Microbiological etiology of community acquired pneumonia in immunocompromised adults.

In a previous observational study 23% of Community Acquired Pneumonia (CAP)
episodes among adults in the Netherlands were caused by pneumococci with
serotypes that are included in the 13-valent conjugate pneumococcal vaccine
(13v PnV). In the CAPiTA trial 84.500 healthy elderly have been randomized to
receive either 13v PnV or placebo, and the incidence of CAP needing
hospitalization and caused by any of the 13 vaccine serotypes is the primary
study endpoint. Yet, study participation was based on strict inclusion
criteria, intentionally creating selection of healthy elderly. Moreover, the
decision to participate among eligibles may also induce selection bias
(*healthy vaccinee effect*). Therefore, the study population may not be
considered generalizable for the whole population of elderly in the
Netherlands, and it is unknown to what extent the microbiological etiology of
the study population differs from other patient populations. This knowledge gap
may influence acceptance of the CAPiTA study results.

Objective of the study is to quantify the microbiological etiology in
immunocompromised patients, at least 18 years of age, with CAP needing
hospitalization. And to determine the severity, antibiotic use and outcome of
CAP in immunocompromised patients, at least 18 years of age, with CAP needing
hospitalization.
Urine for the SSUAD test will be collected from immune-compromised patients
with NO suspicion of a respiratory infectious disease or other acute infectious
disease.

This is an observational study. Patient will be included based on the suspicion
fo CAP. The final diagnosis of CAP will be based on the presence of enough
clinical criteria and presence of an infiltrate on the chest X-ray. When there
is no more suspicion of CAP within 48 hours after admission, patient will not
be included. The final interpretation of the chest X-ray wil be done by
independent radiologists.
The microbiological etiology will be determined upon clinical cultures (blood,
sputum and pleural fluid if indicated), urinary antigen testing (BINAX for
pneumococci and Legionella when clinically indicated), virological examination
of throat swab and the SSUAD test for serotype specific pneumococcal antigen
identification. These diagnostic procedures are identical to the ones used for
CAPiTA patients, with the exception of collection of blood sample.
On presentation on the ER or within 24 hours after admission two study samples
will be taken: 1 pharyngeal swab and 1 urine sample, at least 5mL. Within 48
hours after admission the patient will be asked permission to use these samples
for diagnostic research. If no permission is obtained, the samples will be
destroyed. If the patient does give permission for participation in the trial
and thereby confirming use of the pharyngeal swab and urine sample, these
samples will be analyzed in a central laboratory.
Urine for the SSUAD test will be collected from immune-compromised patients
with NO suspicion of a respiratory infectious disease or other acute infectious
disease.

Burden: 1 pharyngeal swab is taken.
Risks: itchy feeling in the throat, coughing, feeling of throwing up.