Clinical presentation and prognostic factors of Streptococcus pneumoniae meningitis according to the focus of infection

Abstract

Background: We conducted a nationwide study in Denmark to identify clinical features and prognostic factors in patients with Streptococcus pneumoniae according to the focus of infection.

Methods: Based on a nationwide registration, clinical information's was prospectively collected from all reported cases of pneumococcal meningitis during a 2-year period (1999-2000). Clinical and laboratory findings at admission, clinical course and outcome of the disease including follow-up audiological examinations were collected retrospectively. The focus of infection was determined according to the clinical diagnosis made by the physicians and after review of the medical records.

Results: 187 consecutive cases with S. pneumoniae meningitis were included in the study. The most common focus was ear (30%), followed by lung (18%), sinus (8%), and other (2%). In 42% of cases a primary infection focus could not be determined. On admission, fever and an altered mental status were the most frequent findings (in 93% and 94% of cases, respectively), whereas back rigidity, headache and convulsion were found in 57%, 41% and 11% of cases, respectively. 21% of patients died during hospitalisation (adults: 27% vs. children: 2%, Fisher Exact Test, P < 0.001), and the causes of death were due to neurological- and systemic complications or the combination of both in 8%, 5% and 6% of cases, respectively. Other causes (e.g. gastrointestinal bleeding, incurable cancer) accounted for 2% of cases. 41% of survivors had neurological sequelae (hearing loss: 24%, focal neurological deficits: 16%, and the combination of both: 1%). The mortality varied with the focus of the infection (otogenic: 7%, sinusitic: 33%, pneumonic: 26%, other kind of focus: 50%, no primary infection focus: 21%, Log rank test: P = 0.0005). Prognostic factors associated with fatal outcome in univariate logistic regression analysis were advanced age, presence of an underlying disease, history of headache, presence of a lung focus, absence of an otogenic focus, having a CT-scan prior to lumbar puncture, convulsions, requirement of assisted ventilation, and alterations in various CSF parameters (WBC < 500 cells/microL, high protein levels, glucose levels < 1 mmol/L, low CSF/blood glucose levels), P < 0.05. Independent prognostic factor associated with fatal outcome in multivariate logistic regression analysis was convulsions (OR: 4.53, 95%CI: (1.74-11.8), p = 0.002), whereas presence of an otogenic focus was independently associated with a better survival (OR: 6.09, 95%CI: (1.75-21.2), P = 0.005).

Conclusion: These results emphasize the prognostic importance of an early recognition of a predisposing focus to pneumococcal meningitis.

Figure 1

Kaplan Meier Survival curve of 187 patients with S. pneumoniae meningitis in Denmark 1999–2000 according to the focus of the infection. Otogenic focus vs. pneumonic focus, sinusitic focus, other foci, and no primary infection focus: Log rank test: P = 0.0002, 0.008, <0.0001, and 0.03, respectively. Other foci vs. no primary infection focus: P = 0.01.

Figure 2

Age distribution and mortality of 187 patients with S. pneumoniae meningitis in Denmark 1999–2000.

Figure 3

Serotype distribution and mortality of 187 patients with S. pneumoniae meningitis in Denmark 1999–2000. *10 isolates were not capsular serotyped.