Impact of an Ivermectin Mass Drug Administration on Scabies Prevalence in a Remote Australian Aboriginal Community

Abstract

BackgroundScabies 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.MethodsUtilizing 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 FindingsWe 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.ConclusionScabies 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 RegistrationAustralian New Zealand Clinical Trial Register (ACTRN—12609000654257).

The inequitable burden of group A streptococcal diseases in Indigenous Australians

“…Community and primary health programs For decades, the focus in the Northern Territory has been on control of skin disease, 10,11,19 although treatment for sore throat is also promoted. 20 Community skin days and mass drug administration with permethrin 11 have been successful, but their impact is not sustained.…”

“…More recently, a better tolerated treatment regimen for impetigo was reported, with oral co-trimoxazole proven to be non-inferior to intramuscular penicillin; 10 and mass drug administration with oral ivermectin shown to be an effective population approach to reducing scabies and impetigo. 19 However, to date, no approach in Australia has achieved a sustained reduction in GAS impetigo. Overcrowding and population mobility are among the contributing factors and, more recently, the contribution of community members with crusted scabies as core transmitters of the scabies mite has been recognised.…”

“…Overcrowding and population mobility are among the contributing factors and, more recently, the contribution of community members with crusted scabies as core transmitters of the scabies mite has been recognised. 19 New approaches to management of crusted scabies in the NT include surveillance under public health legislation 21 and coordinated case management. 22 However, there remains a need to target the other contributing factors, particularly overcrowding, before sustained reductions can be achieved.…”

In Vitro Efficacy of Moxidectin versus Ivermectin against Sarcoptes scabiei

“…Suboptimal responses to ivermectin in some groups (9)(10)(11) indicate that a more detailed investigation of optimal therapeutic doses in scabies is warranted. This is particularly relevant with the utilization of ivermectin for scabies mass treatment, where a single-dose regimen is desirable (12,13). Moxidectin has demonstrated activity against sarcoptic mange, although several studies suggest that a single 200-g/kg dose is still insufficient to achieve cure (14,15), with long-acting formulations or higher doses required (16).…”

Anaemia Health Literacy of Community Members and Health Practitioners Knowledge of Best Practice Guidelines in a Remote Australian Aboriginal Community

“…The team had extensive experience in conducting research in Aboriginal communities and their employer, Menzies School of Health Research, has over 30 years' experience working with Aboriginal people to improve health outcomes and a long standing track record in working with and building the capacity of community based researchers. [18][19][20] …”