Ectoparasitic Ectoparasitic Arthropods: lice, Arthropods: lice,

fleas, ticks and mitesfleas, ticks and mites

Biology of Louse- AnopluraBiology of Louse- Anoplura

Lice are highly specialized insects Lice are highly specialized insects based on the host species and many based on the host species and many species specifically only feed on species specifically only feed on certain areas of their host's body. As certain areas of their host's body. As lice spend their whole life on the host lice spend their whole life on the host they have developed adaptations they have developed adaptations which enable them to maintain a which enable them to maintain a close contact with the host. close contact with the host.

These adaptations are reflected in These adaptations are reflected in their size (0.5–8 their size (0.5–8 mmmm), stout legs, and ), stout legs, and claws which are adapted to cling claws which are adapted to cling tightly to hair, fur and feathers, tightly to hair, fur and feathers, wingless and dorsoventrally wingless and dorsoventrally flattened.flattened.

Types of LiceTypes of Lice

Three types of lice infest humans: Three types of lice infest humans: the body louse, the body louse, Pediculus humanus Pediculus humanus humanushumanus Linnaeus, also known as Linnaeus, also known as Pediculus humanus corporisPediculus humanus corporis; the ; the head louse head louse Pediculus humanus Pediculus humanus capitiscapitis De Geer; and the crab louse De Geer; and the crab louse (or pubic louse), Pthirus pubis (or pubic louse), Pthirus pubis (Linnaeus) . (Linnaeus) .

Head louseHead louse

Pubic lousePubic louse

Body LouseBody Louse

Head lice and body lice are Head lice and body lice are morphologically indistinguishable, morphologically indistinguishable, although head lice are smaller than although head lice are smaller than body lice. Head lice and pubic lice are body lice. Head lice and pubic lice are highly dependent upon human body highly dependent upon human body warmth and will die if separated from warmth and will die if separated from their host for 24 hours. Body lice are their host for 24 hours. Body lice are more hardy since they live on clothing more hardy since they live on clothing and can survive if separated from and can survive if separated from human contact for up to a week without human contact for up to a week without feeding. feeding.

BiologyBiology Lice have simple or gradual Lice have simple or gradual

metamorphosis. The immatures and adults metamorphosis. The immatures and adults look similar, except for size. Lice do not look similar, except for size. Lice do not have wings or powerful jumping legs so have wings or powerful jumping legs so they move about by clinging to hairs with they move about by clinging to hairs with claw-like legs. Head lice prefer to live on claw-like legs. Head lice prefer to live on the hair of the head although they have the hair of the head although they have been known to wander to other parts of been known to wander to other parts of the body. the body.

Head lice do not normally live within Head lice do not normally live within rugs, carpet, or school buses. Body rugs, carpet, or school buses. Body lice live in the seams of clothing, lice live in the seams of clothing, generally where it touches the skin, generally where it touches the skin, and only contact the body to feed, and only contact the body to feed, usually holding on to the clothing usually holding on to the clothing while they do this. However, while they do this. However, sometimes they will move to the sometimes they will move to the body itself. body itself.

The eggs of lice are called nits. They The eggs of lice are called nits. They are oval white cylinders (1/16 inch are oval white cylinders (1/16 inch long). The eggs of head lice are usually long). The eggs of head lice are usually glued to hairs of the head near the glued to hairs of the head near the scalp. The favorite areas for females to scalp. The favorite areas for females to glue the eggs are near the ears and glue the eggs are near the ears and back of the head. The eggs of body lice back of the head. The eggs of body lice are laid on clothing fibers and are laid on clothing fibers and occasionally on human body hairs. occasionally on human body hairs.

Nits- Eggs of LouseNits- Eggs of Louse

Under normal conditions the eggs will hatch Under normal conditions the eggs will hatch in seven to 11 days. The young lice which in seven to 11 days. The young lice which escape from the egg must feed within 24 escape from the egg must feed within 24 hours or they will die. Newly hatched lice hours or they will die. Newly hatched lice will periodically take blood meals and molt will periodically take blood meals and molt three times before becoming sexually three times before becoming sexually mature adults. Normally a young louse will mature adults. Normally a young louse will mature in 10 to 12 days to an adult (1/8 mature in 10 to 12 days to an adult (1/8 inch in length). Adults range in color from inch in length). Adults range in color from white to brown to dark gray. white to brown to dark gray.

Female lice lay six to seven eggs (nits) Female lice lay six to seven eggs (nits) per day and may lay a total of 50 to 100 per day and may lay a total of 50 to 100 eggs during their life which may last up eggs during their life which may last up to 40 days. Adults can only survive one to 40 days. Adults can only survive one to two days without a blood meal. The to two days without a blood meal. The nymphs and adults all have piercing-nymphs and adults all have piercing-sucking mouthparts which pierce the sucking mouthparts which pierce the skin for a blood meal. The reaction of skin for a blood meal. The reaction of individuals to louse bites can vary individuals to louse bites can vary considerably. considerably.

Both the immature or nymphal forms Both the immature or nymphal forms and adult lice feed on human blood. To and adult lice feed on human blood. To feed, the louse bites through the skin feed, the louse bites through the skin and injects saliva which prevents blood and injects saliva which prevents blood from clotting; it then sucks blood into from clotting; it then sucks blood into its digestive tract. Bloodsucking may its digestive tract. Bloodsucking may continue for a long period if the louse is continue for a long period if the louse is not disturbed. While feeding, lice may not disturbed. While feeding, lice may excrete dark red feces onto the skin. excrete dark red feces onto the skin.

Head lice should be suspected when Head lice should be suspected when there is intense itching and scratching there is intense itching and scratching of the scalp and the back of the neck of the scalp and the back of the neck or when there is a known infestation or when there is a known infestation in the community. Close examination in the community. Close examination of the scalp will reveal small, whitish of the scalp will reveal small, whitish or dark eggs (nits) firmly attached to or dark eggs (nits) firmly attached to hair shafts, especially at the nape of hair shafts, especially at the nape of the neck and above the ears. the neck and above the ears.

Inspection may reveal active lice Inspection may reveal active lice and many itchy, red marks resulting and many itchy, red marks resulting from irritation caused by the saliva of from irritation caused by the saliva of the louse. Although dandruff may the louse. Although dandruff may resemble eggs, it can be removed resemble eggs, it can be removed easily from hair, whereas louse eggs easily from hair, whereas louse eggs are attached firmly to the hair with are attached firmly to the hair with cement secreted by the louse and cement secreted by the louse and cannot be removed easily by pulling. cannot be removed easily by pulling.

When an infestation becomes known, When an infestation becomes known, it is advisable to examine all it is advisable to examine all members of the family, especially members of the family, especially other children, and others who have other children, and others who have been in contact with the infested been in contact with the infested person within recent weeks to be person within recent weeks to be sure that they have not become sure that they have not become infested. infested.

Body lice are found in tight-fitting sites Body lice are found in tight-fitting sites or seams of clothing, usually close to or seams of clothing, usually close to the skin. Only in heavy infestations will the skin. Only in heavy infestations will body lice be seen on other layers of body lice be seen on other layers of clothing. Infestations usually occur clothing. Infestations usually occur where humans continuously wear where humans continuously wear several layers of clothing due to several layers of clothing due to inadequate heating or during periods inadequate heating or during periods of war or natural disasters. of war or natural disasters.

Louse infestations may also occur in Louse infestations may also occur in poorly managed nursing homes, and poorly managed nursing homes, and among the poor and homeless. The among the poor and homeless. The main reasons for these infestations main reasons for these infestations are the failure to change garments are the failure to change garments and/or inadequate laundering. and/or inadequate laundering.

Disease TransmissionDisease Transmission The body louse is the vector of three The body louse is the vector of three

human diseases -- epidemic or louse-borne human diseases -- epidemic or louse-borne typhus, caused by typhus, caused by Rickettsia prowazekiRickettsia prowazeki de de Rocha-Lima; trench fever, caused by Rocha-Lima; trench fever, caused by Rochalimaea quintanaRochalimaea quintana (Schmincke) Krieg (Schmincke) Krieg (long known as (long known as Rickettsia quintanaRickettsia quintana); and ); and louse-borne relapsing fever, caused by louse-borne relapsing fever, caused by Borrellia recurrentisBorrellia recurrentis

Although head lice have been experimentally Although head lice have been experimentally infected with infected with Rickettsia prowazekiRickettsia prowazeki, neither , neither head lice nor pubic lice have been implicated head lice nor pubic lice have been implicated directly in active disease transmission (Roy directly in active disease transmission (Roy and Brown 1954). Although body lice may and Brown 1954). Although body lice may pose the most serious health threat in many pose the most serious health threat in many countries, head lice appear to be the greatest countries, head lice appear to be the greatest nuisance, particularly among school children nuisance, particularly among school children in highly developed countries where their in highly developed countries where their presence is considered intolerable.presence is considered intolerable.

Lice feed on Lice feed on skinskin (epidermal) debris, (epidermal) debris, featherfeather parts, parts, sebaceous secretionssebaceous secretions and and bloodblood. A louse's colour varies from pale . A louse's colour varies from pale beige to dark grey; however, if feeding on beige to dark grey; however, if feeding on blood, it may become considerably darker.blood, it may become considerably darker.

A louse A louse eggegg is commonly called a is commonly called a nitnit. Lice . Lice attach their eggs to their host's hair with attach their eggs to their host's hair with specialized saliva which results in a bond specialized saliva which results in a bond that is very difficult to separate without that is very difficult to separate without specialized products.specialized products.

Lice and humansLice and humansHumans are unique in they host Humans are unique in they host

three different kinds of lice: three different kinds of lice: head licehead lice, , body licebody lice (which live mainly in (which live mainly in clothing), and clothing), and pubic licepubic lice. The DNA . The DNA differences between head lice and differences between head lice and body lice provides corroborating body lice provides corroborating evidence that humans started evidence that humans started wearing clothes approximately wearing clothes approximately 72,000 years ago 72,000 years ago [1][1]..

Recent Recent DNADNA evidence suggests that evidence suggests that pubic lice spread to the ancestors of pubic lice spread to the ancestors of humans approximately 3.3 million humans approximately 3.3 million years ago from the ancestors of years ago from the ancestors of gorillas by sharing the same bed or gorillas by sharing the same bed or other communal areas with them, other communal areas with them, and are more closely related to lice and are more closely related to lice endemic to gorillas than to other lice endemic to gorillas than to other lice species infesting humans species infesting humans [2][2]..

FleasFleas

B. Siphonaptera: fleas ( Pulgas )B. Siphonaptera: fleas ( Pulgas ) CharacteristicsCharacteristics

Fleas are small, wingless insects ranging in Fleas are small, wingless insects ranging in size from approximately 1-10 millimetres in size from approximately 1-10 millimetres in length depending on the species. Almost length depending on the species. Almost everybody, especially those with cats or everybody, especially those with cats or dogs will be familiar with these small biting dogs will be familiar with these small biting insects and will have either seen them or insects and will have either seen them or the effects of their nuisance bites. Fleas can the effects of their nuisance bites. Fleas can be recognised by the following features be recognised by the following features

A Typical FleaA Typical Flea

Laterally compressed bodies Laterally compressed bodies Piercing-sucking mouthparts Piercing-sucking mouthparts Enlarged hind legs adapted for jumping Enlarged hind legs adapted for jumping Strong tarsal claws adapted for holding onto Strong tarsal claws adapted for holding onto

their hosts their hosts Backward pointing hairs and bristles for Backward pointing hairs and bristles for

ease of movement through the hair of a ease of movement through the hair of a host host

Small antennae which tuck away into Small antennae which tuck away into special groves in the head special groves in the head

Life CycleLife CycleFleas mate on their host animal and Fleas mate on their host animal and lay their eggs either onto the animal lay their eggs either onto the animal where they fall to the nest or directly where they fall to the nest or directly in the nest. The small larvae hatch in the nest. The small larvae hatch from the eggs and do not begin to from the eggs and do not begin to feed on blood like that of their parents feed on blood like that of their parents but consume the dead skin and other but consume the dead skin and other dirt and dust from the host animal. dirt and dust from the host animal.

The larvae develop through 3 instars The larvae develop through 3 instars and when fully grown spin a silken and when fully grown spin a silken cocoon and pupate in the nest of the cocoon and pupate in the nest of the host. The vibrations of a host often host. The vibrations of a host often trigger the emergence of the adult flea trigger the emergence of the adult flea from the pupal case, enabling it to from the pupal case, enabling it to immediately find a host and begin immediately find a host and begin feeding. The complete life cycle may feeding. The complete life cycle may take from several weeks to many take from several weeks to many months depending on the species. months depending on the species.

FeedingFeeding Adult fleas feed on the blood of their Adult fleas feed on the blood of their host and although most fleas are host and although most fleas are adapted to one particular animal, many adapted to one particular animal, many are not host specific and will move to are not host specific and will move to other animals if their preferred host is other animals if their preferred host is unavailable. Fleas are very adaptable unavailable. Fleas are very adaptable and are also able to withstand and are also able to withstand unfavourable conditions and can live for unfavourable conditions and can live for many days without food.many days without food.

HabitatHabitat Fleas are always found close by their Fleas are always found close by their hosts, either in direct contact such as hosts, either in direct contact such as among the feathers or hair or within among the feathers or hair or within their nests. Fleas are found in almost their nests. Fleas are found in almost all habitats in Australia where there all habitats in Australia where there is a ready host and many native is a ready host and many native species of flea are closely associated species of flea are closely associated with native marsupials and rodents. with native marsupials and rodents.

The main introduced species are also The main introduced species are also associated with animals that have associated with animals that have been introduced to the country such been introduced to the country such as the cat flea (as the cat flea (Ctenocephalides felisCtenocephalides felis) ) the dog flea (the dog flea (Ctenocephalides canisCtenocephalides canis) ) and the rat flea (and the rat flea (Xenopsylla cheopisXenopsylla cheopis). ).

TICKS- GARAPATATICKS- GARAPATA

TICKS (GARAPATA)TICKS (GARAPATA)

C. Ticks ( Garapata )C. Ticks ( Garapata )Ticks are blood feeding external Ticks are blood feeding external

parasites of mammals, birds, and parasites of mammals, birds, and reptiles throughout the world. reptiles throughout the world. Approximately 850 species have Approximately 850 species have been described worldwide (Furman been described worldwide (Furman and Loomis 1984). There are two well and Loomis 1984). There are two well established families of ticks, the established families of ticks, the Ixodidae (hard ticks), and Argasidae Ixodidae (hard ticks), and Argasidae (soft ticks) (soft ticks)

Both are important vectors of Both are important vectors of disease causing agents to humans disease causing agents to humans and animals throughout the world. and animals throughout the world. Ticks transmit the widest variety of Ticks transmit the widest variety of pathogens of any blood sucking pathogens of any blood sucking arthropod, including bacteria, arthropod, including bacteria, rickettsiae, protozoa, and viruses. rickettsiae, protozoa, and viruses.

Some human diseases of current Some human diseases of current interest in the United States caused interest in the United States caused by tick-borne pathogens include by tick-borne pathogens include Lyme disease, ehrlichiosis, Lyme disease, ehrlichiosis, babesiosis, rocky mountain spotted babesiosis, rocky mountain spotted fever, tularemia, and tick-borne fever, tularemia, and tick-borne relapsing fever.relapsing fever.

Hard Ticks: Family IxodidaeHard Ticks: Family IxodidaeHard ticks have three distinct life Hard ticks have three distinct life

stages. Larvae which emerge from stages. Larvae which emerge from the egg have six legs. After obtaining the egg have six legs. After obtaining a blood meal from a vertebrate host, a blood meal from a vertebrate host, they molt to the nymphal stage and they molt to the nymphal stage and acquire eight legs. Nymphs feed and acquire eight legs. Nymphs feed and molt to the next and final stage - the molt to the next and final stage - the adult, which also has eight legs adult, which also has eight legs

After feeding once more, the adult After feeding once more, the adult female hard ticks lay one batch of female hard ticks lay one batch of thousands of eggs and then die. Only thousands of eggs and then die. Only one blood meal is taken during each of one blood meal is taken during each of the three life stages. The time to the three life stages. The time to completion of the entire life cycle may completion of the entire life cycle may vary from less than a year in tropical vary from less than a year in tropical regions to over three years in cold regions to over three years in cold climates, where certain stages may enter climates, where certain stages may enter diapause until hosts are again available. diapause until hosts are again available.

The mouthparts of hard ticks are The mouthparts of hard ticks are readily visible from above. There are readily visible from above. There are three visible components: the two three visible components: the two outside jointed parts are the highly outside jointed parts are the highly mobile mobile palpspalps; between these are ; between these are paired paired cheliceraechelicerae, which protect the , which protect the center rod-shaped structure, the center rod-shaped structure, the hypostomehypostome. .

The palps move laterally while the The palps move laterally while the tick is feeding and do not enter the tick is feeding and do not enter the skin of the host. The rough skin of the host. The rough hypostome has many beak-like hypostome has many beak-like projections on it. This is the structure projections on it. This is the structure which plunges into the host's skin which plunges into the host's skin while feeding. while feeding.

The backward directed projections The backward directed projections prevent easy removal of the prevent easy removal of the attached tick. In addition, most hard attached tick. In addition, most hard ticks secrete a cement-like substance ticks secrete a cement-like substance produced by the salivary glands produced by the salivary glands which literally glues the feeding tick which literally glues the feeding tick in place; the substance dissolves in place; the substance dissolves after feeding is complete. after feeding is complete.

Hard ticks seek hosts by an Hard ticks seek hosts by an interesting behavior called interesting behavior called "questing." Questing ticks crawl up "questing." Questing ticks crawl up the stems of grass or perch on the the stems of grass or perch on the edges of leaves on the ground in a edges of leaves on the ground in a typical posture with the front legs typical posture with the front legs extended, especially in response to a extended, especially in response to a host passing by. host passing by.

Certain biochemicals such as carbon Certain biochemicals such as carbon dioxide as well as heat and dioxide as well as heat and movement serve as stimuli for movement serve as stimuli for questing behavior. Subsequently, questing behavior. Subsequently, these ticks climb on to a potential these ticks climb on to a potential host which brushes against their host which brushes against their extended front legs extended front legs

Hard ticks are most commonly Hard ticks are most commonly collected for research by the use of collected for research by the use of "flags" or "drags" which are made "flags" or "drags" which are made from 1 m square pieces of roughly from 1 m square pieces of roughly textured fabric such as fleece or textured fabric such as fleece or flannel attached to a rod handle. flannel attached to a rod handle.

The flags are slowly dragged across the The flags are slowly dragged across the surface of vegetation to collect questing surface of vegetation to collect questing ticks. Hard ticks feed for extended ticks. Hard ticks feed for extended periods of time on their hosts, varying periods of time on their hosts, varying from several days to weeks, depending from several days to weeks, depending on such factors as life stage, host type, on such factors as life stage, host type, and species of tick. The outside surface, and species of tick. The outside surface, or cuticle, of hard ticks actually grows to or cuticle, of hard ticks actually grows to accommodate the large volume of blood accommodate the large volume of blood

SOFT TICKS -ARGASIDAESOFT TICKS -ARGASIDAE

The life stages of soft ticks are not The life stages of soft ticks are not readily distinguishable. The first life readily distinguishable. The first life stage to come out of the egg, a six stage to come out of the egg, a six legged larva, takes a blood meal legged larva, takes a blood meal from a host, and molts to the first from a host, and molts to the first nymphal stage. nymphal stage.

Unlike hard ticks, many soft ticks go Unlike hard ticks, many soft ticks go through multiple nymphal stages, through multiple nymphal stages, gradually increasing in size until the gradually increasing in size until the final molt to the adult stage. Some final molt to the adult stage. Some soft ticks pass through up to seven soft ticks pass through up to seven nymphal molts before they become nymphal molts before they become adults adults

Soft ticks feed several times during each Soft ticks feed several times during each life stage, and females lay multiple small life stage, and females lay multiple small batches of eggs between blood meals batches of eggs between blood meals during their lives. The time to during their lives. The time to completion of the entire life cycle is completion of the entire life cycle is generally much longer than that of hard generally much longer than that of hard ticks, lasting over several years. ticks, lasting over several years. Additionally, many soft ticks have an Additionally, many soft ticks have an uncanny resistance to starvation, and uncanny resistance to starvation, and can survive for many years without a can survive for many years without a blood meal blood meal

The mouthparts of soft ticks are are The mouthparts of soft ticks are are not readily visible from above. There not readily visible from above. There are three visible components: the are three visible components: the two outside jointed parts are the two outside jointed parts are the highly mobile highly mobile palpspalps; between these ; between these are paired are paired cheliceraechelicerae, which protect , which protect the center rod-shaped structure, the the center rod-shaped structure, the hypostomehypostome. .

The palps move laterally while the The palps move laterally while the tick is feeding and do not enter the tick is feeding and do not enter the skin of the host. The rough skin of the host. The rough hypostome has many beak-like hypostome has many beak-like projections on it. This is the structure projections on it. This is the structure which plunges into the host's skin which plunges into the host's skin while feeding. The backward directed while feeding. The backward directed projections prevent easy removal of projections prevent easy removal of the attached tick.the attached tick.

Some soft ticks seek hosts by questing on Some soft ticks seek hosts by questing on low-lying vegetation, but the vast majority low-lying vegetation, but the vast majority are nest parasites, residing in sheltered are nest parasites, residing in sheltered environments such as burrows, caves, or environments such as burrows, caves, or nests. Certain biochemicals such as carbon nests. Certain biochemicals such as carbon dioxide as well as heat and movement dioxide as well as heat and movement serve as stimuli for host seeking behavior. serve as stimuli for host seeking behavior. Soft ticks feed for short periods of time on Soft ticks feed for short periods of time on their hosts, varying from several minutes their hosts, varying from several minutes to days, depending on such factors as life to days, depending on such factors as life stage, host type, and species of tick stage, host type, and species of tick

The feeding behavior of many soft The feeding behavior of many soft ticks can be compared to that of ticks can be compared to that of fleas or bedbugs, as once fleas or bedbugs, as once established, they reside in the nest of established, they reside in the nest of the host, feeding rapidly when the the host, feeding rapidly when the host returns and disturbs the host returns and disturbs the contents. contents.

The outside surface, or cuticle, of The outside surface, or cuticle, of soft ticks expands, but does not grow soft ticks expands, but does not grow to accommodate the large volume of to accommodate the large volume of blood ingested, which may be blood ingested, which may be anywhere from 5-10 times their anywhere from 5-10 times their unfed body weight unfed body weight

MITE-BIOLOGYMITE-BIOLOGY

Mites are not insects; they are more Mites are not insects; they are more closely related to ticks and spiders. closely related to ticks and spiders. Most mites are visible to the unaided Most mites are visible to the unaided eye and usually measure 1/8" or less eye and usually measure 1/8" or less in length. Their life cycle has four in length. Their life cycle has four basic stages: egg, larva, nymph and basic stages: egg, larva, nymph and adult. adult.

The egg hatches into a larval stage, The egg hatches into a larval stage, which molts to the nymphal stage. which molts to the nymphal stage. After 1-2 more times, the nymph After 1-2 more times, the nymph matures to an adult. Mites, like ticks, matures to an adult. Mites, like ticks, have three pairs of legs as larvae have three pairs of legs as larvae and four pairs of legs as nymphs and and four pairs of legs as nymphs and adults. adults.

Sarcoptes scabie- a typical Sarcoptes scabie- a typical mitemite

SARCOPTES SCABIESARCOPTES SCABIE

Sarcoptes scabieiSarcoptes scabiei, commonly known as the , commonly known as the scabies, mange or itch mite, is a parasite scabies, mange or itch mite, is a parasite of humans and other animals. Scabies of humans and other animals. Scabies mites are host-specific. The varieties of mites are host-specific. The varieties of scabies that infest domestic animals can scabies that infest domestic animals can penetrate the skin of humans and cause penetrate the skin of humans and cause the typical itching and rash, but they the typical itching and rash, but they cannot complete their life cycles there. cannot complete their life cycles there. The adult female burrows into the outer The adult female burrows into the outer layer of the skin (epidermis) where she layer of the skin (epidermis) where she feeds on tissue fluids and lays eggs that feeds on tissue fluids and lays eggs that she cements to the floor of the burrow she cements to the floor of the burrow

Females lay eggs at a rate of up to 3 per Females lay eggs at a rate of up to 3 per day for a period of 8 weeks, producing day for a period of 8 weeks, producing about 200 eggs over her lifetime. These about 200 eggs over her lifetime. These eggs hatch in 3-4 days and the newly-eggs hatch in 3-4 days and the newly-hatched larvae emerge from the burrows hatched larvae emerge from the burrows onto the surface of the skin and molt to onto the surface of the skin and molt to form the first nymphal stage. form the first nymphal stage.

The rash and intense itching associated The rash and intense itching associated with scabies occurs when the nymphs with scabies occurs when the nymphs burrow into the skin and begin feeding burrow into the skin and begin feeding

These symptoms usually appear These symptoms usually appear several weeks to a month after the several weeks to a month after the initial infestation. The majority of initial infestation. The majority of mites are found in lesions in folds of mites are found in lesions in folds of skin between the fingers, on the sides skin between the fingers, on the sides of the feet, on the wrists and genitals, of the feet, on the wrists and genitals, and in the bends of the knees and and in the bends of the knees and elbows. After feeding on tissue fluids, elbows. After feeding on tissue fluids, the nymphs molt to become adults the nymphs molt to become adults

The life cycle, from egg to adult, can be The life cycle, from egg to adult, can be completed in about two weeks. Scabies completed in about two weeks. Scabies mites are readily transmitted within families mites are readily transmitted within families and within institutions such as nursing and within institutions such as nursing homes. homes. Personal contact, particularly Personal contact, particularly holding or shaking the hands of an holding or shaking the hands of an infested person, is a principal method infested person, is a principal method by which the mites are spread.by which the mites are spread. Intimate Intimate contact and sleeping with an infected contact and sleeping with an infected person can also spread the mites. person can also spread the mites.