Abstract
We screened lung tissue from 770 sigmodontine rodents sampled in the Delta and Paraná Islands ecoregion for Borrelia spp. and obtained sequences clustered within the Borrelia burgdorferi sensu lato (s.l.) complex. Seventeen individuals were PCR-positive (prevalence 2.2%), distributed mainly in Akodon azarae (n = 11) and across five additional species. Using GLMMs that accounted for site and trapping session, infection probability was positively associated with individual body length and with ecological proxies of prior host and vector abundance: Ak. azarae abundance two sessions earlier (lag S−2) and Ixodes loricatus nymph abundance in the previous session (lag S−1) were the strongest predictors. These results point to transmission dynamics driven by recent host and immature-tick abundance rather than by climatic descriptors. Presence of cattle was associated with lower Borrelia prevalence in grazed grids (0.5% vs. 4.8% in Ak. azarae), and a univariable model restricted to Ak. azarae detected a significant negative association with cattle; however, this effect was not statistically significant in multivariable models that included host size and lagged abundance metrics. Our findings indicate localized endemic circulation of B. burgdorferi s.l. linked to host/vector demography, and highlight the need for integrated vector and reservoir monitoring to resolve mechanistic pathways and potential implications for animal and public health.
Data availability
The sequences generated and analysed during the current study are available in the GenBank repository, accession numbers PX740065-PX740080.
References
White, R. J. & Razgour, O. Emerging zoonotic diseases originating in mammals: A systematic review of effects of anthropogenic land‐use change. Mammal Rev. 50, 336–352 (2020).
Jones, B. A. et al. Zoonosis emergence linked to agricultural intensification and environmental change. Proc. Natl. Acad. Sci. U. S. A. 110, 8399–8404 (2013).
Morens, D. M., Folkers, G. K. & Fauci, A. S. The challenge of emerging and re-emerging infectious diseases. Nature 430, 242–249 (2004).
Jongejan, F. & Uilenberg, G. The global importance of ticks. Parasitology 129, S3–S14 (2004).
de la Fuente, J. Overview: Ticks as vectors of pathogens that cause disease in humans and animals.. Front. Biosci. https://doi.org/10.2741/3200 (2008).
Brouqui, P. & Matsumoto, K. Bacteriology and phylogeny of Anaplasmataceae. In Rickettsial Diseases (eds Raoult, D. & Parola, P.) 179–198 (Informa Healthcare, 2007). https://doi.org/10.3109/9781420019971.013.
Rollend, L., Fish, D. & Childs, J. E. Transovarial transmission of Borrelia spirochetes by Ixodes scapularis: A summary of the literature and recent observations. Ticks. Tick. Borne. Dis. 4, 46–51 (2013).
Gervasi, S. S., Civitello, D. J., Kilvitis, H. J. & Martin, L. B. The context of host competence: A role for plasticity in host–parasite dynamics. Trends Parasitol. 31, 419–425 (2015).
Ostfeld, R. S., Levi, T., Keesing, F., Oggenfuss, K. & Canham, C. D. Tick‐borne disease risk in a forest food web. Ecology 99, 1562–1573 (2018).
Rudenko, N., Golovchenko, M., Grubhoffer, L. & Oliver, J. H. Updates on Borrelia burgdorferi sensu lato complex with respect to public health. Ticks. Tick. Borne. Dis. 2, 123–128 (2011).
Marques, A. R., Strle, F. & Wormser, G. P. Comparison of Lyme disease in the United States and Europe. Emerg. Infect. Dis. 27, 2017–2024 (2021).
Krawczyk, A. I. et al. Effect of rodent density on tick and tick-borne pathogen populations: Consequences for infectious disease risk. Parasit. Vectors. 13, 34 (2020).
Wolcott, K. A., Margos, G., Fingerle, V. & Becker, N. S. Host association of Borrelia burgdorferi sensu lato: A review. Ticks Tick-Borne Dis. 12, 101766 (2021).
Barolin, J., Antoniazzi, L. R., Colombo, V. C., Beldomenico, P. M. & Monje, L. D. Sigmodontinae rodents as potential reservoirs for Borrelia burgdorferi sensu lato in the Delta and Paraná Islands ecoregion, Argentina.. Med. Vet. Entomol. https://doi.org/10.1111/mve.12766 (2024).
Mancilla-Agrono, L. Y. et al. Is Borrelia burgdorferi sensu stricto in South America? First molecular evidence of its presence in Colombia. Trop. Med. Infect. Dis. 7, 428 (2022).
Sánchez, R. S. T. et al. Rodents as potential reservoirs for Borrelia spp. in northern Chile.. Rev. Bras. Parasitol. Vet. 29, e000120 (2020).
Weck, B. C., Serpa, M. C. A., Labruna, M. B. & Muñoz-Leal, S. A Novel Genospecies of Borrelia burgdorferi sensu lato associated with cricetid rodents in Brazil. Microorganisms 10, 204 (2022).
Cicuttin, G. L., De Salvo, M. N., Venzal, J. M. & Nava, S. Borrelia spp. in ticks and birds from a protected urban area in Buenos Aires city, Argentina.. Ticks Tick Borne Dis. 10, 101282 (2019).
Flores, F. S., Muñoz-Leal, S., Diaz, A. & Labruna, M. B. Wild birds as host of Borrelia burgdorferi sensu lato in northwestern Argentina. Ticks Tick-Borne Dis. 9, 1586–1589 (2018).
Nava, S. et al. Borrelia infection in Ixodes pararicinus ticks (Acari: Ixodidae) from northwestern Argentina. Acta Trop. 139, 1–4 (2014).
Saracho Bottero, M. N. et al. Presence of Borrelia in different populations of Ixodes pararicinus from northwestern Argentina.. Ticks Tick Borne Dis. 8, 488–493 (2017).
Sebastian, P. S. et al. Borrelia burgdorferi sensu lato in Ixodes cf. neuquenensis and Ixodes sigelos ticks from the Patagonian region of Argentina.. Acta Trop. 162, 218–221 (2016).
Armitano, R. I. et al. Enfermedad de Lyme. Análisis crítico sobre su presencia en Argentina. Medicina (Mex.) (2024).
Labruna, M. B., Faccini-Martínez, Á. A., Muñoz-Leal, S., Szabó, M. P. J. & Angerami, R. N. Lyme borreliosis in Brazil: A critical review on the Baggio–Yoshinari syndrome (Brazilian Lyme-like disease).. Clin. Microbiol. Rev. https://doi.org/10.1128/cmr.00097-24 (2024).
Miziara, C. S. M. G., Gelmeti Serrano, V. A. & Yoshinari, N. Passage of Borrelia burgdorferi through diverse Ixodid hard ticks causes distinct diseases: Lyme borreliosis and Baggio-Yoshinari syndrome. Clinics 73, e394 (2018).
Stanchi, N. O. et al. Retrospective analysis of potential Lyme disease clinical cases in Argentina. Microorganisms 12, 1374 (2024).
Goñi, U. “Everything is burning”: Argentina’s delta fires rage out of control. The Guardian (2020).
Valente, M. Up in smoke? Argentina’s delta blaze sparks worry – and legal action. Reuters (2020).
Kandus, P. & Malvárez, A. I. Vegetation patterns and change analysis in the lower delta islands of the Parana River (Argentina). Wetlands 24, 620–632 (2004).
Zoffoli, M. L., Kandus, P., Madanes, N. & Calvo, D. H. Seasonal and interannual analysis of wetlands in South America using NOAA-AVHRR NDVI time series: The case of the Parana Delta Region. Landsc. Ecol. 23, 833–848 (2008).
Colombo, V. C. et al. Cattle farming and plantation forest are associated with Bartonella occurrence in wild rodents. EcoHealth 20, 381–389 (2023).
Maroli, M., Vadell, M. V., Iglesias, A., Julieta Padula, P. & Gómez Villafañe, I. E. Daily movements and microhabitat selection of Hantavirus reservoirs and other Sigmodontinae rodent species that inhabit a protected natural area of Argentina. EcoHealth 12, 421–431 (2015).
Suárez, O. V. & Bonaventura, S. M. Habitat use and diet in sympatric species of rodents of the low Paraná delta, Argentina. Mamm 65, 167–176 (2001).
Priotto, J., Steinmann, A. & Polop, J. Factors affecting home range size and overlap in Calomys venustus (Muridae: Sigmodontinae) in Argentine agroecosystems. Mamm. Biol. 67, 97–104 (2002).
Steinmann, A. R., Priotto, J. W., Castillo, E. A. & Polop, J. J. Size and overlap of home range in Calomys musculinus (Muridae: Sigmodontinae). Acta Theriol. (Warsz.) 50, 197–206 (2005).
Estrada-Peña, A., Venzal, J. M., Mangold, A. J., Cafrune, M. M. & Guglielmone, A. A. The Amblyomma maculatum Koch, 1844 (Acari: Ixodidae: Amblyomminae) tick group: Diagnostic characters, description of the larva of A. parvitarsum Neumann, 1901, 16S rDNA sequences, distribution and hosts. Syst. Parasitol. 60, 99–112 (2005).
Martins, T. F., Onofrio, V. C., Barros-Battesti, D. M. & Labruna, M. B. Nymphs of the genus Amblyomma (Acari: Ixodidae) of Brazil: Descriptions, redescriptions, and identification key. Ticks Tick-Borne Dis. 1, 75–99 (2010).
Marques, S. et al. Redescription of larva, nymph and adults of Ixodes (I.) loricatus Neumann, 1899 (Acari: Ixodidae) based on light and scanning electron microscopy. Syst. Parasitol. 59, 135–146 (2004).
Eberhardt, A. T., Monje, L. D., Zurvera, D. A. & Beldomenico, P. M. Detection of Trypanosoma evansi infection in wild capybaras from Argentina using smear microscopy and real-time PCR assays. Vet. Parasitol. 202, 226–233 (2014).
Barbour, A. G., Maupin, G. O., Teltow, G. J., Carter, C. J. & Piesman, J. Identification of an uncultivable Borrelia species in the hard tick Amblyomma americanum: Possible agent of a Lyme disease-like illness. J. Infect. Dis. 173, 403–409 (1996).
Bunikis, J. et al. Sequence typing reveals extensive strain diversity of the Lyme borreliosis agents Borrelia burgdorferi in North America and Borrelia afzelii in Europe. Microbiology 150, 1741–1755 (2004).
Kumar, S., Stecher, G. & Tamura, K. MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Mol. Biol. Evol. 33, 1870–1874 (2016).
Burnham, K. P., Anderson, D. R. & Huyvaert, K. P. AIC model selection and multimodel inference in behavioral ecology: Some background, observations, and comparisons. Behav. Ecol. Sociobiol. 65, 23–35 (2011).
Brisson, D. & Dykhuizen, D. E. ospC Diversity in Borrelia burgdorferi. Genetics 168, 713–722 (2004).
Shifflett, S. A. et al. Diversity and host specificity of Borrelia burgdorferi ’s outer surface protein C (ospC) alleles in synanthropic mammals, with a notable ospC allele U absence from mixed infections. Infect. Immun. 92, e00244-e323 (2024).
Brunner, J. L. & Ostfeld, R. S. Multiple causes of variable tick burdens on small-mammal hosts. Ecology 89, 2259–2272 (2008).
Colombo, V. C. et al. Ecology of the interaction between Ixodes loricatus (Acari: Ixodidae) and Akodon azarae (Rodentia: Criceridae). Parasitol. Res. 114, 3683–3691 (2015).
Hofmeister, E. K., Ellis, B. A., Glass, G. E. & Childs, J. E. Longitudinal study of infection with Borrelia burgdorferi in a population of Peromyscus leucopus at a Lyme disease-enzootic site in Maryland. Am. J. Trop. Med. Hyg. 60, 598–609 (1999).
Voordouw, M. J., Lachish, S. & Dolan, M. C. The Lyme disease pathogen has no effect on the survival of its rodent reservoir host. PLoS ONE 10, e0118265 (2015).
Ginsberg, H. S. et al. Local abundance of Ixodes scapularis in forests: Effects of environmental moisture, vegetation characteristics, and host abundance. Ticks Tick Borne Dis. 11, 101271 (2020).
Monje, L. D. et al. Dynamics of exposure to Rickettsia parkeri in cattle in the Paraná River Delta, Argentina. J. Med. Entomol. 53, 660–665 (2016).
Aminikhah, M. et al. Rodent host population dynamics drive zoonotic Lyme Borreliosis and Orthohantavirus infections in humans in Northern Europe. Sci. Rep. 11, 16128 (2021).
Colombo, V. C. et al. Ecological factors shaping the ectoparasite community assembly of the Azara’s Grass Mouse, Akodon azarae (Rodentia: Cricetidae). Parasitol. Res. 122, 2011–2021 (2023).
Nava, S., Venzal, J. M., Martins, T. F., Guglielmone, A. A. & González Acuña, D. Ticks of the Southern Cone of America: Diagnosis, Distribution and Hosts with Taxonomy, Ecology and Sanitary Importance (Academic Press, an impint of Elsevier, 2017).
Colombo, V. C. et al. Factors affecting patterns of Amblyomma triste (Acari: Ixodidae) parasitism in a rodent host. Vet. Parasitol. 211, 251–258 (2015).
Acknowledgements
Authors would like to thank to all personnel of INTA Delta, particularly Natalia Fracassi and Gerardo Mujica for logistic support. We thank Dr. José Venzal (CENUR Litoral Norte, Universidad de la República, Salto, Uruguay) for providing the Borrelia DNA used as positive control and Dr. Ulyses F.J. Pardiñas (Centro Nacional Patagónico, Puerto Madryn, Argentina) for his collaboration in the identification of rodents by cranium morphology.
Funding
This study was supported by Agencia Nacional de Promoción Científica y Tecnológica (Grants PICT2008-00090, PICT2019-1242).
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J.B. carried out molecular analyses on the samples, analysed the data, and helped draft the manuscript; L.R.A. collected data in the field and processed samples; V.C.C. collected data in the field and processed samples; P.M.B. collected data in the field, provided financial support, analysed the data, and drafted the manuscript.; L.D.M. collected data in the field, provided financial support, analysed the data, and drafted the manuscript. All authors gave final approval for publication.
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Barolin, J., Antoniazzi, L.R., Colombo, V.C. et al. Ecoepidemiological determinants of Borrelia infection in sigmodontine rodents from the Delta and Parana Islands ecoregion, Argentina.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-45332-4
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DOI: https://doi.org/10.1038/s41598-026-45332-4
Keywords
Borrelia burgdorferi sensu lato- Infectious diseases
Akodon azarae
Ixodes loricatus
- South America
Source: Ecology - nature.com
