Original Articles
Vol. 21 No. 1 (2026)
Snakebite epidemiology in the State of Mexico, Mexico 2003-2024
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All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Published: 9 April 2026
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In the State of Mexico, several venomous snakes have low median lethal doses, which therefore pose serious health risks. We anal- ysed the epidemiology of snakebites from 2003 to 2024 and examined their relationship with demographic, socioeconomic, and bio- logical factors. Incidence rates and demographic characteristics were calculated, and Getis-Ord Gi* statistics were used to identify snakebite hotspots. We also applied Non-Metric Multi-Dimensional Scaling (NMDS) to explore associations between hotspot cate- gories and socioeconomic conditions. The potential distribution of 14 venomous snake species was modelled to estimate venomous snake diversity across municipalities. A total of 3,972 cases were reported, with an increasing trend over time. Most bites occurred in summer, affecting mainly males aged 25-44. Hotspot analysis identified 27 municipalities as hotspots, 50 as not significant and 48 as coldspots. Southern municipalities showed higher snakebite incidence. Coldspot areas had higher educational attainment and greater employment in services and tertiary sectors, despite similar snake diversity to hotspots. These findings can guide public health strategies, particularly regarding the allocation of antivenoms in regional hospitals.
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Aldridge RD, Siegel DS, Goldberg SR, Pyron RA, 2020. Seasonal timing of spermatogenesis and mating in squamates: a reinterpretation. Copeia 108:231–64. DOI: https://doi.org/10.1643/CH-19-230
Auchincloss AH, Gebreab SY, Mair C,Diez Rox AV, 2012. A review of spatial methods in epidemiology, 2000–2010. Annu Rev Public Health 33:107–122. DOI: https://doi.org/10.1146/annurev-publhealth-031811-124655
Bénard-Valle M, Carbajal-Saucedo A, de Roodt A, López-Vera E, Alagón A, 2014. Biochemical characterization of the venom of the coral snake Micrurus tener and comparative biological activities in the mouse and a reptile model. Toxicon 2014;77:6–15. DOI: https://doi.org/10.1016/j.toxicon.2013.10.005
Bhaumik S, Beri D, Jagnoor J, 2022. The impact of climate change on the burden of snakebite: Evidence synthesis and implications for primary healthcare. J Fam Med Prim Care 11:6147–58. DOI: https://doi.org/10.4103/jfmpc.jfmpc_677_22
Borja M, Neri-Castro E, Castañeda-Gaytán G, Strickland JL, Parkinson CL, Castañeda-Gaytán J, Ponce-López R, Lomonte B, Olvera-Rodríguez A, Alagón A, Pérez-Morales R, 2018.Biological and proteolytic variation in the venom of Crotalus scutulatusscutulatus from Mexico. Toxins (Basel) 8:1–19. DOI: https://doi.org/10.3390/toxins10010035
Calabrese JM, Certain G, Kraan C, Dormann CF, 2014. Stacking species distribution models and adjusting bias by linking them to macroecological models. Glob Ecol Biogeogr 23:99–112. DOI: https://doi.org/10.1111/geb.12102
Campbell JA, Lamar WW, 2004. The venomous reptiles of the western hemisphere. Comstock Publishing.
Carbajal-Saucedo A, López-Vera E, Bénard-Valle M, Smith EN, Zamudio F, de Roodt AR, Olvera-Rodríguez A, 2013. Isolation, characterization, cloning and expression of an alpha-neurotoxin from the venom of the Mexican coral snake Micrurus laticollaris (Squamata: Elapidae). Toxicon 66:64–74. DOI: https://doi.org/10.1016/j.toxicon.2013.02.006
Castoe TA, Spencer CL, Parkinson CL, 2007. Phylogeographic structure and historical demography of the western diamondback rattlesnake (Crotalus atrox): a perspective on North American desert biogeography. Mol Phylogenet Evol 42:193–212. DOI: https://doi.org/10.1016/j.ympev.2006.07.002
Cervantes-Zamora Y, Cornejo-Olgín SL, Lucero-Márquez R, Espinoza-Rodríguez JM, Miranda-Viquez E, Pineda-Velázquez A, 1990. Provincias fisiográficas de México [cited 2021 Aug 10]. Available from: http://conabio.gob.mx/informacion/metadata/gis/rfisio4mgw.xml
Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, 2021. División política municipal 1:250000 [cited 2026 Jan 23]. Available from: http://geoportal.conabio.gob.mx/metadatos/doc/html/mun22gw.html
Contreras-Landgrave G, Tetelboin-Henrion C, 2011. El seguro popular de salud y la reforma a las políticas de salud en el Estado de México. Rev Gerenc Polit Salud21:10–32.
Cruz-Ramírez K, Sigala-Rodríguez JJ, Gómez-Martínez RF, Villalobos-Juárez I, 2025. Epidemiología de las mordeduras por serpiente y distribución de faboterápicos en Aguascalientes. México. Rev Latinoam Herpeto l8:69–83. DOI: https://doi.org/10.22201/fc.25942158e.2025.2.1117
D'Amen M, Dubuis A, Fernandes RF, Pottier J, Pellissier L, Guisan A, 2015. Using species richness and functional traits predictions to constrain assemblage predictions from stacked species distribution models. J Biogeogr 42:1255–66. DOI: https://doi.org/10.1111/jbi.12485
Da Costa MKB, Da Fonseca CS, Navoni JA, Freire EMX, 2019. Snake bite accidents in Rio Grande do Norte state, Brazil: Epidemiology, health management and influence of the environmental scenario. Trop Med Int Health 24:432–442. DOI: https://doi.org/10.1111/tmi.13207
Dirección General de Epidemiología. Boletín Epidemiológico Nacional,2024.Histórico Boletín Epidemiológico [cited 2024 Jun 20]. Available from: https://epidemiologia.salud.gob.mx/gobmx/salud/documentos/boletin/2024.zip
Dormann CF, Elith J, Bacher S, Buchmann C, Carl G, Carré G, Marquéz JRG, Gruber B, Lafourcade B, Leitão PJ, Münkemüller T, McClean C, Osborne PE, Reineking B, Schröder B, Skidmore AK, Zurell D, Lautenbach S, 2013. Collinearity: a review of methods to deal with it and a simulation study evaluating their performance. Ecography 36:27-46. DOI: https://doi.org/10.1111/j.1600-0587.2012.07348.x
Escobar-Latapí A, 2020. Women and men in farm work in Mexico: trends and gaps, 2005–2019. CIESAS Bull1:1–5.
Escobar-Latapí A, Martin P, Stabridis O, 2019. Farm labor and Mexico’s export produce industry, Wilson Center.
Fick SE, Hijmans RJ, 2017. WorldClim 2: new 1 km spatial resolution climate surfaces for global land areas. Int J Climatol 37:4302–4315. DOI: https://doi.org/10.1002/joc.5086
Fielding AH, Bell JF, 1997. A review of methods for the assessment of prediction errors in conservation presence/absence models. Environ Conserv 24:38–49. DOI: https://doi.org/10.1017/S0376892997000088
Fry BG. 2008. Snakebite: when the human touch becomes a bad touch. Toxins (Basel) 10:170. DOI: https://doi.org/10.3390/toxins10040170
García E, 2004. Modificaciones al sistema de clasificación climática de Köppen, UNAM.
Garrocho C, 1990. Localización geográfica de los servicios de salud en un subsistema de asentamientos rurales del Estado de México. Estud Demogr Urbanos 5: 127–148. DOI: https://doi.org/10.24201/edu.v5i1.754
GBIF, 2025. GBIF occurrence download. [cited 2025 Jul 3]. Available from: https://doi.org/10.15468/dl.zatxey
Getis A, Ord JK, 1992. The analysis of spatial association by use of distance statistics. Geogr Anal 24:189–206. DOI: https://doi.org/10.1111/j.1538-4632.1992.tb00261.x
Goldberg SR, 1999. Reproduction in the blacktail rattlesnake, Crotalus molossus (Serpentes: Viperidae). Tex J Sci 51:323–8.
Gosh S, Maisnam I, Murmu BK, Mitra PK, Roy A, Simpson ID, 2008. A locally developed snakebite management protocol significantly reduces overall antivenom utilization in West Bengal, India. Wilderness Environ Med 19:267–74. DOI: https://doi.org/10.1580/08-WEME-OR-219.1
Granados-Alcantar JA, Quezada-Ramírez MF, 2018. Trends in internal migration among the indigenous population in Mexico, 1990–2015. Estud Demogr Urbanos 33:327–63. DOI: https://doi.org/10.24201/edu.v33i2.1726
Greene S, Ruha AM, Campleman S, Brent J, Wax P, 2021. Epidemiology, clinical features, and management of Texas coral snake (Micrurus tener) envenomations reported to the North American Snakebite Registry. J Med Toxicol 17:51–56.
Gutiérrez JM, Calvete JJ, Habib AG, Harrison RA, Williams DJ, Warrell DA, 2017. Snakebite envenoming. Nat Rev Dis Primers 3:17063. DOI: https://doi.org/10.1038/nrdp.2017.63
Hammer Ø, Harper DAT, Ryan PD, 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontol Electron 4:1–9.
Harrison RA, Gutiérrez JM, 2016. Priority actions and progress to substantially and sustainably reduce the mortality, morbidity and socioeconomic burden of tropical snakebite. Toxins (Basel) 8:1–14. DOI: https://doi.org/10.3390/toxins8120351
INEGI,2021. Censo de Población y Vivienda 2020[cited 2021 Aug 10]. Available from: https://www.inegi.org.mx/programas/ccpv/2020/default.html
Kasturiratne A, Wickremasinghe AR, de Silva N, Gunawardena NK, Pathmeswaran A, Premaratna R, Savioli L, Lalloo DG, Janaka de Silva H, 2008. The global burden of snakebite: a literature analysis and modelling based on regional estimates of envenoming and deaths. PLoS Med 5:e218. DOI: https://doi.org/10.1371/journal.pmed.0050218
Lara-Galvan JL, Montesino-San Martín M, Herrero-Otero X, Martínez-Montoya JF, Sigala-Rodríguez JJ, Marcia-Barbosa A, 2025. Venomous snakebite risk and its implications in Zacatecas State, Mexico 2007-2017. Geospat Health 20:1404. DOI: https://doi.org/10.4081/gh.2025.1404
Lawson AB, 2006. Statistical methods in spatial epidemiology. Wiley. DOI: https://doi.org/10.1002/9780470035771
Legendre P, Legendre L, 2012. Numerical ecology, developments in environmental modelling. Elsevier.
Lemos-Espinal JA, Smith GR, 2020. A conservation checklist of the amphibians and reptiles of the State of Mexico, Mexico with comparisons with adjoining states. Zoo Keys 953:137–59. DOI: https://doi.org/10.3897/zookeys.953.50881
Longbottom J, Shearer FM, Devine M, Alcoba G, Chappuis F, Weiss DJ, Ray SE, Ray N, Warrell DA, Ruiz de Castañeda R, Williams DJ, Hay SI, Pigott DM, 2018. Vulnerability to snakebite envenoming: a global mapping of hotspots. Lancet 392:673–84. DOI: https://doi.org/10.1016/S0140-6736(18)31224-8
Luna-Trejo J, 2018. Análisis epidemiológico del accidente por animales venenosos en el Estado de México del 2004 al 2016 [bachelor’sthesis]. Universidad Autónoma del Estado de México.
Martínez Vaca-León OI, Maya-García SJ, Manjarrez J, Estrada-García LE, 2019. Snake interspecific aggregation: Crotalus polystictus, Thamnophis eques and T. scaliger. Herpetol Notes12:327–329.
Meik JM, Mociño-Deloya E, Setser K, 2007. New distribution records for the Querétero dusky rattlesnake Crotalus aquilus (Viperidae), with comments on morphology and habitat use. West N Am Nat 67:601–604. DOI: https://doi.org/10.3398/1527-0904(2007)67[601:NDRFTQ]2.0.CO;2
Monroy-Vilchis O, González-Desales GA, Balbuena-Serrano A, Robles-Rodríguez J, Zarco-González MM, 2024. Potential distribution of Agkistrodon bilineatus (Squamata: Viperidae) and first records in Central Mexico. Caldasia 46:361–370. DOI: https://doi.org/10.15446/caldasia.v46n2.101348
Monter-Pozos A, Reyes-Velázquez EA, Hernández-Gallegos O, Gómez-Benitez A, 2025. Filling gaps: on the distribution of Crotalus intermedius Troschel, 1865 (Squamata, Viperidae) and its first record in the State of Mexico, Mexico. Check List 21:443–450. DOI: https://doi.org/10.15560/21.2.443
Neri-Castro E, Bénard-Valle M, Gil G, Borja M, López-de León J, Alagón A, 2020. Serpientes venenosas en México: una revisión al estudio de los venenos, los antivenenos y la epidemiología. Rev Latinoam Herpetol 3:5–22. DOI: https://doi.org/10.22201/fc.25942158e.2020.2.205
Nordberg EJ, Cobb VA, 2016. Midwinter emergence in hibernating timber rattlesnakes (Crotalus horridus). J Herpetol 50:203–8. DOI: https://doi.org/10.1670/14-113
Onyishi IE, Nwonyi SK, Pazda A, Prokop A, 2021. Attitudes and behaviour toward snakes on the part of Igbo people in southeastern Nigeria. Sci Total Environ 763:1–37. DOI: https://doi.org/10.1016/j.scitotenv.2020.143045
Ord JK, Getis A, 1995. Local spatial autocorrelation statistics: distributional issues and an application. Geogr Anal 27:286–306. DOI: https://doi.org/10.1111/j.1538-4632.1995.tb00912.x
Pacheco-Barrios K, Cardenas-Rojas A, Giannoni-Luza S, Fregni F, 2020.COVID-19 pandemic and Farr’s law: A global comparison and prediction of outbreak acceleration and deceleration rates. PLoS ONE 15:e0239175. DOI: https://doi.org/10.1371/journal.pone.0239175
Palci A, LeBlanc ARH, Panagiotopoulou O, Cleuren SGC, Mehari-Abraha H, Hutchinson MN, Evans AR, Caldwell MW, Lee MSY, 2021. Plicidentine and the repeated origins of snake venom fangs. Proc Biol Sci 288:e20210062. DOI: https://doi.org/10.1098/rspb.2021.1391
Pandey DP, Pandey GS, Devkota K, Goode M, 2016. Public perceptions of snakes and snakebite management: implications for conservation and human health in southern Nepal J Ethnobiol Ethnomed 12:1–24. DOI: https://doi.org/10.1186/s13002-016-0092-0
Pebesma E, Bivand R, 2023. Spatial data science with applications in R. Chapman & Hall. DOI: https://doi.org/10.1201/9780429459016
Pérez-Mendoza HA, Sanabria-Tobón SR, Jaramillo-Alba JL, Solano-Zavaleta I, Vázquez-Vega LF, Díaz de la Vega-Pérez AH, 2018. Reproductive traits of dusky rattlesnakes (Crotalus triseriatus) in Central Mexico. J Herpetol 52:6–11. DOI: https://doi.org/10.1670/16-003
Rangel-Camacho R, Yáñez-Arenas C, Chippaux JP, Martínez G, 2025. Socioeconomic and ecological drivers of snakebite incidence in Mexico: A spatial analysis of risk factors. PLoS Negl Trop Dis 9:e0013582. DOI: https://doi.org/10.1371/journal.pntd.0013582
Rodríguez-Canseco JM, Arnaud-Franco G, Gutiérrez-López E, Romero-Figueroa G, 2021. Epidemiological overview of snakebites in the Baja California peninsula, Mexico (2003–2018). Gac Med Mex 157:579–585. DOI: https://doi.org/10.24875/GMM.21000105
Samuel SP, Chinnaraju S, Williams HF, Pichamuthu E, Subharao M, Vaiyapuri M, Arumugam S, Vaiyapuri R, Baksh MF, Patel K, Trim SA, Duncombe TE, Vaiyapuri S, 2020. Venomous snakebites: rapid action saves lives—a multifaceted community education programme increases awareness about snakes and snakebites among the rural population of Tamil Nadu, India. PLoS Negl Trop Dis 14:e0008103. DOI: https://doi.org/10.1371/journal.pntd.0008911
Schield DR, Card DC, Adams RH, Jezkova T, Reyes-Velasco J, Proctor FN, Spencer CL, Herrmann HW, Mackessy SP, Castoe TA, 2015. Incipient speciation with biased gene flow between two lineages of the Western Diamondback Rattlesnake (Crotalus atrox). Mol Phylogenet Evol 82:213–223. DOI: https://doi.org/10.1016/j.ympev.2014.12.006
Schuett GW, Carlisle SL, Holycross AT, O’leile JK, Hardy DL, Van Kirk EA Sr, Murdoch WJ, 2002. Mating system of male Mojave rattlesnakes (Crotalus scutulatus): seasonal timing of mating, agonistic behavior, spermatogenesis, sexual segment of the kidney, and plasma sex steroids, In: Schuett GW, Höggren H, Douglas ME, Greene HW, editors. Biology of the vipers, Eagle Mountain Publishing. 515–532 pp.
Schuett GW, Repp RA, Taylor EN, DeNardo DF, Early RL, Van Kirk EA, Murdoch WJ, 2006. Winter profile of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, Crotalus atrox (Serpentes: Viperidae). Gen Comp Endocrinol 149:72–80. DOI: https://doi.org/10.1016/j.ygcen.2006.05.005
Setser K, Mociño-Deloya E, Pleguezuelos JM, Lazcano D, Kardon A, 2012. Reproductive ecology of female Mexican lance-headed rattlesnakes. J Zool 281:175–182. DOI: https://doi.org/10.1111/j.1469-7998.2010.00692.x
Siria-Hernández CG, Arellano-Bravo A, 2009. Mordeduras por serpiente venenosa: panorama epidemiológico en México. Salud Publica Mex 51:95–96. DOI: https://doi.org/10.1590/S0036-36342009000200002
Soria-Díaz L, Astudillo-Sánchez CC, Gómez-Ortiz Y, Manjarrez J, Mundo-Hernández V, Rubio-Blanco T, Domínguez-Vega H, 2021. Hidden in plain sight: detectability and habitat selection of the Central Plateau dusky rattlesnake in anthropized landscapes. Herpetol J 31:91–98. DOI: https://doi.org/10.33256/31.2.9198
Sunny A, Gandarilla-Aizpuro FJ, Monroy-Vilchis O, Zarco-Gonzalez MM, 2019. Potential distribution and habitat connectivity of Crotalus triseriatus in Central Mexico. Herpetozoa 32:139–148. DOI: https://doi.org/10.3897/herpetozoa.32.e36361
Sunny A, Marmolejo C, Vidal-López R, Falconi-Briones FA, Cuervo-Robayo AP, Bolom-Huet R, 2025. EcoNicheS: enhancing ecological niche modeling, niche overlap and connectivity analysis using the shiny dashboard and R package. Peer J 28:e19136. DOI: https://doi.org/10.7717/peerj.19136
Sunny A, Monroy-Vilchis O, Zarco-González MM, Mendoza-Martínez GD, Martínez-Gómez D, 2015. Genetic diversity and genetic structure of an endemic Mexican dusky rattlesnake (Crotalus triseriatus) in a highly modified agricultural landscape: implications for conservation. Genetica 143:705–16. DOI: https://doi.org/10.1007/s10709-015-9868-8
Tobeña M, Prieto R, Machete M, Silva MA, 2016. Modeling the potential distribution and richness of cetaceans in the Azores from fisheries observer program data. Front Mar Sci 3:1–19. DOI: https://doi.org/10.3389/fmars.2016.00202
Togridou A, Graham SA, Owens JB, Santra V, Bharti O, Malhotra A, 2020. Prevention is better than cure: snakebite education in India. Educ Sci 10:75–96.
Waller LA, Gotway CA, 2004. Applied spatial statistics for public health data. Wiley. DOI: https://doi.org/10.1002/0471662682
World Health Organization, 2019. Snakebite [cited 2021 Aug 10]. Available from: https://www.who.int/health-topics/snakebite#tab=tab_1
Yañez-Arenas C, 2014. Análisis temporal y geográfico del envenenamiento por mordedura de serpiente en Veracruz, México (2003–2012). Gac Med Mex 150:60–64.
Yañez-Arenas C, Yañes-Arenas A, Martínez-Ortíz D, 2016. Panorama epidemiológico de las mordeduras por serpiente venenosa en el Estado de Yucatán, México (2003–2012). Gac Med Mex 152:568–574.
Zar JH, 1999. Biostatistical Analysis, Prentice Hall.
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Snakebite epidemiology in the State of Mexico, Mexico 2003-2024. (2026). Geospatial Health, 21(1). https://doi.org/10.4081/gh.2026.1468
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