Blood cultures in sick children

Background. Blood cultures (BCs) are frequently performed in sick children. A recent audit of BCs among adult patients documented high rates of contamination by coagulase-negative staphylococci (CoNS).Objectives. To describe BC contamination rates and common pathogenic organisms causing bloodstream infection in children at a tertiary- level children’s hospital.Methods. BC results for children admitted to Red Cross War Memorial Children’s Hospital from 2008 to 2012 were extracted from the National Health Laboratory Service database. Pathogenic and non-pathogenic (contaminated) growth on BCs in children <1 year of age and >1 year of age, were analysed. Data analysis was performed using Epi Info version 3.5.1.Results. A total of 47 677 BCs were performed in the 5-year period. The proportion of contaminated specimens ranged between 5.9% and 7.2% per year (p=0.4). CoNS was the predominant isolate in 53.8% of all contaminated BCs. Children <1 year of age experienced higher contamination rates than children >1 year of age (8.7% v. 4.7%; relative risk 1.84; 95% confidence interval (CI) 1.71 - 1.97). Pathogenic organisms were isolated in 6.2% (95% CI 6.0 - 6.4) of all BC specimens. Among Gram-positive organisms, the proportion of Streptococcus pneumoniae isolates declined from 14.3% to 4.7% (p<0.00001), while there was a significant increase in Gram-negative organisms (51.8% - 57.9%; p=0.04) over the 5-year period. Klebsiella pneumoniae, the predominant Enterobacteriaceae isolated, decreased from 45.8% to 31.7% (p=0.004). Conclusion. This study identified unacceptably high BC contamination rates, emphasising the importance of collecting BC specimens under sterile conditions.

Klebsiella pneumoniae bloodstream infections at a South African children’s hospital 2006–2011, a cross-sectional study

Background: Klebsiella pneumoniae (KP) is a significant paediatric bloodstream pathogen in children. There is little data from Africa. In this study we describe the epidemiology of multi-drug resistant Klebsiella pneumoniae bloodstream infection (KPBSI) at Red Cross War Memorial Children’s Hospital, Cape Town, South Africa. Methods: We conducted a retrospective cross-sectional study of KPBSI from 1 January 2006 to 31 December 2011 using conventional descriptive and inferential statistical methods. Results: Of 410 hospitalised children with laboratory confirmed KPBSI, 339 (83 %) were caused by extendedspectrum β-lactamase (ESBL) producing isolates. The median age (IQR) was 5.0 (2–16) months, 212 (51.7 %) were male, 82 (20 %) were HIV-infected, and 241 (58.8 %) were moderately or severely underweight. The infection was hospital-acquired or healthcare-associated in 389 (95 %) children and community-acquired in 21 (5 %) children. Significant risk factors for ESBL-KPBSI included cephalosporin exposure in the 12 months prior to the KPBSI, adjusted risk ratio (aRR) 1.18 (95 % CI: 1.06–1.31); HIV infection, aRR 1.14 (1.04–1.25), and intravenous infusions for more than 3 days before the KPBSI, aRR 1.15 (95 % CI: 1.04–1.28). A total of 109 (26.6 %) children died within 30 days of the KPBSI, their median age was four (IQR 1–11) months. The median (IQR) time between KPBSI and death was three (1–9) days. HIV-infection, aRR 2.44(95 % CI: 1.59–3.74); skin erosions at the time of KPBSI, aRR 2.15 (95 % CI: 1.54–3.00); being in PICU at the time of the KPBSI, aRR 1.64 (95 % CI: 1.03–2.61) or needing PICU admission after developing KPBSI, aRR 1.72 (95 % CI: 1.10–2.70) were significant risk factors for death. Conclusion: ESBL-producing KP is an important cause of laboratory confirmed bloodstream infection in hospitalised children and is associated with high mortality

Outbreak of multi-drug resistant Pseudomonas aeruginosa bloodstream infection in the haematology unit of a South African academic hospital

Objective: To describe an outbreak of multi-resistant Pseudomonas aeruginosa bloodstream infections (MRPA-BSI) that occurred in the haematology ward of a tertiary academic hospital in Cape Town, South Africa, and determine risk factors for acquisition of MRPA-BSI. METHODS: The outbreak investigation included a search for additional cases, review of patient records, environmental and staff screening, molecular typing using pulsed-field gel electrophoresis (PFGE) and Multi-locus sequencing (MLST) and a retrospective case-control study. RESULTS: Ten MRPA-BSI cases occurred in the haematology ward between January 2010 and January 2011. The case fatality rate was 80%. Staff screening specimens were negative for MRPA and an environmental source was not identified. PFGE showed that 9/10 isolates were related. MLST showed that 3 of these 9 isolates belonged to Sequence type (ST) 233 while the unrelated isolate belonged to ST260. CONCLUSION: We have described an outbreak of MRPA-BSI occurring over an extended period of time among neutropenic haematology patients. Molecular typing confirms that the outbreak was predominantly due to a single strain. The source of the outbreak was not identified, but the outbreak appears to have been controlled following intensive infection control measures

Impact of an educational intervention and clinical performance dashboard on neonatal bloodstream infections

Background. Blood cultures are the most direct method of detecting bacteraemia. Reducing contamination rates improves the specificity and positive predictive value of the blood culture. Clinical performance dashboards have been shown to be powerful tools in improving patient care and outcomes.Objectives. To determine whether prospective surveillance of bloodstream infections (BSIs), introduction of an educational intervention and the use of a clinical performance dashboard could reduce BSIs and blood culture contamination rates in a neonatal nursery. Methods. We compared two time periods, before and after an intervention. Blood culture data were extracted from the local microbiology laboratory database. The educational intervention included the establishment of hand-washing protocols, blood culture techniques and video tools. A clinical performance dashboard was developed to demonstrate the monthly positive blood culture and contamination rates, and this was highlighted and referred to weekly at the unit staff meeting. Results. Before the intervention, 1 460 blood cultures were taken; 206 (14.1%) were positive, of which 104 (7.1% of the total) were contaminants. In the period following the intervention, 1 282 blood cultures were taken; 131 (10.2%) were positive, of which 42 (3.3% of the total) were contaminants. The number of positive blood cultures and contamination rates after the intervention were both statistically significantly reduced (p=0.002 and p<0.001, respectively). Conclusion. This study demonstrates that adopting a relatively simple educational tool, making use of a clinical performance dashboard indicator and benchmarking practice can significantly reduce the level of neonatal sepsis while also reducing contaminated blood cultures.

Syphilitic lymphadenitis clinically and histologically mimicking lymphogranuloma venereum

An inguinal lymph node was discovered incidentally during surgery for a suspected strangulated inguinal hernia. The patient had recently been treated for candidal balanoposthitis and was known to have a paraphimosis. A new foreskin ulcer was discovered when he was admitted for the hernia surgery. The lymph node histology showed stellate abscesses suggestive of lymphogranuloma venereum (LGV). Chlamydial serologic tests were negative. As the histological appearance and clinical details provided were thought to suggest LGV, tissue was also sent for a real-time quadriplex polymerase chain reaction assay. This was used to screen for Chlamydia trachomatis in conjunction with other genital ulcer-related pathogens. The assay was negative for C. trachomatis, but positive for Treponema pallidum. Further histochemical staining of the histological specimen confirmed the presence of spirochaetes.

Invasive carbapenem-resistant Enterobacteriaceae infection at a paediatric hospital: A case series

Background. There are no paediatric reports of invasive infection caused by carbapenem-resistant Enterobacteriaceae (CRE) from Africa.Objectives. To document a series of cases of CRE infections at a tertiary children’s hospital in Cape Town, South Africa, describing the clinical and microbiological findings in these children.Methods. A retrospective, descriptive study was completed using data from a series of children with invasive CRE infection between 2010 and 2015, sourced from their clinical notes and microbiology results.Results. The first of 10 invasive CRE infections during the study period occurred in November 2012. Nine CRE infections were caused by Klebsiella pneumoniae, and one by both K. pneumoniae and Escherichia coli. The median age was 25 months (interquartile range (IQR) 5 - 60). All 10 CRE infections were hospital acquired. The median length of hospitalisation before CRE infection was 28.5 days (IQR 20 - 44). Eight of the children were exposed to carbapenems during the 12-month period prior to invasive CRE infection. Six were treated with colistin and carbapenem combination therapy, of whom 2 died, including 1 of a non-CRE event. The other 4 children received colistin monotherapy. All these children died, including 2 from non-CRE events.Conclusions. Children with invasive CRE infection and severe underlying disease must be treated with combination antibiotic therapy. Strict infection control practice and antibiotic stewardship are necessary to contain the spread of CRE and limit the number of new infections