Impact of an Ivermectin Mass Drug Administration on Scabies Prevalence in a Remote Australian Aboriginal Community
journal contributionposted on 23.07.2021, 02:47 by TM Kearns, R Speare, AC Cheng, J McCarthy, JR Carapetis, DC Holt, BJ Currie, W Page, Jennifer ShieldJennifer Shield, R Gundjirryirr, L Bundhala, E Mulholland, M Chatfield, RM Andrews
Background: 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. Clinical Trial Registration: Australian New Zealand Clinical Trial Register (ACTRN—12609000654257).
This work was supported by National Health and Medical Research Council (GTN0605804 - TMK RS ACC JM JRC DCH BJC WP EM RMA & GNT0545239 - TMK) https://www.nhmrc.gov.au/; Cooperative Research Centre for Aboriginal Health (HS331 - RMA) http://www.lowitja.org.au/; and Northern Territory Research Innovation Board and Fund (Grant round 6-2008 - TMK) http://www.bulletpoint.com.au/northern-territory-research-and-innovation-fund/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
JournalPLoS Neglected Tropical Diseases
Article NumberARTN e0004151
PublisherPublic Library of Science
Rights StatementThe Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.
Science & TechnologyLife Sciences & BiomedicineInfectious DiseasesParasitologyTropical MedicineNORTHERN-TERRITORYCRUSTED SCABIESDISEASEPERMETHRINMANAGEMENTHumansScabiesIvermectinInsecticidesTreatment OutcomeDrug TherapyAdministration, OralPrevalencePregnancyAdolescentAdultChildOceanic Ancestry GroupAustraliaFemaleMaleYoung AdultControlled Before-After Studies