Norovirus genotypes involved in the outbreaks of gastroenteritis in Croatia during the winter season 2004--2005

Seven outbreaks and four sporadic cases of the non-bacterial gastroenteritis caused by a norovirus (NoV) were detected in Croatia between November 2004 and February 2005. An enzyme immunoassay (EIA) and three different RT-PCRs for the viral polymerase (ORF1 RT-PCR) and genogroup I (GI) or II (GII) of capsid gene regions (GI-ORF2 RT-PCR; GII-ORF2 RT-PCR) were performed to detect NoV in 21 stool samples. To characterize NoVs, sequencing of the ORF1 region was performed on 12 RT-PCR positive samples, whereas the ORF2 region was sequenced for 5 cases. Four outbreaks were caused by the genotype GII.4 (Lordsdale) and one outbreak was caused by the genotype GI.1 (Norwalk). One of the outbreaks was characterized as potentially mixed GII.4 and GI.1 infection. In the monitored period, genotype GII.4 dominated as the cause of noroviral infections in adults.     

Naive and memory CD4+ T-cells in the cerebrospinal fluid of children with aseptic meningitis following measles-mumps-rubella vaccination and enteroviral meningitis

We investigated the distribution of memory (CD45RO⁺) and naive (CD45RA⁺CD62L⁺) CD4⁺ T-cells as well as CD8⁺ T-cells and total T-cells in the CSF of children with aseptic meningitis following measles-mumps-rubella (MMW) vaccination and those with enteroviral meningitis. Flow cytometric analysis of CSF cells was performed in 12 children with MMR vaccine-associated meningitis and 11 children with enteroviral meningitis. Percentages of total T-cells, CD4⁺ and CD8⁺ T-cells and monocytes in CSF of patients from the two groups were not significantly different. The majority of CD4⁺ T-cells in the CSF of both patient groups were of memory phenotype. Percentages of CSF naive CD4⁺ T-cells were increased in children with aseptic meningitis following MMR vaccination. Further studies focused on the more detailed immunophenotyping of CSF cells are needed to fully establish the usefulness of flow cytometry in the diagnostic workup of inflammatory CNS diseases in children.     

Comparative randomized pilot study of azithromycin and doxycycline efficacy in the treatment of prostate infection caused by Chlamydia trachomatis

The study included 125 adult patients (> 18years of age) who had symptoms of chronic prostatitis and proven presence of Chlamydia trachomatis. The presence of C. trachomatis was confirmed in expressed prostatic secretion or in voided bladder urine collected immediately after prostatic massage by a DNA/RNA hybridization method and/or by isolation on McCoy culture and then by immunofluorescent typing with monoclonal antibodies. The patients were randomized in the ratio 2/1; azithromycin/doxycycline, to receive a total of 4.0 g azithromycin over 4 weeks, given as a single dose of 1 x 1000 mg weekly for 4 weeks or doxycycline 100 mg b.i.d. for 28 days. Patients' sexual partners were treated at the same time. Clinical and bacteriological efficacy was evaluated 4-6 weeks after the end of therapy. In the group of patients with chlamydial infection of the prostate, there was no significant difference between the eradication rates (azithromycin 65/82, doxycycline 33/43; P = 0.82) and the clinical cure rates (azithromycin 56/82, doxycycline 30/43; P = 0.94) of the two antimicrobials.     

Mumps virus strains isolated in Croatia in 1998 and 2005: Genotyping and putative antigenic relatedness to vaccine strains

Two mumps virus strains 9218/Zg98 and Du/CRO05 were isolated in two locations in Croatia in 1998 and 2005, respectively. Genetic characterization of these temporally distinct mumps virus isolates was carried out in order to determine their genotype and putative antigenic relatedness to mumps virus vaccine strains. Sequence analysis of the small hydrophobic (SH) gene revealed that isolate 9218/Zg98 shows less than 95% of similarity to any reference strain, thus representing a potential reference strain for a new genotype. Isolate Du/CRO05 clearly belongs to genotype G with the 97% of homology to the reference strain Glouc1/UK96. When compared to each other, the two Croatian strains have extremely low level of homology of only 89% indicating no relatedness between them. Putative antigenic properties of the HN protein of these two isolates were compared to different vaccine strains. The results reveal a higher level of homology of antigenic determinants to non-A genotype vaccine strains than to A genotype vaccine strain.     

Detection of genetic lineages of human metapneumovirus in Croatia during the winter season 2005/2006

Human metapneumovirus (HMPV) is an important respiratory pathogen, especially among young children. The genetic characteristics of HMPV circulating in Croatia have not been studied so far. The aim of this study was to determine the incidence of HMPV infection in hospitalized children with acute respiratory tract infection (ARTI) in the season 2005/2006 in Croatia, as well as to perform the genotypic analysis of detected HMPV strains. From December 1 to March 31 nasopharyngeal secretions (NPSs) were collected from 402 inpatients up to 5 years of age with ARTI. NPSs were tested by real-time RT-PCR assay targeting the nucleoprotein (N) gene of HMPV. HMPV infection was detected in 33 patients (8.2%). To perform the phylogenetic study, partial nucleotide sequences were obtained for HMPV fusion (F) gene of 30 HMPV positive samples. Phylogenetic analysis showed the circulation of two main genetic lineages (A and B), with B lineages being prevalent. It also showed the existence of two sublineages within the group B (B1 and B2) and three subclusters within lineage A (A1, A2a and A2b). Further molecular analysis revealed point mutations in HMPV strains of sublineage B1.     

Clinical and molecular characterization of a parechovirus type 1 outbreak in neonates in Croatia

During July 2009 an outbreak in neonates represented with gastrointestinal and respiratory symptoms was observed at the Neonatal Postintensive Care Unit, Clinical Hospital Center, Zagreb. Human parechovirus type 1 (HPeV1) was isolated from seven patients, one of whom was asymptomatic. All but one were premature neonates with serious underlying conditions, and all recovered fully after several days. In order to characterize the HPeV1s, sequencing of the VP1/2A region was conducted on six isolates from the outbreak and four isolates detected in Croatia in 2008 and 2007. The analysis of sequence similarity showed that the nucleotide identity between the prototype strain (Harris) and HPeV1 isolated in Croatia was 76.5-77.5%. Croatian strains from 2007 and 2009 clustered together with strains from the Netherlands and Germany detected in 2003 and 2006, respectively, while strains from 2008 clustered with the strain from Finland detected in 2000. Change of the dominant strains each year may suggest antigenic variation as a result of viral response to specific immunity of the target population.     

The role of Chlamydia trachomatis in prostatitis syndrome--our experience in diagnosis and treatment

Since the beginning of 1999, over 1500 patients with symptoms of chronic prostatitis were examined at Dr. Fran Mihaljevi? University Hospital for Infectious Diseases in Zagreb. In almost all of these patients urethral swabs and quantitative segmented bacteriologic cultures and microscopy of expressed prostatic secretion (EPS) or voided bladder urine3 (VB3) were performed as described by Meares and Stamey. Urethral swabs, EPS or VB3 were examined for the presence of Chlamydia (C.) trachomatis by McCoy culture and Lugol stain or by immunofluorescent typing with monoclonal antibodies. In the majority of patients C. trachomatis was demonstrated in parallel in EPS or VB3 by DNA/RNA hybridization method. Normal white blood cell count viewed per high power field<10 was found in 362 (68%) of 536 patients with symptoms of chronic prostatitis and C. trachomatis detected in EPS or VB3. These findings additionally suggest that C. trachomatis can be suspected as a causative pathogen in all categories of chronic prostatitis syndrome. Furthermore, this paper summarizes the results of five previously published clinical studies on the efficacy and tolerability of various treatment schemes for chronic chlamydial prostatitis, conducted from the beginning of 1999 until the end of 2003.