Bacteraemia in children in Iceland 1994-2005

Paediatric bacteraemias in tropical Australia

AIM

Bacteraemias in children are an important cause of morbidity and mortality. Knowledge of local epidemiology and trends is important to inform practitioners of likely pathogens in the sick child. This study aimed to determine trends over time in pathogenic organisms causing paediatric bacteraemia in North Queensland and to audit a hospital's blood culture results with respect to contamination rate.

METHODS

This was a retrospective review of 8385 blood cultures collected from children attending a tertiary centre in North Queensland over a 10-year period (2001-2010).

RESULTS

There were 696 positive blood cultures (8.3%) with 70 different bacterial species detected. Gram-positive and Gram-negative bacteria accounted for 48.6% and 51.4% of isolates, respectively. Overall, bacteraemia accounted for 4.7 per 1000 admissions. The rate of contamination was 60.6% among positive blood cultures and 5.0% for all blood cultures sampled. These results were compared with previous published reports. Notable differences were seen in the frequencies of Salmonella and group A Streptococcus bacteraemias in North Queensland when compared with other reports. There was also a decline in vaccine-preventable infections such as S. pneumoniae and an increasing trend of community-acquired MRSA bacteraemia.

CONCLUSION

This study has demonstrated the unique profile of causative pathogens of paediatric bacteraemias in tropical Australia. In light of the increasing prevalence of MRSA, empiric treatment for sepsis for children in this region needs to be reconsidered.

Species determination within Staphylococcus genus by extended PCR-restriction fragment length polymorphism of saoC gene

Genetic methods based on PCR-restriction fragment length polymorphism (RFLP) are widely used for microbial species determination. In this study, we present the application of saoC gene as an effective tool for species determination and within-species diversity analysis for Staphylococcus genus. The unique sequence diversity of saoC allows us to apply four restriction enzymes to obtain RFLP patterns, which appear highly distinctive even among closely related species as well as atypical isolates of environmental origin. Such patterns were successfully obtained for 26 species belonging to Staphylococcus genus. What is more, tracing polymorphisms detected by different restriction enzymes allowed for basic phylogeny analysis for Staphylococcus aureus, which is potentially applicable for other staphylococcal species.

Pneumococcemia in children--a retrospective study before universal pneumococcal vaccinations

AIM

To evaluate the incidence and characteristics of blood culture-positive occult pneumococcemia compared with blood culture-positive pneumococcal pneumonia in children.

METHODS

In years 2001-2010, 105 children with positive blood cultures for Streptococcus pneumoniae were identified from hospital electronic files. The patient cards were retrospectively charted for clinical and laboratory data, and 38 patients had and 67 had not pneumonia.

RESULTS

The annual incidence of pneumococcemia was, on average, 29.0/10 000 at 0-12 months, 5.3/10 000 at 13-24 months and 1.9/10 000 at 2-4 years of ages, with no increasing or decreasing trend. The incidence of bacteraemic pneumococcal pneumonia increased (p = 0.022) during the study period. The duration of fever before hospitalization (<24 h 73.9% vs. 25.0%, p = 0.022) and the duration of intravenous antibiotics, usually G-penicillin (median 72 vs. 96 h, p = 0.021) was shorter in pneumococcemia patients. On admission, blood leucocyte count was higher in pneumococcemia (mean 26.6 vs. 21.9 × 10E9/L, p = 0.012), but serum CRP was higher in pneumonia (median 160 vs. 67.4 mg/L, p < 0.001). The serotypes 6B and 14 caused 53.2% of pneumococcemia cases.

CONCLUSION

The incidence of pneumococcemia was highest in 1-2-year-old children, and typical for pneumococcemia was rapid onset of fever, high blood leucocyte count and a modestly elevated CRP on admission.

Age and risk factors influence the microbial aetiology of bloodstream infection in children

AIM

To study the aetiology of bloodstream infections (BSI) in children 0-17 years, the influence of age and underlying co-morbidity on BSI rate, distribution of pathogens and outcome; and to provide data on antimicrobial susceptibility patterns.

METHODS

A retrospective population-based study. Data on blood cultures were collected at yearly intervals during 1998-2008. Information about risk factors, focal infection and outcome was retrieved from the patient charts.

RESULTS

We identified 1097 BSI. The incidence of BSI was 0.4/1000. The age-specific incidence was 2.3/1000 in neonates (0-28 days old) and 0.2/1000 in the age group 6-17 years. Staphylococcus aureus was the most common pathogen. The number of species causing BSI in previously healthy children was lower compared with children with co-morbidity. Most children requiring intensive care had a serious underlying illness. Antimicrobial resistance was rare and did not influence outcome. The case-fatality rate was 14.4% in neonates, 5.4% in children with co-morbidity and 1.7% in previously healthy children.

CONCLUSION

Mortality from BSI is low, and a limited spectrum of pathogens is isolated from previously healthy children compared with children with co-morbidity. When choosing empirical therapy for suspected BSI, age and presence of risk factors should be taken into account.