Infestation of the human body by lice is an increasingly prevalent social and health problem in many countries in the world. Lice infest hundreds of millions of people each year. Lice are very small insects, about 2-3 mm in length. They deposit eggs either on a hair or fabric fiber and attach them firmly with a cement-like excretion.
The life cycle of lice comprises an egg stage, three nymphal stages, and an adult stage, and takes about one month. A female louse lays approximately 100 eggs, which are glued to hairs of the host. The eggs generally hatch in about six to ten days, depending on temperature. The nymphs, (the larval stage in insect development), and adults suck blood, causing disturbance (itching, also known as pruritus) and secondary infection. The empty shells remaining after the nymphs emerge from the eggs look like white grains of sand.
Lice, being insects, use tracheae for respiration. Tracheae are a system of internal tubes (invaginations of the cuticle) penetrating the insect's body, through which air diffuses or is being pumped directly to the body tissues. Within body cells, chemical respiration takes place in the mitochondria, where ATP is produced under oxygen consumption.
The common treatment methods against lice involve liquids or lotions.
An apparatus and process for killing human and animal vermin, which discloses treatment of lice within a gas-tight garment by using a volatile liquid, specifically methyl-formate, that is spread on a pad inside the garment and evaporates inside the garment, is described in U.S. Pat. No. 2,033,357 of Riker et al. patented 1936.
A method and device for eradicating lice and nits form an infested area, particularly the scalp of a human being, comprises a plastic or rubber cap for covering the head of a human being, and means for filling the cap with an inner gas, such as carbon dioxide from a pressurized-gas cartridge, in order to suffocate the lice and the nits enclosed by the cap, is described in European Patent Application No. 86630160.9, publication No. EP0221004, of Scolnik et al. filed Oct. 30, 1986.
A formulation for controlling human lice, which discloses pediculicidal formulations comprising a spinosyn, or a physiologically acceptable derivative or salt thereof, and a physiologically acceptable carrier, and methods of controlling lice infestations in a human with these formulations are provided in International Patent Application No. PCT/US1999/013925, publication No. WO/2000/001347, of Snyder, filed Jun. 21, 1999.
A pediculicide composition, in particular, a composition comprising a sesquiterpene alcohol and a suitable carrier, is described in International Patent Application No. PCT/AU2006/001720, publication No. WO/2007/056813, of Found, filed Nov. 17, 2006.
A method and composition for controlling lice on an organism is described in International Patent Application No. PCT/NL2000/000196, publication No. WO/2000/057704, of Kussendrager et al. filed Mar. 23, 2000.
All of these applications are incorporated by reference for all purposes as if fully set forth herein.
Although the various breeds of human lice are related, each of them has specific characteristics with regard to habitat and feeding. For example, head lice are small hard-shelled ectoparasites which cling to hair shafts while feeding, mating and laying eggs. The louse must remain on the head or it will die within a short period of time. Head lice proliferate at an incredible rate. A louse is ready to mate and reproduce within 10 hours after hatching. Under ideal conditions, a female louse may produce up to 300 eggs in its lifetime. Ideal conditions include an adequate food supply, environmental temperatures from about 28° C. to about 32° C., and relative humidity of about 70% to about 90%.
The louse's hard chitinous exoskeleton serves as protection from external elements. Lice eggs (or ova) are similarly protected by a chitinous sheath surrounding the eggs and attached to the hair shaft. Although lice may be affected by the use of an insecticide, the eggs often remain resistant to attack. Thus, present art optimum treatment of a lice infestation includes both a pediculicide, which kills the adult lice, and an ovicide, which interrupts the development of the eggs.
Treatment for eliminating head lice traditionally included home remedies such as smearing mayonnaise, olive oil, hair pomade, or some other heavily viscous material about an infested scalp coupled with rigorous combing of the hair and meticulous removal of adult lice, nymphs, and nits. Though these home remedies do not kill head lice, the prevailing thought is that the viscosity of the material makes it hard for head lice to roam about the scalp, making for easy removal. Such home remedies are usually ineffective at controlling head lice due to the ability of the lice to revive rapidly once these materials are removed.
More effective treatments for eliminating head lice involve massaging the infested scalp with over-the-counter (OTC) topical creams containing active insecticides. Because of their potential toxicity to the human host, the use of these topical formulas is regulated by the FDA. Over-the-counter insecticides typically have pyrethrins or permethrin as active ingredients
Biologically active agents have been used for some time in attempts to control lice. For example, lindane (gammabenzene hexachloride), organophosphates (malathion), natural pyrethrins, and synthetic compounds known as pyrethroids (such as permethrin) have been used as pediculicides in lice treatment formulations. These agents however, have drawbacks. Lindane has a poor safety profile, and lice have developed resistance to it. Natural pyrethrin requires frequent follow-up treatments because it provides only short term residual action. Synthetic pyrethroids, although more effective against lice than natural pediculicides, are often more toxic to the subject being treated.
Strains of head lice have been identified worldwide which are resistant to all currently available topical treatments. Possible neural damage to the human host prevents raising the insecticide levels above the current threshold in an attempt to combat these newer treatment resistant head lice.
A system for treating lice with gaseous compounds in an airtight space is described in European Patent Application No. 09163262.0 publication No. EP2255778, of Ritterband, Menachem and Shlomi, Yinon, which is incorporated by reference for all purposes as if fully set forth herein.
FIG. 1a of the prior art illustrates a system for treating lice and nits 1, on a head 10 of a patient, according to European Patent Application No. 09163262.0.
A container 14 is connected on both ends to connecting tubes 13. In this configuration, the container 14 contains active agent 15 in a gas state. The flow of the active agent 15 is achieved by releasing vaporizing and circulating gas 12 from within a vaporizing and circulating gas source 11. The releasing is enabled by opening a valve, for example by a gas source handle 11a. 
FIG. 1b of the prior art shows a container 14, according to the European Patent Application No. 09163262.0.
The container 14 contains an immersed material 16, which is a sponge, immersed with active agent 15. In this configuration, an active agent 15, of acetic acid type is inserted into the container 14 and then evaporates.
This method of storage of the active agent 15 is insufficiently effective.
FIG. 2 of the prior art is a schematic block diagram of a system for treating lice and nits 1, according to the European Patent Application No. 09163262.0.
A vaporizing and circulating gas source 11 contains a vaporizing and circulating gas 12, which during activation flows through a connecting tube 13 to a container 14. Container 14 contains active agent 15 and immersed material 16, such as a sponge.
The vaporizing and circulating gas 12 vaporizes the active agent 15 and causes it to flow through a connecting tube 13 to a cap 17 for the purpose of performing the treatment of lice and nits.
None of the prior art provides a sufficiently effective solution, and there is therefore a need for a system and a method for treating an infestation of head lice.