Bed bugs are a type of [insect]( that feed on human [blood]( usually at night.[[7]]( Their bites can result in a number of health impacts including [skin rashes]( psychological effects and [allergic]( symptoms.[[5]]( Bed bug bites may lead to skin changes ranging from invisible to small areas of redness to prominent [blisters]([[1]]([[2]]( Symptoms may take between minutes to days to appear and itchiness is generally present.[[2]]( Some individuals may feel tired or have a [fever]([[2]]( Typically, uncovered areas of the body are affected and often three bites occur in a row.[[2]]( Bed bugs bites are not known to transmit any [infectious disease]([[5]]([[7]]( Complications may rarely include [areas of ■■■■ skin]( or [vasculitis]([[2]](
Bed bug bites are caused primarily by two [species]( of insects of the [Cimex]( type: [Cimex lectularius]( (the common bed bug) and [Cimex hemipterus]( , primarily in the [tropics]([[3]]( Their size ranges between 1 and 7 mm.[[7]]( They spread by crawling between nearby locations or by being carried within personal items.[[2]]( [Infestation]( is rarely due to a lack of [hygiene]( but is more common in high-density areas.[[2]]([[8]]( Diagnosis involves both finding the bugs and the occurrence of compatible symptoms.[[5]]( Bed bugs spend much of their time in dark, hidden locations like mattress seams or cracks in a wall.[[2]](
Treatment is [directed towards the symptoms]([[2]]( Eliminating bed bugs from the home is often difficult, partly because bed bugs can survive up to a year without feeding.[[2]]( Repeated treatments of a home may be required.[[2]]( These treatments may include heating the room to 50 °C (122 °F) for more than 90 minutes, frequent [vacuuming]( washing clothing at high temperatures, and the use of various [pesticides]([[2]](
Bed bugs occur in all regions of the globe.[[7]]( Rates of infestations are relatively common, following an increase since the 1990s.[[3]]([[4]]([[6]]( The exact causes of this increase are unclear; theories including increased human travel, more frequent exchange of second-hand furnishings, a greater focus on control of other pests, and increasing [resistance to pesticides]([[4]]( Bed bugs have been known human parasites for thousands of years.[[2]](
Contents
- [1Signs and symptoms](
- [1.1Skin](
- [1.2Psychological](
- [1.3Other](
- [2Insect](
- [2.1Spread](
- [3Diagnosis](
- [3.1Detection](
- [3.2Differential diagnosis](
- [4Prevention](
- [5Management](
- [6Epidemiology](
- [6.1Species](
- [7History](
- [7.120th century](
- [8Society and culture](
- [8.1Legal action](
- [8.2Literature](
- [9Research](
- [10References](
- [11External links](
Signs and symptoms[[edit](]
[,[[3]]([[5]]( to small [macular]( spots, to prominent [wheals and bullae]( along with intense [itching]( that may last several days.[[5]]( The bites often occur in a line. A central spot of [bleeding]( may also occur due to the release of [anticoagulants]( in the bug’s saliva.[[4]](
Symptoms may not appear until some days after the bites have occurred.[[5]]( Reactions often become more brisk after multiple bites due to possible sensitization to the salivary proteins of the bed bug.[[3]]( The skin reaction usually occurs in the area of the bite which is most commonly the arms, shoulders and legs as they are more frequently exposed at night.[[5]]( Numerous bites may lead to an [erythematous rash]( or [urticaria]([[5]](
Psychological[[edit](]
Serious infestations and chronic attacks can cause anxiety, stress, and [insomnia]([[5]]( Development of refractory [delusional parasitosis]( is possible, as a person develops an overwhelming obsession with bed bugs.[[9]](
Other[[edit](]
A number of other symptoms may occur from either the bite of the bed bugs or from their exposure. [Anaphylaxis]( from the injection of serum and other nonspecific proteins has been rarely documented.[[5]]([[10]]( Due to each bite taking a tiny amount of [blood]( chronic or severe infestation may lead to [anemia]([[5]]( [Bacterial]( skin infection may occur due to skin break down from scratching.[[5]]([[11]]( Systemic poisoning may occur if the bites are numerous.[[12]]( Exposure to bed bugs may trigger an [asthma]( attack via the effects of airborne allergens although evidence of this association is limited.[[5]]( There is no evidence that bed bugs transmit [infectious diseases]([[5]]([[7]]( even though they appear physically capable of carrying [pathogens]( this possibility has been investigated.[[3]]([[5]]( The bite itself may be painful thus resulting in poor sleep and worse work performance.[[5]](
Similar to humans, pets can also be bitten by bed bugs. The signs left by the bites are the same as in case of people and cause identical symptoms (skin irritation, scratching etc).[ [citation needed]( ]
Insect[[edit](]
Main article: [Cimex](
[ and [Cimex hemipterus]( .[[3]]( These insects feed exclusively on blood and may survive a year without eating.[[3]]( Adult Cimex are light brown to reddish-brown, flat, oval, and have no hind wings. The front wings are [vestigial]( and reduced to pad-like structures. Adults grow to 4–5 mm (0.16–0.20 in) long and 1.5–3 mm (0.059–0.118 in) wide.
Bed bugs have five immature ■■■■■ life stages and a final sexually mature adult stage.[[13]]( They shed their skins through [ecdysis]( at each stage, discarding their outer exoskeleton.[[14]]( Newly hatched [nymphs]( are translucent, lighter in color, and become browner as they [moult]( and reach [maturity]( Bed bugs may be mistaken for other insects, such as [booklice]( small [■■■■■■■■■■■■■ or [carpet beetles]( however, when warm and active, their movements are more ant-like, and like most other [true bugs]( they emit a characteristic disagreeable odor when crushed.
Bed bugs are obligatory [bloodsuckers]( They have mouth parts that saw through the skin and inject saliva with [anticoagulants]( and painkillers. Sensitivity of humans varies from extreme allergic reaction to no reaction at all (about 20%). The bite usually produces swelling with no red spot, but when many bugs feed on a small area, reddish spots may appear after the swelling subsides.[[15]]( Bedbugs prefer exposed skin, preferably the face, neck, and arms of a sleeping person.
Bed bugs are attracted to their hosts primarily by [carbon dioxide]( secondarily by warmth, and also by certain chemicals.[[4]]([[16]]([[17]]([[18]]( Cimex lectularius feeds only every five to seven days, which suggests that it does not spend the majority of its life searching for a host. When a bed bug is starved, it leaves its shelter and searches for a host. It returns to its shelter after successful feeding or if it encounters exposure to light.[[19]]( Cimex lectularius aggregate under all life stages and mating conditions. Bed bugs may choose to aggregate because of predation, resistance to desiccation, and more opportunities to find a mate. Airborne pheromones are responsible for aggregations.[[20]](
Spread[[edit](]
Infestation is rarely caused by a lack of [hygiene]([[8]]( Transfer to new places is usually in the personal items of the human they feed upon.[[3]]( Dwellings can become infested with bed bugs in a variety of ways, such as:
- Bugs and eggs inadvertently brought in from other infested dwellings on a visiting person’s clothing or luggage;
- Infested items (such as furniture especially beds or couches, clothing, or backpacks) brought in a home or business;
- Proximity of infested dwellings or items, if easy routes are available for travel, e.g. through ducts or false ceilings;
- Wild animals (such as bats or birds)[[21]]([[22]]( that may also harbour bed bugs or related species such as the [bat bug](
- People visiting an infested area (e.g. dwelling, means of transport, entertainment venue, or lodging) and carrying the bugs to another area on their clothing, luggage, or bodies. Bedbugs are increasingly found in air travel.[[23]](
Though bed bugs will opportunistically feed on pets, they do not live or travel on the skin of their hosts, and pets are not believed to be a factor in their spread.[[24]](
Diagnosis[[edit](]
A definitive diagnosis of health effects due to bed bugs requires a search for and finding of the insect in the sleeping environment as symptoms are not sufficiently [specific]([[5]]( Bed bugs classically form a line of bites colloquially referred to as “breakfast, lunch, and dinner” and rarely feed in the armpit or behind the knee which may help differentiate it from other biting insects.[[4]]( If the number in a house is large a pungent sweet odor may be described.[[4]]( There are specially trained [dogs]( that can detect this smell.[[2]](
Detection[[edit](]
Bed bugs can exist singly, but tend to congregate once established. Although strictly parasitic, they spend only a tiny fraction of their lifecycles physically attached to hosts. Once a bed bug finishes feeding, it relocates to a place close to a known host, commonly in or near beds or couches in clusters of adults, juveniles, and eggs—which entomologists call harborage areas or simply harborages to which the insect returns after future feedings by following chemical trails. These places can vary greatly in format, including luggage, inside of vehicles, within furniture, among bedside clutter—even inside electrical sockets and nearby laptop computers. Bed bugs may also nest near animals that have nested within a dwelling, such as bats, birds,[[22]]( or [rodents]( They are also capable of surviving on domestic cats and dogs, though humans are the preferred host of C. lectularius .[[25]](
Bed bugs can also be detected by their characteristic smell of rotting [raspberries]([[26]]( [Bed bug detection dogs]( are trained to pinpoint infestations, with a possible accuracy rate between 11% and 83%.[[6]]( Homemade detectors have been developed.[[27]]([[28]](
- [.[[5]]( There however is no evidence that medications improve outcomes, and symptoms usually resolve without treatment in 1–2 weeks.[[3]]([[4]](
Avoiding repeated bites can be difficult, since it usually requires [eradicating bed bugs]( from a home or workplace; eradication frequently requires a combination of [pesticide]( and non-pesticide approaches.[[3]]( Pesticides that have historically been found to be effective include [pyrethroids]( [dichlorvos]( and [malathion]([[4]]( Resistance to pesticides has increased significantly over time, and there are concerns about [harm to health]( from their use.[[3]]( Mechanical approaches, such as vacuuming up the insects and heat-treating or wrapping mattresses have been recommended.[[3]](
Once established, bed bugs are extremely difficult to get rid of.[[3]]( This frequently requires a combination of non-pesticide approaches and the use of [insecticides]([[3]]([[4]](
Mechanical approaches, such as vacuuming up the insects and heat-treating or wrapping mattresses, are effective.[[3]]([[6]]( An hour at a temperature of 45 °C (113 °F) or over, or two hours at less than −17 °C (1 °F) kills them.[[6]]( This may include a domestic [clothes drier]( for fabric or a commercial steamer. Bed bugs and their eggs will die on contact when exposed to surface temperatures above 180 °F (82 °C) and a steamer can reach well above 230 °F (110 °C).[[15]]([[31]]( A study found 100% mortality rates for bed bugs exposed to temperatures greater than 50 °C (122 °F) for more than 2 minutes. The study recommended maintaining temperatures of above 48 °C (118 °F) for more than 20 min to effectively kill all life stages of bed bugs, and because in practice treatment times of 6 to 8 hours are used to account for cracks and indoor clutter.[[32]]( This method is expensive and has caused fires.[[6]]([[15]]( Starving bedbugs is not effective, as they can survive without eating for 100 to 300 days, depending on temperature.[[6]](
It was stated in 2012 that no truly effective insecticides were available.[[6]]( Insecticides that have historically been found effective include [pyrethroids]( [dichlorvos]( and [malathion]([[4]]( Resistance to pesticides has increased significantly in recent decades.[[3]]( The [carbamate]( insecticide [propoxur]( is highly toxic to bed bugs, but it has potential toxicity to children exposed to it, and the [US Environmental Protection Agency]( has been reluctant to approve it for indoor use.[[33]]( [Boric acid]( occasionally applied as a safe indoor insecticide, is not effective against bed bugs[[34]]( because they do not groom.[[35]](
Epidemiology[[edit](]
Main article: [Epidemiology of bed bugs](
Bed bugs occur around the world.[[36]]( Before the 1950s about 30% of houses in the United States had bedbugs.[[2]]( Rates of infestation in [developed countries]( while decreasing from the 1930s to the 1980s, have increased dramatically since the 1980s.[[3]]([[4]]([[36]]( This is believed to be partly due to the use of [DDT]( to kill ■■■■■■■■■■■■■■■■■■■ The invention of the [vacuum cleaner]( and simplification of furniture design may have also played a role.[[37]]( Others believe it might simply be the cyclical nature of the organism.[[38]](
The dramatic increase in bedbug populations in the developed world, which began in the 1980s, is thought to be due to greater foreign travel, increased immigration from the developing world to the developed world, more frequent exchange of second-hand furnishings among homes, a greater focus on control of other pests, resulting in neglect of bed bug countermeasures, and increasing bedbug resistance to pesticides.[[4]]([[39]]( Lower ■■■■■■■■■ populations due to [insecticide]( use may have aided bed bugs’ resurgence, since ■■■■■■■■■■■ are known to sometimes predate them.[[40]]( [Bans on DDT]( and other potent pesticides may have also contributed.[[41]]([[42]](
The U.S. [National Pest Management Association]( reported a 71% increase in bed bug calls between 2000 and 2005.[[43]]( The number of reported incidents in [New York City]( alone rose from 500 in 2004 to 10,000 in 2009.[[44]]( In 2013, [Chicago]( was listed as the number 1 city in the United States for bedbug infestations.[[45]]( As a result, the [Chicago City Council]( passed a bed bug control ordinance to limit their spread. Additionally, bed bugs are reaching places in which they never established before, such as southern South America.[[46]]([[47]](
The rise in infestations has been hard to track because bed bugs are not an easily identifiable problem and is one that people prefer not to discuss. Most of the reports are collected from pest-control companies, local authorities, and hotel chains.[[48]]( Therefore, the problem may be more severe than is currently believed.[[49]](
Species[[edit](]
The common bed bug ( C. lectularius ) is the species best adapted to human environments. It is found in [temperate]( climates throughout the world. Other species include [Cimex hemipterus]( , found in [tropical regions]( which also infests poultry and bats, and [Leptocimex boueti]( , found in the tropics of West Africa and South America, which infests bats and humans. [Cimex pilosellus]( and [Cimex pipistrella]( primarily infest bats, while [Haematosiphon inodora]( , a species of North America, primarily infests poultry.[[50]](