Management and Prevention

Epidemiology:
Lice are endemic in the United States and are present across most of the continents of the world. Lice are present in Africa, in Ethiopia, Egypt, Rwanda, Burundi and Zaire in particular, in the Mediterranean, in Libya, Morocco, Tunisia, Algeria, and Jordan, in South America, in Bolivia, Peru and Ecuador, as well as in the Western World of Europe and the United States, especially within poorer Eastern European countries.
Lice outbreaks are common in places where there is more poverty and poor personal hygiene, as well as more overcrowding. They are also common in places where heavy clothing is worn (at night for example). In these areas lice infestations and the incidence of louse-borne typhus are greater. Lice infestations are a very common problem everywhere: in the US there are 6-12 million cases of all three types of lice annually. Outbreaks of head lice are frequent in schools: in the US in the 1996-1997 school year 80 percent of school districts reported at least one outbreak of head lice. Head lice are probably the most common form of lice across the world, but numbers of cases are unreliable because most cases go unreported.
However, despite this underreporting,recent trends seem to indicate an increase in prevalence of head lice and pubic lice worldwide.

Management and Therapy:
To eliminate pediculosis, both motile adult lice and all of the eggs must be killed through physical removal using a nit comb and chemical treatment. The exact contents of chemical treatment depends on the louse, but the chemicals are topical treatments that are applied either in once dose or in regular doses until the lice and nits are dead. To kill P. pubis, .5% malathion lotion or 1% lindane is recommended, while permethrin and pyrethrin with butoxide are recommended as supplements to the latter when treating P. humanus capitus (head lice). Commercial chemical products are available over-the-counter at drug and grocery stores. These include Rid, Nix, Clear and AcuMed Comb brands, which combine combing with one or more topical chemical treatments. However, these products are not always 100 percent effective in killing the nits. Home treatments, along with combing, such as the use of mayonnaise to smother the lice or rinsing the hair with a 1:1 diluted vinegar solution, have also been found effective. Furthermore, body lice are most effectively eliminated by regular bathing and decontamination of clothing and personal articles by dry cleaning them or washing them at hot temperatures (greater than 50 degrees Celsius. In terms of developing new, faster, more effective chemical treatments, one study has been conducted in Egypt in the use of Ivermectin in killing lice, in which one liquid application killed the lice within 28 hours. However, more testing is needed to affirm the safety and effectiveness of this treatment for the host.

Public Health and Prevention Strategies:
Because lice are so easily spread through human contact, both treatment of individuals and mass control of populations are necessary. Controlling the spread of lice in overcrowded environments such as jails, refugee camps, army barracks and schools is particularly difficult because of this host to host transmission, so one effective way of reducing outbreaks is by reducing overcrowding. Furthermore, personal hygiene and bathing are essential to eliminating lice. Other mass contol methods of eliminating lice include spraying insecticides such as DDT over large areas, which kills the lice but has severe environmental and health effects and mass delousing programs with chemical treatment in endemic areas in isolated poor communities. Another important step in preventing lice outbreaks is education increased information about how lice are spread. School policies that send home newsletters to parents about head lice outbreaks are an example of an effective information policy that helps reduce the public health problem. By improving general public health measures and sanitation, as well as education, we can counter and eliminate the resurging public health problem of pediculosis.

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