Acute bacterial meningitis cases diagnosed by culture and PCR in a children's hospital throughout a 9-Year period (2000-2008) in Athens, Greece.

BACKGROUND AND OBJECTIVES: Acute bacterial meningitis is one of the most severe infectious diseases, affecting mainly infants and, secondarily, older children and adolescents. Diagnosis in the early stages is often difficult and despite treatment with appropriate antibiotic therapy, the case fatality rate remains high. In the present study, the incidence of bacterial meningitis was registered in a general pediatric hospital in Athens, Greece, during a 9-year period (2000-2008), and the use of molecular methods in the diagnosis of bacterial meningitis versus the conventional cultural methods was evaluated. The impact of vaccination against meningitis-causing bacteria on the incidence of bacterial meningitis was also assessed. METHODS: From a total of 1833 children hospitalized with suspected clinical symptoms and signs of meningitis, all cerebrospinal fluid (CSF) and blood samples were analyzed by white blood cell (WBC) count, measurement of glucose, protein, and C-reactive protein (CRP) levels, as well as by conventional bacteriologic culture methods. If samples showed altered CSF markers that were consistent with meningitis in general, they were further investigated by PCR for bacterial pathogens. RESULTS: Of the 1833 patients, 289 (15.76%) were found to be positive for meningitis after CSF examination, based on white blood cell count and differentiation, glucose, protein, and CRP. Fifty-six of the 289 (19.37%) had confirmed bacterial meningitis, as diagnosed by either culture and/or PCR. Of these 56 cases, 44 (78.6%) were detected only by PCR, and 12 cases (21.4%) were confirmed by PCR and culture. The predominant microorganism was Neisseria meningitidis serogroup B (n = 40; 71.4%), followed by Streptococcus pneumoniae not typed [NT] (n = 7; 12.5%), Streptococcus spp. (n =4; 7.1%), Haemophilus influenzae NT (n = 2; 3.6%), and S. pneumoniae serotype 3, Streptococcus group B, and S. pneumoniae serotype 18C (each n = 1; 1.8%). CONCLUSION: In Greece, according to data from the National Meningitis Reference Laboratory, vaccination against N. meningitidis serogroup C since 2001 led to a 10-fold decrease in the incidence of meningitis cases, vaccination against S. pneumoniae serotypes included in the heptavalent conjugate vaccine since 2005 led to a 3.4-fold incidence decrease, and vaccination against H. influenzae type b since 1992 led almost to an absence of cases. In the population of the present study, none of the cases were caused by the above-mentioned vaccine pathogens, except for one S. pneumoniae serotype 18C case with no history of past vaccination. The introduction of vaccination against meningitis-causing bacteria has drastically decreased the emergence of the infection. The improved molecular amplification assays proved to be superior to conventional bacteriologic methods and should be introduced into routine diagnosis, as well as the epidemiologic surveillance of bacterial meningitis.

Detection of human metapneumovirus in infants with acute respiratory tract infection.

Both respiratory syncytial virus (RSV) and human metapneumovirus (hMPV), a recently discovered respiratory pathogen classified in the Paramyxoviridae family, have been associated with acute respiratory tract infections (ARTI) in infants. The aim of our study was to determine the incidence and clinical features of hMPV infection in infants presenting with ARTI at a tertiary children's hospital in Greece during the 2007-2008 and 2008-2009 winter seasons. Routine nasal swabs were obtained from 127 infants younger than 12 months of age. The specimens were tested for the presence of hMPV and RSV antigens using validated enzyme-linked immunoassays. The mean age of the studied infants was 3 months (range 19 days to 12 months). hMPV was detected in 8 (6.3%) children, 4 boys and 4 girls, while RSV was detected in 39 (30.7%) children, 22 boys and 17 girls. In 7 children, hMPV was identified as a unique viral pathogen, while only 1 child was co-infected with hMPV and RSV. Bronchiolitis was diagnosed in all hMPV-positive cases, while only two cases required hospitalization and supplemental oxygen therapy. Our results provide further evidence of the importance of hMPV as a pathogen associated with community-acquired ARTI in infants in Greece.

Antimicrobial susceptibilities of Campylobacter jejuni isolates from hospitalized children in Athens, Greece, collected during 2004-2005.

A total of 170 Campylobacter jejuni strains isolated from the stool of children with clinical gastroenteritis, aged from 3 months to 14 years, were collected during a two-year period (2004-2005). From the 170 strains 30% were resistant to ciprofloxacin (MIC > or = 4 microg/ml), 55% to tetracycline (MIC > 8 microg/ml), 13% to clindamycin (MIC > or = 8 microg/ml), 4% to ampicillin (MIC > 16 microg/ml), 6% to erythromycin (MIC > or = 8 microg/ml), 4% to coamoxiclav (MIC > or = 16/8 microg/ml) and 0% to gentamicin. Compared to previous reports from Greece, the antimicrobial resistance rates to erythromycin, ampicillin and coamoxiclav remain low, while they are still high for tetracycline and ciprofloxacin. Considering similar reports from many other countries and the high incidence of Campylobacter gastroenteritis worldwide, the value of ciprofloxacin as a first choice drug in the empiric treatment of the infection is questionable.

Genotyping of human Campylobacter jejuni isolates in Greece by pulsed-field gel electrophoresis.

BACKGROUND: Pulsed-field gel electrophoresis (PFGE) typing has been recognized by several groups as a relatively simple and quick method for genotyping of Campylobacter jejuni (C. jejuni). The present study was carried out to determine the genetic variations among clinical isolates of C. jejuni from Greece and to establish a database, which could be used for future epidemiological and clinical studies. METHODS: A total of 93 C. jejuni clinical isolates of known flagellin subunit A (flaA) genotype, serotype, and antimicrobial susceptibility pattern, were collected from a general hospital in the Attica region of Greece, between the years 2000 and 2003. The PFGE profiles of SmaI DNA digests of each strain were compared using a bin analysis based on 44 molecular size intervals. RESULTS: Forty-three different PFGE types, designated as C. jejuni (C. j.) 1 Greece (GR) to C. j. 43 GR, were identified. There was no statistically significant association of PFGE type with flaA genotype, serotype, or antimicrobial susceptibility pattern. However, PFGE typing did show a remarkable discriminatory ability within the non-serotypable group. CONCLUSION: Evaluating our results, we observed that (i) there was no statistically significant clonality of a certain PFGE type among the strains examined, and (ii) the discriminatory ability of PFGE typing was much better than that of the other typing methods. This is the first report of the use of bin patterns to compare the PFGE genotypes identified.