Scabies and mortality

Recent work shows that scabies mites secrete complement inhibitors into burrows, which potentially facilitates the establishment of secondary streptococcal and staphylococcal infections and subsequent invasive bacterial disease.3Staphylococcus aureus bacteraemia (SAB) carries a high mortality independent of scabies, with a 30-day mortality of 16·1% (95% CI 14·5-17·8) in Australia (2014).4 Between 2006 and mid-2016 at the Royal Darwin Hospital-a 360-bed hospital in the tropical north of Australia-237 patients were admitted with a microscopy-confirmed scabies diagnosis, reflecting severe or crusted scabies. In the context of SAB in other highly comorbid Australian populations, this mortality is higher than that reported for major limb amputation (22%) and elderly patients on haemodialysis (18-19%).5 Most patients with scabies at the Royal Darwin Hospital were Indigenous Australians from disadvantaged remote communities, where scabies is hyperendemic. 30-day mortality 2 (7%) 4 (2%) 0·08 22 (9%) 0·73 1-year mortality 7 (26%) 16 (8%) 0·002 43 (18%) 0·35 1 C Karimkhani, DV Colombara, AM Drucker, The global burden of scabies: a cross-sectional analysis from the Global Burden of Disease Study 2015, Lancet Infect Dis, 2017, published online Sep 20., (accessed Sept 23, 2017) 2 LJ Roberts, SE Huffam, SF Walton, BJ Currie, Crusted scabies: clinical and immunological findings in seventy-eight patients and a review of the literature, J Infect, Vol. 50, 2015, 375-381 3 PM Swe, SL Reynolds, K Fischer, Parasitic scabies mites and associated bacteria joining forces against host complement defence, Parasite Immunol, Vol. 36, 2014, 585-593 4 GW Coombs, DA Daley, Y Thin Lee, Staphylococcus aureus, Sepsis Outcome Programme annual report, 2014, Commun Dis Intell Q Rep, Vol. 40, 2016, E244-E254 5 C McKercher, H Chan, P Clayton, Dialysis outcomes of elderly Indigenous and non-Indigenous Australians, Nephrology, Vol. 19, 2014, 610-616