Efficacy of mass drug administration with ivermectin for control of scabies and impetigo, with coadministration of azithromycin: a single-arm community intervention trial

Abstract

Summary Background In small community-based trials, mass drug administration of ivermectin has been shown to substantially decrease the prevalence of both scabies and secondary impetigo; however, their effect at large scale is untested. Additionally, combined mass administration of drugs for two or more neglected diseases has potential practical advantages, but efficacy of potential combinations should be confirmed. Methods The azithromycin ivermectin mass drug administration (AIM) trial was a prospective, single-arm, before-and-after, community intervention study to assess the efficacy of mass drug administration of ivermectin for scabies and impetigo, with coadministration of azithromycin for trachoma. Mass drug administration was offered to the entire population of Choiseul Province, Solomon Islands, and of this population we randomly selected two sets of ten sentinel villages for monitoring, one at baseline and the other at 12 months. Participants were offered a single dose of 20 mg/kg azithromycin, using weight-based bands. Children weighing less than 12·5 kg received azithromycin oral suspension (20 mg/kg), and infants younger than 6 months received topical 1% tetracycline ointment. For ivermectin, participants were offered two doses of oral ivermectin 200 μg/kg 7–14 days apart using weight-based bands, or 5% permethrin cream 7–14 days apart if ivermectin was contraindicated. Our study had the primary outcomes of safety and feasibility of large-scale mass coadministration of oral ivermectin and azithromycin, which have been previously reported. We report here the prevalence of scabies and impetigo in residents of the ten baseline villages compared with those in the ten 12-month villages, as measured by examination of the skin, which was a secondary outcome of the trial. Further outcomes were comparison of the number of all-cause outpatient attendances at government clinics in Choiseul Province at various timepoints before and after mass drug administration. The trial was registered with the Australian and New Zealand Trials Registry (ACTRN12615001199505). Findings During September, 2015, over 4 weeks, 26 188 people (99·3% of the estimated population of Choiseul [n=26 372] as determined at the 2009 census) were treated. At baseline, 1399 (84·2%) of 1662 people living in the first ten villages had their skin examined, of whom 261 (18·7%) had scabies and 347 (24·8%) had impetigo. At 12 months after mass drug administration, 1261 (77·6%) of 1625 people in the second set of ten villages had their skin examined, of whom 29 (2·3%) had scabies (relative reduction 88%, 95% CI 76·5–99·3) and 81 (6·4%) had impetigo (relative reduction 74%, 63·4–84·7). In the 3 months after mass drug administration, 10 614 attended outpatient clinics for any reason compared with 16 602 in the 3 months before administration (decrease of 36·1%, 95% CI 34·7–37·6), and during this period attendance for skin sores, boils, and abscesses decreased by 50·9%...

The public health control of scabies: priorities for research and action

“…Further work in the Solomon Islands using ivermectin-based MDA in a much larger population reported reductions in scabies prevalence of around 90%, and in impetigo prevalence of around 75%. 14,130 Conversely, ivermectin-based MDA for scabies in northern Australia was not associated with a sustained reduction in prevalence. 79 Implementation research of integration of scabies control with other NTDs, particularly those affecting the skin, has the potential to demonstrate cost-efficient delivery of multiple health interventions.…”

Control of scabies and secondary impetigo: optimising treatment effectiveness in endemic settings

“…And a comparison of outpatient attendance at government clinics across the province in the 3 months before and after mass drug administration showed that the number of people presenting with skin sores, boils, and abscesses decreased by 50·9% (95% CI 48·6-53·1). 9 Compared with interventions in individuals, a lot of data is now available in endemic or epidemic settings from mass drug administration for treatment of scabies, whether adults or children, or other diseaseseg, onchocerciasis. 11,12 Which drug should be used for scabies and whether it should be combined with antibiotics are important decisions.…”

An Antibody Persistent and Protective Two rSsCLP-Based Subunit Cocktail Vaccine against Sarcoptes scabiei in a Rabbit Model

“…Scabies is historically a challenging global infectious disease, for which acaricides are currently used as measures of controlling the scabies mite [12,13]; however, the unreasonable use of acaricides can lead to the development of drug resistance, toxicity, and associated side-effects [14,15]. Therefore, the development of a vaccine remains a high priority for global research.…”