User login
What’s Eating You? Update on the Sticktight Flea (Echidnophaga gallinacea)
Fleas (order Siphonaptera) are vectors for various diseases, such as plague (as carriers of Yersinia pestis) and rickettsial infections.1-4 The sticktight flea (Echidnophaga gallinacea) commonly is seen on birds and mammals, including ground squirrels, dogs, cats, and rodents, and can attach to its host for days at a time by burrowing its head into the skin. Similar to other fleas, the sticktight flea needs a blood supply to reproduce.5 Therefore, it is important to study the sticktight flea, its habitat, and infection patterns to improve public health and prevent infestation.
Identification
Echidnophaga gallinacea is named for the female flea’s behavior—it “sticks tight” to the surface of the host by embedding its head into the skin for days at a time.5 The sticktight flea and the rat flea (Xenopsylla cheopis) can be differentiated by the sticktight’s reduced thorax and lack of a pleural rod (the vertical ridge that divides the mesosternum above the second pair of legs)(Figure, A and B). The sticktight flea can be differentiated from the dog flea (Ctenocephalides canis) and the cat flea (Ctenocephalides felis) by its lack of genal ctenidia (horizontal combs in the mustache area) and pronotal ctenidia (vertical combs behind the head)(Figure, B and C).6,7 Other defining features of E gallinacea include 2 pairs of large postantennal setae (hairs) on its anteriorly flattened head; a C-shaped reproductive organ known as the spermatheca; and broad maxillary lacinia (Figure, C).8
Habitat, Seasonality, and Behavior
Echidnophaga gallinacea commonly infests the comb, wattles, and surrounding ears of chickens; the flea also has been found on dogs, cats, rodents, and other species of birds.9 The sticktight flea is more prevalent in summer and autumn, which may explain its predominance in warmer climates, including California, Florida, Mexico, Egypt, Africa, and Iran.1,9-11
When a female sticktight flea begins to feed, it stays on the host for days at a time, waiting for a male.5 The female deposits its fertilized eggs in nests on the host or in lesions caused by infestation. Eventually, eggs hatch and fall into soil, where they lay dormant or grow to adulthood.5
Cutaneous Reaction to Infestation
Flea bites cause a hypersensitivity reaction, with pruritic pustules and erythematous papules that have a central punctum.12 In a reported case in Los Angeles, California, a female sticktight flea buried itself into the cheek of a young boy for more than 12 hours. The lesion was not marked by surrounding erythema, tenderness, pruritus, or swelling; however, several days after the flea was removed, erythema developed at the site then spontaneously resolved.7 In a study of dogs that were infested with E gallinacea, the flea never disengaged to attach to a human; when the flea was deliberately placed on a human, it fed and left hastily.11
Management
Because E gallinacea burrows its head into the skin, the best removal method is applying slow gentle traction under sterile conditions to ensure removal of mouthparts.7 An oral antihistamine can be administered or a topical antihistamine or corticosteroid can be applied to the affected area.12 Flea infestation should be treated with an insecticide. Affected animals should be treated by a veterinarian using a pesticide, such as fipronil, selamectin, imidacloprid, metaflumizone, nitenpyram, lufenuron, methoprene, or pyriproxyfen.13
- Hubbart JA, Jachowski DS, Eads DA. Seasonal and among-site variation in the occurrence and abundance of fleas on California ground squirrels (Otospermophilus beecheyi). J Vector Ecol. 2011;36:117-123. doi:10.1111/j.1948-7134.2011.00148.x
- Jiang J, Maina AN, Knobel DL, et al. Molecular detection of Rickettsia felis and Candidatus Rickettsia asemboensis in fleas from human habitats, Asembo, Kenya. Vector Borne Zoonotic Dis. 2013;13:550-558. doi:10.1089/vbz.2012.1123
- López-Pérez AM, Chaves A, Sánchez-Montes S, et al. Diversity of rickettsiae in domestic, synanthropic, and sylvatic mammals and their ectoparasites in a spotted fever-epidemic region at the western US-Mexico border. Transbound Emerg Dis. 2022;69:609-622. doi:10.1111/tbed.14027
- Ehlers J, Krüger A, Rakotondranary SJ, et al. Molecular detection of Rickettsia spp., Borrelia spp., Bartonella spp. and Yersinia pestis in ectoparasites of endemic and domestic animals in southwest Madagascar. Acta Trop. 2020;205:105339. doi:10.1016/j.actatropica.2020.105339
- Boughton RK, Atwell JW, Schoech SJ. An introduced generalist parasite, the sticktight flea (Echidnophaga gallinacea), and its pathology in the threatened Florida scrub-jay (Aphelocoma coerulescens). J Parasitol. 2006;92:941-948. doi:10.1645/GE-769R.1
- Bitam I, Dittmar K, Parola P, et al. Fleas and flea-borne diseases. Int J Infect Dis. 2010;14:e667-e676. doi:10.1016/j.ijid.2009.11.011
- Linardi PM, Santos JLC. Ctenocephalides felis felis vs. Ctenocephalides canis (Siphonaptera: Pulicidae): some issues in correctly identify these species. Rev Bras Parasitol Vet. 2012;21:345-354. doi:10.1590/s1984-29612012000400002
- Carlson JC, Fox MS. A sticktight flea removed from the cheek of a two-year-old boy from Los Angeles. Dermatol Online J. 2009;15:4. https://doi.org/10.5070/D36vb8p1b1
- Mirzaei M, Ghashghaei O, Yakhchali M. Prevalence of ectoparasites of indigenous chickens from Dalahu region, Kermanshah province, Iran. Turkiye Parazitol Derg. 2016;40:13-16. doi:10.5152/tpd.2016.4185
- Farid DS, Sallam NH, Eldein AMS, et al. Cross-sectional seasonal prevalence and relative risk of ectoparasitic infestations of rodents in North Sinai, Egypt. Vet World. 2021;14:2996-3006. doi:10.14202/vetworld.2021.2996-3006
- Harman DW, Halliwell RE, Greiner EC. Flea species from dogs and cats in north-central Florida. Vet Parasitol. 1987;23:135-140. doi:10.1016/0304-4017(87)90031-8
- Anderson J, Paterek E. Flea bites. StatPearls [Internet]. StatPearls Publishing; 2023. Updated August 8, 2023. Accessed November 27, 2023. https://www.ncbi.nlm.nih.gov/books/NBK541118/
- Gyimesi ZS, Hayden ER, Greiner EC. Sticktight flea (Echidnophaga gallinacea) infestation in a Victoria crowned pigeon (Goura victoria). J Zoo Wildl Med. 2007;38:594-596. doi:10.1638/2007-0062.1
Fleas (order Siphonaptera) are vectors for various diseases, such as plague (as carriers of Yersinia pestis) and rickettsial infections.1-4 The sticktight flea (Echidnophaga gallinacea) commonly is seen on birds and mammals, including ground squirrels, dogs, cats, and rodents, and can attach to its host for days at a time by burrowing its head into the skin. Similar to other fleas, the sticktight flea needs a blood supply to reproduce.5 Therefore, it is important to study the sticktight flea, its habitat, and infection patterns to improve public health and prevent infestation.
Identification
Echidnophaga gallinacea is named for the female flea’s behavior—it “sticks tight” to the surface of the host by embedding its head into the skin for days at a time.5 The sticktight flea and the rat flea (Xenopsylla cheopis) can be differentiated by the sticktight’s reduced thorax and lack of a pleural rod (the vertical ridge that divides the mesosternum above the second pair of legs)(Figure, A and B). The sticktight flea can be differentiated from the dog flea (Ctenocephalides canis) and the cat flea (Ctenocephalides felis) by its lack of genal ctenidia (horizontal combs in the mustache area) and pronotal ctenidia (vertical combs behind the head)(Figure, B and C).6,7 Other defining features of E gallinacea include 2 pairs of large postantennal setae (hairs) on its anteriorly flattened head; a C-shaped reproductive organ known as the spermatheca; and broad maxillary lacinia (Figure, C).8
Habitat, Seasonality, and Behavior
Echidnophaga gallinacea commonly infests the comb, wattles, and surrounding ears of chickens; the flea also has been found on dogs, cats, rodents, and other species of birds.9 The sticktight flea is more prevalent in summer and autumn, which may explain its predominance in warmer climates, including California, Florida, Mexico, Egypt, Africa, and Iran.1,9-11
When a female sticktight flea begins to feed, it stays on the host for days at a time, waiting for a male.5 The female deposits its fertilized eggs in nests on the host or in lesions caused by infestation. Eventually, eggs hatch and fall into soil, where they lay dormant or grow to adulthood.5
Cutaneous Reaction to Infestation
Flea bites cause a hypersensitivity reaction, with pruritic pustules and erythematous papules that have a central punctum.12 In a reported case in Los Angeles, California, a female sticktight flea buried itself into the cheek of a young boy for more than 12 hours. The lesion was not marked by surrounding erythema, tenderness, pruritus, or swelling; however, several days after the flea was removed, erythema developed at the site then spontaneously resolved.7 In a study of dogs that were infested with E gallinacea, the flea never disengaged to attach to a human; when the flea was deliberately placed on a human, it fed and left hastily.11
Management
Because E gallinacea burrows its head into the skin, the best removal method is applying slow gentle traction under sterile conditions to ensure removal of mouthparts.7 An oral antihistamine can be administered or a topical antihistamine or corticosteroid can be applied to the affected area.12 Flea infestation should be treated with an insecticide. Affected animals should be treated by a veterinarian using a pesticide, such as fipronil, selamectin, imidacloprid, metaflumizone, nitenpyram, lufenuron, methoprene, or pyriproxyfen.13
Fleas (order Siphonaptera) are vectors for various diseases, such as plague (as carriers of Yersinia pestis) and rickettsial infections.1-4 The sticktight flea (Echidnophaga gallinacea) commonly is seen on birds and mammals, including ground squirrels, dogs, cats, and rodents, and can attach to its host for days at a time by burrowing its head into the skin. Similar to other fleas, the sticktight flea needs a blood supply to reproduce.5 Therefore, it is important to study the sticktight flea, its habitat, and infection patterns to improve public health and prevent infestation.
Identification
Echidnophaga gallinacea is named for the female flea’s behavior—it “sticks tight” to the surface of the host by embedding its head into the skin for days at a time.5 The sticktight flea and the rat flea (Xenopsylla cheopis) can be differentiated by the sticktight’s reduced thorax and lack of a pleural rod (the vertical ridge that divides the mesosternum above the second pair of legs)(Figure, A and B). The sticktight flea can be differentiated from the dog flea (Ctenocephalides canis) and the cat flea (Ctenocephalides felis) by its lack of genal ctenidia (horizontal combs in the mustache area) and pronotal ctenidia (vertical combs behind the head)(Figure, B and C).6,7 Other defining features of E gallinacea include 2 pairs of large postantennal setae (hairs) on its anteriorly flattened head; a C-shaped reproductive organ known as the spermatheca; and broad maxillary lacinia (Figure, C).8
Habitat, Seasonality, and Behavior
Echidnophaga gallinacea commonly infests the comb, wattles, and surrounding ears of chickens; the flea also has been found on dogs, cats, rodents, and other species of birds.9 The sticktight flea is more prevalent in summer and autumn, which may explain its predominance in warmer climates, including California, Florida, Mexico, Egypt, Africa, and Iran.1,9-11
When a female sticktight flea begins to feed, it stays on the host for days at a time, waiting for a male.5 The female deposits its fertilized eggs in nests on the host or in lesions caused by infestation. Eventually, eggs hatch and fall into soil, where they lay dormant or grow to adulthood.5
Cutaneous Reaction to Infestation
Flea bites cause a hypersensitivity reaction, with pruritic pustules and erythematous papules that have a central punctum.12 In a reported case in Los Angeles, California, a female sticktight flea buried itself into the cheek of a young boy for more than 12 hours. The lesion was not marked by surrounding erythema, tenderness, pruritus, or swelling; however, several days after the flea was removed, erythema developed at the site then spontaneously resolved.7 In a study of dogs that were infested with E gallinacea, the flea never disengaged to attach to a human; when the flea was deliberately placed on a human, it fed and left hastily.11
Management
Because E gallinacea burrows its head into the skin, the best removal method is applying slow gentle traction under sterile conditions to ensure removal of mouthparts.7 An oral antihistamine can be administered or a topical antihistamine or corticosteroid can be applied to the affected area.12 Flea infestation should be treated with an insecticide. Affected animals should be treated by a veterinarian using a pesticide, such as fipronil, selamectin, imidacloprid, metaflumizone, nitenpyram, lufenuron, methoprene, or pyriproxyfen.13
- Hubbart JA, Jachowski DS, Eads DA. Seasonal and among-site variation in the occurrence and abundance of fleas on California ground squirrels (Otospermophilus beecheyi). J Vector Ecol. 2011;36:117-123. doi:10.1111/j.1948-7134.2011.00148.x
- Jiang J, Maina AN, Knobel DL, et al. Molecular detection of Rickettsia felis and Candidatus Rickettsia asemboensis in fleas from human habitats, Asembo, Kenya. Vector Borne Zoonotic Dis. 2013;13:550-558. doi:10.1089/vbz.2012.1123
- López-Pérez AM, Chaves A, Sánchez-Montes S, et al. Diversity of rickettsiae in domestic, synanthropic, and sylvatic mammals and their ectoparasites in a spotted fever-epidemic region at the western US-Mexico border. Transbound Emerg Dis. 2022;69:609-622. doi:10.1111/tbed.14027
- Ehlers J, Krüger A, Rakotondranary SJ, et al. Molecular detection of Rickettsia spp., Borrelia spp., Bartonella spp. and Yersinia pestis in ectoparasites of endemic and domestic animals in southwest Madagascar. Acta Trop. 2020;205:105339. doi:10.1016/j.actatropica.2020.105339
- Boughton RK, Atwell JW, Schoech SJ. An introduced generalist parasite, the sticktight flea (Echidnophaga gallinacea), and its pathology in the threatened Florida scrub-jay (Aphelocoma coerulescens). J Parasitol. 2006;92:941-948. doi:10.1645/GE-769R.1
- Bitam I, Dittmar K, Parola P, et al. Fleas and flea-borne diseases. Int J Infect Dis. 2010;14:e667-e676. doi:10.1016/j.ijid.2009.11.011
- Linardi PM, Santos JLC. Ctenocephalides felis felis vs. Ctenocephalides canis (Siphonaptera: Pulicidae): some issues in correctly identify these species. Rev Bras Parasitol Vet. 2012;21:345-354. doi:10.1590/s1984-29612012000400002
- Carlson JC, Fox MS. A sticktight flea removed from the cheek of a two-year-old boy from Los Angeles. Dermatol Online J. 2009;15:4. https://doi.org/10.5070/D36vb8p1b1
- Mirzaei M, Ghashghaei O, Yakhchali M. Prevalence of ectoparasites of indigenous chickens from Dalahu region, Kermanshah province, Iran. Turkiye Parazitol Derg. 2016;40:13-16. doi:10.5152/tpd.2016.4185
- Farid DS, Sallam NH, Eldein AMS, et al. Cross-sectional seasonal prevalence and relative risk of ectoparasitic infestations of rodents in North Sinai, Egypt. Vet World. 2021;14:2996-3006. doi:10.14202/vetworld.2021.2996-3006
- Harman DW, Halliwell RE, Greiner EC. Flea species from dogs and cats in north-central Florida. Vet Parasitol. 1987;23:135-140. doi:10.1016/0304-4017(87)90031-8
- Anderson J, Paterek E. Flea bites. StatPearls [Internet]. StatPearls Publishing; 2023. Updated August 8, 2023. Accessed November 27, 2023. https://www.ncbi.nlm.nih.gov/books/NBK541118/
- Gyimesi ZS, Hayden ER, Greiner EC. Sticktight flea (Echidnophaga gallinacea) infestation in a Victoria crowned pigeon (Goura victoria). J Zoo Wildl Med. 2007;38:594-596. doi:10.1638/2007-0062.1
- Hubbart JA, Jachowski DS, Eads DA. Seasonal and among-site variation in the occurrence and abundance of fleas on California ground squirrels (Otospermophilus beecheyi). J Vector Ecol. 2011;36:117-123. doi:10.1111/j.1948-7134.2011.00148.x
- Jiang J, Maina AN, Knobel DL, et al. Molecular detection of Rickettsia felis and Candidatus Rickettsia asemboensis in fleas from human habitats, Asembo, Kenya. Vector Borne Zoonotic Dis. 2013;13:550-558. doi:10.1089/vbz.2012.1123
- López-Pérez AM, Chaves A, Sánchez-Montes S, et al. Diversity of rickettsiae in domestic, synanthropic, and sylvatic mammals and their ectoparasites in a spotted fever-epidemic region at the western US-Mexico border. Transbound Emerg Dis. 2022;69:609-622. doi:10.1111/tbed.14027
- Ehlers J, Krüger A, Rakotondranary SJ, et al. Molecular detection of Rickettsia spp., Borrelia spp., Bartonella spp. and Yersinia pestis in ectoparasites of endemic and domestic animals in southwest Madagascar. Acta Trop. 2020;205:105339. doi:10.1016/j.actatropica.2020.105339
- Boughton RK, Atwell JW, Schoech SJ. An introduced generalist parasite, the sticktight flea (Echidnophaga gallinacea), and its pathology in the threatened Florida scrub-jay (Aphelocoma coerulescens). J Parasitol. 2006;92:941-948. doi:10.1645/GE-769R.1
- Bitam I, Dittmar K, Parola P, et al. Fleas and flea-borne diseases. Int J Infect Dis. 2010;14:e667-e676. doi:10.1016/j.ijid.2009.11.011
- Linardi PM, Santos JLC. Ctenocephalides felis felis vs. Ctenocephalides canis (Siphonaptera: Pulicidae): some issues in correctly identify these species. Rev Bras Parasitol Vet. 2012;21:345-354. doi:10.1590/s1984-29612012000400002
- Carlson JC, Fox MS. A sticktight flea removed from the cheek of a two-year-old boy from Los Angeles. Dermatol Online J. 2009;15:4. https://doi.org/10.5070/D36vb8p1b1
- Mirzaei M, Ghashghaei O, Yakhchali M. Prevalence of ectoparasites of indigenous chickens from Dalahu region, Kermanshah province, Iran. Turkiye Parazitol Derg. 2016;40:13-16. doi:10.5152/tpd.2016.4185
- Farid DS, Sallam NH, Eldein AMS, et al. Cross-sectional seasonal prevalence and relative risk of ectoparasitic infestations of rodents in North Sinai, Egypt. Vet World. 2021;14:2996-3006. doi:10.14202/vetworld.2021.2996-3006
- Harman DW, Halliwell RE, Greiner EC. Flea species from dogs and cats in north-central Florida. Vet Parasitol. 1987;23:135-140. doi:10.1016/0304-4017(87)90031-8
- Anderson J, Paterek E. Flea bites. StatPearls [Internet]. StatPearls Publishing; 2023. Updated August 8, 2023. Accessed November 27, 2023. https://www.ncbi.nlm.nih.gov/books/NBK541118/
- Gyimesi ZS, Hayden ER, Greiner EC. Sticktight flea (Echidnophaga gallinacea) infestation in a Victoria crowned pigeon (Goura victoria). J Zoo Wildl Med. 2007;38:594-596. doi:10.1638/2007-0062.1
Practice Points
- The sticktight flea (Echidnophaga gallinacea) attaches to its host by embedding its head in the skin for days at a time.
- Unlike other fleas that bite and run, the sticktight flea can be identified dermoscopically.
- The sticktight flea serves as a vector for plague as a carrier of Yersinia pestis, rickettsial infections, and other diseases.
