[Bacterial causes of meningitis in newborns]

Bacterial meningitis jeopardizes the life of affected newborns and in survived children often leaves permanent sequels. The sooner the diagnosis is established and the therapy is started, the more a prosperous outcome can be expected. When the indication is established, lumbar punction should be performed. On the basis of the results of cytological and biochemical analyses of the cerebrospinal fluid (CSF) that point to bacterial meningitis, the initial therapy should begin even before the results of bacteriological analyses. It is important to know which causes are to be expected in order to make an adequate choice of antibiotics for initial therapy. The AIM of this study is to identify the causes of meningitis, frequency of their occurrings and mortality-rate in the affected newborns.

A prospective study was carried out in the Paediatric Department of the Institute from January 1, 1978 to December 31, 2000. Patients originated from all parts of Yugoslavia. After the establishing of indication, lumbar punction was performed. CSF was sent to cytological, biochemical and bacteriological analyses. Diagnosis of meningitis was established when at least two criteria of four were fulfilled: 1. isolation of the cause by CSF culture; 2. elevation of CSF leukocyte count more than 20 with predominance of polymorphonuclear leukocytes; 3. hypoglucorrhachia (glycaemia less than 40 mg percent or less than 50 percent of glycaemia); 4. identification of bacteria by the Gram stain of CSF sediment. In 173 newborns the cause of bacterial meningitis was confirmed.

Causes of meningitis were as follows: E. coli in 46 newborns (N) (26.5%), Streptococcus B haemolyticus group B in 35 N (20.2%), K. pneumoniae in 27 N (15.6%), K. oxytoca in 3 N (1.7%), Proteus spp in 14 N (8%), Salmonella spp in 12 N, Pseudomonas spp in 9 N, Streptococcus pneumoniae in 9 N, Acinetobacter calcoaceticus in 4 N, Enterobacter spp in 3 N, L. monocytogenes and Serratia marcescens and Staphylococcus aureus in 2 N each, and in one N. meningitidis, Streptococcus group D, Citrobacter, Morganella morganii and Alkaligenes xilosoxidans. Over the period 1978-1987, the most frequent causes were: E. coli (28.2%), SBHB (26.8%) and Klebsiella spp (11.3%). Over the period 1991-2000, order and frequency of causes had been changed: Klebsiella spp (26.8%), E. coli (19.2%), SBHB (14.1%), etc. In addition, new causes appeared, namely: Morganella morganii, Citrobacter, K. oxitoca and Alkaligenes xylosoxidans (Table 2). Of a total of 173 patients, 52 (30.1%) died: of 124 children with meningitis caused by gram-negative bacteria, 39 (31.4%) died, and of 49 children with gram-positive bacteria, 13 (26.5%) died (Table 1). Comparing the first and the last decade, mortality decreased by only 0.2% (Table 2). The explanation might be that the patients came to the Institute too late, and after manifestation of resistant and multiresistant causes that obscured the appropriate selection of antibiotics for initial therapy. The precious time between the onset of the disease and start of the therapy was lost in this way. Newborns with bacterial meningitis should be treated only in health institutions where the intensive care units for newborns exist.

The most frequent causes of meningitis are the following: E. coli, SBHB and Klebsiella pn. Frequency of causes of meningitis changed with time. New uncommon causes have appeared. The mortality-rate remained very high.