Associations ofAnaplasma phagocytophilumBacteria Variants inIxodes scapularisTicks and Humans, New York, USA

Abstract

Anaplasmosis, caused by the tickborne bacterium Anaplasma phagocytophilum , is an emerging public health threat in the United States. In the northeastern United States, the blacklegged tick ( Ixodes scapularis ) transmits the human pathogenic genetic variant of A. phagocytophilum (Ap-ha) and a nonpathogenic variant (Ap-V1). New York has recently experienced a rapid and geographically focused increase in cases of anaplasmosis. We analyzed A. phagocytophilum– infected I. scapularis ticks collected across New York during 2008–2020 to differentiate between variants and calculate an entomological risk index (ERI) for each. Ap-ha ERI varied between regions and increased in all regions during the final years of the study. Space-time scan analyses detected expanding clusters of Ap-ha located within documented anaplasmosis hotspots. Ap-ha ERI was more positively correlated with anaplasmosis incidence than non-genotyped A. phagocytophilum ERI. Our findings help elucidate the relationship between the spatial ecology of A. phagocytophilum variants and anaplasmosis.

Spatiotemporal distribution of Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) and coinfection with other tick-borne pathogens in host-seeking Ixodes scapularis (Acari: Ixodidae) from New York State, USA

“…miyamotoi ERI in Region 4, an area known as the “Capital District Region”, was also significantly higher than risk in Region 5, which includes the Adirondack Mountains. The relatively higher levels of risk in Regions 3 and 4 are not surprising, as these areas of NYS also have increased prevalence of other I. scapularis -associated pathogens, including A. phagocytophilum (Russell et al 2021, Prusinski et al 2023), Bo. burgdorferi (Prusinski et al 2014, Lin et al 2019) and Ba.…”

“…All real-time mulitplex PCR data were interpreted with a cut-off of cycle 40 and analyzed using the Applied Biosystems 7500 SDS Software Version 1.4 (Applied Biosystems, Foster City, CA) as previously described (Piedmonte et al 2018). Samples testing positive for A. phagocytophilum by multiplex PCR were further tested using a custom TaqMan SNP genotyping PCR assay to differentiate between the Ap-ha and Ap-V1 variants of A. phagocytophilum as described elsewhere (Krakowetz et al 2014, Prusinski et al 2023).…”

Bacterial Vector-Borne Zoonotic Diseases and One Health Approach. A Review

“…Severe illness is more frequently reported in older and immunocompromised patients, but it can also affect immunocompetent individuals and may lead to hospitalization or death if appropriate treatment is not provided promptly. Generally, patients show significant improvement within 24-48 hours after starting antimicrobial treatment with doxycycline [28].…”

Host–pathogen associations revealed by genotyping of European strains of Anaplasma phagocytophilum to describe natural endemic cycles

“…Studies on the spatial distribution of A. phagocytophilum genotypes have also been conducted; for example, in Asia a common cycle for ruminant livestock and small rodents based on the 16S rRNA and the partial p44ESup1 genes was proposed [ 11 ]. Spatial studies carried out in North America detected two main variants, also based on the 16S rRNA of A. phagocytophilum [ 12 , 13 ], with both strains differing in their pathogenicity for humans. While white-footed mice (Peromyscus leucopus) are suspected to carry the human pathogenic strain AP-ha, white-tailed deer (Odocoileus virginianus) are suspected to carry variant AP-Variant-1 which is less pathogenic to humans [ 7 , 14 ].…”