One versus two doses of ivermectin-based mass drug administration for the control of scabies: A cluster randomised non-inferiority trial.

BACKGROUND: Mass drug administration (MDA) based on two doses of ivermectin, one week apart, substantially reduces prevalence of both scabies and impetigo. The Regimens of Ivermectin for Scabies Elimination (RISE) trial assessed whether one-dose ivermectin-based MDA would be as effective. METHODS: RISE was a cluster-randomised trial in Solomon Islands. We assigned 20 villages in a 1:1 ratio to one- or two-dose ivermectin-based MDA. We planned to test whether the impact of one dose on scabies prevalence at 12 and 24 months was non-inferior to two, at a 5% non-inferiority margin. RESULTS: We deferred endpoint assessment to 21 months due to COVID-19. We enrolled 5239 participants in 20 villages at baseline and 3369 at 21 months from an estimated population of 5500. At baseline scabies prevalence was similar in the two arms (one-dose 17·2%; two-dose 13·2%). At 21 months, there was no reduction in scabies prevalence (one-dose 18·7%; two-dose 13·4%), and the confidence interval around the difference included values substantially greater than 5%. There was however a reduction in prevalence among those who had been present at the baseline assessment (one-dose 15·9%; two-dose 10·8%). Additionally, we found a reduction in both scabies severity and impetigo prevalence in both arms, to a similar degree. CONCLUSIONS: There was no indication of an overall decline in scabies prevalence in either arm. The reduction in scabies prevalence in those present at baseline suggests that the unexpectedly high influx of people into the trial villages, likely related to the COVID-19 pandemic, may have compromised the effectiveness of the MDA. Despite the lack of effect there are important lessons to be learnt from this trial about conducting MDA for scabies in high prevalence settings. TRIAL REGISTRATION: Registered with Australian New Zealand Clinical Trials Registry ACTRN12618001086257.

Scabies increase during the COVID-19 pandemic: should we change our treatment strategy during the pandemic?

Scabies is a highly contagious, parasitic infestation caused by Sarcoptes scabiei var. hominis. There are some reports which claim the incidence of scabies has increased during COVID-19 lockdown. In this study, we aimed to compare the prevalence of scabies between March to September 2020 - the first six months of the COVID-19 outbreak in Turkey - and March to September 2019 - the same period in the previous year. Case number percentages were compared month-over-month and by total numbers for each specified period. Pearson's chi-squared test was the comparison tool used. We checked the records of 36,469 patients who were admitted to Bezmialem Vakif University, Faculty of Medicine, Dermatology Department, a tertiary healthcare center, between March and September 2019, and out of this number, 258 patients had been diagnosed with scabies. The overall scabies case percentage was 0.71% and the range of monthly prevalence was 0.57%-0.83%. During the corresponding period in 2020, 26,219 dermatology patients were admitted, and 465 of those patients were diagnosed with scabies. The overall scabies case percentage was 1.77% and the range of monthly prevalence was 1.37%-3.46%. Scabies prevalence percentages were statistically significantly higher in all months and in the overall total in 2020 (P<0.001). Our nine patients, who admitted in 2020, did not respond to permethrin treatment but responded well to an ivermectin and permethrin combination. Scabies incidence has increased during the COVID-19 pandemic according to our study. We believe there may be an underreported resistance to permethrin and that starting treatment with oral ivermectin in combination with topical permethrin in extraordinary times, such as a pandemic, may help to control outbreaks.

Effects of the COVID-19 pandemic on head lice and scabies infestation dynamics: a population-based study in France.

BACKGROUND: Lockdowns and physical distancing have dramatically limited the circulation of SARS-CoV-2 and other common communicable infections. However, little is known about their impact on head lice and scabies. AIM: To assess the impact of the 2020 French National lockdowns (17 March-11 May 2020, and 30 October-15 December 2020) and physical distancing recommendations (from February 2020) on the dynamics of head lice and scabies infestations. METHODS: The weekly sales of topical head lice treatments, topical scabies treatments and oral ivermectin were extracted from the database of the healthcare science company IQVIA (60% of all French retail pharmacies) and analysed over a 5-year period (March 2016-December 2020). A periodic regression model was fitted to drug sales before the COVID-19 period (2016-2019) and extrapolated to compare the observed sales in 2020 to the expected sales. RESULTS: A decrease of the sales of tracer topical treatments for head lice and scabies was observed from March 2020, synchronously with the first French national lockdown. For the period March-December 2020, the mean reduction in observed vs. expected sales for head lice and scabies topical treatments was 44% and 14%, respectively. By contrast, although there was an observed decrease in oral ivermectin sales after March 2020, it was much lower (4%), probably because of studies reporting the potential positive effects of this drug on COVID-19 infection. CONCLUSION: COVID-19 lockdown and physical distancing reduce circulation of head lice and scabies in France. Further studies are needed to assess the long-term impact of these social behaviour changes.