Authors:
Kearns TM, Speare R, Cheng AC, McCarthy J, Carapetis J, Holt DC, et al.
Authors notes:
PLoS neglected tropical diseases. 2015;9(10):1-13.
Keywords:
Ivermectin, Mass Drug Administration, Scabies, Scabies Prevalence, Australian, Aboriginal Community
Abstract:
Scabies is endemic in many Aboriginal and Torres Strait Islander communities, with 69% of infants infected in the first year of life.
We report the outcomes against scabies of two oral ivermectin mass drug administrations (MDAs) delivered 12 months apart in a remote Australian Aboriginal community.
Methods: Utilizing a before and after study design, we measured scabies prevalence through population census with sequential MDAs at baseline and month 12.
Surveys at months 6 and 18 determined disease acquisition and treatment failures.
Scabies infestations were diagnosed clinically with additional laboratory investigations for crusted scabies.
Non-pregnant participants weighing ≥15 kg were administered a single 200 μg/kg ivermectin dose, repeated after 2-3 weeks if scabies was diagnosed, others followed a standard alternative algorithm.
Principal Findings: We saw >1000 participants at each population census.
Scabies prevalence fell from 4% at baseline to 1% at month 6.
Prevalence rose to 9% at month 12 amongst the baseline cohort in association with an identified exposure to a presumptive crusted scabies case with a higher prevalence of 14% amongst new entries to the cohort.
At month 18, scabies prevalence fell to 2%.
Scabies acquisitions six months after each MDA were 1% and 2% whilst treatment failures were 6% and 5% respectively.
Conclusion: Scabies prevalence reduced in the six months after each MDA with a low risk of acquisition (1-2%).
However, in a setting where living conditions are conducive to high scabies transmissibility, exposure to presumptive crusted scabies and population mobility, a sustained reduction in prevalence was not achieved.