Scabicide sales before and during the COVID-19 epidemic in Israel

Dear Editor

The human scabies mite, Sarcoptes scabiei var hominis (Acari: Sarcoptidae), is the causative agent of human scabiosis, an intensive pruritic skin condition induced by a delayed-type hypersensitivity response. Prolonged skin-to-skin contact among sexual partners and between family members and contact with infested bedding and clothing can lead to infestation with scabies. The distribution of scabies is global and affects all socio-economic classes. However, young children, elderly and immune-compromised people, and resource-poor and overcrowded populations are especially vulnerable. The Global Burden of Disease Study estimated in 2010 that the worldwide prevalence of scabies was around 100 million. In 2017, scabies was added to the WHO list of Neglected Tropical Diseases.

In March 2020, the WHO declared the Covid-19 outbreak a pandemic. Starting in March 2020, the Israeli government established mandatory lockdowns, including school closures, for extensive periods. The resulting social distancing naturally reduced direct contact between people, thus potentially affecting the transmission of scabies. This study aimed to compare the scabicide sale numbers between 2010 and 2019 and during the Covid-19 pandemic in 2020 and the year after as a surrogate marker for scabies incidence.

Data regarding the sales of scabicide units during 2010–2021 were obtained from the largest pharmacy chain in Israel (Super-Pharm Ltd., Israel), which sells approximately half of the drugs retailed in pharmacies throughout the country. Data regarding the total population of Israel during 2010-2021 were retrieved from the database of the Central Bureau of Statistics (Israel). Tukey's method was used to identify outliers in the data for annual scabicide sales per 1000 people. The linearity of the annual change in scabicide sales per 1000 people was confirmed using scatterplots. A linear regression analysis estimated the yearly change in scabicide sales per 1000 people. All data were analyzed using IBM SPSS Statistics for Mac, Version 28.0 (IBM Corp. Released 2020. Armonk, NY).

Data regarding the annual change in scabicide sales and the total population from 2010 to 2021 are presented in Fig. 1 and Supplementary Table 1. During 2010- 2021, there was a constant and significant increasing trend in annual scabicide sales from 7767 units in 2010 to 21,640 in 2021, averaging 1261 units per year. A ratio of annual scabicide units sold per 1000 people was examined after adjusting the annual scabicide sales rate to the annual population growth. The average annual increase was 0.12 units per 1000 people, increasing from 1.01 units/1000 people in 2010 to 2.29 units/1000 people in 2021. A drop in the ratio of scabicide units sold per 1000 people, seen in 2017 and 2020, was insignificant using Tukey's method. A linear regression model found a significantly increasing linear trend in the annual scabicide sales per 1000 people (R2 = 0.9161, p < 0.001).

Fig. 1.

Annual scabicide sales in Israel, population size and sales per 1000 population.

In the present study, it was shown that scabicide sales significantly increased between 2010-2021. Although there was a slight decrease during the isolation time in 2020, the difference was not significant. Our findings before and during confinement time agree with those from a study in France which reported that the weekly sales of topical pediculicides decreased by 44%, while scabicide sales decreased by only 14% [1]. Other studies that reported diagnosis of scabies over the years, including the Covid-19 period, have shown even a slighter increase in scabies during Covid-19 in Spain [2], Italy [3], and Turkey [4].

Throughout 2010-2021 there were four main scabicidal agents sold in Israel: Eurax cream (Crotamiton 10%), Lyclear cream (Permethrin 5%), Duo-scabil cream (Crotamiton 10%, Sulphur precipitated 8%), and Scabicin lotion (Gamma benzene hexachloride), the marketing of which was discontinued in 2013. Generally, the sales of specific scabicides followed similar trends throughout the study period (Supplementary Table 2).

There is an ever-growing number of scabies infestations worldwide. Accordingly, the increase during the beginning of Covid-19 was only the continuation of the infestation rate observed in developed countries such as in Germany, Norway, and Turkey.

Many studies show that scabies epidemics occur every 15–30 years. Though two of the studies coincided with WW I and II, epidemics were also reported in the 1960s in many parts of the world, including Switzerland and Germany. In the Israeli army, there was a low incidence of scabies in 1968-1981 and a significant increase between 1981-1986. The observed rise in scabies infestations in the 1980s and 1990s could be a result of the re-occurring epidemic of scabies after the 1960s; the increase of scabies in recent years could be a new epidemic after 30-40 years. The proposed theory to explain this phenomenon is herd immunity. Accordingly, a large part of the population at risk will develop immunity to the disease, thus decreasing the infestation rate [5].

Since the company that provides all the data regarding scabicide sales in Israel sells approximately 50% of the pharmaceuticals in the country, we assume that 15,000–43,000 scabicides have been sold yearly in the last 11 years.

Limitations of this study: our results are based on the sales of one pharmacy chain, although the largest, in Israel. However, we do not know whether the ever-growing number of scabicide sales results from the company's more successful/aggressive sale strategy. The strength of our study is that it reflects the overall situation in Israel.

In conclusion, Scabies infestations are increasing in many developed countries, including Israel. The increase in scabicide sales in the last 12 years is a continuation of this trend and was not affected by the isolation period during the Covid-19 pandemic.

Conflicts of interest

Non to declare.

Appendix A. Supplementary data

The following are the Supplementary data to this article.