Severe Invasive Pneumococcal Disease in Two Siblings: Austrian Syndrome and Infected Aortic Aneurysm

Invasive pneumococcal disease (IPD) is a severe form of Streptococcus pneumoniae infection, defined by its isolation from a normally sterile site (such as blood or cerebrospinal fluid (CSF)), and carries high mortality (approximately 20% in adults, rising to 30-40% in the elderly), particularly with multiorgan involvement. Its rarer forms include endocarditis, aortitis, infected aneurysms and Austrian syndrome (the triad of pneumonia, meningitis and endocarditis).

We describe two cohabitating brothers, unvaccinated against pneumococcus, both smokers and with alcohol use disorder, admitted to the hospital two weeks apart. The first patient, aged 53, presented with pneumonia, meningitis/ventriculitis and aortitis progressing to infected aortic aneurysms, requiring two operations and prolonged antibiotic therapy. S. pneumoniae was isolated from blood cultures and CSF S. pneumoniae real-time polymerase chain reaction (rt-PCR) was positive. The second patient, aged 48, presented with pneumonia, meningitis and aortic valve endocarditis (Austrian syndrome), requiring valve replacement. CSF was also rt-PCR positive for S. pneumoniae and blood cultures grew S. pneumoniae. An immunodeficiency work-up was normal in both brothers.

These cases illustrate the rare, near-simultaneous occurrence of severe IPD in cohabiting siblings and the complexity of its cardiovascular and neurological complications, underlining the importance of early diagnosis, a multidisciplinary approach and pneumococcal vaccination of at-risk groups; when severe disease occurs without classic risk factors, an underlying immunodeficiency should be excluded.