Introduction:
CA-MRSA rates have been increasing internationally, and contribute to a growing “global health security threat” as reported by the WHO. We previously reported the 10-year characteristics of CA-MRSA in upper extremity infections at the Auckland Regional Hand Unit, demonstrating far lower rates in our region overall than those reported internationally. However, substantial ethnic disparities surfaced, and because our unit uniquely services one of the highest percentages of ethnic minorities in New Zealand, we sought to further evaluate this.
Methodology:
ICD10 codes were used to identify patients admitted to the Auckland Regional Hand Unit with upper extremity infections between 2011 and 2014 inclusive and cross referenced with all microbiology data obtained over the study period. Medical records were reviewed to exclude hospital acquired infections. Cases were divided according to ethnicity and further evaluated according to organism, sensitivity, site of infection, length of stay, and other factors.
Results:
966 patients were evaluated. The ethnic representation of hand infections were: European 37%; Pacific Islanders 34%; Maori 20%; Asian 3.6%; Indian 3.6%; and other 1.4%. The overall prevalence of CA-MRSA were: Pacific Island 14.8%; Maori 12.9%; Indian 11.4%; European 8.9%; Asian 8.6%; and other 0%. Of note within the CA-MRSA group, Pacific Islanders represented 44% of all MRSA infections while Europeans represented 29%.
Conclusion:
Despite an equivalent incidence of upper extremity infections amongst Europeans and Pacific Islanders treated at our Unit, Pacific Islanders were substantially more affected by CA-MRSA and demonstrated a prevalence in recent years exceeding guidelines for empiric antibiotic treatment. Interestingly, CA-MRSA amongst Maori also drastically increased in 2014,exceeding other ethnicities. Further validation amongst Maori in a subsequent study period is currently underway and will be presented. Translational treatment implications have been formally explored with the Infectious Diseases department at Middlemore and will be discussed.