An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infestation in pigs

Abstract

BackgroundThe most common treatments for scabies in human and veterinary settings are topical 5% permethrin or systemic treatment with ivermectin. However, these treatments have very little activity against arthropod eggs, and therefore repeated treatment is frequently required. In-vitro, biochemical and molecular studies have demonstrated that human mites are becoming increasingly resistant to both acaricides. To identify alternate acaricides, we undertook a pilot study of the in vivo activity of the benzoylphenyl urea inhibitor of chitin synthesis, fluazuron, in pigs with sarcoptic mange.FindingsPigs (n = 5) were infested with S. scabei var suis, and randomised to treatment at the start of peak infestation with fluazuron at a dose of 10 mg/kg/day per os for 7 days (n = 3) or no treatment (n = 2). Clinical scores, skin scrapings for mite counts and blood sampling for pharmacokinetic analysis were undertaken. Fluazuron was well absorbed in treated pigs with measureable blood levels up to 4 weeks post treatment. No adverse effects were observed. Modest acaricidal activity of the compound was observed, with a reduction in severity of skin lesions in treated pigs, as well as a reduction in number of scabies mite's early life stages.ConclusionsThe moderate efficacy of fluazuron against scabies mites indicates a lead to the development of alternate treatments for scabies, such as combination therapies that maybe applicable for human use in the future.

Tackling scabies: novel agents for a neglected disease

“…It has reduced the severity of skin lesions and reduced the early mite forms in sarcoptic mange of pigs. It may have potential as an adjunct to traditional acaricides …”

Scabies in the age of increasing drug resistance

“…It resulted in a decrease in the number of juvenile stages and in the arrest of clinical progression of lesions for up to 5 weeks. Therefore, if combined with the traditional scabicides, this drug could potentially eliminate the need for a second dose [ 26 ].…”

A Review of Scabies: An Infestation More than Skin Deep

“…The use of fluazuron in pigs with S. scabiei var. suis infestation resulted in a reduced number of early stage mites, and clinical improvement [82]. Using this in combination with traditional acaricides could offer improved efficacy and might for example eliminate the need for a second dose of ivermectin.…”