Head lice / louse
The head louse (Pediculus humanus capitis) is an obligate ectoparasite of humans that causes head lice infestation (pediculosis capitis).[1]
Head lice are wingless insects spending their entire lives on the human scalp and feeding exclusively on human blood.[1] Humans are the only known hosts of this specific parasite, while chimpanzees host a closely related species, Pediculus schaeffi. Other species of lice infest most orders of mammals and all orders of birds,[1] as well as other parts of the human body.
Lice differ from other hematophagic ectoparasites such as fleas in spending their entire lifecycle on a host.[2] Head lice cannot fly, and their short, stumpy legs render them incapable of jumping, or even walking efficiently on flat surfaces.[2]
The non-disease-carrying head louse differs from the related disease-carrying body louse (Pediculus humanus humanus) in preferring to attach eggs to scalp hair rather than to clothing. The two subspecies are morphologically almost identical, but do not normally interbreed, although they will do so in laboratory conditions. From genetic studies, they are thought to have diverged as subspecies about 30,000–110,000 years ago, when many humans began to wear a significant amount of clothing.[3][4] A much more distantly related species of hair-clinging louse, the pubic or crab louse (Pthirus pubis), also infests humans. It is visually different from the other two species and is much closer in appearance to the lice which infest other primates.[5] Lice infestation of any part of the body is known as pediculosis.[6]
Head lice (especially in children) have been, and still are, subject to various eradication campaigns. Unlike body lice, head lice are not the vectors of any known diseases. Except for rare secondary infections that result from scratching at bites, head lice are harmless, and they have been regarded by some as essentially a cosmetic rather than a medical problem. Head lice infestations might be beneficial in helping to foster a natural immune response against lice which helps humans in defense against the far more dangerous body louse, which is capable of transmission of dangerous diseases.[7]
Collierville
Collierville is a town in Shelby County, Tennessee, United States, and a suburb located in the Memphis metropolitan area. The town had a population of 43,965 at the 2010 census.[5]
Collierville is a town of large houses and considerable retail expansion. Smaller, older houses are still found in the heart of Collierville, mainly between Byhalia Road and Collierville-Arlington on the east and west and Shelton and Highway 72 on the north and south. Some industry, notably Pepsi and Carrier, still dots the areas located south of Poplar Avenue.
Collierville is home to the Avenue at Carriage Crossing, an 800,000+ sq ft shopping center which opened in October 2005. Baptist Hospital, Collierville, serves the medical needs of the town’s residents. Collierville will become part of the Interstate 69 highway plan integrating Bill Morris Parkway (SR 385) as Interstate 269, part of this USDOT project linking Canada and Mexico with the United States.
Collierville was chosen as one of Relocate-America’s Top 100 Places to Live in 2008.[6] In 2014, Collierville’s historic town square was ranked by Parade Magazine as the “Best Main Street” in America.[7]