Other Foci of Infections in Community Acquired Central Nervous System Infections

PM: Pneumococcal Meningitis, BM: Brucellar Meningitis, TBM: Tuberculous Meningitis, HME: Herpetic Meningoencephalitis

The treatment strategies in central nervous system (CNS) infections have its own characteristics. Accordingly, the therapeutic approaches may require different features in the management infections other than the CNS disease. Thus, the clinical diagnosis of all infectious foci in a CNS infection patient is crucial in the management of the patient. Additionally, detection of the presence of a non-CNS focus may help predicting the causative agent of the disease in a CNS infection patient. To the best of our knowledge, the distribution of other focal involvement in this subgroup of patients is inconsistent in the literature [1-3].

Our clinical research group (Infectious Diseases International Research Initiative/ID-IRI) has been carrying on multicenter/multinational studies since 2008. ID-IRI has produced bulk of information on pneumococcal meningitis [4], brucellar meningitis [5], tuberculous meningitis [6,7], and herpetic meningoencephalitis [8]. Among these CNS infection studies [5-8] are the largest case series ever reported in the literature. The strength of these studies was that all patients included were confirmed microbiologically and patients with presumptive diagnoses were excluded. Thus, the databases of ID-IRI for community-acquired CNS infection studies were reanalyzed to disclose patients with other foci of infections.

In this analysis, one fourth of pneumococcal and brucellar meningitis patients, and slightly less than half of tuberculous meningitis cases had another non-CNS involvement. Herpetic meningoencephalitis had only 7% of coexistent other focal involvement. Other than that 28 out of 506 TBM cases (5.5%) had presented a miliary pattern. In almost all patients with pneumococcal meningitis, the other site of involvement was the respiratory system. Acute sinusitis, acute otitis media, and pneumonia were most frequently seen in these cases in descending order. Similarly, the other site of involvement was the respiratory system in more than half of the patients with tuberculous meningitis. However, four-fifths of patients with brucellar meningitis experiencing another involved site had osteoarticular involvement. Finally, although relatively infrequent, herpetic skin eruptions comprised the majority of other site of involvement in herpetic meningoencephalitis cases (Table 1).

Table 1: Foci of involvement other than the central nervous system.

In conclusion, another focus of infection is not rare in due course of community acquired CNS infections. Thus, the treating clinician should not undervalue the presence of another site of involvement in a CNS infection patient. Clues related to other focal involvements should particularly be chased in these patients.

The ID-IRI study group included all authors in the references [4-8].