Evaluation of the epidemiological, clinical and microbiological characteristics of children under 5 years of age who were examined with a pre-diagnosis of meningitis

Introduction and Purpose Bacterial meningitis is an acute inflammation of the meninges with high mortality and morbidity in children. It is vital to understand the most common microorganisms causing the disease for rapid diagnosis and to direct the treatment strategies accordingly. Therefore, our study aims to investigate the most common microbial agents of bacterial meningitis in our country's children under 5 years of age to examine their clinical features, laboratory findings, treatments, complications and sequelae. Material-Method In this study, 226 children under the age of 5 who underwent lumbar puncture and diagnosed with meningitis between January 2012 and September 2020 at Bezmialem Vakıf University Medical Faculty Hospital were retrospectively diagnosed and analyzed. The detection of bacteria in the CSF culture along with clinical and CSF findings that were compatible with bacterial meningitis, while the detection of bacteria in the blood culture was accepted as proven bacterial meningitis. According to the culture results, patients were divided into two groups:13 proven meningitis and 213 suspected meningitis. In addition, demographic characteristics of the patients, complaints on admission, antibiotic use before admission, physical examination findings, laboratory findings (C-reactive protein, procalcitonin, white blood cell count, absolute neutrophil and lymphocyte count, platelet, hemoglobin, hematocrit values, glucose), blood culture growths, CSF features (cell count, CSF culture, CSF glucose and protein levels), cranial imaging findings, antibiotics intake during hospitalization, hospitalization period, complications, and sequelae were retrospectively analyzed over an electronic database and compared between the two groups. Results Of our 13 patients diagnosed with bacterial meningitis, 10 were accepted as bacterial meningitis with evidence of growth in the CSF culture and 3 with evidence of growth in the blood culture. Of 10 patients with growth in CSF culture, 4 (31%) Streptococcus pneumoniae, 3 (23%) Neisseria meningitidis, 1 (7.7%) Streptococcus pyogenes, 1 (7.7%) Salmonella typhimuirum, 1 (7.7%) Streptococcus agalactiae growths were found. There was no growth in the CSF culture of 3 (23%) patients diagnosed with bacterial meningitis based on clinical and CSF findings, but the growth was detected in the blood culture (Streptococcus pneumoniae in 2 patients, Escherichia coli in 1 patient). In the meantime, the same agents were grown in both CSF culture and blood culture in 7 of our patients with proven bacterial meningitis (Neisseria meningitidis in 3 patients, Streptococcus pneumoniae in 3 patients, Salmonella typhimuirum in 1 patient). Patients in the proven bacterial meningitis group had a male predominance (54%), with a median age of 8 months (2-28). The most common symptoms and signs in patients with proven bacterial meningitis group were fever (100%), vomiting (46%), altered consciousness (46%), meningeal irritation findings (38%), and fontanel bulge (56%) in infants. These clinical findings were significantly higher in the proven meningitis group. While CRP, procalcitonin, CSF protein and CSF leukocyte counts were found to be considerably higher in cases with proven meningitis (respectively p=<0.001, p=0.005, p=<0.001, p=<0.001), serum lymphocyte count, CSF glucose, and CSF glucose /serum glucose ratio were significantly lower (respectively p=0.009, p=<0.001, p=<0.001). Complications or sequelae developed in 4 of our 13 patients with proven bacterial meningitis. Subdural empyema was observed in 1 patient, subdural empyema and cerebrovascular abnormality in 1 patient, subdural effusion complication was observed in 1 patient, and epilepsy and mental retardation sequelae developed in 1 patient. Conclusion Herein, we confirmed the presence of the meningitis agents by culture or other methods. In our study, we found Streptococcus pneumoniae as the most common cause of bacterial meningitis in children under 5 years of age. Moreover, we proposed that application of agent-specific antibiotic therapy can provide an effective treatment option and prevent the unnecessary use of antibiotics. Keywords: Bacterial meningitis, childhood, microbiological features.