Molecular analysis of Streptococcus pneumoniae clones causing invasive disease in children in Singapore.

Streptococcus pneumoniae remains a leading cause of serious paediatric disease. However, there are few published epidemiological data regarding invasive pneumococcal disease (IPD) in many countries in South East Asia, including Singapore. Baseline data for IPD are essential to inform policy regarding pneumococcal conjugate vaccine (PCV) use in Singapore. To our knowledge, this is the first study to use multilocus sequence typing (MLST) to investigate clonal relationships among Singaporean IPD isolates. We characterized 86 invasive pneumococci isolated from Singaporean children between 2001 and 2006 using serotyping and MLST. The objectives were to compare Singaporean MLST data to worldwide data and to assess serotype distribution in relation to current PCV formulations. We observed 50 sequence types (STs), a high proportion of which (n = 16) were novel STs. Despite the presence of these novel STs, serotype distribution was similar to that observed elsewhere. Serotypes 14, 6B, 19A and 19F accounted for 85 % of IPD cases. PCV7, PCV10 and PCV13 covered 85 %, 86 % and 97 % of IPD isolates, respectively. We have demonstrated a pressing need for larger studies to determine the molecular epidemiology and antibiotic susceptibility of circulating pneumococcal clones from both carriage and disease in Singapore.

Influenza A/H1N1 (2009) infection in pregnancy--an Asian perspective.

OBJECTIVE: To describe the characteristics of an obstetric population with influenza A/H1N1 (2009) infection, with a focus on the need for hospitalisation and complications. DESIGN: Cohort study. SETTING: Tertiary referral centre. POPULATION: Two hundred and eleven pregnant women with influenza A/H1N1 (2009) infection diagnosed by nasopharyngeal swab polymerase chain reaction (PCR). METHODS: Obstetric patients presenting to our centre were recruited and followed up. Data collected included demographic and clinical information. MAIN OUTCOME MEASURES: H1N1 and pregnancy complications, and hospitalisation needs. RESULTS: The median age of the cohort was 29.0 years (range 16-42 years), the median gestation at referral was 23.0 weeks (range 4-38 weeks), the median time interval between illness onset and presentation was 2.0 days (range 1-7 days), and the median time interval between illness onset and commencement of oseltamivir was 2.0 days (range 1-11 days). Hospital admission was significantly associated with the presence of co-morbidity (OR 4.14, 95% CI 1.82-9.37, P = 0.0001), breathlessness (OR 5.2, 95% CI 2.19-12.41, P = 0.0003) and sore throat (OR 0.35, 95% CI 0.16-0.73, P = 0.005). There were two cases of pneumonia complicating H1N1 infection, but no mortality. Nine cases developed pregnancy complications. All women recovered. CONCLUSIONS: The need for hospitalisation was significantly associated with breathlessness and co-morbidity. There was minimal morbidity and no mortality observed. We attribute this to early presentation, diagnosis and treatment.

Epidemiology of beta-haemolytic group G streptococcal bacteraemia in Singapore (1996 to 1998).

INTRODUCTION: Group G streptococcus (GGS) accounted for 8% to 44% of all bacteraemias due to beta-haemolytic streptococci according to various reports. The aims of this study were 1) to describe the epidemiology of GGS bacteraemia in Singapore for which local data are lacking and 2) to compare its frequency of isolation to the other Lancefield groups. PATIENTS AND METHODS: The study period was from 1 January 1996 to 30 June 1998. The laboratory records of 2 large acute care hospitals were examined. There was a total of 85 patients. The medical records of 52 patients were available for analysis. In addition, laboratory microbiological data from 1993 to 1999 were reviewed and the number of blood cultures that were positive for beta-haemolytic streptococci groups A, B, C and G was collated. RESULTS: The majority involved the elderly. The mean age was 67 years. The skin was the major portal of entry. Local conditions predisposing the skin to infection occurred in 40.4%. Co-morbidity included malignancies in 28.8% of patients, diabetes mellitus in 11.5% and liver disease in 9.6%. Mortality was 15.4% including fatal septic shock. Recurrent bacteraemia occurred in 5.8% of the patients. The majority (90.4%) were community-acquired infections. GGS, along with group B streptococcus (GBS), was the most common streptococcus among the beta-haemolytic streptococci causing bacteraemia in these 2 hospitals.

Aseptic meningitis in children--the Singapore experience.

OBJECTIVE: To study the incidence, aetiology, clinical characteristics and management of paediatric aseptic meningitis in a paediatric hospital in Singapore. MATERIALS AND METHODS: Patients with cerebrospinal fluid (CSF) pleocytosis, a negative Gram stain and bacterial culture were reviewed retrospectively from 1 January to 31 December 2000. Eighty-seven patients who fulfilled the criteria for aseptic meningitis and without neurological deficits were studied. In addition, reverse transcriptase polymerase chain reaction (RT-PCR) using pan enterovirus primers was subsequently performed on 73 of these CSF specimens which were available for storage. RESULTS: The incidence of aseptic meningitis was approximately 37 cases per 10,000 admissions. Non-polio enteroviruses were isolated from 29 of 64 (45.3%) CSF and 38 of 52 (73.1%) stool samples. RT-PCR was positive in 43 (58.9%) of the archived CSF specimens. The aetiologies of the remaining cases were mostly unidentified. Their ages ranged from 5 days to 12 years (median, 2 months). All patients except 1 had fever. Vomiting or poor feeding occurred in 44.7%, cough or running nose in 35.3%, irritability was observed in 35.3%, seizures in 7.1%, a rash in 10.6% and diarrhoea in 5.9%. All patients recovered without sequelae. The median CSF white cell count was 212 cells/mm3 (range, 7 to 12,000). The median glucose concentration was 2.7 mmol/L (range, 1.6 to 4.4). The median CSF/blood glucose ratio was 0.52 (range, 0.23 to 0.73). Median length of stay was 7 days (range, 4 to 17). Eighty-four patients (96.6%) received antibiotics for a median of 5.5 days (range, 2 to 14). CONCLUSION: Enteroviruses were the most common aetiologic agent identified. A method of early diagnosis using RT-PCR for enteroviruses is necessary to reduce the current duration of antibiotic usage and to decrease the length of hospital stay.

Infection of central nervous system by motile Enterococcus: first case report.

A 66-year-old man with four indwelling ventriculoperitoneal shunts for multiloculated hydrocephalus from a complicated case of meningitis a year before developed shunt infection based on a syndrome of fever, drowsiness, and cerebrospinal fluid neutrophil pleocytosis in the background of repeated surgical manipulation to relieve successive shunt blockages. The cerebrospinal fluid culture, which yielded a motile Enterococcus species, was believed to originate from the gut. This isolate was lost in storage and could not be characterized further. The patient improved with vancomycin and high-dose ampicillin therapy. He relapsed a month later with Enterococcus gallinarum shunt infection, which responded to high-dose ampicillin and gentamicin therapy. This is probably the first case report of motile Enterococcus infection of the central nervous system.