniae, or pneumococcus, is the most prevalent bacterial pathogen causing community-acquired pneumonia (CAP).

The first part of this thesis is about diagnostic testing in patients with CAP. It was found that large inter-hospital variation exists in resource utilization in CAP care, mainly in microbiological testing. Also, more microbiological diagnostic testing was associated with early alteration of antibiotic therapy.

The focus of second part is on Streptococcus pneumoniae. As of 2006, pneumococcal vaccination is included in the Dutch national immunization program for children to protect them from severe pneumococcal infections. This thesis shows that the introduction of these vaccines was followed by a reduction in vaccine-type severe pneumococcal disease, but also in adults hospitalized with non-invasive pneumococcal CAP.
Bangladesh introduced a pneumococcal vaccine in 2015. It is shown in this thesis that the coverage of vaccine-type serotypes causing non-bacteremic pneumococcal pneumonia by the current vaccine is low.

The last part of this thesis describes the results of a study in which adults hospitalized with CAP received dexamethasone or a placebo, in addition to standard therapy. The length of hospital stay was shorter and there were less ICU admission in the dexamethasone group, but more side effects were observed in this group as well. It remains unclear for which patients the risk-benefit ratio is optimal.
Lastly, it was shown that serum troponin T (an indicator of cardiac damage) at hospital admission with CAP predicts short- and long-term mortality.