Body louse
A blood-feeding louse that spreads typhus and other diseases.
The body louse (Pediculus humanus humanus, also known as Pediculus humanus corporis) or clothing louse, informally called the cootie, is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse and the crab louse or pubic louse. Body lice are disease vectors and can transmit pathogens that cause human diseases such as epidemic typhus, trench fever, and relapsing fever.
- Scientific name
- Pediculus humanus humanus
- Also known as
- Clothing louse, cootie
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Psocodea
- Family
- Pediculidae
- Adult lifespan
- About 30 days
Lore & Background
Body lice are morphologically indistinguishable from head lice, and the two subspecies will interbreed under laboratory conditions. In their natural state, however, they occupy different habitats and do not usually meet. They can feed up to five times a day. Adults can live for about thirty days, but if separated from their host they will die within two days. The life cycle consists of three stages: egg, nymph, and adult. Eggs (nits) are attached to clothes or hairs and hatch within 6 to 9 days. Nymphs molt three times over 9–12 days before becoming adults. The adult body louse is about 2.5–3.5 mm long, wingless, and tan to grayish-white in color. Body lice were first described by Carl Linnaeus in the 10th edition of Systema Naturae. However, recent transcriptome analyses cast doubt on whether lice provide a means to date the origin of clothes, finding that body and head lice were almost genetically identical, with phenotypic flexibility probably resulting from regulatory changes triggered by environmental signals.
Reader's Guide
Body lice are significant primarily as disease vectors, transmitting Rickettsia prowazekii (epidemic typhus), Borrelia recurrentis (relapsing fever), and Bartonella quintana (trench fever). Epidemic typhus, if left untreated, has a fatality rate of 30%; relapsing fever, 10–40%; and trench fever, less than 1%. In developed countries, infestations are only a problem in areas of poverty with poor hygiene, crowded living conditions, and lack of access to clean clothing. Outbreaks occur globally in prisons, homeless populations, refugees of war, and after natural disasters when sanitation is unavailable. Body lice cannot jump or fly; they spread by direct contact or contact with infested clothing or bed sheets. Treatment involves changing and washing clothes and bedding in hot water (at least 50°C) and drying on a hot cycle. Itching can be treated with corticosteroids and antihistamines; secondary infections with antibiotics. When regular changing is not possible, insecticides may be used. The body louse belongs to the phylum Arthropoda, class Insecta, order Psocodea, and family Pediculidae.
Did You Know?
- Body lice are indistinguishable in appearance from head lice and will interbreed under laboratory conditions.
- Body lice can transmit epidemic typhus, trench fever, and relapsing fever.
Frequently Asked Questions
What is a body louse?
The body louse, also called the clothing louse or colloquially a cootie, is a blood-feeding external parasite that infests humans. It is one of three louse species that parasitize people, alongside the head louse and the crab (pubic) louse.
What diseases can the body louse spread?
Body lice are recognized vectors for epidemic typhus, trench fever, and relapsing fever. They transmit these pathogens from one human host to another while taking blood meals.
How is the body louse different from head lice?
Although both are human-parasitic lice, the body louse lives and deposits its eggs in the seams of clothing rather than directly on the scalp. This habitat distinction is what separates Pediculus humanus humanus from the head louse.
What is the body louse's full scientific classification?
Its binomial name is Pediculus humanus humanus, and it is also referred to as Pediculus humanus corporis. Taxonomically it falls under the order Psocodea, family Pediculidae, class Insecta, and phylum Arthropoda.
Why is the body louse historically significant?
Because it transmits epidemic typhus, the body louse has driven devastating outbreaks in crowded, unsanitary settings such as wartime trenches and refugee camps. This made it one of the most feared human parasites in recorded history.
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