Jump to content

Mosquito: Difference between revisions

Edit links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
Undid revision 222221850 by 71.239.121.165 (talk)
→Mosquito Saliva: sucks for you, rvv
Line 44: Line 44:
===Mosquito Saliva===
===Mosquito Saliva===


In order for a mosquito to obtain a blood meal it must surmount the [[vertebrate]] physiological responses.I goy bit on my eyelid :(. The mosquito, as with all blood-feeding [[arthropods]], has evolved mechanisms to effectively block the [[hemostasis]] system with their saliva which contains a complex mixture of secreted proteins. Mosquito saliva affects [[vascular constriction]], [[blood clotting]], platelet aggregation, [[inflammation]], [[immunity]], and [[angiogenesis]].<ref>{{cite journal |author=Ribeiro JM, Francischetti IM |title=Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives |journal=Annu. Rev. Entomol. |volume=48 |issue= |pages=73–88 |year=2003 |pmid=12194906 |doi=10.1146/annurev.ento.48.060402.102812}}</ref> Universally, hematophagous arthropod saliva contains at least one anticlotting, one anti-platelet, and one vasodilatory substance. Mosquito saliva also contains enzymes that aid in sugar feeding<ref>{{cite journal |author=Grossman GL, James AA |title=The salivary glands of the vector mosquito, Aedes aegypti, express a novel member of the amylase gene family |journal=Insect Mol. Biol. |volume=1 |issue=4 |pages=223–32 |year=1993 |pmid=7505701| doi = 10.1111/j.1365-2583.1993.tb00095.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> and [[antimicrobial agents]] to control bacterial growth in the sugar meal.<ref>{{cite journal |author=Rossignol PA, Lueders AM |title=Bacteriolytic factor in the salivary glands of Aedes aegypti |journal=Comp. Biochem. Physiol., B |volume=83 |issue=4 |pages=819–22 |year=1986 |pmid=3519067| doi = 10.1016/0305-0491(86)90153-7 <!--Retrieved from CrossRef by DOI bot-->}}</ref> The composition of mosquito saliva is relatively simple as it usually contains fewer than 20 dominant [[proteins]].<ref>{{cite journal |author=Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM |title=Toward a description of the sialome of the adult female mosquito Aedes aegypti |journal=Insect Biochem. Mol. Biol. |volume=32 |issue=9 |pages=1101–22 |year=2002 |pmid=12213246 | doi = 10.1016/S0965-1748(02)00047-4 <!--Retrieved from CrossRef by DOI bot-->}}</ref> Despite the great strides in knowledge of these molecules and their role in bloodfeeding achieved recently, scientists still cannot ascribe functions to more than half of the molecules found in [[arthropod]] saliva.<ref>{{cite journal |author=Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM |title=Toward a description of the sialome of the adult female mosquito Aedes aegypti |journal=Insect Biochem. Mol. Biol. |volume=32 |issue=9 |pages=1101–22 |year=2002 |pmid=12213246 | doi = 10.1016/S0965-1748(02)00047-4 <!--Retrieved from CrossRef by DOI bot-->}}</ref>
In order for a mosquito to obtain a blood meal it must surmount the [[vertebrate]] physiological responses. The mosquito, as with all blood-feeding [[arthropods]], has evolved mechanisms to effectively block the [[hemostasis]] system with their saliva which contains a complex mixture of secreted proteins. Mosquito saliva affects [[vascular constriction]], [[blood clotting]], platelet aggregation, [[inflammation]], [[immunity]], and [[angiogenesis]].<ref>{{cite journal |author=Ribeiro JM, Francischetti IM |title=Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives |journal=Annu. Rev. Entomol. |volume=48 |issue= |pages=73–88 |year=2003 |pmid=12194906 |doi=10.1146/annurev.ento.48.060402.102812}}</ref> Universally, hematophagous arthropod saliva contains at least one anticlotting, one anti-platelet, and one vasodilatory substance. Mosquito saliva also contains enzymes that aid in sugar feeding<ref>{{cite journal |author=Grossman GL, James AA |title=The salivary glands of the vector mosquito, Aedes aegypti, express a novel member of the amylase gene family |journal=Insect Mol. Biol. |volume=1 |issue=4 |pages=223–32 |year=1993 |pmid=7505701| doi = 10.1111/j.1365-2583.1993.tb00095.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> and [[antimicrobial agents]] to control bacterial growth in the sugar meal.<ref>{{cite journal |author=Rossignol PA, Lueders AM |title=Bacteriolytic factor in the salivary glands of Aedes aegypti |journal=Comp. Biochem. Physiol., B |volume=83 |issue=4 |pages=819–22 |year=1986 |pmid=3519067| doi = 10.1016/0305-0491(86)90153-7 <!--Retrieved from CrossRef by DOI bot-->}}</ref> The composition of mosquito saliva is relatively simple as it usually contains fewer than 20 dominant [[proteins]].<ref>{{cite journal |author=Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM |title=Toward a description of the sialome of the adult female mosquito Aedes aegypti |journal=Insect Biochem. Mol. Biol. |volume=32 |issue=9 |pages=1101–22 |year=2002 |pmid=12213246 | doi = 10.1016/S0965-1748(02)00047-4 <!--Retrieved from CrossRef by DOI bot-->}}</ref> Despite the great strides in knowledge of these molecules and their role in bloodfeeding achieved recently, scientists still cannot ascribe functions to more than half of the molecules found in [[arthropod]] saliva.<ref>{{cite journal |author=Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM |title=Toward a description of the sialome of the adult female mosquito Aedes aegypti |journal=Insect Biochem. Mol. Biol. |volume=32 |issue=9 |pages=1101–22 |year=2002 |pmid=12213246 | doi = 10.1016/S0965-1748(02)00047-4 <!--Retrieved from CrossRef by DOI bot-->}}</ref>


It is now well recognized that the feeding ticks, sandflies, and, more recently, mosquitoes have an ability to modulate the [[immune response]] of the animals (hosts) they feed on.<ref>{{cite journal |author=Ribeiro JM, Francischetti IM |title=Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives |journal=Annu. Rev. Entomol. |volume=48 |issue= |pages=73–88 |year=2003 |pmid=12194906 |doi=10.1146/annurev.ento.48.060402.102812}}</ref> The presence of this activity in vector saliva is a reflection of the inherent overlapping and interconnected nature of the host [[hemostatic]] and [[inflammatory]]/[[immunological]] responses and the intrinsic need to prevent these host defenses from disrupting successful feeding. The mechanism for mosquito saliva-induced alteration of the host immune response is unclear, but the data has become increasingly convincing that such an effect occurs. Early work described a factor in saliva that directly suppresses [[TNF-α]] release, but not antigen-induced [[histamine]] secretion, from activated [[mast cells]].<ref>{{cite journal |author=Bissonnette EY, Rossignol PA, Befus AD |title=Extracts of mosquito salivary gland inhibit tumour necrosis factor alpha release from mast cells |journal=Parasite Immunol. |volume=15 |issue=1 |pages=27–33 |year=1993 |pmid=7679483| doi = 10.1111/j.1365-3024.1993.tb00569.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> Experiments by Cross et al. (1994) demonstrated that the inclusion of ''Ae. aegypti'' mosquito saliva into naïve cultures led to a suppression of [[interleukin]] (IL)-2 and [[IFN-γ]] production, while the cytokines [[IL-4]] and [[IL-5]] are unaffected by mosquito saliva.<ref>{{cite journal |author=Cross ML, Cupp EW, Enriquez FJ |title=Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti |journal=Am. J. Trop. Med. Hyg. |volume=51 |issue=5 |pages=690–6 |year=1994 |pmid=7985763 |doi=}}</ref> Cellular proliferation in response to IL-2 is clearly reduced by prior treatment of cells with SGE.<ref>{{cite journal |author=Cross ML, Cupp EW, Enriquez FJ |title=Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti |journal=Am. J. Trop. Med. Hyg. |volume=51 |issue=5 |pages=690–6 |year=1994 |pmid=7985763 |doi=}}</ref> Correspondingly, activated splenocytes isolated from mice fed upon by either'' Ae. aegypti'' or ''Cx. pipiens'' mosquitoes produce markedly higher levels of IL-4 and [[IL-10]] concurrent with suppressed IFN-γ production.<ref>{{cite journal |author=Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR |title=Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice |journal=Parasite Immunol. |volume=21 |issue=1 |pages=35–44 |year=1999 |pmid=10081770 | doi = 10.1046/j.1365-3024.1999.00199.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> Unexpectedly, this shift in cytokine expression is observed in [[splenocytes]] up to 10 days after mosquito exposure, suggesting that natural feeding of mosquitoes can have a profound, enduring, and systemic effect on the immune response.<ref>{{cite journal |author=Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR |title=Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice |journal=Parasite Immunol. |volume=21 |issue=1 |pages=35–44 |year=1999 |pmid=10081770 | doi = 10.1046/j.1365-3024.1999.00199.x <!--Retrieved from CrossRef by DOI bot-->}}</ref>
It is now well recognized that the feeding ticks, sandflies, and, more recently, mosquitoes have an ability to modulate the [[immune response]] of the animals (hosts) they feed on.<ref>{{cite journal |author=Ribeiro JM, Francischetti IM |title=Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives |journal=Annu. Rev. Entomol. |volume=48 |issue= |pages=73–88 |year=2003 |pmid=12194906 |doi=10.1146/annurev.ento.48.060402.102812}}</ref> The presence of this activity in vector saliva is a reflection of the inherent overlapping and interconnected nature of the host [[hemostatic]] and [[inflammatory]]/[[immunological]] responses and the intrinsic need to prevent these host defenses from disrupting successful feeding. The mechanism for mosquito saliva-induced alteration of the host immune response is unclear, but the data has become increasingly convincing that such an effect occurs. Early work described a factor in saliva that directly suppresses [[TNF-α]] release, but not antigen-induced [[histamine]] secretion, from activated [[mast cells]].<ref>{{cite journal |author=Bissonnette EY, Rossignol PA, Befus AD |title=Extracts of mosquito salivary gland inhibit tumour necrosis factor alpha release from mast cells |journal=Parasite Immunol. |volume=15 |issue=1 |pages=27–33 |year=1993 |pmid=7679483| doi = 10.1111/j.1365-3024.1993.tb00569.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> Experiments by Cross et al. (1994) demonstrated that the inclusion of ''Ae. aegypti'' mosquito saliva into naïve cultures led to a suppression of [[interleukin]] (IL)-2 and [[IFN-γ]] production, while the cytokines [[IL-4]] and [[IL-5]] are unaffected by mosquito saliva.<ref>{{cite journal |author=Cross ML, Cupp EW, Enriquez FJ |title=Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti |journal=Am. J. Trop. Med. Hyg. |volume=51 |issue=5 |pages=690–6 |year=1994 |pmid=7985763 |doi=}}</ref> Cellular proliferation in response to IL-2 is clearly reduced by prior treatment of cells with SGE.<ref>{{cite journal |author=Cross ML, Cupp EW, Enriquez FJ |title=Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti |journal=Am. J. Trop. Med. Hyg. |volume=51 |issue=5 |pages=690–6 |year=1994 |pmid=7985763 |doi=}}</ref> Correspondingly, activated splenocytes isolated from mice fed upon by either'' Ae. aegypti'' or ''Cx. pipiens'' mosquitoes produce markedly higher levels of IL-4 and [[IL-10]] concurrent with suppressed IFN-γ production.<ref>{{cite journal |author=Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR |title=Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice |journal=Parasite Immunol. |volume=21 |issue=1 |pages=35–44 |year=1999 |pmid=10081770 | doi = 10.1046/j.1365-3024.1999.00199.x <!--Retrieved from CrossRef by DOI bot-->}}</ref> Unexpectedly, this shift in cytokine expression is observed in [[splenocytes]] up to 10 days after mosquito exposure, suggesting that natural feeding of mosquitoes can have a profound, enduring, and systemic effect on the immune response.<ref>{{cite journal |author=Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR |title=Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice |journal=Parasite Immunol. |volume=21 |issue=1 |pages=35–44 |year=1999 |pmid=10081770 | doi = 10.1046/j.1365-3024.1999.00199.x <!--Retrieved from CrossRef by DOI bot-->}}</ref>

Revision as of 19:34, 28 June 2008

For other uses, see Mosquito (disambiguation).

Mosquito
A female Culiseta longiareolata
Secure
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Subphylum:
Hexapoda
Class:
Insecta
Subclass:
Pterygota
Infraclass:
Neoptera
Superorder:
Endopterygota
Order:
Diptera
Suborder:
Nematocera
Infraorder:
Culicomorpha
Superfamily:
Culicoidea
Family:
Culicidae
Genera

See text.

Diversity
41 genera

Mosquitoes are insects which make up the family Culicidae. They have a pair of scaled wings, a pair of halteres, a slender body, and long legs. The females of most mosquito species suck blood (hematophagy) from other animals, which has made them the most deadly disease vectors known, killing millions of people over thousands of years and continuing to kill millions per year by the spread of diseases.[1][2]

Length varies but is rarely greater than 16 mm (0.6 inch)[3], and weight up to 2.5 mg (0.04 grain). A mosquito can fly for 1 to 4 hours continuously at up to 1–2 km/h[4] travelling up to 10 km in a night. Most species are nocturnal or crepuscular (dawn or dusk) feeders. During the heat of the day most mosquitoes rest in a cool place and wait for the evenings. They may still bite if disturbed.[5]

Feeding habits

Both male and female mosquitoes are nectar feeders, but the female of many species is also capable of haematophagy (drinking blood). Females do not require blood for survival, but they do need supplemental substances (like protein and iron) to develop eggs. Prior to and during blood feeding, they inject saliva. The Toxorhynchites species of mosquito never drink blood.[6] This genus includes the largest of the extant mosquitoes, the larvae of which are predatory on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents with varying success.[7]

Mosquitoes hunt their host by detecting CO2 being breathed out from a distance. When they get closer they can also pick up on the infrared heat being emitted which identifies the host as a warm blooded animal.

Mosquito Saliva

In order for a mosquito to obtain a blood meal it must surmount the vertebrate physiological responses. The mosquito, as with all blood-feeding arthropods, has evolved mechanisms to effectively block the hemostasis system with their saliva which contains a complex mixture of secreted proteins. Mosquito saliva affects vascular constriction, blood clotting, platelet aggregation, inflammation, immunity, and angiogenesis.[8] Universally, hematophagous arthropod saliva contains at least one anticlotting, one anti-platelet, and one vasodilatory substance. Mosquito saliva also contains enzymes that aid in sugar feeding[9] and antimicrobial agents to control bacterial growth in the sugar meal.[10] The composition of mosquito saliva is relatively simple as it usually contains fewer than 20 dominant proteins.[11] Despite the great strides in knowledge of these molecules and their role in bloodfeeding achieved recently, scientists still cannot ascribe functions to more than half of the molecules found in arthropod saliva.[12]

It is now well recognized that the feeding ticks, sandflies, and, more recently, mosquitoes have an ability to modulate the immune response of the animals (hosts) they feed on.[13] The presence of this activity in vector saliva is a reflection of the inherent overlapping and interconnected nature of the host hemostatic and inflammatory/immunological responses and the intrinsic need to prevent these host defenses from disrupting successful feeding. The mechanism for mosquito saliva-induced alteration of the host immune response is unclear, but the data has become increasingly convincing that such an effect occurs. Early work described a factor in saliva that directly suppresses TNF-α release, but not antigen-induced histamine secretion, from activated mast cells.[14] Experiments by Cross et al. (1994) demonstrated that the inclusion of Ae. aegypti mosquito saliva into naïve cultures led to a suppression of interleukin (IL)-2 and IFN-γ production, while the cytokines IL-4 and IL-5 are unaffected by mosquito saliva.[15] Cellular proliferation in response to IL-2 is clearly reduced by prior treatment of cells with SGE.[16] Correspondingly, activated splenocytes isolated from mice fed upon by either Ae. aegypti or Cx. pipiens mosquitoes produce markedly higher levels of IL-4 and IL-10 concurrent with suppressed IFN-γ production.[17] Unexpectedly, this shift in cytokine expression is observed in splenocytes up to 10 days after mosquito exposure, suggesting that natural feeding of mosquitoes can have a profound, enduring, and systemic effect on the immune response.[18]

T cell populations are decidedly susceptible to the suppressive effect of mosquito saliva, showing enhanced mortality and decreased division rates.[19] Parallel work by Wasserman et al. (2004) demonstrated that T- and B-cell proliferation was inhibited in a dose dependent manner with concentrations as low as 1/7th of the saliva in a single mosquito.[20] Depinay et al. (2005) observed a suppression of antibody-specific T cell responses mediated by mosquito saliva and dependent on mast cells and IL-10 expression.[21] A recent study suggests that mosquito saliva can also decrease expression of interferon−α/β during early mosquito-borne virus infection.[22] The contribution of type I interferons (IFN) in recovery from infection with viruses has been demonstrated in vivo by the therapeutic and prophylactic effects of administration of IFN-inducers or IFN,[23] and recent research suggests that mosquito saliva exacerbates West Nile virus infection,[24] as well as other mosquito-transmitted viruses.[25]

Mosquitoes and humans

Mosquitoes and health

Endemic range of yellow fever in Africa (2005)
Endemic range of yellow fever in South America (2005)

Mosquitoes are a vector agent that carries disease-causing viruses and parasites from person to person without catching the disease themselves. Female mosquitoes suck blood from people and other animals as part of their eating and breeding habits. When a mosquito bites, she also injects saliva and anti-coagulants into the blood which may also contain disease-causing viruses or other parasites. This cycle can be interrupted by killing the mosquitoes, isolating infected people from all mosquitoes while they are infectious or vaccinating the exposed population. All three techniques have been used, often in combination, to control mosquito transmitted diseases. Window screens, introduced in the 1880s, were called "the most humane contribution the 19th century made to the preservation of sanity and good temper."[26]

Mosquitoes are estimated to transmit disease to more than 700 million people annually in Africa, South America, Central America, Mexico and much of Asia with millions of resulting deaths. In Europe, Russia, Greenland, Canada, the United States, Australia, New Zealand, Japan and other temperate and developed countries, mosquito bites are now mostly an irritating nuisance; but still cause some deaths each year.[27] Historically, before mosquito transmitted diseases were brought under control, they caused tens of thousands of deaths in these countries and hundreds of thousands of infections.[28] Mosquitoes were shown to be the method by which yellow fever and malaria were transmitted from person to person by Walter Reed, William C. Gorgas and associates in the U.S. Army Medical Corps first in Cuba and then around the Panama Canal in the early 1900s.[29][30] Since then other diseases have been shown to be transmitted the same way.

The mosquito genus Anopheles carries the malaria parasite (see Plasmodium). Worldwide, malaria is a leading cause of premature mortality, particularly in children under the age of five, with around 5.3 million deaths annually, according to the Centers for Disease Control. Some species of mosquito can carry the filariasis worm, a parasite that causes a disfiguring condition (often referred to as elephantiasis) characterized by a great swelling of several parts of the body; worldwide, around 40 million people are living with a filariasis disability. The viral diseases yellow fever and dengue fever are transmitted mostly by Aedes aegypti mosquitoes. Other viral diseases like epidemic polyarthritis, Rift Valley fever, Ross River Fever, St. Louis encephalitis, West Nile virus (WNV), Japanese encephalitis, La Crosse encephalitis and several other encephalitis type diseases are carried by several different mosquitoes. Eastern equine encephalitis (EEE) and Western equine encephalitis (WEE) occurs in the United States where it causes disease in humans, horses, and some bird species. Because of the high mortality rate, EEE and WEE are regarded as two of the most serious mosquito-borne diseases in the United States. Symptoms range from mild flu-like illness to encephalitis, coma and death.[31] Viruses carried by arthropods such as mosquitoes or ticks are known collectively as arboviruses. West Nile virus was accidentally introduced into the United States in 1999 and by 2003 had spread to almost every state with over 3,000 cases in 2006.

A mosquito's period of feeding is often undetected; the bite only becomes apparent because of the immune reaction it provokes. When a mosquito bites a human, she injects saliva and anti-coagulants. For any given individual, with the initial bite there is no reaction but with subsequent bites the body's immune system develops antibodies and a bite becomes inflamed and itchy within 24 hours. This is the usual reaction in young children. With more bites, the sensitivity of the human immune system increases, and an itchy red hive appears in minutes where the immune response has broken capillary blood vessels and fluid has collected under the skin. This type of reaction is common in older children and adults. Some adults can become desensitized to mosquitoes and have little or no reaction to their bites, while others can become hyper-sensitive with bites causing blistering, bruising, and large inflammatory reactions, a response known as Skeeter Syndrome.

Mosquito control and integrated mosquito management

Dragonflies are natural predators of mosquitoes.
Main article: Mosquito control

There are two kinds of mosquito control: large, organized programs to reduce mosquito populations over a wide area, and actions individuals can take to control or exclude mosquitoes with respect to themselves and their own property.

Organized mosquito control programs today draw on the principles of integrated pest management. An integrated mosquito control program typically includes the following measures, all guided by surveillance of mosquito populations and knowledge of the mosquito life cycle:[32]

  • source reduction - the removal of mosquito breeding habitats
  • habitat modification - manipulating habitats to reduce breeding or access
  • biocontrol - introducing natural predators of mosquitoes
  • larvicide - using pesticides to reduce larval populations
  • adulticide - using pesticides to reduce adult populations

Some solutions for malaria control efforts in the third world are: mosquito nets (klamboe), mosquito nets treated with insecticide (often permethrin), and DDT.[33] Nets are treated with insecticide because mosquitoes can sometimes get past an imperfect net. Insecticide-treated nets (ITN) are estimated to be twice as effective as untreated nets in preventing mosquito bites.[34] Untreated mosquito nets are less expensive, and they are effective in protecting humans when the nets do not have any holes and are tightly sealed around the edges. Insecticide free nets do not adversely affect the health of natural predators such as dragonflies.

The role of DDT in combating mosquitoes has been the subject of considerable controversy. While some argue that DDT deeply damages biodiversity, others argue that DDT is the most effective weapon in combating mosquitoes and hence malaria. While some of this disagreement is based on differences in the extent to which disease control is valued as opposed to the value of biodiversity, there is also genuine disagreement amongst experts about the costs and benefits of using DDT. Moreover, DDT-resistant mosquitoes have started to increase in numbers, especially in tropics due to mutations, reducing the effectiveness of this chemical.

Mosquito repellents and personal mosquito control

A mosquito net
Main article: Insect repellent

One of the main, non-chemical ways to prevent mosquito bites is the mosquito net. Mosquito netting if properly used and maintained (no holes), provides the maximum possible personal protection against biting insects. In many areas of the world, mosquitoes are not only a nuisance, but also pose a serious health threat. Sleeping under a bednet is highly recommended by the World Health Organization (WHO)[35] and the U.S. Center for Disease Control (CDC)[36] if staying in these areas.

One of the most popular chemical treatments is N,N-diethyl-meta-toluamide, commonly known as DEET. It has been used widely since its invention by the U.S. Department of Agriculture in 1945. DEET products have been widely used for many years but these products have occasionally been associated with some minor to moderate adverse reactions. DEET concentrations in repellents range from 5% up to 100%.

Other less commonly used mosquito repellents include: catnip oil extract, nepetalactone (no known credible tests), citronella 10% solution (84% effective for about 1 hour), or eucalyptus oil extract.[37] A soybean oil-based product worked for about 1.5 hours[citation needed] and a lemon eucalyptus-based solution worked for about 3 hours[citation needed].

Oils of Syzygium aromaticum (clove) and Zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in Thailand, were prepared as 10 experimental repellent products in gel or cream form against Aedes aegypti, Culex quinquefasciatus, and Anopheles dirus under laboratory conditions, using the human-arm-in-cage method. Two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species under field conditions. In laboratory tests, 0.1 g of each product was applied to 3x10 cm of exposed area on a volunteer's forearm, while in field trials, 1.0 g was applied to each volunteer's leg (from knee to ankle). In the laboratory, the gel dosage form contained 20% clove oil (Gel B) or 10% clove plus 10% makaen oil mixture (Gel E) were promising plant-based repellents against three mosquito species and gave significantly longer complete protection times of 4-5 hours than all other developing products. Therefore, their efficacy in the field was evaluated. Under field conditions, Gel E showed complete protection for 4 hours and gave 95.7% repellency after 5 hours application, whereas Gel B and 20% deet (di-methyl benzamide) provided only 86.8 and 82.7% repellency after treatment, respectively against Ae. aegypti, daytime-biting mosquitoes. For nighttime-biting, the 3 repellents under development yielded equally excellent (average 97.1%) repellency for 5 hours against the predominant Cx. quinquefasciatus and Mansonia uniformis, but they gave 89.0% repellency against Cx. tritaeniorhynchus and Cx. gelidus. This finding demonstrated the effectiveness of Gel B and Gel E products for possible use by low-income rural communities against various mosquito species.

Picaridin, first used in Europe in 2001, has been reported to be effective by Consumer Reports (7% solution)[38] and the Australian Army (20% solution).[39] Consumer Report retests in 2006 show that a 7% solution of picaridin now has a protection time of about 0 minutes[citation needed] and a 15% solution was only good for about one hour.[40] So far DEET is the champion effective repellent against mosquitoes, especially when worn in conjunction with light coloured clothing, long sleeved pants and shirts and a hat.

Mosquitoes use carbon dioxide (CO2) and 1-octen-3-ol from human and animal breath and sweat as odor cues and DEET inhibits the detection of the latter in insects.[41]

Other commercial products offered for household mosquito "control" include small electrical mats, mosquito repellent vapor, DEET-impregnated wrist bands, and mosquito coils containing a form of the chemical allethrin. Mosquito-repellent candles containing citronella oil are sold widely in the U.S. All of these have been used with mixed reports of success and failure. Some claim that plants like wormwood or sagewort, lemon balm, lemon grass, lemon thyme and the mosquito plant (Pelargonium) will act against mosquitoes. However, scientists have determined that these plants are “effective” for a limited time only when the leaves are crushed and applied directly to the skin.[42]

There are several, widespread, unproven theories about mosquito control such as the assertion that Vitamin B, in particular B1 Thiamine, garlic, ultrasonic devices, incense, can be used to repel or control mosquitoes.[43] [44] Moreover, some manufacturers of "mosquito repelling" ultrasonic devices have been found to be fraudulent,[45] and their devices were deemed "useless" in tests by the UK Consumer magazine Which?[46]

Bug zappers kill a wide range of flying insects including many beneficial insects that eat mosquitoes as well as some mosquitoes. Bug zappers have not been proven effective at controlling overall mosquito population.

Some newer mosquito traps or known mosquito attractants emit a plume of carbon dioxide together with other mosquito attractants such as sugary scents, lactic acid, octenol, warmth, water vapor and sounds. By mimicking a mammal’s scent and outputs, female mosquitoes are drawn toward the trap, where they are typically sucked into a net or holder by an electric fan where they are collected. According to the American Mosquito Control Association,[47] "these devices will, indeed, trap and kill measurable numbers of mosquitoes," but their effectiveness in any particular case will depend on a number of factors such as the size and species of the mosquito population and the type and location of the breeding habitat. They are useful in specimen collection studies to determine the types of mosquitoes prevalent in an area but are typically far too inefficient to be useful in reducing mosquito populations.

Natural Predators

The dragonfly eats mosquitoes at all stages of development and is quite effective in controlling populations[48]. Although bats and Purple Martins can be prodigious consumers of insects, many of which are pests, less than 1% of their diet typically consists of mosquitoes. Bats are known carriers of rabies, and neither they nor Purple Martins are known to control or even significantly reduce mosquito populations[49].

Treatment of mosquito bites

Visible, irritating bites are due to an immune response from the binding of IgG and IgE antibodies to antigens in the mosquito's saliva. Some of the sensitizing antigens are common to all mosquito species, whereas others are specific to certain species. There are both immediate hypersensitivity reactions (Types I & III) and delayed hypersensitivity reactions (Type IV) to mosquito bites (see Clements, 2000).

There are several commercially available anti-itch medications. These are usually orally or topically applied antihistamines and, for more severe cases, corticosteroids such as hydrocortisone and triamcinolone. Many home remedy and recipes exist, most of which are effective against itching, including calamine lotion, baking soda, rubbing alcohol, vinegar. Ammonia has been clinically demonstrated to be an effective treatment[50].

Scratching, cooling, and heat are effective but bring relief only during the application, although scratching a mosquito bite usually serves to irritate and inflame the area further and increase the risk of infection and scarring.

Cultural views

According to the “Mosquitoes” chapter in Kwaidan: Stories and Studies of Strange Things, by Lafcadio Hearn (1850–1904), mosquitoes are seen as reincarnations of the dead, condemned by the errors of their former lives to the condition of Jiki-ketsu-gaki, or "blood-drinking pretas".[51]

The Babylonian Talmud (Gittin 56b) asserts that the Roman Emperor Titus was punished by God for having destroyed the Temple in Jerusalem by having a mosquito fly into Titus' nose, picking at his brain, ceaselessly buzzing, driving him crazy and eventually causing his death. No such account appears in any Roman source, but it is quite well known that Titus died prematurely, after only two years in power, from unclear causes.

Systematics

Identification

  • Brunhes, J.; Rhaim, A.; Geoffroy, B. Angel G. Hervy P. Les Moustiques de l'Afrique mediterranéenne French/English. Interactive identification guide to mosquitoes of North Africa, with database of information on morphology, ecology, epidemiology, and control. Mac/PC Numerous illustrations. IRD/IPT [12640] 2000 CD-ROM. ISBN 2-7099-1446-8 Mosquito species can also be identified through their DNA, however this is relatively expensive so it is not commonly performed. See the Use of DNA in forensic entomology.

See also

References

  1. ^ Molavi, Afshin (2003-06-12). "Africa's Malaria Death Toll Still "Outrageously High"". National Geographic. Retrieved 2007-07-27. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
  2. ^ "Pest Control—Mosquitoes". Retrieved 2007-07-27.
  3. ^ "Mosquito". Retrieved 2007-05-19.
  4. ^ http://www.sove.org/Journal%20PDF/journal%202004%20pdfs/Kaufmann.pdf
  5. ^ Rest boxes as mosquito surveillance tools
  6. ^ The carnivores, Toxorhynchites
  7. ^ http://www.pestscience.com/PDF/BNIra56.PDF
  8. ^ Ribeiro JM, Francischetti IM (2003). "Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives". Annu. Rev. Entomol. 48: 73–88. doi:10.1146/annurev.ento.48.060402.102812. PMID 12194906.
  9. ^ Grossman GL, James AA (1993). "The salivary glands of the vector mosquito, Aedes aegypti, express a novel member of the amylase gene family". Insect Mol. Biol. 1 (4): 223–32. doi:10.1111/j.1365-2583.1993.tb00095.x. PMID 7505701.
  10. ^ Rossignol PA, Lueders AM (1986). "Bacteriolytic factor in the salivary glands of Aedes aegypti". Comp. Biochem. Physiol., B. 83 (4): 819–22. doi:10.1016/0305-0491(86)90153-7. PMID 3519067.
  11. ^ Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM (2002). "Toward a description of the sialome of the adult female mosquito Aedes aegypti". Insect Biochem. Mol. Biol. 32 (9): 1101–22. doi:10.1016/S0965-1748(02)00047-4. PMID 12213246.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ^ Valenzuela JG, Pham VM, Garfield MK, Francischetti IM, Ribeiro JM (2002). "Toward a description of the sialome of the adult female mosquito Aedes aegypti". Insect Biochem. Mol. Biol. 32 (9): 1101–22. doi:10.1016/S0965-1748(02)00047-4. PMID 12213246.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. ^ Ribeiro JM, Francischetti IM (2003). "Role of arthropod saliva in blood feeding: sialome and post-sialome perspectives". Annu. Rev. Entomol. 48: 73–88. doi:10.1146/annurev.ento.48.060402.102812. PMID 12194906.
  14. ^ Bissonnette EY, Rossignol PA, Befus AD (1993). "Extracts of mosquito salivary gland inhibit tumour necrosis factor alpha release from mast cells". Parasite Immunol. 15 (1): 27–33. doi:10.1111/j.1365-3024.1993.tb00569.x. PMID 7679483.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. ^ Cross ML, Cupp EW, Enriquez FJ (1994). "Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti". Am. J. Trop. Med. Hyg. 51 (5): 690–6. PMID 7985763.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Cross ML, Cupp EW, Enriquez FJ (1994). "Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti". Am. J. Trop. Med. Hyg. 51 (5): 690–6. PMID 7985763.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR (1999). "Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice". Parasite Immunol. 21 (1): 35–44. doi:10.1046/j.1365-3024.1999.00199.x. PMID 10081770.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ^ Zeidner NS, Higgs S, Happ CM, Beaty BJ, Miller BR (1999). "Mosquito feeding modulates Th1 and Th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice". Parasite Immunol. 21 (1): 35–44. doi:10.1046/j.1365-3024.1999.00199.x. PMID 10081770.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ^ Wanasen N, Nussenzveig RH, Champagne DE, Soong L, Higgs S (2004). "Differential modulation of murine host immune response by salivary gland extracts from the mosquitoes Aedes aegypti and Culex quinquefasciatus". Med. Vet. Entomol. 18 (2): 191–9. doi:10.1111/j.1365-2915.2004.00498.x. PMID 15189245.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. ^ Wasserman HA, Singh S, Champagne DE (2004). "Saliva of the Yellow Fever mosquito, Aedes aegypti, modulates murine lymphocyte function". Parasite Immunol. 26 (6–7): 295–306. doi:10.1111/j.0141-9838.2004.00712.x. PMID 15541033.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. ^ Depinay N, Hacini F, Beghdadi W, Peronet R, Mécheri S (2006). "Mast cell-dependent down-regulation of antigen-specific immune responses by mosquito bites". J. Immunol. 176 (7): 4141–6. PMID 16547250.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  22. ^ Schneider BS, Soong L, Zeidner NS, Higgs S (2004). "Aedes aegypti salivary gland extracts modulate anti-viral and TH1/TH2 cytokine responses to sindbis virus infection". Viral Immunol. 17 (4): 565–73. doi:10.1089/vim.2004.17.565. PMID 15671753.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  23. ^ Taylor JL, Schoenherr C, Grossberg SE (1980). "Protection against Japanese encephalitis virus in mice and hamsters by treatment with carboxymethylacridanone, a potent interferon inducer". J. Infect. Dis. 142 (3): 394–9. PMID 6255036.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  24. ^ Schneider BS, Soong L, Girard YA, Campbell G, Mason P, Higgs S (2006). "Potentiation of West Nile encephalitis by mosquito feeding". Viral Immunol. 19 (1): 74–82. doi:10.1089/vim.2006.19.74. PMID 16553552.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  25. ^ Schneider BS, Higgs S (2008). "The enhancement of arbovirus transmission and disease by mosquito saliva is associated with modulation of the host immune response". Trans. R. Soc. Trop. Med. Hyg. 102: 400. doi:10.1016/j.trstmh.2008.01.024. PMID 18342898.
  26. ^ History/reason of mosquito control in nj
  27. ^ Mosquitoes and Mosquito Repellents: A Clinician's Guide by Mark S. Fradin: Annals of Internal Medicine, 1 June 1998. 128:931-940. Retrieved 10 July 2006.
  28. ^ The American Plague, by Molly Caldwell Crosby, pg 12, Berkley Books, New York, 2005, ISBN 0-425-21202-5
  29. ^ The Path Between the Seas: the Creation of the Panama Canal 1870-1914, by David McCullough,1977, Simon and Shuster, ISBN 0-971-22563-4
  30. ^ The American Plague, by Molly Caldwell Crosby, pg 100-202, Berkley Books, New York, 2005, ISBN 0-425-21202-5
  31. ^ Mosquito-borne diseases, infectious disease information, NCID, CDC
  32. ^ C:\MyFiles\Dame\Chap-3\Chap03-pdf.wpd
  33. ^ Vector Control | CDC Malaria
  34. ^ Hull, Kevin. (2006) "Malaria: Fever Wars". PBS Documentary
  35. ^ http://www.who.int/malaria/docs/healthworkers/healthworkers.pdf |pg. 19
  36. ^ Division of Parasitic Diseases - West African trypanosomiasis Fact Sheet
  37. ^ Fradin M S, Day J F. "Comparative efficacy of insect repellents against mosquito bites." New England Journal of Medicine 2002; 347: 13-18.
  38. ^ Consumerreports.Org - Consumer Reports Confirms Effectiveness Of New Alternative To Deet
  39. ^ http://www.bioone.org/perlserv/?request=get-document&issn=0022-2585&volume=041&issue=03&page=0414
  40. ^ Consumer Report magazine, June 2006|Bug Repellents
  41. ^ Mathias Ditzen, Maurizio Pellegrino, Leslie B. Vosshall (2008). "Insect Odorant Receptors Are Molecular Targets of the Insect Repellent DEET". Sciencexpress. 319: 1838. doi:10.1126/science.1153121. PMID 18339904.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  42. ^ Page Error
  43. ^ Insect bites and stings. DermNet NZ
  44. ^ http://www.vnh.org/NHB/HW9421Mosquito2.html [dead link‍]
  45. ^ Lentek International-08/28/02
  46. ^ "The great mosquito sting". 6 Sept 2005. Retrieved 2007-08-09. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  47. ^ Traps - AMCA
  48. ^ Singh SP, Singh RK. "Laboratory studies on the predatory potential of dragon-fly nymphs on mosquito larvae". J Commun Dis. 35: 96–101.
  49. ^ Fradin MS. "Mosquitoes and mosquito repellents: a clinician's guide". Ann Intern Med. 128: 931–40.
  50. ^ Maibach, Howard I. "Mosquito Bite Therapy: Evidenced-Based" (PDF). Exogenous Dermatology. 3 (6): 332–338. doi:10.1159/000093650. Retrieved 2007-10-08. {{cite journal}}: Cite has empty unknown parameters: |coauthors= and |unused_data= (help); Text "location" ignored (help)
  51. ^ Hearn, Lafcadio. Kwaidan: Stories and Studies of Strange Things. Dover Publications, Inc., 1968 (ISBN 0-486-21901-1)
  • Clements, A.N. 2000. The Biology of Mosquitoes. Volume 1: Development, Nutrition and Reproduction. CABI Publishing, Oxon. ISBN 0-85199-374-5
  • Davidson, E. (ed.) 1981. Pathogenesis of Invertebrate Micorobial Diseases. Allanheld, Osmun & Co. Publishers, Inc., Totowa, New Jersey, USA. 562 pages.
  • Jahn, G. C., Hall, D.W., and Zam, S. G. 1986. A comparison of the life cycles of two Amblyospora (Microspora: Amblyosporidae) in the mosquitoes Culex salinarius and Culex tarsalis Coquillett. J. Florida Anti-Mosquito Assoc. 57, 24–27.
  • Kale, H.W., II. 1968. The relationship of purple martins to mosquito control. The Auk 85: 654-661.
Wikimedia Commons has media related to Culicidae.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Mosquito&oldid=222330690"