Calculation of the age of the first infection for skin sores and scabies in five remote communities in northern Australia

Epidemiol Infect. 2018 Jul;146(9):1194-1201. doi: 10.1017/S0950268818001061. Epub 2018 May 8.


Prevalence of skin sores and scabies in remote Australian Aboriginal communities remains unacceptably high, with Group A Streptococcus (GAS) the dominant pathogen. We aim to better understand the drivers of GAS transmission using mathematical models. To estimate the force of infection, we quantified the age of first skin sores and scabies infection by pooling historical data from three studies conducted across five remote Aboriginal communities for children born between 2001 and 2005. We estimated the age of the first infection using the Kaplan-Meier estimator; parametric exponential mixture model; and Cox proportional hazards. For skin sores, the mean age of the first infection was approximately 10 months and the median was 7 months, with some heterogeneity in median observed by the community. For scabies, the mean age of the first infection was approximately 9 months and the median was 8 months, with significant heterogeneity by the community and an enhanced risk for children born between October and December. The young age of the first infection with skin sores and scabies reflects the high disease burden in these communities.

Keywords: Skin Sores; aboriginal health; age of first infection; northern territory; scabies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Child, Preschool
  • Cost of Illness
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Kaplan-Meier Estimate
  • Male
  • Models, Biological
  • Native Hawaiian or Other Pacific Islander*
  • Northern Territory / epidemiology
  • Prevalence
  • Proportional Hazards Models
  • Retrospective Studies
  • Rural Health*
  • Scabies / ethnology
  • Scabies / transmission*
  • Skin Ulcer / ethnology
  • Skin Ulcer / microbiology*
  • Streptococcal Infections / ethnology
  • Streptococcal Infections / transmission*
  • Streptococcus pyogenes*