The infection of human skin by schistosome cercariae: studies using Franz cells.

Franz cells (2-chambered, air/fluid phase static diffusion devices, previously used for the study of drugs across viable human skin) are utilized for the first time to investigate the process of infection of human skin by Schistosoma mansoni cercariae. Skin obtained from cosmetic surgery sources was used in the Franz cells to describe the temporal dynamics of the early interaction of cercariae with skin. At 38 degrees C, about 50% of cercariae applied in water to the epidermal surface of the skin were irreversibly attached within 1 min and after 5 min about 85%, were similarly irrecoverable. The technique also provides the means of following the early penetration path of cercariae by histological methods. Franz cell results on the dynamics of attachment/early penetration have been compared with those obtained using artificial skin equivalents and non-human mammalian skin models in the context of the physical and chemical differences between these systems and viable human skin. It is concluded that Franz cells provide a convenient system for directly investigating the early phases of S. mansoni cercariae interaction with human skin.