Scabies and risk of skin sores in remote Australian Aboriginal communities: A self-controlled case series study

PLoS Negl Trop Dis. 2018 Jul 25;12(7):e0006668. doi: 10.1371/journal.pntd.0006668. eCollection 2018 Jul.

Abstract

Background: Skin sores caused by Group A streptococcus (GAS) infection are a major public health problem in remote Aboriginal communities. Skin sores are often associated with scabies, which is evident in scabies intervention programs where a significant reduction of skin sores is seen after focusing solely on scabies control. Our study quantifies the strength of association between skin sores and scabies among Aboriginal children from the East Arnhem region in the Northern Territory.

Methods and results: Pre-existing datasets from three published studies, which were conducted as part of the East Arnhem Healthy Skin Project (EAHSP), were analysed. Aboriginal children were followed from birth up to 4.5 years of age. Self-controlled case series design was used to determine the risks, within individuals, of developing skin sores when infected with scabies versus when there was no scabies infection. Participants were 11.9 times more likely to develop skin sores when infected with scabies compared with times when no scabies infection was evident (Incidence Rate Ratio (IRR) 11.9; 95% CI 10.3-13.7; p<0.001), and this was similar across the five Aboriginal communities. Children had lower risk of developing skin sores at age ≤1 year compared to at age >1 year (IRR 0.8; 95% CI 0.7-0.9).

Conclusion: The association between scabies and skin sores is highly significant and indicates a causal relationship. The public health importance of scabies in northern Australia is underappreciated and a concerted approach is required to recognise and eliminate scabies as an important precursor of skin sores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Case-Control Studies
  • Child, Preschool
  • Cohort Studies
  • Female
  • Humans
  • Impetigo / epidemiology*
  • Impetigo / etiology
  • Impetigo / microbiology
  • Infant
  • Male
  • Northern Territory / epidemiology
  • Sarcoptes scabiei / physiology*
  • Scabies / complications*
  • Scabies / epidemiology
  • Scabies / pathology
  • Skin / microbiology
  • Skin / pathology
  • Streptococcal Infections / epidemiology*
  • Streptococcal Infections / etiology
  • Streptococcal Infections / microbiology
  • Streptococcus / physiology

Grants and funding

The project is partly supported by the National Health and Medical Research Council (NHMRC) grant #1098319. JMV is supported by an NHMRC Principal Research Fellowship (#1117140); ST is supported by a NHMRC Career Development Fellowship (#1145033); and JAS is supported by a NHMRC Senior Research Fellowship (#1104975). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.