High burden of complicated skin and soft tissue infections in the Indigenous population of Central Australia due to dominant Panton Valentine leucocidin clones ST93-MRSA and CC121-MSSA
journal contributionposted on 2017-01-01, 00:00 authored by S A J Harch, E MacMorran, S Y C Tong, D C Holt, J Wilson, Eugene AthanEugene Athan, S Hewagama
BACKGROUND: Superficial skin and soft tissue infections (SSTIs) are common among the Indigenous population of the desert regions of Central Australia. However, the overall burden of disease and molecular epidemiology of Staphylococcus aureus complicated SSTIs has yet to be described in this unique population. METHODS: Alice Springs Hospital (ASH) admission data was interrogated to establish the population incidence of SSTIs. A prospective observational study was conducted on a subset of S. aureus complicated SSTIs (carbuncles and furuncles requiring surgical intervention) presenting during a one month period to further characterize the clinical and molecular epidemiology. High resolution melting analysis was used for clonal complex discrimination. Real-time polymerase chain reaction identifying the lukF component of the Panton Valentine leucocidin (pvl) gene determined pvl status. Clinical and outcome data was obtained from the ASH medical and Northern Territory shared electronic health records. RESULTS: SSTIs represented 2.1% of ASH admissions during 2014. 82.6% occurred in Indigenous patients (n = 382) with an estimated incidence of 18.9 per 1, 000 people years compared to the non-Indigenous population of 2.9 per 1000, with an incident rate ratio of 6.6 (95% confidence interval 5.1-8.5). Clinical and molecular analysis was performed on 50 isolates from 47 patients. Community-associated methicillin-resistant S. aureus (CA-MRSA) predominated (57% of isolates). The high burden of SSTIs is partly explained by the prevalence of pvl positive strains of S. aureus (90% isolates) for both CA-MRSA and methicillin-susceptible S. aureus (MSSA). ST93-MRSA and CC121-MSSA were the most prevalent clones. SSTIs due to ST93-MRSA were more likely to require further debridement (p = 0.039), however they also more frequently received inactive antimicrobial therapy (p < 0.001). CONCLUSIONS: ST93-MRSA and CC121-MSSA are the dominant causes of carbuncles and furuncles in Central Australia. Both of these virulent clones harbor pvl but the impact on clinical outcomes remains uncertain. The high prevalence of CA-MRSA supports empiric vancomycin use in this population when antimicrobial therapy is indicated. Prompt surgical intervention remains the cornerstone of treatment.
JournalBMC infectious diseases
Pagination1 - 7
Indigenous contentThis research output may contain the names and images of Aboriginal and Torres Strait Islander people now deceased. We apologise for any distress that may occur.
Publication classificationC Journal article; C1 Refereed article in a scholarly journal
Copyright notice2017, The Authors
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AbscessMethicillin resistancePanton Valentine leucocidinStaphylococcus aureusAdolescentAdultBacterial ToxinsChildCommunity-Acquired InfectionsExotoxinsFemaleHumansLeukocidinsMaleMethicillin-Resistant Staphylococcus aureusMiddle AgedMolecular EpidemiologyNorthern TerritoryPopulation GroupsPrevalenceProspective StudiesSkinSoft Tissue InfectionsStaphylococcal InfectionsYoung AdultScience & TechnologyLife Sciences & BiomedicineInfectious DiseasesRESISTANT STAPHYLOCOCCUS-AUREUSNORTHERN AUSTRALIAEPIDEMIOLOGYCOMPLEX