Amblyomma spp. Tick Parasitizing a Veterinarian, an Occupational Risk

Ticks of the genus Amblyomma are blood-sucking arthropods that parasitize humans and potentially transmit pathogens of public health relevance. In the event of a tick bite, it is imperative to understand the correct method for removing, preserving, identifying and potentially utilizing them for the purpose of pathogen detection. Healthcare professionals and the public should be aware of the health implications associated with these ectoparasites. Specimen handling could have been improved to facilitate precise species determination and screening of pathogens with public health significance.

Ticks are classified within the taxonomic order Ixodidae, which comprises a diverse group of hematophagous arthropods that have the capacity to parasitize humans and domestic and wild animals. There are three families of ticks, which compose the order Ixodidade; the soft ticks (Argasidae), the hard ticks (Ixodidae) and a family, consisting of a species that combines characteristics of hard and soft ticks (Nuttalliellidae) [1]. The genus Amblyomma has the highest number of described species among hard ticks worldwide except Antarctica, are known for their aggressiveness and play a very important role in veterinary public health [2]. For example, ticks of the genera Haemaphysalis, Ixodes, and Rhipicephalus are known to wait for their potential host by perching on vegetation; in contrast, ticks of the genera Amblyomma are proactive hunters, searching for their potential host by moving along the ground [3].

Ticks of the genus Amblyomma can parasitize any terrestrial vertebrate, including amphibians, birds, mammals and reptiles [4]. Worldwide, the genus Amblyomma has 136 species [5], while in Mexico is represented by 26 species [4]. Several species of the genus Amblyomma has been reported parasitizing humans worldwide [6-11] and Mexico is not the exception as for this type of reports [12-16]. In this study, we present a case of an Amblyomma tick feeding on a veterinarian while working in a field setting.

The infestation was first documented on 4 November 2024 on a farm in the municipality of Marquelia, in the state of Guerrero, Mexico. Subsequent to the termination of the working day at the aforementioned location, the veterinary surgeon observed the ectoparasite attached to the skin of his hand after a brief period of managing cattle. The ectoparasite was observed in the fold of the junction of the between the metacarpal and trapezium bones (Figure 1). At the time of the incident, the individual did not possess any materials with which to preserve the specimen. Consequently, he was only able to obtain a photograph, and subsequently removed the specimen from his hand, crushing it between two stones. The area was thoroughly cleaned with soap and water, with the addition of iodine solution to ensure disinfection. The attachment site had not become inflamed or painful, and consequently, the individual did not show symptoms of tick-borne disease or that would raise suspicion of such a condition. Following the collection of photographic evidence, an approximate estimation of the tick gender could be made.

As general features, adult ticks of the genus Amblyomma usually measure between 6-7 mm, their mouthparts are elongated, their legs have pale rings, and their shield is ornate [17]. Ticks of this genus have a three-host life cycle, it is slow and can last from a few months to several years; larvae emerge from eggs, feed once on a host, then detach and burrow into the soil or vegetation to molt to nymph; on this stage feeds once and molts into either a female or a male; the female feeds once, mates, detaches to lay eggs, and then dies, whereas the male may feed several times, mate, and eventually die; the life cycle of three-host ticks is slow, from six months to several years in natural conditions [17]. Under laboratory conditions, variations in the life cycle of some Amblyomma species have been reported; for more specific details regarding the duration of life cycle developmental events, please consult the listed references [18-23].

It is known the potential of Amblyomma spp. ticks on pathogen transmission [24-27]. In view of the above, individuals involved in high-risk outdoor activities to pay attention to any bites by one or more ticks, as well as to any possible signs consistent with a disease transmitted by these ectoparasites [28]. Especially, some ticks can carry multiple pathogens simultaneously, capable of producing coinfections [29,30]. There are records of the genus Amblyomma parasitizing humans in various parts of the world, among these, the species A. americanum [8], A. albolimbatum [7], A. hebraeum [11], A. parkeri [6], A. neumani, A. parvum and A. tigrinum [10] have been mentioned; while in Mexico the species A. americanum [16], A. cajenense [16], A. dissimile [15,16], A. maculatum [16], A. mixtum [12,13], A. parvum [13] are mentioned.

According to the general prevention rules, any tick that is located on the body should be removed immediately and completely [31]. Normally, the mechanical method is employed, using the fingers; however, if the proper knowledge is not available, the head or mouthparts of the tick may remain in the skin, with the resulting complications [32,33]. Even depending on the species of tick and its location, surgical removal may be necessary [34]. There is evidence that a feeding tick can begin transmitting pathogens from 15 minutes to 72 hours post-attachment, depending on the pathogen [35-40]. Regardless of how the tick was removed from the skin, people should be monitored for up to 30 days for signs and symptoms of a possible tick-borne illness [22].

Ticks are blood-feeding arthropods known to parasitize humans, particularly those exposed to natural or animal environments. The public should be educated on proper tick bite management, including the safe removal of the tick and the utilization of specialist services. In order to accurately identify the genus and species of arthropod, it is imperative to take appropriate measures to ensure the proper preservation of the specimen. If circumstances permit, a diagnostic test should be conducted in order to whether the arthropod is harboring a pathogen of medical significance. Furthermore, it is imperative that health professionals receive adequate training to offer proper guidance to individuals who have suffered a tick bite. It is evident that the appropriate handling of the specimen, including its collection and preservation, would have greatly improved species identification of the species in question. Moreover, its potential utilization in the identification of pathogens that may pose a public health risk would have been greatly enhanced.

1. Nicholson WL, Sonenshine DE, Noden BH, Brown RN. Ticks (ixodida). In: Medical and veterinary entomology. Amsterdam: Elsevier; 2019;603-672. Available from: https://doi.org/10.1016/B978-0-12-814043-7.00027-3
2. Smit A, Mulandane F, Labuschagne M, Wójick SH, Malabwa C, Sili G, et al. Intra- and interspecific variation of Amblyomma ticks from southern Africa. Parasites Vectors. 2024;17:364. Available from: https://doi.org/10.1186/s13071-024-06394-3
3. Perumalsamy N, Sharma R, Subramanian M, Nagarajan SA. Hard ticks as vectors: The emerging threat of tick-borne diseases in India. Pathogens. 2024;13:556. Available from: https://doi.org/10.3390/pathogens13070556
4. Guzmán-Cornejo C, Robbins RG, Guglielmone AA, Montiel-Parra G, Pérez TM. The Amblyomma (Acari: Ixodida: Ixodidae) of Mexico: identification keys, distribution and hosts. Zootaxa. 2011;2998:16-38. Available from: https://doi.org/10.11646/zootaxa.2998.1.2
5. Guglielmone AA, Nava S, Robbins RG. Geographic distribution of the hard ticks (Acari: Ixodida: Ixodidae) of the world by countries and territories. Zootaxa. 2023;5251:1-274. Available from: https://doi.org/10.11646/zootaxa.5251.1.1
6. Borsoi ABP, Bitencourth K, de Oliveira SV, Amorim M, Gazêta GS. Human parasitism by Amblyomma parkeri ticks infected with candidatus Rickettsia paranaensis, Brazil. Emerg Infect Dis. 2019;25:2339-2341. Available from: https://doi.org/10.3201/eid2512.190988
7. Egan SL, Lettoof DC, Oskam CL. First record of the stump-tailed lizard tick, Amblyomma albolimbatum (Ixodida, Ixodidae) parasitising a human. Ticks Tick Borne Dis. 2022;13:101873. Available from: https://doi.org/10.1016/j.ttbdis.2021.101873
8. Kennedy AC, Marshall E. Lone Star Ticks (Amblyomma americanum): An emerging threat in Delaware. Dela J Public Health. 2021;7:66-71. Available from: https://doi.org/10.32481/djph.2021.01.013
9. Martins TF, Teixeira RHF, Souza JC, Luz HR, Montenegro MM, Jerusalinsky L, et al. Ticks (Parasitiformes: Ixodida) on new world wild primates in Brazil. Int J Acarol. 2021;47:95-106. Available from: https://doi.org/10.1080/01647954.2020.1870554
10. Nava S, Caparrós JA, Mangold AJ, Guglielmone AA. Ticks (Acari: Ixodida: Argasidae, Ixodidae) infesting humans in Northwestern Córdoba province, Argentina. Medicina (B Aires). 2006;66:225-228. Available from: https://www.scielo.org.ar/pdf/medba/v66n3/v66n3a06.pdf
11. Ledger KJ, Innocent H, Lukhele SM, Dorleans R, Wisely SM. Entomological risk of African tick-bite fever (Rickettsia africae infection) in Eswatini. PLoS Negl Trop Dis. 2022;16:e0010437. Available from: https://doi.org/10.1371/journal.pntd.0010437
12. Castillo-Martínez A, Cueto-Medina SM, Hernández-Rodríguez S, Salinas-Ramírez N, Romero-Santos RD, Martínez-Patricio G, et al. Amblyomma mixtum Koch (Acari: Ixodidae) en ambientes peridomésticos de la Región Otomí-Tepehua, Hidalgo, México. Rev Chil Entomol. 2020;46:661-669. Available from: http://dx.doi.org/10.35249/rche.46.4.20.12
13. Rodríguez-Vivas RI, Apanaskevich DA, Ojeda-Chi MM, Trinidad-Martínez I, Reyes-Novelo E, Esteve-Gassent MD, et al. Ticks collected from humans, domestic animals, and wildlife in Yucatan, Mexico. Vet Parasitol. 2016;215:106-113. Available from: https://doi.org/10.1016/j.vetpar.2015.11.010
14. Rodríguez-Vivas RI, Ojeda-Chi MM, Ojeda Robertos NF, Dzul-Rosado KR. The tick Amblyomma parvum as a potential vector of pathogens in animals and humans. Bioagrosciences. 2022;15:1-9. Available from: https://www.revista.ccba.uady.mx/ojs/index.php/BAC/article/view/4163
15. Rodríguez-Vivas RI, Ojeda-Chi MM, Torres-Castro MA, Sánchez-Montes S, PantiMay A, Reyes-Novelo E. Amblyomma dissimile (Acari: Ixodidae): Tick of amphibians and reptiles. Bioagrociencias. 2022;15:56-64. Available from: https://www.revista.ccba.uady.mx/ojs/index.php/BAC/article/view/4283
16. Sosa-Gutierrez CG, Vargas-Sandoval M, Torres J, Gordillo-Pérez G. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico. J Vet Sci. 2016;17:353-360. Available from: https://doi.org/10.4142/jvs.2016.17.3.353
17. Walker AR, Bouattour A, Camicas J-L, Preston PM. Ticks of Domestic Animals in Africa: A Guide to Identification of Species. Edinburgh: Bioscience Reports; 2014. Available from: https://www.alanrwalker.com/assets/PDF/tickguide-africa.pdf
18. Almazán C, Torres-Torres A, Torres-Rodriguez L, Soberanes-Cespedes N, Ortiz-Estrada M. Biological aspects of Amblyomma mixtum (Koch, 1844) in northeastern Mexico. Queh Cient Chiapas. 2016;11:10-19. Available from: https://www.dgip.unach.mx/index.php/16-revista-quehacer-cientifico-en-chiapas/231-volumen-11-numero-2-julio-diciembre-de-2016
19. Labruna MB, Souza SL, Menezes AC, Horta MC, Pinter A, Gennari SM. Life-cycle and host specificity of Amblyomma tigrinum (Acari: Ixodidae) under laboratory conditions. Exp Appl Acarol. 2002;26:115-125. Available from: https://doi.org/10.1023/a:1020957122256
20. Olegário MM, Gerardi M, Tsuruta SA, Szabó MP. Life cycle of the tick Amblyomma parvum Aragão, 1908 (Acari: Ixodidae) and suitability of domestic hosts under laboratory conditions. Vet Parasitol. 2011;179:203-208. Available from: https://doi.org/10.1016/j.vetpar.2011.01.056
21. Piña FTB, da Silva Rodrigues V, de Oliveira Souza Higa L, Garcia MV, Barros JC, de León AAP, et al. Life cycle of Amblyomma mixtum (Acari: Ixodidae) parasitizing different hosts under laboratory conditions. Exp Appl Acarol. 2017;73:257-267. Available from: https://doi.org/10.1007/s10493-017-0178-y
22. Sanches GS, Bechara GH, Garcia MV, Labruna MB, Szabó MP. Biological aspects of Amblyomma brasiliense (Acari: Ixodidae) under laboratory conditions. Exp Appl Acarol. 2008;44:43-48. Available from: https://doi.org/10.1007/s10493-007-9127-5
23. Szabó MP, Pereira Lde F, Castro MB, Garcia MV, Sanches GS, Labruna MB. Biology and life cycle of Amblyomma incisum (Acari: Ixodidae). Exp Appl Acarol. 2009;48:263-271. Available from: https://doi.org/10.1007/s10493-008-9234-y
24. Binder LC, Tauro LB, Farias AA, Labruna MB, Diaz A. Molecular survey of flaviviruses and orthobunyaviruses in Amblyomma spp. ticks collected in Minas Gerais, Brazil. Rev Bras Parasitol Vet. 2019;28:764-768. Available from: https://doi.org/10.1590/s1984-29612019071
25. Childs JE, Paddock CD. The ascendancy of Amblyomma americanum as a vector of pathogens affecting humans in the United States. Annu Rev Entomol. 2003;48:307-337. Available from: https://doi.org/10.1146/annurev.ento.48.091801.112728
26. Guzmán-Cornejo C, Herrera-Mares A, García-Prieto L, Oceguera-Figueroa A, López-Pérez AM, Dzul-Rosado K. Potential zoonotic role of the tick Amblyomma cf. oblongoguttatum (Ixodida: Ixodidae) in the bacterial transmission of Ehrlichia chaffeensis (Rickettsiales: Anaplasmataceae) in a deciduous tropical forest in Mexico. J Med Entomol. 2024;61:1026-1030. Available from: https://doi.org/10.1093/jme/tjae047
27. Lippi CA, Gaff HD, White AL, Ryan SJ. Scoping review of distribution models for selected Amblyomma ticks and rickettsial group pathogens. PeerJ. 2021;9:e10596. Available from: https://doi.org/10.7717/peerj.10596
28. Prado RFS, Araújo IM, Cordeiro MD, Baêta BA, Silva JB, Fonseca AH. Diversity of tick species (Acari: Ixodidae) in military training areas in Southeastern Brazil. Braz J Vet Parasitol. 2022;31(2):e001322. Available from: https://doi.org/10.1590/S1984-29612022027
29. Uilenberg G. Veterinary significance of ticks and tick-borne diseases. In: Tick Vector Biology. Berlin, Heidelberg: Springer; 1992;23-33. Available from: https://doi.org/10.1007/978-3-642-76643-5_2
30. Maggi RG, Mascarelli PE, Havenga LN, Naidoo V, Breitschwerdt EB. Co-infection with Anaplasma platys, Bartonella henselae and Candidatus Mycoplasma haematoparvum in a veterinarian. Parasit Vectors. 2013;6:103. Available from: https://doi.org/10.1186/1756-3305-6-103
31. Van Gestel M, Heylen D, Verheyen K, Fonville M, Sprong H, Matthysen E. Recreational hazard: Vegetation and host habitat use correlate with changes in tick-borne disease hazard at infrastructure within forest stands. Sci Total Environ. 2024;919:170749. Available from: https://doi.org/10.1016/j.scitotenv.2024.170749
32. Roupakias S, Mitsakou P, Nimer AA. Tick removal. J Prev Med Hyg. 2011;52:40-44. Available from: https://pubmed.ncbi.nlm.nih.gov/21710824/
33. Ozkan OV. Tick removal from the skin. ANZ J Surg. 2009;79:308-309. Available from: https://doi.org/10.1111/j.1445-2197.2009.04872.x
34. Haddad V Jr, Haddad MR, Santos M, Cardoso JLC. Skin manifestations of tick bites in humans. An Bras Dermatol. 2018;93:251-255. Available from: https://doi.org/10.1590/abd1806-4841.20186378
35. Roupakias S, Mitsakou P, Al Nimer A. Surgical tick removal. Wilderness Environ Med. 2012;23:97-99. Available from: https://doi.org/10.1016/j.wem.2011.09.003
36. Eisen L. Pathogen transmission in relation to duration of attachment by Ixodes scapularis ticks. Ticks Tick Borne Dis. 2018;9:535-542. Available from: https://doi.org/10.1016/j.ttbdis.2018.01.002
37. Levin ML, Troughton DR, Loftis AD. Duration of tick attachment necessary for transmission of Anaplasma phagocytophilum by Ixodes scapularis (Acari: Ixodidae) nymphs. Ticks Tick Borne Dis. 2021;12:101819. Available from: https://doi.org/10.1016/j.ttbdis.2021.101819
38. Militzer N, Bartel A, Clausen P-H, Hoffmann-Köhler P, Nijhof AM. Artificial feeding of all consecutive life stages of Ixodes ricinus. Vaccines. 2021;9:385. Available from: https://doi.org/10.3390/vaccines9040385
39. Richards SL, Langley R, Apperson CS, Watson E. Do tick attachment times vary between different tick-pathogen systems? Environments. 2017;4:37. Available from: https://doi.org/10.3390/environments4020037
40. Rocha SC, Velásquez CV, Aquib A, Al-Nazal A, Parveen N. Transmission cycle of tick-borne infections and co-infections, animal models and diseases. Pathogens. 2022;11:1309. Available from: https://doi.org/10.3390/pathogens11111309