Fleas and smaller fleas: virotherapy for parasite infections.

Bacteriophages are viruses of bacteria that are used for controlling bacterial food-borne pathogens and have been proposed for more extensive usage in infection control. Protists are now recognised to harbour viruses and virus-like particles. We propose that investigation of their prevalence in parasites be intensified. We also propose that such viruses might be considered for virotherapy to control certain parasite infections of man and animals.

Phage choice, isolation, and preparation for phage therapy.

Phage therapy is the use of bacteriophages--viruses that use bacteria as their host cells--as biocontrol agents of bacteria. Currently, phage therapy is garnering renewed interest as bacterial resistance to antibiotics becomes widespread. Historically, phage therapy was largely abandoned in the West in the 1940s due to the advent of chemical antibiotics, and the unreliability of phage-based treatments when compared to antibiotics. The choice of phage strain and the methods of phage preparation are now thought to have been critical to the success or failure of phage therapy trials. Insufficiently virulent phages, especially against actual target bacteria, allow bacteria to survive treatment while poorly prepared phage stocks, even if of sufficiently virulent phages, lack the numbers of viable phages required for adequate treatment. In this review we discuss the factors that determine the methods of isolation, analysis, and identification of phage species for phage therapy. We go on to discuss the various methods available for purifying phages as well as considerations of the degree of purification which is sufficient for various applications. Lastly, we review the current practices used to prepare commercial phage therapy products.

Drugs and other product choices.

Dermatologists have at their disposal a wide range of products to recommend or prescribe to their patients, all of which are regulated in some way by the Food and Drug Administration (FDA). However, the degree to which FDA has confirmed the safety and efficacy of a dermatological product can vary widely. Most prescription and some over-the-counter drugs and medical devices are approved by the FDA based on scientific data. Most over-the-counter drugs are marketed in compliance with FDA regulations based on expert medical review. The FDA clears most medical devices based on their substantial equivalence to other legally marketed devices. Cosmetics, medical foods, and dietary supplements are subject only to general postmarket prohibitions against adulterated and misbranded products, although the FDA may review ingredient safety and specific claims for dietary supplements. Some product information is available on FDA's Web site, but the prudent physician should supplement that information by reviewing available scientific literature.