We report a patient in North Carolina, USA, with Heartland virus infection whose diagnosis was complicated by previous Ehrlichia chaffeensis infection. We identified E. ewingii-infected and Bourbon virus-infected tick pools at the patient's residence. Healthcare providers should consider testing for tickborne viruses if ehrlichiosis is suspected.

Amblyomma maculatum Koch, the Gulf Coast tick, is expanding northward from its original range in the southeastern United States. In 2013, its most northern collection was in Delaware. Amblyomma maculatum has since been found in Connecticut, Illinois, and New York. It is the vector of the human pathogen Rickettsia parkeri, the causative agent of R. parkeri rickettsiosis. We report the first finding of an established population of A. maculatum in Salem County, NJ, with a R. parkeri infection prevalence rate of 23.8%. Our finding of A. maculatum is consistent with other recent findings in the northeastern United States in that specimens were found in open areas devoid of tree canopy. This discovery demonstrates the importance of tick surveillance in order to identify expanding tick populations and the pathogens they may transmit.

The Pacific Coast tick (Dermacentor occidentalis Marx, 1892) is a frequently encountered and commonly reported human-biting tick species that has been recorded from most of California and parts of southwestern Oregon, southcentral Washington, and northwestern Mexico. Although previous investigators have surveyed populations of D. occidentalis for the presence of Rickettsia species across several regions of California, populations of this tick have not been surveyed heretofore for rickettsiae from Baja California, Oregon, or Washington. We evaluated 1,367 host-seeking, D. occidentalis adults collected from 2015 to 2022 by flagging vegetation at multiple sites in Baja California, Mexico, and Oregon and Washington, United States, using genus- and species-specific assays for spotted fever group rickettsiae. DNA of Rickettsia 364D, R. bellii, and R. tillamookensis was not detected in specimens from these regions. DNA of R. rhipicephali was detected in D. occidentalis specimens obtained from Ensenada Municipality in Baja California and southwestern Oregon, but not from Washington. All ompA sequences of R. rhipichephali that were amplified from individual ticks in southwestern Oregon were represented by a single genotype. DNA of the Ixodes pacificus rickettsial endosymbiont was amplified from specimens collected in southwestern Oregon and Klickitat County, Washington; to the best of our knowledge, this Rickettsia species has never been identified in D. occidentalis. Collectively, these data are consistent with a relatively recent introduction of Pacific Coast ticks in the northernmost extension of its recognized range.

Hard ticks (Acari: Ixodidae) have been historically identified by morphological methods which require highly specialized expertise and more recently by DNA-based molecular assays that involve high costs. Although both approaches provide complementary data for tick identification, each method has limitations which restrict their use on large-scale settings such as regional or national tick surveillance programs. To overcome those obstacles, the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been introduced as a cost-efficient method for the identification of various organisms, as it balances performance, speed, and high data output. Here we describe the use of this technology to validate the distinction of two closely related Dermacentor tick species based on the development of the first nationwide MALDI-TOF MS reference database described to date. The dataset obtained from this protein-based approach confirms that tick specimens collected from United States regions west of the Rocky Mountains and identified previously as Dermacentor variabilis are the recently described species, Dermacentor similis. Therefore, we propose that this integrative taxonomic tool can facilitate vector and vector-borne pathogen surveillance programs in the United States and elsewhere.

Feral swine, Sus scrofa L., have become a nuisance to landowners across the United States by damaging agriculture, property, and ecosystems. Additionally, these animals have been found to host various ixodid ticks including Amblyomma americanum (L.), Amblyomma maculatum Koch, Dermacentor variabilis (Say), and Ixodes scapularis Say, which can maintain and transmit several rickettsial pathogens to livestock, wildlife, and humans. Though previous research has identified the maintenance cycle of several rickettsial pathogens in ticks and native wildlife, little is known about the role S. scrofa plays in supporting ixodid ticks and the pathogens these ticks could be harboring. This study sought to identify rickettsial agents (Rickettsiales: Anaplasmataceae and Rickettsiaceae) in ticks collected from S. scrofa obtained in Florida and South Carolina. Overall, ticks from four species (A. americanum, D. variabilis, I. scapularis, and A. maculatum) totaling 258 collected individuals were obtained from S. scrofa (n = 45). We found an Ehrlichia chaffeensis Anderson et al. infection prevalence in A. americanum of 2.7% and 2.9% in Florida and South Carolina, respectively. A Rickettsia parkeri Lackman et al. prevalence of 100% and 33% was found in A. maculatum from Florida and South Carolina, respectively. Additionally, a 0.9% infection prevalence of R. parkeri was identified in A. americanum collected in South Carolina. A 1.9% Ehrlichia ewingii Anderson et al. infection prevalence was documented in collected A. americanum in South Carolina. Further studies are warranted to better understand the role S. scrofa plays in the natural maintenance of rickettsial agents in various regions of the United States.

Anaplasmosis is increasingly common in the United States, with cases being reported over an expanding geographic area. To monitor for changes in risk of human infection, the U.S. Centers for Disease Control and Prevention monitors the distribution and abundance of host-seeking vector ticks (Ixodes scapularis and Ixodes pacificus) and their infection with Anaplasma phagocytophilum. While several variants of A. phagocytophilum circulate in I. scapularis, only the human-active variant (Ap-ha) appears to be pathogenic in humans. Failure to differentiate between human and non-human variants may artificially inflate estimates of the risk of human infection. Efforts to differentiate the Ap-ha variant from the deer variant (Ap-V1) in ticks typically rely on traditional PCR assays coupled with sequencing of PCR products. However, laboratories are increasingly turning to Next Generation Sequencing (NGS) to increase testing efficiency, retain high sensitivity, and increase specificity compared with traditional PCR assays. We describe a new NGS assay with novel targets that accurately segregate the Ap-ha variant from other non-human variants and further identify unique clades within the human and non-human variants. Recognizing that not all investigators have access to NGS technology, we also developed a PCR assay based on one of the novel targets so that variants can be visualized using agarose gel electrophoresis without the need for subsequent sequencing. Such an assay may be used to improve estimates of human risk of developing anaplasmosis in North America.

The Asian longhorned tick, Haemaphysalis longicornis, an invasive species associated with human pathogens, has spread rapidly across the eastern USA. Questing H. longicornis ticks recovered from active surveillance conducted from 1 May to 6 September, 2019 throughout Pennsylvania were tested for rickettsial pathogens. Of 265 ticks tested by PCR for pathogens, 4 (1.5%) were positive for Anaplasma phagocytophilum. Sequence analysis of the 16S rRNA gene confirmed two positives as A. phagocytophilum-human agent variant. This is the first reported detection of A. phagocytophilum-human pathogenic strain DNA in exotic H. longicornis collected in the USA.

The Asian longhorned tick, Haemaphysalis longicornis, is an invasive species, originally from eastern Asia, and was first reported in the USA in New Jersey. It is now reported in several eastern states. In 2018, researchers reported H. longicornis in northwest Arkansas (Benton County). This tick species is a proven vector of livestock and human diseases, which prompted the current survey of ticks in southwest Missouri. A tick drag in Greene County, Missouri, produced 2 H. longicornis nymphs on June 9, 2021. This is the first report of this species for both the state and county.

We identified an established population of the Gulf Coast tick (Amblyomma maculatum Koch) infected with Rickettsia parkeri in Connecticut, representing the northernmost range limit of this medically relevant tick species. Our finding highlights the importance of tick surveillance and public health challenges posed by geographic expansion of tick vectors and their pathogens.

87: Theileria buffeli Infections in Grazing Cattle Located in Mountainous Areas of the Republic of Korea Kyoung-Seong Choi*, Joon-Seok Chae, Do-Hyeon Yu, Jinho Park, Bae-Keun Park, Hyeong-Chul Kim Abstract #88: Small Mammals as Hosts of Ehrlichia muris eauclairensis and Other Rickettsial Pathogens in Eau Claire, Wisconsin Bryan N. Ayres*, Audrey E. Osterbind, Jamie L. Perniciaro, Joy A. Hecht, William L. Nicholson Abstract #89: Serological Survey of Canine Tick-borne Infections Using Species-specific Serological Markers Jiayou Lui*, M. E. McCown, C. Fiorello, D. Scorpio, M. Filipovic, J. Saucier, B. Thatcher, R. Chandrashekar Abstract #90: Consistencies in Spatio-Temporal Trends, and Climatic and Other Geospatial Risk Factors for Rickettsial Diseases in the Central Midwestern United States Ram K. Raghavan*, Gary A. Anderson, Doug. G. Goodin, Roman R. Ganta88: Small Mammals as Hosts of Ehrlichia muris eauclairensis and Other Rickettsial Pathogens in Eau Claire, Wisconsin Bryan N. Ayres*, Audrey E. Osterbind, Jamie L. Perniciaro, Joy A. Hecht, William L. Nicholson Abstract #89: Serological Survey of Canine Tick-borne Infections Using Species-specific Serological Markers Jiayou Lui*, M. E. McCown, C. Fiorello, D. Scorpio, M. Filipovic, J. Saucier, B. Thatcher, R. Chandrashekar Abstract #90: Consistencies in Spatio-Temporal Trends, and Climatic and Other Geospatial Risk Factors for Rickettsial Diseases in the Central Midwestern United States Ram K. Raghavan*, Gary A. Anderson, Doug. G. Goodin, Roman R. Ganta Abstract #91: A Distributional Survey of Ticks (Acari: Ixodida) in Georgia, USA William L. Nicholson* Abstract #92: Spotted Fever Group Rickettsiae in Baltic Region Algimantas Paulauskas*, Jana Radzijevskaja, Asta Aleksandraviciene91: A Distributional Survey of Ticks (Acari: Ixodida) in Georgia, USA William L. Nicholson* Abstract #92: Spotted Fever Group Rickettsiae in Baltic Region Algimantas Paulauskas*, Jana Radzijevskaja, Asta Aleksandraviciene Abstract #93: Spotted Fever Group Rickettsia Species Identified among Ticks in Georgia Ekaterine Zhgenti*, Roena Sukhiashvili, Richard J. Obiso, Christina M. Farris, Ju Jiang, Allen L. Richards Abstract #94: Risk Assessment for Vector-borne Diseases at Gateway National Recreation Area, NY: Monitoring Ticks, Preliminary Study, 2014 Ellen Stromdahl*, Garrett Heck, Mary Vince, Waheed Bajwa, Zahir Shah, David Wong93: Spotted Fever Group Rickettsia Species Identified among Ticks in Georgia Ekaterine Zhgenti*, Roena Sukhiashvili, Richard J. Obiso, Christina M. Farris, Ju Jiang, Allen L. Richards Abstract #94: Risk Assessment for Vector-borne Diseases at Gateway National Recreation Area, NY: Monitoring Ticks, Preliminary Study, 2014 Ellen Stromdahl*, Garrett Heck, Mary Vince, Waheed Bajwa, Zahir Shah, David Wong Abstract #95: Evaluating an Ecological Niche Model for Rickettsia montanensis Infected Dermacentor variabilis Based on Ticks Collected from Humans Using Environmentally Captured Ticks Heidi K. St. John*, Penny M. Masuoka, Melissa K. Miller, Melissa L. Adams, Johanna G. Flyer-Adams, Ju Jiang, Patrick J. Rozmajzl, Ellen Y. Stromdahl, Allen L. Richards95: Evaluating an Ecological Niche Model for Rickettsia montanensis Infected Dermacentor variabilis Based on Ticks Collected from Humans Using Environmentally Captured Ticks Heidi K. St. John*, Penny M. Masuoka, Melissa K. Miller, Melissa L. Adams, Johanna G. Flyer-Adams, Ju Jiang, Patrick J. Rozmajzl, Ellen Y. Stromdahl, Allen L. Richards Abstract #96: Survey for Rickettsia Species in Dermacentor variabilis Ticks Collected from National Parks and Monuments across the Eastern United States Sandor E. Karpathy*, Joy A. Hecht, Tammi L. Johnson, Rebecca J. Eisen, Christopher D. Paddock Abstract #97: Flea-borne Rickettsiae in Southeastern Georgia, USA Marina E. Eremeeva*, Danielle Capps, Amanda Jo Williams-Newkirk, Gregory A. Dasch, Lorenza Beati, Lance Durden96: Survey for Rickettsia Species in Dermacentor variabilis Ticks Collected from National Parks and Monuments across the Eastern United States Sandor E. Karpathy*, Joy A. Hecht, Tammi L. Johnson, Rebecca J. Eisen, Christopher D. Paddock Abstract #97: Flea-borne Rickettsiae in Southeastern Georgia, USA Marina E. Eremeeva*, Danielle Capps, Amanda Jo Williams-Newkirk, Gregory A. Dasch, Lorenza Beati, Lance Durden Abstract #98: Prevalence of Q Fever and Rickettsia in Ticks in Northeastern Azerbaijan Rita Ismayilova*, Agarahim Mammadsalahov, Rakif Abdullayev, Esmiralda Seyidova, Sabina Ibrahimova, Elvin Naghiyev98: Prevalence of Q Fever and Rickettsia in Ticks in Northeastern Azerbaijan Rita Ismayilova*, Agarahim Mammadsalahov, Rakif Abdullayev, Esmiralda Seyidova, Sabina Ibrahimova, Elvin Naghiyev Abstract #99: Coxiella burnetii Small RNA 12 (CbsR12) Targets carA Transcripts In vitro Shaun Wachter*, Indu Warrier, Michael F. Minnick99: Coxiella burnetii Small RNA 12 (CbsR12) Targets carA Transcripts In vitro Shaun Wachter*, Indu Warrier, Michael F. Minnick Abstract #100: Alterations in Dermacentor andersoni Transcription in Response to Anaplasma marginale Infection Susan M. Noh*, Forgivemore Magunda, Sebastian Aguilar, Kelly A. Brayton Abstract #101: Characterization of Small, Noncoding RNAs in Rickettsia prowazekii Casey L. C. Schroeder*, Hema P. Narra, Mark Rojas, Abha Sahni, Kamil Khanipov, Jignesh Patel, Yuriy Fofanov, Sanjeev K. Sahni100: Alterations in Dermacentor andersoni Transcription in Response to Anaplasma marginale Infection Susan M. Noh*, Forgivemore Magunda, Sebastian Aguilar, Kelly A. Brayton Abstract #101: Characterization of Small, Noncoding RNAs in Rickettsia prowazekii Casey L. C. Schroeder*, Hema P. Narra, Mark Rojas, Abha Sahni, Kamil Khanipov, Jignesh Patel, Yuriy Fofanov, Sanjeev K. Sahni Abstract #102: Metagenomics of Head Lice Using the Ion Torrent PGM Gregory A. Dasch*, Zachary C. Holmes, T. Brian Shirey, Marina E. Eremeeva, Sarah Zohdy102: Metagenomics of Head Lice Using the Ion Torrent PGM Gregory A. Dasch*, Zachary C. Holmes, T. Brian Shirey, Marina E. Eremeeva, Sarah Zohdy Abstract #103: Decoding the Post-transcriptional Regulatory Networks in Rickettsia conorii Hema P. Narra*, Casey L.C. Schroeder, Abha Sahni, Yuriy Fofanov, Sanjeev K. Sahni Abstract #104: Cytoskeleton Interactions with the Coxiella burnetii Parasitophorous Vacuole Heather Miller*, Charlie Larson, Robert Heinzen103: Decoding the Post-transcriptional Regulatory Networks in Rickettsia conorii Hema P. Narra*, Casey L.C. Schroeder, Abha Sahni, Yuriy Fofanov, Sanjeev K. Sahni Abstract #104: Cytoskeleton Interactions with the Coxiella burnetii Parasitophorous Vacuole Heather Miller*, Charlie Larson, Robert Heinzen Abstract #105: Examination of Tick Vectorial Capacity Factors during Tick-borne Bacterial Infection Kathryn E. Reif*, Jessica K. Ujzco, Deb C. Alprin, Susan M. Noh Abstract #106: Nuclear Trafficking of the Anti-apoptotic Coxiella burnetii Effector Protein AnkG Requires Binding to p32 and Importin-α1 Walter Schäfer*, Rita A. Eckart, Benedikt Schmid, Kerstin Hof, Yves Muller, Bushra Amin, Anja Lührmann105: Examination of Tick Vectorial Capacity Factors during Tick-borne Bacterial Infection Kathryn E. Reif*, Jessica K. Ujzco, Deb C. Alprin, Susan M. Noh Abstract #106: Nuclear Trafficking of the Anti-apoptotic Coxiella burnetii Effector Protein AnkG Requires Binding to p32 and Importin-α1 Walter Schäfer*, Rita A. Eckart, Benedikt Schmid, Kerstin Hof, Yves Muller, Bushra Amin, Anja Lührmann Abstract #107: Effects of Novel Bacteriophage on Abalone Exposed to Candidatus Xenohaliotis californiensis – The Causative Agent of Abalone Withering Syndrome James D. Moore*, Ashley Vater, Barbara A. Byrne Abstract #108: Ehrlichia chaffeensis TRP120 Effector Autoubiquitinates and Contains a C-terminal HECT E3 Ligase Domain Bing Zhu*, Tierra R. Farris, Seema Das, Jere W. McBride Abstract #109: Ehrlichia chaffeensis TRP32 is a Nucleomodulin that Directly Regulates Host Gene Expression Tierra Farris*, Bing Zhu, Jere W. McBride107: Effects of Novel Bacteriophage on Abalone Exposed to Candidatus Xenohaliotis californiensis – The Causative Agent of Abalone Withering Syndrome James D. Moore*, Ashley Vater, Barbara A. Byrne Abstract #108: Ehrlichia chaffeensis TRP120 Effector Autoubiquitinates and Contains a C-terminal HECT E3 Ligase Domain Bing Zhu*, Tierra R. Farris, Seema Das, Jere W. McBride Abstract #109: Ehrlichia chaffeensis TRP32 is a Nucleomodulin that Directly Regulates Host Gene Expression Tierra Farris*, Bing Zhu, Jere W. McBride Abstract #110: Molecular Detection of Rickettsia Species in Ticks and Fleas in Eastern Missouri and Southern Illinois Catherine Santanello*, Redir Barwari110: Molecular Detection of Rickettsia Species in Ticks and Fleas in Eastern Missouri and Southern Illinois Catherine Santanello*, Redir Barwari Abstract #111: Molecular Survey of Arthropod Vectors for Rickettsia in the Eastern Thailand Darunee Utennam*, Kamonwan Siriwatthanakul, Chakrit Hirunpetcharat, Wuttikorn Rodkvamtook, Charnchudhi Chanyasanha, Pimmada Sakpisal, Narupon Kuttasingkee, Yutthapong Sudsawat, Chanakan Suwanbongkot, Jariyanart Gaywee Abstract #112: Rickettsia cf sp. Infection in Thailand Jariyanart Gaywe*, Wuttikon Rodkvamtook, Walairat Pronwiroon, Darunee Utainnam, Piyanate Salyakumthorn, Pimmada Sakpisal, Narupon Kuttasingkee, Kamonwan Siriwatthanakul, Chanakan Suwanbongkot, Allen L. Richards, Suradet Jaruchinda111: Molecular Survey of Arthropod Vectors for Rickettsia in the Eastern Thailand Darunee Utennam*, Kamonwan Siriwatthanakul, Chakrit Hirunpetcharat, Wuttikorn Rodkvamtook, Charnchudhi Chanyasanha, Pimmada Sakpisal, Narupon Kuttasingkee, Yutthapong Sudsawat, Chanakan Suwanbongkot, Jariyanart Gaywee Abstract #112: Rickettsia cf sp. Infection in Thailand Jariyanart Gaywe*, Wuttikon Rodkvamtook, Walairat Pronwiroon, Darunee Utainnam, Piyanate Salyakumthorn, Pimmada Sakpisal, Narupon Kuttasingkee, Kamonwan Siriwatthanakul, Chanakan Suwanbongkot, Allen L. Richards, Suradet Jaruchinda Abstr