A composition for topical administration containing particles and a pharmaceutically acceptable carrier. The particles may be composed of a metal oxide such as titanium oxide or zinc oxide, and may be coated with an external coating. The composition may also contain one or more organic components that are either bound or unbound to the particles. The composition may be used to prevent mosquitoes from extracting blood from a host and/or from infecting a host with a mosquito-borne disease or infection, or to protect a host from blood extraction and/or infection by a mosquito.