Chemistry:Toxicology of red imported fire ant venom

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Short description: Overview of toxicology of imported fire ant venom

The toxicology of fire ant venom is relatively well studied. The venom plays a central role in the biology of Red imported fire ants, such as in capturing prey,[1] and in defending itself from competitors,[2] assailants,[3] and diseases.[4] Some 14 million people are stung annually in the United States,[5] suffering reactions that vary from mild discomfort, to pustule formation, swelling,[6] and in rare cases, systemic reactions followed by anaphylactic shock.[7] Fire ant venoms are mainly composed (>95%) of a complex mixture of insoluble alkaloids added to a watery solution of toxic proteins.[8] For the Red imported fire ant Solenopsis invicta Buren there are currently 46 described proteins,[9] of which four are well-characterised as potent allergens.[10]

Venom

Solenopsin, one of the components of the venom

Venom plays an important role in the biology of fire ants, being used to capture prey items,[1] nest defense,[2] and antimicrobial action.[11] On average, however, a worker stores very little venom (only about 0.5 µg at any given time).[12] Newborn workers contain little to no venom within their reservoirs, but workers that are only one day old can produce 1.17 µg/day. However, workers that are 17 days old only produce 0.3 µg/day. Workers deliver 0.66 nl of venom when they sting, which amounts to 3.1% of their supply. Older workers deliver less venom when they sting, but middle-aged workers and nest-defenders deliver much higher quantities.[13] Like all fire ant species, venom is secreted by the venom gland and is stored in the poison sac.[14] When in use, it is ejected through the stinger's main duct. Capacity is between 20 and 40 nl, but this depends on the worker's size.[15] The American entomologist Justin O. Schmidt described it as being "sharp, sudden, mildly alarming", therefore ranking at "1" in the Schmidt sting pain index, a pain scale which ranks the pain intensity of an insect's sting from 0 to 4.[16]

Over 95% of the venom components are water-insoluble piperidine alkaloids. Piperidines include trans-2-methyl-6-n-undecylpiperidines, trans-2-methyl-6-n-tridecylpiperidine, trans-2-methyl-6-(cis-4-tridecenyl) piperidines, trans-2-methyl-6-n-pentadecylpiperidine, trans-2-methyl-6-(cis-6-pentadecenyl)piperidine and 2,6-dialkylpiperidines (the ants' venom is dominated by the trans- stereoisomers of this specific ingredient).[17][18][19] trans-2-Methyl-6-n-undecylpiperidine (solenopsin) has been shown to have cytotoxic, hemolytic, necrotic, insecticidal, antibacterial, antifungal, and anti-HIV properties.[20] As well as that, the alkaloid has shown antiangiogenic activity.[21] These components are responsible for the formation of hives, and also for the development of sterile pustules on areas where the ant has stung.[22] Experiments indicate that the median lethal dose (LD50) on tested female rats is 0.36 mg/kg.[23]

Approximately 46 proteins have been identified in the red imported fire ant's venom,[9] although scientists have long believed the venom only contained alkaloids.[24][25] This assumption was mostly due to the difficulties in obtaining sufficient venom for analysis because of its low protein content, which is only 0.1% of the venom's total weight.[26]

These proteins are experimentally suggested to directly account for the anaphylactic reactions seen in humans sensitive to the venom.[27] Whilst including a number of neurotoxins and potential allergens, not all of these proteins are involved with venom function.[9] At least four protein allergens have been characterised, named Sol i 1-4. Of these, Sol i 3, is part of the antigen 5 family, and Sol i 1 is a phospholipase A1B; Sol i 1 shows a close relation with wasp venom phospholipases.[22][28][29][30] Sol i 2 and 4 are unique, odorant-binding proteins of poorly understood function. Other proteins found in the venom may benefit the colony; some of these proteins can kill off bacteria, which may explain why workers spray venom around their nests by vibrating their gasters. Other proteins also bind pheromones which may assist a worker to lay chemical trails to communicate with other nestmates.[12][9][31]

Incidence

In the United States, more than 40 million people live in areas infested with fire ant populations and 14 million people are stung by them annually. A quarter of all victims stung by red imported fire ants are expected to develop sensitivity to the venom, and approximately 6,000 will suffer anaphylaxis.[32] 51% of people who relocated themselves to infested areas report getting stung within three weeks after arrival.[33] In a survey conducted in South Carolina, 33,000 people (or 94 per 10,000 population) received medical attention due to red imported fire ants, and 660 people (1.9 per 10 000 population) were treated for anaphylaxis.[34] In Texas, 79% of participants in a survey stated they had been stung by red imported fire ants, while 20% had not. 61% of West Texans state they had been stung by the ants before, compared to 90% in central Texas, 89% in east Texas, 86% in the gulf coastal regions, 78% in the south and 72% in the north.[35] In separate survey, 87% of individuals classed their reactions as mild, 12% as moderate and 1% as severe.[36] In Australia, 64,000 homes are within red imported fire ant infested areas, and 140,000 consultations and 3,000 anaphylactic reaction cases are predicted every year by 2030 if government efforts to eradicate the ant fail.[37] A survey conducted in China shows that one-third of participants in infested areas were victims of red imported fire ant stings.[38]

Studies suggest that the rate of systemic reactions to stings may be associated with seasonal variations in the venom's potency. 51% of allergic reactions occurred in summer, and 19% in spring. However, A survey reported a higher incidence during spring (39.9%) than summer (31.9%).[39] Younger people, usually those under 20 years, experience the highest rate of sting attacks (50%), but the rate declines with older people. Among men and women, the rate varies as some studies report more women being attacked than men and vice versa.[36][38] Deaths from red imported fire ant stings are rare, but may become common the more the ant spreads. Many cases have also been reported in the past.[40] It is reported that more than 80 deaths have been recorded; of these, 22 cases were recorded in Florida and 19 in Texas. However, when duplicate reports are excluded, four deaths were recorded in Alabama, 10 in Florida, two in Georgia and Louisiana, and 14 in Texas.[41][42][43] People can be educated and be made aware of the dangers of red imported fire ants.[44]

Signs and symptoms

Formation of pustules on a human leg

Reactions seen in humans vary; some are hypersensitive to venom while others show resilience. Hypersensitivity can be attributed to certain medical problems such as heart conditions or diabetes. Bacterial infections attributed to sting injuries also pose a problem and may require further medical attention. Most humans can withstand many stings, but others may suffer from severe reactions such as anaphylaxis.[45]

People who are stung by red imported fire ants may experience intense local burning or flare-ups, followed by reddening of the skin at the sting site. This area will swell into a bump, hive or vesicle within 20 minutes. White fluid-filled sterile pustules begin to form within hours or days after being stung.[45][38][46][47] Pustules on the skin remain for a couple of days, and may become infected which would require medical attention. In most cases, pustules dry up in a matter of weeks and leave brown scars that either remain for several months or become permanent.[45] The formation of pustules occurs in almost every person stung by the ants. In one study, 96% of participants reported the formation of pustules, whereas 2% reported large local reactions.[33] Between 17% and 56% of people stung develop venom-specific IgE. Many of them will experience pruritic lumps around areas where the ants stung, known as late-phase responses or cutaneous allergic reactions.[42][48][49]

Pustule formation can only be prevented if the ants are removed before they have a chance to sting. Once venom has been injected, pustules will form and no form of treatment will prevent them from occurring. Medications such as antibiotics, diphenylhydrazines, epinephrines or topical steroids will not affect pustular reactions.[45][49][50]

Anaphylaxis occurs in 0.6 to 6% of people who have been stung by the ants, and it can be fatal if left untreated.[40][42] Typical symptoms of anaphylaxis include dizziness, headaches, fever, severe chest pain, nausea, severe sweating, low blood pressure, loss of breath, serious swelling, and slurred speech.[45][38][51] One case reports a victim feeling strong vertigo 5 to 10 minutes after being stung, followed by glassy eyes, dry mouth, paleness, unconsciousness and severe cramps on the sting sites.[52] In addition, neuropathy, seizures (even without any evidence of prior systemic reactions), cerebrovascular accidents, and nephrotic syndrome have been associated with red imported fire ant stings.[45][42][53] A series of neurotoxins have been identified in red imported fire ant venom, which may explain why some victims experience hallucinations after they have been stung.[12]

Treatment

Adrenaline (also called epinephrine) can quickly reverse the adverse events of dyspnoea and hypotension

It is suggested that a conservative approach be used when treating sting injuries; specifically, the kind of treatment used should be based on the symptoms. For minor sting injuries, with symptoms only including pustule formations and pain, over-the-counter products are available to prevent infection. Ants should be removed by washing the area with antiseptic soap, and itchiness. It is rare for ant sting sites to become infected, so the use of antibiotic prophylaxis is not always required.[45][54]

Victims who show signs of anaphylaxis are treated with antihistamines, epinephrines, and parenteral corticosteroids.[42] Epinephrine is the first product for use to treat systemic allergic responses, particularly if a patient is experiencing dyspnoea or hypotension because it is capable of reversing adverse events quickly and is very safe to use. It is recommended that people who have suffered from anaphylaxis carry an epinephrine autoinjector (EpiPen), should dyspnoea or hypotension begin to occur.[37]

Whole body extract immunotherapy (WBE) to treat victims of anaphylaxis[55][56] has been in use since 1973.[57][58] Anyone who has a suspected allergy to the venom is redirected to an allergist for assessment.[45] The treatment uses the entire body of the ant and not just the venom, and unlike fire ant venom immunotherapy (which is occasionally used), WBE contains venom proteins.[59][56] To reduce a patient's sensitivity to the venom, gradual increases of dose extracts are injected into the body.[60] WBE immunotherapy appears to be very effective in preventing systemic reactions;[55][56] in one study[61] of participants who completed WBE immunotherapy, two out of fifteen participants suffered from allergic reactions upon being stung 18 months after immunotherapy.[54] As mentioned, fire ant venom immunotherapy is occasionally used, and studies show it can reduce the risk of systemic reactions.[62][63] In fact, another study claims that fire ant venom immunotherapy is more effective than WBE immunotherapy.[64] Fire ant venom immunotherapy is not recommended for children with large local reactions, although an exception may be made for those who live in heavily infested areas. There is also an increased risk of systemic allergic reactions to future stings in children who have cutaneous manifestations after getting stung. This makes many experts put some children on fire ant venom immunotherapy, while others do not.[54][65]

The recommended maintenance dose is between 0.5 mL of a 1:100 w/v 1:10 w/v WBE.[66] For fire ant venom immunotherapy, the most common maintenance dose is 0.5 mL of a 1:200 (wt/vol) dilution.[67] During the build-up phase, it is recommended that dosing is given weekly or biweekly, although some scientists suggest that rush protocols can be successful.[54][68] It is recommended that patients going through immunotherapy receive treatment for three to five years, and lifelong therapy, although there is no consensus as to how long an individual should be treated.[54][69]

Stings to animals

The stings of the red imported fire ant in animals are painful, and may prove life-threatening.[70] In dogs, stings from the red imported fire ant can cause pustular dermatosis, a condition where pustules appear in crops as a result of the ant sting.[71] After getting stung, the immediate response consists of erythema and swelling. The pustules remain for approximately 24 hours, whereas in humans they can last for several days.[72] In livestock, red imported ants mostly sting animals in regions with no hair, particularly around the ears, eyes, muzzle, the perineum and ventral portion of the abdomen. Newborn or young livestock can be blinded or killed when attacked by the ants.[73][74] Healthy individuals are less likely to be attacked than weak or sick animals. Red papule and mild swelling occur, followed by vesicopustule with a red halo developing within 24 to 48 hours. The eyes and eyelids are commonly damaged from the stings; in sheep and goats, ophthalmic ointment containing antibiotics and corticosteroids can be used to treat the eyes of sheep and goats, but this treatment is not recommended for horses. In non-domestic animals, cases of red imported fire ants stings in animals such as ferrets, moles squirrels, white-tailed deer, cottontail rabbits, and newborn blackbucks have been reported, as well as lizards and screech owl nestlings. The aftermath of the injuries is like those in domestic animals.[73]

Red imported fire ants are known to actively kill vertebrate animals, and cause significant livestock losses.[75] Animals may trigger major stinging episodes when they disturb active nests, with thousands of ants participating in the attack. During such episodes, an animal may suffer from hundreds to thousands of individual stings. It is suspected that many victims of the red imported fire ants may be depressed as a result of the effects of the toxin. Some animals may swallow red imported fire ants as they lick or bite around the sites they are stinging. This can cause additional injuries inside the animal itself, especially in the upper gastrointestinal tract. In suckling white tail deer fawns, sting sites have been found in the oesophagus and abomasum; toxins from the ingested ants may cause inflammation of the gastrointestinal lining.[73]

References

  1. 1.0 1.1 Lai, Li-Chuan; Kuo, Tai-Chih; Huang, Rong-Nan; Wu, Wen-Jer (1 October 2012). "The Insecticidal Activities of Fire Ant (Hymenoptera: Formicidae) Venoms Against Plutella xylostella (Lepidoptera: Plutellidae) Larvae". Journal of Economic Entomology 105 (5): 1591–1596. doi:10.1603/EC12075. PMID 23156154. 
  2. 2.0 2.1 Greenberg, Les; Kabashima, John N.; Allison, Clinton J.; Rust, Michael K.; Klotz, John H.; Hurvois, Jean-Pierre; Paine, Timothy D. (1 November 2008). "Lethality of Red Imported Fire Ant Venom to Argentine Ants and Other Ant Species". Annals of the Entomological Society of America 101 (6): 1162–1168. doi:10.1603/0013-8746-101.6.1162. 
  3. Haight, K. L. (February 2006). "Defensiveness of the fire ant, Solenopsis invicta, is increased during colony rafting". Insectes Sociaux 53 (1): 32–36. doi:10.1007/s00040-005-0832-y. 
  4. Obin, Martin S.; Vander Meer, Robert K. (December 1985). "Gaster flagging by fire ants (Solenopsis spp.): Functional significance of venom dispersal behavior". Journal of Chemical Ecology 11 (12): 1757–1768. doi:10.1007/BF01012125. PMID 24311339. https://zenodo.org/record/1232476. 
  5. Taber 2000, p. 308.
  6. Hoffman, Donald R (August 2010). "Ant venoms". Current Opinion in Allergy and Clinical Immunology 10 (4): 342–346. doi:10.1097/ACI.0b013e328339f325. PMID 20445444. 
  7. Stafford, Chester T. (August 1996). "Hypersensitivity to Fire Ant Venom". Annals of Allergy, Asthma & Immunology 77 (2): 87–99. doi:10.1016/S1081-1206(10)63493-X. PMID 8760773. 
  8. Fox 2016, p. [page needed].
  9. 9.0 9.1 9.2 9.3 Pinto, José R. A.; Fox, Eduardo G. P.; Saidemberg, Daniel M.; Santos, Lucilene D.; da Silva Menegasso, Anally R.; Costa-Manso, Eliúde; Machado, Ednildo A.; Bueno, Odair C. et al. (22 August 2012). "Proteomic View of the Venom from the Fire Ant Buren". Journal of Proteome Research 11 (9): 4643–4653. doi:10.1021/pr300451g. PMID 22881118. 
  10. Hoffman, DR; Dove, DE; Jacobson, RS (November 1988). "Allergens in Hymenoptera venom. XX. Isolation of four allergens from imported fire ant (Solenopsis invicta) venom.". The Journal of Allergy and Clinical Immunology 82 (5 Pt 1): 818–27. doi:10.1016/0091-6749(88)90084-X. PMID 3192865. 
  11. Jouvenaz, D. P.; Blum, M. S.; MacConnell, J. G. (1 October 1972). "Antibacterial Activity of Venom Alkaloids from the Imported Fire Ant, Solenopsis invicta Buren1". Antimicrobial Agents and Chemotherapy 2 (4): 291–293. doi:10.1128/AAC.2.4.291. PMID 4670503. 
  12. 12.0 12.1 12.2 Gebel, E. (20 August 2012). "Proteins Revealed In Fire Ant Venom". Chemical & Engineering News. ISSN 0009-2347. http://cen.acs.org/articles/90/web/2012/08/Proteins-Revealed-Fire-Ant-Venom.html. 
  13. Haight, K.L.; Tschinkel, W.R. (2003). "Patterns of venom synthesis and use in the fire ant, Solenopsis invicta". Toxicon 42 (6): 673–682. doi:10.1016/j.toxicon.2003.09.005. PMID 14602123. http://www.bio.fsu.edu/~tschink/publications/2003-1.pdf. 
  14. Paterson Fox, Eduardo Gonçalves; Correa Bueno, Odair; Yabuki, Antônio Teruyoshi; jesus, Carlos Massuretti de; Solis, Daniel Russ; Rossi, Mônica Lanzoni; Nogueira, Neusa de Lima (March 2010). "General Morphology and Ultrastructure of the Venom Apparatus and Convoluted Gland of the Fire Ant". Journal of Insect Science 10 (24): 24. doi:10.1673/031.010.2401. PMID 20578888. 
  15. Tschinkel 2006, p. 365.
  16. Schmidt, J.O.; Blum, M.S.; Overal, W.L. (1983). "Hemolytic activities of stinging insect venoms". Archives of Insect Biochemistry and Physiology 1 (2): 155–160. doi:10.1002/arch.940010205. 
  17. Buren, W.F. (1972). "Revisionary studies on the taxonomy of the imported fire ants". Journal of the Georgia Entomological Society 7: 1–26. doi:10.5281/zenodo.27055. 
  18. Jouvenaz, D.P.; Blum, M.S.; MacConnell, J.G. (1972). "Antibacterial activity of venom alkaloids from the imported fire ant, Solenopsis invicta Buren". Antimicrobial Agents and Chemotherapy 2 (4): 291–293. doi:10.1128/AAC.2.4.291. PMID 4670503. 
  19. Chen, L.; Fadamiro, H.Y. (2009). "Re-investigation of venom chemistry of Solenopsis fire ants. II. Identification of novel alkaloids in S. invicta". Toxicon 53 (5): 479–486. doi:10.1016/j.toxicon.2009.01.016. PMID 19673093. 
  20. Howell, G.; Butler, J.; Deshazo, R.D.; Farley, J.M.; Liu, H.L.; Nanayakkara, N.P.; Yates, A.; Yi, G.B. et al. (2005). "Cardiodepressant and neurologic actions of Solenopsis invicta (imported fire ant) venom alkaloids". Annals of Allergy, Asthma & Immunology 94 (3): 380–386. doi:10.1016/S1081-1206(10)60991-X. PMID 15801250. 
  21. Arbiser, J.L.; Kau, T.; Konar, M.; Narra, K.; Ramchandran, R.; Summers, S.A.; Vlahos, C.J.; Ye, K. et al. (2007). "Solenopsin, the alkaloidal component of the fire ant (Solenopsis invicta), is a naturally occurring inhibitor of phosphatidylinositol-3-kinase signaling and angiogenesis". Blood 109 (2): 560–565. doi:10.1182/blood-2006-06-029934. PMID 16990598. 
  22. 22.0 22.1 Hoffman, D.R. (2010). "Ant venoms". Current Opinion in Allergy and Clinical Immunology 10 (4): 342–346. doi:10.1097/aci.0b013e328339f325. PMID 20445444. http://antgenomes.org/publications/hoffman2010antVenoms.pdf. 
  23. Alley, E.G. (1973). "The use of mirex in control of the imported fire ant". Journal of Environmental Quality 2 (1): 52–61. doi:10.2134/jeq1973.00472425000200010005x. 
  24. BLUM, MS; WALKER, JR; CALLAHAN, PS; NOVAK, AF (8 August 1958). "Chemical, insecticidal and antibiotic properties of fire ant venom.". Science 128 (3319): 306–7. doi:10.1126/science.128.3319.306. PMID 13568785. Bibcode1958Sci...128R.306B. 
  25. Baer, Harold; Liu, T.-Y.; Anderson, Martha C.; Blum, Murray; Schmid, William H.; James, Frank J. (January 1979). "Protein components of fire ant venom (Solenopsis invicta)". Toxicon 17 (4): 397–405. doi:10.1016/0041-0101(79)90267-8. PMID 494321. 
  26. Fox, Eduardo G P; Solis, Daniel R; Santos, Lucilene D R; Pinto, Jose Roberto; Menegasso, Anally R S; Silva, Rafael CMC; Palma, Mario S; Bueno, Odair C et al. (April 2013). "A simple, rapid method for the extraction of whole fire ant venom (Insecta: Formicidae: Solenopsis)". Toxicon 65: 5–8. doi:10.1016/j.toxicon.2012.12.009. PMID 23333648. 
  27. Zamith-Miranda, Daniel; Fox, Eduardo G. P.; Monteiro, Ana Paula; Gama, Diogo; Poublan, Luiz E.; de Araujo, Almair Ferreira; Araujo, Maria F. C.; Atella, Georgia C. et al. (26 September 2018). "The allergic response mediated by fire ant venom proteins". Scientific Reports 8 (1): 14427. doi:10.1038/s41598-018-32327-z. PMID 30258210. Bibcode2018NatSR...814427Z. 
  28. Hoffman, D.R.; Sakell, R.H.; Schmidt, M. (2005). "Sol i 1, the phospholipase allergen of imported fire ant venom". Journal of Allergy and Clinical Immunology 115 (3): 611–616. doi:10.1016/j.jaci.2004.11.020. PMID 15753912. 
  29. Hoffman, D.R.; Dove, D.E.; Jacobson, R.S. (1988). "Allergens in Hymenoptera venom. XX. Isolation of four allergens from imported fire ant (Solenopsis invicta) venom". Journal of Allergy and Clinical Immunology 82 (5 Pt 1): 818–827. doi:10.1016/0091-6749(88)90084-X. PMID 3192865. 
  30. Hoffman, D.R. (1993). "Allergens in Hymenoptera venom XXIV: the amino acid sequences of imported fire ant venom allergens Sol i II, Sol i III, and Sol i IV". The Journal of Allergy and Clinical Immunology 91 (1 Pt 1): 71–78. doi:10.1016/0091-6749(93)90298-T. PMID 8423273. 
  31. Obin, M.S.; Vander Meer, R.K. (1985). "Gaster flagging by fire ants (Solenopsis spp.): Functional significance of venom dispersal behavior". Journal of Chemical Ecology 11 (12): 1757–1768. doi:10.1007/BF01012125. PMID 24311339. https://zenodo.org/record/1232476. 
  32. Taber 2000, p. 130.
  33. 33.0 33.1 Tracy, J.M.; Demain, J.G.; Quinn, J.M.; Hoffman, D.R.; Goetz, D.W.; Freeman, T.M. (1995). "The natural history of exposure to the imported fire ant (Solenopsis invicta)". Journal of Allergy and Clinical Immunology 95 (4): 824–828. doi:10.1016/S0091-6749(95)70125-7. PMID 7722162. 
  34. Caldwell, S.T.; Schuman, S.H.; Simpson, W.M. Jr. (1999). "Fire ants: a continuing community health threat in South Carolina". Journal of the South Carolina Medical Association (1975) 95 (6): 231–235. PMID 10389385. 
  35. "Solenopsis invicta (red imported fire ant)". Invasive Species Compendium. CABI. 2014. http://www.cabi.org/isc/datasheet/50569. 
  36. 36.0 36.1 Adams, C.T.; Lofgren, C.S. (1981). "Red imported fire ants (Hymenoptera: Formicidae): frequency of sting attacks on residents of Sumter County, Georgia". Journal of Medical Entomology 18 (5): 378–382. doi:10.1093/jmedent/18.5.378. PMID 7299792. 
  37. 37.0 37.1 Solley, G.O.; Vanderwoude, C.; Knight, G.K. (2002). "Anaphylaxis due to red imported fire ant sting". The Medical Journal of Australia 176 (11): 521–523. doi:10.5694/j.1326-5377.2002.tb04548.x. PMID 12064982. http://era.daf.qld.gov.au/id/eprint/7054/. 
  38. 38.0 38.1 38.2 38.3 Xu, Y.; Huang, J.; Zhou, A.; Zeng, L. (2012). "Prevalence of Solenopsis invicta (Hymenoptera: Formicidae) venom allergic reactions in mainland China". The Florida Entomologist 95 (4): 961–965. doi:10.1653/024.095.0421. 
  39. Hannan, C. Jr.; Stafford, C.; Rhoades, R.; Wray, B.; Baer, H.; Anderson, M. (1986). "Seasonal variation in antigens of the imported fire ant Solenopsis invicta". Journal of Allergy and Clinical Immunology 78 (2): 331–336. doi:10.1016/S0091-6749(86)80085-9. PMID 3734284. 
  40. 40.0 40.1 Prahlow, J.A.; Barnard, J.J. (1998). "Fatal anaphylaxis due to fire ant stings". The American Journal of Forensic Medicine and Pathology 19 (2): 137–142. doi:10.1097/00000433-199806000-00007. PMID 9662108. 
  41. Rhoades, R.B.; Stafford, C.T.; James, F.K. (1989). "Survey of fatal anaphylactic reactions to imported fire ant stings". Journal of Allergy and Clinical Immunology 84 (2): 159–162. doi:10.1016/0091-6749(89)90319-9. PMID 2760357. 
  42. 42.0 42.1 42.2 42.3 42.4 deShazo, R.D.; Williams, D.F.; Moak, E.S. (1999). "Fire ant attacks on residents in health care facilities: a report of two cases". Annals of Internal Medicine 131 (6): 424–429. doi:10.7326/0003-4819-131-6-199909210-00005. PMID 10498558. 
  43. Lockey & Ledford 2014, pp. 409–410.
  44. "Integrated Pest Management Manual: Fireants". National Park Service. United States Department of the Interior. 2010. http://www.nature.nps.gov/biology/ipm/manual/fireants.cfm. 
  45. 45.0 45.1 45.2 45.3 45.4 45.5 45.6 45.7 Drees, B.M. (2002). "Medical problems and treatment considerations for the red imported fire ant". Texas Imported Fire Ant Research and Management Project. Texas A&M University. https://fireant.tamu.edu/files/2011/12/FAPFS023_2002rev_Medical.pdf. 
  46. Schneiderman & Grossman 2006, p. 93.
  47. Potiwat, R.; Sitcharungsi, R. (2015). "Ant allergens and hypersensitivity reactions in response to ant stings". Asian Pacific Journal of Allergy and Immunology 33 (4): 267–275. PMID 26708389. 
  48. Stafford, C.T. (1992). "Fire ant allergy". Allergy Proceedings 13 (1): 11–16. doi:10.2500/108854192778878971. PMID 1577260. 
  49. 49.0 49.1 Caro, M.R.; Derbes, V.J.; Jung, R. (1957). "Skin responses to the sting of the imported fire ant (Solenopsis Saevissima)". Archives of Dermatology 75 (4): 475–488. doi:10.1001/archderm.1957.01550160001001. PMID 13410107. 
  50. Parrino, J.; Kandawalla, N.M.; Lockey, R.F. (1981). "Treatment of local skin response to imported fire ant sting". Southern Medical Journal 74 (11): 1361–1364. doi:10.1097/00007611-198111000-00017. PMID 7302637. 
  51. "Insects and Scorpions – Fire Ants". The National Institute for Occupational Safety and Health. Centers for Disease Control and Prevention. 2008. https://www.cdc.gov/niosh/topics/insects/fireants.html. 
  52. Haddad Junior, V.; Larsson, C.E. (2015). "Anaphylaxis caused by stings from the Solenopsis invicta, lava-pés ant or red imported fire ant". Anais Brasileiros de Dermatologia 90 (3): 22–25. doi:10.1590/abd1806-4841.20153420. PMID 26312665. 
  53. Candiotti, Keith A.; Lamas, Ana M. (1993). "Adverse neurologic reactions to the sting of the imported fire ant". International Archives of Allergy and Immunology 102 (4): 417–420. doi:10.1159/000236592. PMID 8241804. 
  54. 54.0 54.1 54.2 54.3 54.4 Pesek, R.D.; Lockey, R.F. (2013). "Management of insect sting hypersensitivity: an update". Allergy, Asthma & Immunology Research 5 (3): 129–137. doi:10.4168/aair.2013.5.3.129. PMID 23638310. 
  55. 55.0 55.1 Freeman, T.; Hylander, R.; Ortiz, A.; Martin, M. (1992). "Imported fire ant immunotherapy: Effectiveness of whole body extracts". Journal of Allergy and Clinical Immunology 90 (2): 210–215. doi:10.1016/0091-6749(92)90073-B. PMID 1500625. https://zenodo.org/record/1258303. 
  56. 56.0 56.1 56.2 Paull, B.R. (1984). "Imported fire ant allergy. Perspectives on diagnosis and treatment". Postgraduate Medicine 76 (1): 155–162. doi:10.1080/00325481.1984.11698672. PMID 6739381. 
  57. Moffitt, J.E.; Barker, J.R.; Stafford, C.T. (1997). "Management of imported fire ant allergy: Results of a survey". Annals of Allergy, Asthma & Immunology 79 (2): 125–130. doi:10.1016/S1081-1206(10)63098-0. PMID 9291416. 
  58. Triplett, R.F. (1973). "Sensitivity to the imported fire ant: successful treatment with immunotherapy". Southern Medical Journal 66 (4): 477–480. doi:10.1097/00007611-197304000-00019. PMID 4708246. 
  59. Nordvall, S.L.; Johansson, S.G.; Ledford, D.K.; Lockey, R.F. (1988). "Allergens of the imported fire ant.". The Journal of Allergy and Clinical Immunology 82 (4): 567–576. doi:10.1016/0091-6749(88)90966-9. PMID 3171000. 
  60. "Types of Allergies: Insect Sting Allergy". American College of Allergy, Asthma & Immunology. http://acaai.org/allergies/types/insect-sting-allergies. 
  61. Quinn, J.M., Tajiri, K.S., Motta, P. and Freeman, T.M., 1994, January. LONG-TERM EFFICACY AFTER DISCONTINUATION OF IMPORTED FIRE ANT (SOLENOPSIS-INVICTA) IMMUNOTHERAPY. In JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY (Vol. 93, No. 1, pp. 223-223). 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318: MOSBY-YEAR BOOK INC.. 
  62. Stafford, C.T (1996). "Hypersensitivity to fire ant venom". Annals of Allergy, Asthma & Immunology 77 (2): 87–99. doi:10.1016/S1081-1206(10)63493-X. PMID 8760773. 
  63. Letz, A.G.; Quinn, J.M. (2009). "Frequency of imported fire ant stings in patients receiving immunotherapy". Annals of Allergy, Asthma & Immunology 102 (4): 303–307. doi:10.1016/S1081-1206(10)60335-3. PMID 19441601. 
  64. Hunt, K.J.; Valentine, M.D.; Sobotka, A.K.; Benton, A.W.; Amodio, F.J.; Lichtenstein, L.M. (1978). "A controlled trial of immunotherapy in insect hypersensitivity". New England Journal of Medicine 299 (4): 157–161. doi:10.1056/NEJM197807272990401. PMID 78446. 
  65. Freeman, T.M. (2004). "Hypersensitivity to Hymenoptera stings". New England Journal of Medicine 351 (19): 1978–1984. doi:10.1056/NEJMcp042013. PMID 15525723. 
  66. Moffitt, J.E.; Golden, D.B.K.; Reisman, R.E.; Lee, R.; Nicklas, R.; Freeman, T.; deShazo, R.; Tracy, J. et al. (2004). "Stinging insect hypersensitivity: A practice parameter update". Journal of Allergy and Clinical Immunology 114 (4): 869–886. doi:10.1016/j.jaci.2004.07.046. PMID 15480329. 
  67. Haymore, B.R.; McCoy, R.L.; Nelson, M.R. (2009). "Imported fire ant immunotherapy prescribing patterns in a large health care system during a 17-year period". Annals of Allergy, Asthma & Immunology 102 (5): 422–425. doi:10.1016/S1081-1206(10)60515-7. PMID 19492665. 
  68. Tankersley, M.S.; Walker, R.L.; Butler, W.K.; Hagan, L.L.; Napoli, D.C.; Freeman, T.M. (2002). "Safety and efficacy of an imported fire ant rush immunotherapy protocol with and without prophylactic treatment". The Journal of Allergy and Clinical Immunology 109 (3): 556–562. doi:10.1067/mai.2002.121956. PMID 11898006. https://zenodo.org/record/1236034. 
  69. Golden, D.B.K.; Moffitt, J.; Nicklas, R.A.; Freeman, T.; Graft, D.F.; Reisman, R.E.; Tracy, J.M.; Bernstein, D. et al. (2011). "Stinging insect hypersensitivity: A practice parameter update 2011". Journal of Allergy and Clinical Immunology 127 (4): 852–854.e23. doi:10.1016/j.jaci.2011.01.025. PMID 21458655. 
  70. Prahlow, Joseph A.; Barnard, Jeffrey J. (June 1998). "Fatal Anaphylaxis Due to Fire Ant Stings". The American Journal of Forensic Medicine and Pathology 19 (2): 137–142. doi:10.1097/00000433-199806000-00007. PMID 9662108. 
  71. Conceição, L.G.; Haddad, V. Jr.; Loures, F.H. (2006). "Pustular dermatosis caused by fire ant (Solenopsis invicta) stings in a dog". Veterinary Dermatology 17 (6): 453–455. doi:10.1111/j.1365-3164.2006.00555.x. PMID 17083579. http://www.locus.ufv.br/handle/123456789/19457. 
  72. Rakich, P.M.; Latimer, K.S.; Mispagel, M.E.; Steffens, W.L. (1993). "Clinical and histologic characterization of cutaneous reactions to stings of the imported fire ant (Solenopsis invicta) in dogs". Veterinary Pathology 30 (6): 555–559. doi:10.1177/030098589303000609. PMID 8116149. 
  73. 73.0 73.1 73.2 Drees, B.M.; Jensen, J.M.; Joyce, J.R.; Barr, C.L.; Reagor, J.C. (2002). "Diagnosing and treating animals for red imported fire ant injury". Texas Imported Fire Ant Research and Management Project. Texas A&M University. http://fireant.tamu.edu/files/2013/02/FAPFS022.2002rev.pdf. 
  74. Capinera 2008, p. 189.
  75. Adams 1986.

Sources