is pubic lice bacterial or viral ?
Question
Anna M. Burns
Leave an answer
Sorry, you do not have a permission to answer to this question. Only Registered Members can answer the questions. Registration is Free
Answer ( 1 )
Pediculosis is caused by two species of lice: Pediculus humanus and Phthirus pubis. P. humanus has two subspecies: Pediculus humanus capitus (head louse) which primarily affects the scalp, and Pediculus humanus corporis (body louse), which primarily affects the trunk.
Phthirus pubis (pubic louse) primarily affects the genital area, but the axilla and eyebrows can be involved as well.
The body louse is the vector for several human pathogens, notably Rickettsia prowazekii, the cause of epidemic typhus, whereas the head louse and the pubic louse are not vectors of human disease.
Important Properties
Lice are easily visible, being roughly 2 to 4 mm long. They Have six legs armed with claws by which they attach to the Hair and skin. Pediculus has an elongated Body, whereas Phthirus has a short body and resembles a Crab, and hence its nickname, the crab louse. People infected with Phthirus are said to have “crabs”. Nits are the eggs of the louse and are typically found Attached to the hair shaft. They are white and can be seen with the naked eye. Nits of the body louse are often attached to the fibers of clothing.
Transmission
Head lice are transmitted primarily by fomites such as hats, combs, and towels. These are especially common in school children. Body lice live primarily on clothing and are transmitted either by clothing or by personal contact. Body lice leave the clothing when they require a blood meal.
Public lice are transmitted primarily by sexual contact. Widespread infestations of body lice occur when personal hygiene is poor (e.g., during wartime or in crowded refugee camps).
Pathogenesis
Adult lice feed on blood and, in the process, inject saliva into the skin, which induces a hypersensitivity reaction and, as a consequence, pruritus.
Clinical Findings
Pruritus is the main symptom. Excoriations may result from scratching, and secondary bacterial infections may occur. In pediculosis capitis, the adult lice are often difficult to see, but the nits are easily visualized. In pediculosis corporis, the adult lice are primarily in the clothing rather than on the body. In pediculosis pubis, the adult lice and nits can be seen attached to the pubic hair.
Laboratory Diagnosis
The laboratory is not involved in diagnosis. Nits fluoresce under ultraviolet light of a Wood’s lamp, which can be used to screen the hair of large numbers of people.
Treatment
Permethrin (Nix, RID) is the treatment of choice, as it is both pediculicidal and ovicidal. However, resistance to permethrin is increasing. Ivermectin (Sklice) is also effective, and resistance has not been reported. Nits are removed using a fine-toothed (nit) comb. Patients with body lice often do not need to be treated, but the clothing should be either discarded or treated.
Prevention
Children should not share articles of clothing. Many schools have a policy that children cannot attend school until they are nit-free, but the need for this exclusionary approach is under review. The personal items of affected individuals, such as towels, combs, hair brushes, clothing, and bedding, should be treated. Sexual partners of those infested with pubic lice should be treated and tested for other sexually transmitted diseases.