A recent molecular study conducted in the Brazilian Atlantic Forest has identified a significant Anaplasma lineage in wildlife, specifically within populations of wild coatis (Nasua nasua). Researchers investigated the presence of various tick-borne pathogens in the blood of coatis captured within the Iguaçu National Park. The findings highlight the critical role these mammals play in the epidemiology of haemoparasites in South American ecosystems.

High Prevalence Rates in Coati Populations

The research team analyzed blood samples from 73 coatis across three distinct sites. PCR assays specifically targeted the 16S rRNA and 23S rRNA genes to detect Anaplasma spp., Ehrlichia spp., Borrelia spp., and Piroplasmida. Notably, the results revealed that 47.9% of the animals tested positive for Anaplasma DNA. In contrast, none of the samples showed the presence of other pathogens like Borrelia or Ehrlichia, suggesting a host-specific dominance of Anaplasma in this region.

Analyzing the Unique Anaplasma Lineage in Wildlife

Genetic sequencing provided deeper insights into the nature of these infections. All positive samples were genetically identical and shared a close relationship with Anaplasma platys, a species often associated with canine cyclic thrombocytopenia. Furthermore, phylogenetic analyses across multiple loci revealed distinct clades. This evidence supports the circulation of a unique variant of Anaplasma lineage in wildlife that differs from strains typically found in cattle or local tick populations. Consequently, this genetic divergence suggests that the strains infecting the mammalian hosts and the tick vectors may belong to separate transmission cycles.

Epidemiological Implications and Zoonotic Potential

These findings significantly expand our understanding of wildlife reservoirs. Coatis appear to be primary hosts for these diverse Anaplasma lineages in the Atlantic Forest. Because Anaplasma species can cause human granulocytic anaplasmosis and other febrile illnesses, identifying wildlife reservoirs is essential for public health surveillance. Moreover, the high prevalence in coatis indicates a robust environmental maintenance of the pathogen, which could pose risks to domestic animals and humans in proximity to these forest fragments.

Frequently Asked Questions

What is the clinical significance of finding Anaplasma in coatis?

Finding a high prevalence of Anaplasma in wild coatis identifies them as potential reservoirs for tick-borne diseases. This discovery helps researchers understand the environmental cycle of pathogens that may eventually affect domestic animals and humans.

How does this lineage compare to known Anaplasma species?

Genetic analysis shows that this specific Anaplasma lineage in wildlife is closely related to Anaplasma platys. However, it forms a distinct clade, suggesting it is a unique variant adapted specifically to coatis in the Atlantic Forest.

Why did the study exclude other pathogens like Ehrlichia?

The PCR assays were designed to detect multiple pathogens, but the coatis in this specific study population only tested positive for Anaplasma. This indicates that Anaplasma is currently the dominant haemoparasite circulating among coatis in the Iguaçu National Park.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Cordeiro MD et al. High prevalence of a host-associated Anaplasma lineage in wild coatis (Nasua nasua) from the Brazilian Atlantic Forest. Med Vet Entomol. 2026 Apr 18. doi: 10.1111/mve.70074. PMID: 41999192.

2. De Sousa KCM, Calchi AC, Herrera HM, et al. Anaplasmataceae agents among wild mammals and ectoparasites in Brazil. Epidemiol Infect. 2017;145(16):3424-3437.

3. Li H, et al. Of goats and men: rethinking anaplasmoses as zoonotic infections. Lancet Infect Dis. 2015;15(6):620-622.