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Background: Rickettsial infections are often neglected and poorly recognized by physicians in many tropical and subtropical regions. Despite a number of recent reports describing rickettsial diseases in new locations and the discovery of new rickettsiae, medical science and research have largely neglected the diagnosis and antimicrobial treatment of rickettsial infections in subtropical and tropical areas; thus, much remains to be discovered. This study aimed to detect and characterize spotted fever group (SFG) rickettsiae in ixodid ticks infesting domestic ruminants in Khartoum State., Methods: Polymerase chain reaction targeting both genes that encode for citrate synthase (gltA) and outer membrane protein (ompA) was performed for the presence of SFG rickettsia followed by sequence and phylogenetic analysis., Results: Of the 202 ticks examined for the presence of SFG rickettsia, gltA gene was detected in 4 samples (2%). Furthermore, gltA-positive samples were used to amplify the ompA gene, in which only two samples yielded positive results. Sequence and phylogenetic analysis of the positive samples revealed four different species of SFG rickettsiae: Rickettsia aeschlimannii, Rickettsia rhipicephali, Rickettsia massiliae and Rickettsia raoultii., Conclusions: These results indicated the presence of SFG rickettsia in Sudanese ticks. This also indicates that humans have an opportunity to acquire these infections. It is important to keep in mind the need for careful consideration of rickettsial infections in individuals with a fever of unknown origin., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Background: Most of the rickettsioses are transmitted by ticks, and often overlooked by the medical profession, but are clinically important as they cause major human diseases. Recent studies have shown the existence of some rickettsial species in Iran, but very little information is available about the status of rickettsial epidemiology and ecology. This study investigated the presence of Rickettsia spp. in ticks and ruminants in western of Iran by molecular methods. Materials and Methods: 250 blood samples were collected from sheep and goats, as well as 244 ticks were collected opportunistically from ruminants in the Kurdistan province. The collected samples were tested using a real-time quantitative PCR (qPCR) assay targeting the Rickettsia 16SrRNA gene. Rickettsia spp. positive by the qPCR were further amplified by conventional PCR of the gltA and OmpA genes. These ampliqons were further analyzed by sequencing. Results: The ticks species collected in this study included Rhipicephalus sanguineus , Rh. turanicus , Haemaphysalis concinna , and Dermacentor marginatus . In total, DNA of Rickettsia spp. was detected in 131 collected ticks (53.7%). Of the positives, Rickettsia slovaca (59.2%) and Ri. hoogstraalii (16.3%) were the most common species identified followed by Ri. raoultii , Ri. massiliae , Ri. sibirica , and Ri. conorii subsp. israelensis . In contrast, there were no positives observed in the blood samples collected from ruminants. Conclusion: The results indicate the presence of rickettsial species in ticks. The detection of these pathogens is significant because they cause clinical disease in humans. The results support the notion that the Iranian public health system needs to be more aware of these diseases.

Vector-borne diseases account for nearly 20% of all globally recognised infectious diseases. Within the spectrum of flea-borne pathogens, Bartonella and Rickettsia bacteria are prominent, contributing to the emergence and resurgence of diseases on a global scale. This study investigates the presence of species of Bartonella and Rickettsia harboured by fleas collected from wild rodents in northwestern Argentina (NWA). A total of 28 fleas from three genera and seven species were assessed. DNA of Bartonella and Rickettsia spp. was found in 12 fleas (42.8%). Phylogenetic analysis of concatenated sequences of gltA and rpoB genes showed the presence of Bartonella quintana in eight fleas of two species, Craneopsylla minerva minerva and Polygenis acodontis. Phylogenetic analysis of concatenated sequences of gltA, ompA and ompB genes identified Rickettsia felis in ten fleas of five species, C. m. minerva, P. acodontis, Polygenis bohlsi bohlsi, Polygenis byturus and Tiamastus palpalis. These bacterial species mark the first report in all flea species studied. This study represents the first survey of flea-borne bacteria for NWA. The results provide information to address strategies for the control and prevention of bartonellosis and rickettsiosis that could have an impact on public health in one of the geographical areas of Argentina with the highest incidence of infections transmitted to humans by ectoparasites., (© 2024. The Author(s).)

Arthropod-borne rickettsioses comprise a wide variety of subtypes that are endemic in Cambodia, but there remains very little data on the geographic distribution of the pathogens or their vectors. Surveys were conducted in Koh Kong and Preah Sihanouk Provinces between September 2017 and June 2018 to collect ectoparasites from peridomestic animals and the environment using dragging and flagging methods. Collected ectoparasites were sorted and identified morphologically, then pooled by species, host, and location for molecular detection using Rickettsia genus- and species-specific qPCR and/or multilocus sequence typing (MLST) assays. A total of 14,254 ectoparasites were collected including seven new locality records. Rickettsia species were detected in 35.5% (174/505) of the pools screened representing 3,149 randomly selected ectoparasites from the total collected. Rickettsia asembonensis was detected in 89.6% (147/164) of Rickettsia-positive flea pools and 3.6% (6/164) of the flea pools were positive for both R. asembonensis and Rickettsia felis. Candidatus Rickettsia senegalensis from Ctenocephalides orientis fleas and Rickettsia sp. close to Rickettsia japonica and Rickettsia heilongjiangensis from Haemaphysalis ticks were identified by MLST. This appears to be the first report of these new ectoparasite records and rickettsial species in southern Cambodia, suggesting a potential health risk to military and civilians in this region., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Hyalomma marginatum is an invasive tick species recently established in mainland southern France. This tick is known to host a diverse range of human and animal pathogens. While information about the dynamics of these pathogens is crucial to assess disease risk and develop effective monitoring strategies, few data on the spatial dynamics of these pathogens are currently available. We collected ticks in 27 sites in the Occitanie region to characterize spatial patterns of H. marginatum -borne pathogens. Several pathogens have been detected: Theileria equi (9.2%), Theileria orientalis (0.2%), Anaplasma phagocytophilum (1.6%), Anaplasma marginale (0.8%), and Rickettsia aeschlimannii (87.3%). Interestingly, we found a spatial clustered distribution for the pathogen R. aeschlimannii between two geographically isolated areas with infection rates and bacterial loads significantly lower in Hérault/Gard departments (infection rate 78.6% in average) compared to Aude/Pyrénées-Orientales departments (infection rate 92.3% in average). At a smaller scale, R. aeschlimannii infection rates varied from one site to another, ranging from 29% to 100%. Overall, such high infection rates (87.3% on average) and the effective maternal transmission of R. aeschlimannii might suggest a role as a tick symbiont in H. marginatum . Further studies are thus needed to understand both the status and the role of R. aeschlimannii in H. marginatum ticks.IMPORTANCETicks are obligatory hematophagous arthropods that transmit pathogens of medical and veterinary importance. Pathogen infections cause serious health issues in humans and considerable economic loss in domestic animals. Information about the presence of pathogens in ticks and their dynamics is crucial to assess disease risk for public and animal health. Analyzing tick-borne pathogens in ticks collected in 27 sites in the Occitanie region, our results highlight clear spatial patterns in the Hyalomma marginatum -borne pathogen distribution and strengthen the postulate that it is essential to develop effective monitoring strategies and consider the spatial scale to better characterize the circulation of tick-borne pathogens., Competing Interests: The authors declare no conflict of interest.

The feline population is extensive in urban areas worldwide, comprising stray and domestic cats. Cats, acting as reservoirs, can transmit various zoonotic organisms to humans, which can cause significant public health issues. We evaluated the seroprevalence of zoonotic pathogens in stray cats in an urban area of northeast Spain (the city of Zaragoza) to assess potential risks to human health. A total of 88 sampled cats (52 females and 36 males) underwent antibody evaluation using the indirect immunofluorescence technique. Seroprevalence rates were determined for IgG antibodies to Bartonella henselae (36.3%), Toxoplasma gondii (31.8%), Rickettsia felis (14.7%), Rickettsia typhi (9%), and Leishmania infantum (10.2%). Our results confirmed the presence in stray cats of antibodies against all those pathogens, indicating that they all circulate in the feline population in Zaragoza. Male cats exhibited a higher predisposition to T. gondii, whereas females showed an increased likelihood of contracting B. henselae. This difference may be attributed to distinct behaviors according to sex. Our findings underscore the importance of maintaining and intensifying surveillance coupled with preventive measures against zoonotic pathogens in cats. They highlight the need for comprehensive control strategies designed to mitigate public health risks associated with feline populations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Rickettsia and related diseases have been identified as significant global public health threats. This study involved comprehensive field and systematic investigations of various rickettsial organisms in Yunnan Province., Methods: Between May 18, 2011 and November 23, 2020, field investigations were conducted across 42 counties in Yunnan Province, China, encompassing small mammals, livestock, and ticks. Preliminary screenings for Rickettsiales involved amplifying the 16S rRNA genes, along with additional genus- or species-specific genes, which were subsequently confirmed through sequencing results. Sequence comparisons were carried out using the Basic Local Alignment Search Tool (BLAST). Phylogenetic relationships were analyzed using the default parameters in the Molecular Evolutionary Genetics Analysis (MEGA) program. The chi-squared test was used to assess the diversities and component ratios of rickettsial agents across various parameters., Results: A total of 7964 samples were collected from small mammals, livestock, and ticks through Yunnan Province and submitted for screening for rickettsial organisms. Sixteen rickettsial species from the genera Rickettsia, Anaplasma, Ehrlichia, Neoehrlichia, and Wolbachia were detected, with an overall prevalence of 14.72%. Among these, 11 species were identified as pathogens or potential pathogens to humans and livestock. Specifically, 10 rickettsial organisms were widely found in 42.11% (24 out of 57) of small mammal species. High prevalence was observed in Dremomys samples at 5.60%, in samples from regions with latitudes above 4000 m or alpine meadows, and in those obtained from Yuanmou County. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis were broadly infecting multiple genera of animal hosts. In contrast, the small mammal genera Neodon, Dremomys, Ochotona, Anourosorex, and Mus were carrying individually specific rickettsial agents, indicating host tropism. There were 13 rickettsial species detected in 57.14% (8 out of 14) of tick species, with the highest prevalence (37.07%) observed in the genus Rhipicephalus. Eight rickettsial species were identified in 2375 livestock samples. Notably, six new Rickettsiales variants/strains were discovered, and Candidatus Rickettsia longicornii was unambiguously identified., Conclusions: This large-scale survey provided further insight into the high genetic diversity and overall prevalence of emerging Rickettsiales within endemic hotspots in Yunnan Province. The potential threats posed by these emerging tick-borne Rickettsiales to public health warrant attention, underscoring the need for effective strategies to guide the prevention and control of emerging zoonotic diseases in China., (© 2024. The Author(s).)

Tick-borne diseases are important for animal and human health, because they can cause death if not diagnosed and treated early. Canine monocytic ehrlichiosis (CME) can cause high morbidity in dog populations. Rocky Mountain Spotted Fever (RMSF) is among the most virulent infectious in humans; dogs are also susceptible to infection. The aims of this study were to evaluate the presence of Ehrlichia canis and Rickettsia spp. infections in domestic dogs, and to identify tick species parasitizing dogs among urban areas of two municipalities (Sobral and Alcântaras) in the Ceará State, Northeastern Brazil. A total of 208 domiciled dogs was sampled. After clinical evaluation, blood samples and ticks were collected and submitted to Real-Time Polymerase Chain Reaction (RT-PCR) targeting E. canis DNA. Serum samples were screened by Indirect Immunofluorescence Assays (IFA) for antibodies against different strains of Rickettsia spp. previously recognized in Brazil. The results of this study indicate the molecular detection of E. canis in the state of Ceará, Brazil, where the proportion of canine infection in Sobral (9.9%) was higher than in Alcântaras (5.6%). Rhipicephalus sanguineus sensu lato was the prevalent tick species infesting the dogs in both municipalities (43.5 and 53.3%, respectively). Our serological results indicate that dogs of the study area were at low risk of exposure to these tick-borne Rickettsia spp. of the spotted fever group. Our study offers epidemiological data of these diseases to better understanding Rickettsiales epidemic and enzootic cycles in the Brazilian semiarid region, improving prevention and control measures., Competing Interests: Declaration of competing interest There were no conflicting interests that could have influenced the conduction of this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Bed bugs, common blood-feeding pests, have received limited attention regarding their potential involvement in emerging pathogen transmission. This study aimed to investigate the main vector-borne bacteria within bed bugs collected from Tunisian governorates and to genetically characterize the identified species. Molecular screening was conducted on field-collected bed bug samples, targeting zoonotic vector-borne bacteria from the Anaplasmataceae family, as well as the genera Rickettsia, Ehrlichia, Bartonella, and Borrelia. A total of 119 Cimex lectularius specimens were collected and grouped into 14 pools based on sampling Tunisian sites. Using genus-specific PCR assays, DNA of Rickettsia and Ehrlichia spp. was detected in a single pool. Sequencing and BLAST analysis of the obtained partial ompB and dsb sequences from positive samples revealed 100% similarity with those of Ehrlichia canis and Rickettsia felis available in GenBank. Obtained partial sequences showed phylogenetic similarity to R. felis and E. canis isolates found in dogs and ticks from American and European countries. To the best of our knowledge, this study is the first to investigate bed bugs in Tunisia and to report the worldwide identification of R. felis and E. canis DNA in the common bed bug, C. lectularius. These findings highlight the need for further research to explore the potential role of bed bugs in the epidemiology of these vector-borne bacteria., Competing Interests: Declaration of Competing Interest The authors declared that they have no potential conflicts of interest with respect to the research, authorship and publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Rickettsia occurs worldwide and rickettsiosis is recognized as an emerging infection in several parts of the world. Ticks are reservoir hosts for pathogenic Rickettsia species in humans and domestic animals. Most pathogenic Rickettsia species belong to the spotted Fever Group (SFG). This study aimed to identify and diagnose tick fauna and investigate the prevalence of Rickettsia spp. in ticks collected from domestic animals and dogs in the rural regions of Kerman Province, Southeast Iran. In this study, tick species (fauna) were identified and 2100 ticks (350 pooled samples) from two genera and species including Rhipicephalus linnaei (1128) and Hyalomma deteritum (972) were tested to detect Rickettsia genus using Real-time PCR. The presence of the Rickettsia genus was observed in 24.9% (95%CI 20.28-29.52) of the pooled samples. Sequencing and phylogenetic analyses revealed the presence of Rickettsia aeschlimannii (48.98%), Rickettsia conorii israelensis (28.57%), Rickettsia sibirica (20.41%), and Rickettsia helvetica (2.04%) in the positive samples. The results showed a significant association between county variables and the following variables: tick spp. (p < 0.001), Rickettsia genus infection in ticks (p < 0.001) and Rickettsia spp. (p < 0.001). In addition, there was a significant association between tick species and host animals (dogs and domestic animals) (p < 0.001), Rickettsia spp infection in ticks (p < 0.001), and Rickettsia spp. (p < 0.001). This study indicates a high prevalence of Rickettsia spp. (SFG) in ticks of domestic animals and dogs in rural areas of Kerman Province. The health system should be informed of the possibility of rickettsiosis and the circulating species of Rickettsia in these areas., (© 2024. The Author(s).)

Cervids are highly exposed to ticks, however, their role in the life cycle of these rickettsiae has not been fully elucidated. Given the expanding distribution and growing population of deer species in Portugal, coupled with their direct and indirect interactions with humans during hunting, it becomes crucial to explore their role as sentinels and potential reservoirs of Rickettsia. The present investigation aimed to detect and evaluate exposure to Rickettsia in free-living deer from Portugal. Blood samples (n = 77) were collected from hunted game animals (red deer and fallow deer) from different areas throughout Portugal (Idanha-a-Nova, Monte Fidalgo, Montalvão and Arraiolos) and sera were tested by immunofluorescence assay, to detect antibodies. Additionally, blood DNA samples were screened for SFGR by nested-polymerase chain reaction targeting a fragment of the outer membrane protein B (ompB) gene, as well as for Anaplasma and Ehrlichia spp. targeting the 16S rRNA gene. Thirty-five per cent (25 deer and two fallow deer) tested positive (sera with a titer ≥1:64) for IgG antibodies against Rickettsia conorii. No rickettsial DNA was detected by PCR for the ompB gene, and all DNA samples tested negative for Anaplasma and Ehrlichia. As far as we know, this study is the first screening of cervid species in Portugal for Rickettsia antibodies. The findings suggest that these animals serve as useful sentinel indicators for the circulation of rickettsiae, offering a complementary perspective to studies focused on ticks. The increasing numbers of hunted deer in Portugal and the potential zoonotic features of Rickettsia spp. highlight the importance of continued surveillance directed at tick-borne diseases, especially those involving wild animals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Wild boars or feral pigs are classified by the Brazilian Institute for the Environment and Renewable Resources (IBAMA) in "Category I of invasive exotic species". They cause economic losses, harm the environment, serve as hosts and reservoirs for several zoonotic disease agents, and provide a blood meal for tick species that act as vectors for zoonotic diseases. The objective of this study was to identify tick species on wild boars, assess host-seeking ticks in the related environment, and identify other potential tick hosts coexisting with wild boars on a farm located in the state of Minas Gerais, southeastern Brazil. Additionally, the study aimed to determine the presence of rickettsiae in these arthropods and assess the exposure of wild boars to rickettsiae species from the Spotted Fever Group and Rickettsia bellii through serology. A total of 3585 host-seeking ticks from three species (Amblyomma sculptum - 41.58%; Amblyomma dubitatum - 0.39% and Rhipicephalus microplus - 0.05%) were collected in the environment and A. sculptum was the most abundant species. Thirty-one wild boars were evaluated, resulting in the collection of 415 ticks, all of which were A. sculptum. Rickettsia DNA was not detected in samples of A. sculptum and R. microplus from the environment or in A. sculptum ticks from wild boars. However, all A. dubitatum ticks (n = 14) had Rickettsia bellii DNA confirmed by the species-specific PCR protocol. Out of the 31 serum samples from wild boars, 24 reacted with at least one Rickettsia antigen. Among these, seven individuals exhibited a reaction to a probable homologous antigen (PHA) of three rickettsiae species: R. rickettsii (n = 3), R. amblyommatis (n = 3) and R. rhipicephali (n = 1). Despite the high prevalence of seroreactivity, titers were low, indicating limited exposure to Rickettsia spp. Camera traps generated 874 animal records, capturing a total of 1688 individuals. At least 11 species of birds and 14 species of mammals (12 wild and two domestic) shared the environment with wild boars and potentially shared ticks with them. These findings provide baseline information for understanding the sharing of ticks and tick-borne pathogens between wild boars and other animals within the Cerrado biome. Further studies are necessary to monitor the potential and actual risk of wild boars to harbor infected ticks and their role in the transmission and maintenance cycle of Rickettsia spp., Competing Interests: Declaration of competing interest All authors declare that there is no conflict of interest in the research work submitted., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: To investigate the prevalence of tick-borne rickettsial infections in selected areas of Liupanshui City, Guizhou Province, 2023, so as to provide insights into the management of tick-borne rickettsioses in the city., Methods: Ticks were captured from the body surface of bovines and sheep in Gaoxing Village, Dashan Township, Liupanshui City, Guizhou Province during the period between April and June, 2023, and tick species were identified using morphological and molecular biological techniques. In addition, tick-borne Rickettsia was identified using a nested PCR assay, including spotted fever group rickettsiae (SFGR), Coxiella spp., Anaplasma spp., Ehrlichia spp., and Orientia spp., and positive amplified fragments were sequenced and aligned with known sequences accessed in the GenBank database., Results: A total of 200 ticks were collected and all tick species were identified as Rhipicephalus microplus . Nestle PCR assay combined with sequencing identified ticks carrying Candidatus Rickettsia jingxinensis (40.50%), Coxiella burnetii (1.50%), and Coxiella -like endosymbionts (27.00%), and Anaplasma spp., Ehrlichia spp. or Orientsia spp. was not detected., Conclusions: R. microplus carried Candidatus R. jingxinensis , C. burnetii , and Coxiella -like endosymbionts in selected areas of Liupanshui City, Guizhou Province. Intensified monitoring of tickborne rickettsial infections is needed in livestock and humans to reduce the damages caused by rickettsioses.

Introduction: To date, a total of 2574 validated flea species have been discovered. Vermipsyllidae is a family of fleas that comprises at least eight species. Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Here a novel Vermipsylla species was described, and rickettsial agent was also detected in it., Methods: A total of 128 fleas were collected directly from 260 pastured sheep in China. Of these, eight representative fleas (four males and four females) were identified by key morphological features. Meanwhile, 120 flea DNAs, including six flea samples for molecular taxonomy, were subjected to Rickettsia spp. DNA detection. The molecular identity of fleas was determined by amplification and sequenmce analysis of four genetic markers (the 28S rDNA genes, the 18S rDNA genes, the mitochondrial cytochrome c oxidase subunit I and subunit II). In addition, five Rickettsia-specific gene fragments were used to identify the species of the rickettsial agents. The amplified products were sequenced and phylogenetically analyzed., Results: The morphological characteristics of the flea species identified in this study were similar to Vermipsylla alakurt, but presented difference in hair number of the metepimeron, the third tergum, the genitals and the tibiae of hind leg. The 18S rDNA, 28S rDNA and COII genetic markers from fleas showed the highest identity to those of V. alakurt, shared 98.45% (954/969), 95.81% (892/931) and 85.86% (571/665) similarities, respectively. However, the COI sequence showed the highest identity to that of Dorcadia ioffi with 88.48% (576/651) similarity. Rickettsia raoutii tested positive in 14.17% (17/120) flea DNA samples., Conclusion: Our study reports the detection of R. raoultii in V. alakurt-like fleas infesting sheep in China., (© 2024. The Author(s).)

Outbreaks of acute encephalitis syndrome (AES) with unknown aetiology are reported every year in Gorakhpur district, Uttar Pradesh, India, and Orientia tsutsugamushi, the rickettsial pathogen, responsible for scrub typhus has been attributed as the primary cause of AES problem. However, information on the prevalence of other rickettsial infections is lacking. Hence, this study was carried out to assess any occurrence of tick- and flea-borne rickettsial agents in villages reporting AES cases in this district. In total, 825 peridomestic small mammals were trapped, by setting 9254 Sherman traps in four villages with a trap success rate of 8.9%. The Asian house shrew, Suncus murinus, constituted the predominant animal species (56.2%) and contributed to the maximum number (87.37%) of ectoparasites. In total, 1552 ectoparasites comprising two species of ticks and one species each of flea and louse were retrieved from the trapped rodents/shrews. Rhipicephalus sanguineus, the brown dog tick, was the predominant species retrieved from the trapped rodents/shrews, and the overall infestation rate was 1.75 per animal. In total, 4428 ectoparasites comprising five tick species, three louse species and one flea species were collected from 1798 domestic animals screened. Rhipicephalus microplus was the predominant tick species collected from the domestic animals. The cat flea, Ctenocephalides felis, constituted 1.5% of the total ectoparasites. Of all the ectoparasite samples (5980) from domestic animals and rodents, tested as 1211 pools through real-time PCR assays, 64 pools were positive for 23S rRNA gene of rickettsial agents. The PCR-positive samples were subjected to multi-locus sequence typing (MLST). In BLAST and phylogenetic analysis, the ectoparasites were found to harbour Rickettsia asembonensis (n = 9), Rickettsia conorii (n = 3), Rickettsia massiliae (n = 29) and Candidatus Rickettsia senegalensis (n = 1). A total of 22 pools were detected to have multiple rickettsial agents. The prevalence of fleas and high abundance of tick vectors with natural infections of rickettsial agents indicates the risk of transmission of tick- and flea-borne rickettsial diseases in rural villages of Gorakhpur. Further epidemiological studies are required to confirm the transmission of these agents to humans., (© 2023 Royal Entomological Society.)

The current study aims to assess the prevalence of different genera of Rickettsiales, intracellular bacteria, in dogs across various regions of Iran. Rickettsiales, as zoonotic pathogens, can have various manifestations in different species, including immunosuppression, anaemia and neuropathy. Due to their close interactions with people and livestock, dogs can serve as reservoirs and transmit these pathogens to humans and other animals. The data from this research can be valuable for managing and controlling related diseases and complications in Iran and possibly neighbouring countries. Pertinent data for this study was gathered without time limitations until 1 March 2022, from different databases. Of all the inspected studies, 26 were eligible based on the inclusion criteria. The Egger test result and asymmetry in the funnel plot revealed significant publication bias; therefore, the meta-analysis model was corrected with the trim-and-fill method. After correction, the prevalence of rickettsial infections among dogs varies by genus - 20.1% for Anaplasma spp. and 10% for Ehrlichia spp. - with an overall prevalence estimated at 18.3% by random-effects analysis. The highest and lowest estimated pooled prevalences were associated with the southwestern (38.5%) and southern (0.3%) provinces of Iran, respectively. The pooled prevalence of rickettsial infection was higher in female dogs (OR = 1.198; p < 0.978; 95% CI, 0.842-1.705) and in dogs ≤2 years (OR = 1.014; p < 0.312; 95% CI, 0.598-1.72), but the difference was not statistically significant. Ultimately, the pooled prevalence of rickettsial infections among dogs is relatively low compared to other countries like Qatar, Iraq, Saudi Arabia and Turkey, which are nearby Iran. Given the significant clinical outcomes of this disease, necessary measures for prevention should be taken., (© 2024 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Background: Tick-borne rickettsioses have become a health concern worldwide following the increasing incidence in recent decades. However, there is limited information about these diseases in Islamic Republic of Iran., Aim: This cross-sectional study was conducted to estimate the Rickettsia infection among ixodid ticks collected from cattle, sheep and goats in Islamic Republic of Iran., Methods: The DNA of ixodid ticks collected from cattle, sheep and goats in 54 villages of Zanjan Province, Islamic Republic of Iran, were collected and analysed using a spectrophotometer. Rickettsial-positive samples were screened by targeting the htrA gene and fragments of gltA gene were analysed. The variables were analysed using descriptive statistics and the χ 2 test was used to compare the variables., Results: A total of 528 ticks were tested. Overall, Rickettsia infection rate was 6.44%. Nine of the 12 tick species were infected. Rickettsial positive rates in Hyalomma marginatum and Dermacentor marginatus were 21.33% and 12.77%, respectively. R. aeschlimannii, the predominant rickettsia, was detected only in Hy. marginatum. R. raoultii, R. sibirica and R. slovaca comprised about half of the positive ticks and were recovered from more than one tick species., Conclusion: Considering the discovery of infected ticks in the Islamic Republic of Iran, there is a need to establish a tick control programme in the country, paying attention to populations at high-risk., (Copyright: © Authors 2024; Licensee: World Health Organization. EMHJ is an open access journal. This paper is available under the Creative Commons Attribution Non-Commercial ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo).)

Determining the occurrence of Rickettsia spp. and Anaplasma phagocytophilum in municipalities with no case records is important to define surveillance strategies and is essential to reduce lethality in different regions. Therefore, an approach aimed at enhancing surveillance in municipalities with an unknown epidemiological situation was tested, according to the classification suggested by Resolution SMA/SES 07/01/16. Canine sera collected in the annual anti-rabies campaign were submitted to the indirect fluorescent antibody test for Rickettsia amblyommatis, R. belli, R. parkeri, R. rickettsii and A. phagocytophilum. Titers ≥1:64 and ≥1:320 were considered positive for Rickettsia spp. and A. phagocytophilum, respectively. For Rickettsia spp., 61.8% of dogs were seropositive, with 26% positive for more than one species, and 42.3% were seropositive for R. rickettsii. Dogs from the urban area presented 5.16 (CI 1.18; 7.69) times greater odds of seropositivity for R. parkeri (p = 0.037) and 3.39 (CI 1.04; 3.70) times greater odds for R. belli (p = 0.017). Considering the 1:40 cutoff point, 19.1% of dogs were reactive for A. phagocytophilum. Two (1%) dogs in rural areas were positive (titer 1:640). The results indicate all species ever tested in Lavras/MG, since the present study is the city's first report on the subject. According to classifications of the aforementioned Resolution, the results determine that the municipality of Lavras should be considered a "risk area" for Brazilian spotted fever(BSF). The methodology presented is efficient, straight forward to perform and inexpensive for diagnosing a risk situation for BSF and human granulocytic anaplasmosis. Moreover, its use can be applied throughout Brazil and other countries as a public health alert guideline., Competing Interests: Declaration of Competing Interest I declare that there are no conflicts of interest between the authors of the article entitled: “DOGS (Canis familiaris) AS SENTINELS FOR DETERMINING THE RISK OF OCCURRENCE OF Rickettsia spp. AND Anaplasma phagocytophilum IN PREVIOUSLY UNDIAGNOSED AREAS” submitted for consideration at VETERINARY PARASITOLOGY: REGIONAL STUDIES AND REPORTS., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Rickettsia africae causes zoonotic African tick bite fever, which is a disease of "One Health" importance. There have been reported cases of tourists from Europe and Asia who have been bitten by ticks whilst visiting South Africa's nature reserves, and on their return to their countries, the display African Tick Bite Fever sickness. Hence, the aim of this study was to determine the occurrence of Rickettsia africae in Amblyomma hebraeum ticks infesting livestock in the North West Province. A total of 358 A. hebraeum ticks were collected from 60 ruminants (cattle, sheep and goats) in Mafikeng City of North West Province, South Africa. Ticks were identified morphologically and further confirmed by sequencing of their ITS2 gene. DNA was extracted from 60 pools of ticks which consisted of 5-6 adult ticks that were from the same ruminant host. Infections with Rickettsia spp. were found in 48%, 40%, and 32% of cattle, sheep, and goats, respectively, in amplification by PCR using the ompA gene. The ompA gene sequences showed that the Rickettsia spp. were identified as R. africae. Although the animals from whom the ticks were collected did not exhibit any clinical symptoms, it is well recognised that R. africae is a disease with significant zoonotic potential. Thus, it is important to use the "One Health" approach to formulate prevention and control measures for this pathogen for animal and human health as well as the tourism sector due to the ecotourism importance of the resultant disease., Competing Interests: Declaration of Competing Interest Authors have no conflict of interest in the study., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Rickettsia helvetica has been reported at varying prevalences in Danish and other European Ixodes ricinus populations. Though apparently widespread and with reported cases of human infection, the significance of the bacteria as a threat to public health remains unclear. We present a nation-wide survey of rickettsia in ticks, roe deer and humans in Denmark. Ticks were collected by flagging and screened for presence of rickettsial DNA by polymerase chain reaction. Sera from roe deer, hunters, neuroborreliosis patients and blood donors were analyzed for presence of anti-R. helvetica and Rickettsia felis antibodies by immunofluorescence microscopy. The Rickettsia minimum infection rate in ticks was 4.9 % (367/973 pools positive, 7510 ticks in total), with 3.9 % in nymphs and 9.3 % in adults. Rickettsia helvetica accounted for 4.17 % and Rickettsia monacensis for 0.03 %, 0.6 % comprised non-differentiable rickettsial DNA. The prevalence of antibodies against R. helvetica was 2.8 % (9/319) in roe deer, while no hunters (n = 536) or blood donors (n = 181) were positive. The prevalence of anti-R. helvetica antibodies among Lyme neuroborreliosis patients was 6 % (3/47), where it co-occurred with Anaplasma phagocytophilum. Based on our study autochthonous rickettsiosis is of limited concern to the public health in Denmark, but our finding of R. monacensis for the first time in Denmark illustrates the dynamic nature of tick-borne pathogens, emphasizing that continuous surveillance is necessary., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2023. Published by Elsevier GmbH.)

Rocky Mountain spotted fever (RMSF), caused by the bacterium Rickettsia rickettsii, is a re-emerging tick-borne zoonosis in North America, with hundreds of human fatalities in multiple outbreaks in northern Mexico and the southwestern US in the past few decades. Free-roaming dogs are key because they are reservoirs for the pathogen and the main hosts of the brown dog tick (Rhipicephalus sanguineus), which vectors RMSF in this region. Because coyotes (Canis latrans) can be infected with R. rickettsii and infested with Rh. sanguineus, we hypothesized that space sharing among dogs and coyotes could enhance disease risks. In summer 2021, we captured and sampled 11 coyotes at two sites in Baja California, Mexico, near population centers with human cases of RMSF, and fitted seven individuals with GPS logging collars. We also tested tissue samples, sera, and ectoparasites for DNA of R. rickettsii with PCR and used serology to detect antibodies to R. rickettsii. Finally, we deployed an array of cameras to document dog-coyote interactions. Mean home range size was 40.37 km2. Both GPS and camera data showed considerable home range overlap both between individual coyotes and between coyotes and dogs. Coyotes were active in areas where dogs occur including the domestic interface surrounding human settlements. Although none of our samples were positive for R. rickettsii on PCR, 72.7% (8/11) of the samples were seropositive with titers ≥64. Our data confirm shared space use and risk of shared parasites and disease between coyotes and dogs., (© Wildlife Disease Association 2023.)

The Eastern Uttar Pradesh region of India is known for its endemicity of acute encephalitis syndrome (AES). Decades of research have established that Orientia tsutsugamushi, a causative of scrub typhus, is a substantial contributor (>60%) for the AES cases besides other aetiology, but additional factors in the remaining proportion are still unidentified. Rickettsial infections are challenging to diagnose in clinical settings due to overlapping clinical symptoms, the absence of definitive indicators, a low index of suspicion, and the lack of low-cost, rapid diagnostic tools. Hence, the present study was designed to determine the load of rickettsial infections among AES cases. Furthermore, we aim to find out the prevalent rickettsial species in AES cases as well as in the vector population at this location. The study included the whole blood/cerebrospinal fluid of AES patients and arthropod specimens from rodents. The molecular identification was performed using the 23S-5S intergenic spacer region and ompB gene with genomic DNA obtained from studied specimens. We detected 5.34% (62/1160) of rickettsial infection in AES cases. Among these, phylogenetic analysis confirmed the presence of 54.8% Rickettsia conorii (n = 34) and 16.1% of Rickettsia felis (n = 10), while the rest proportion of the isolates was unidentified at the species level. Furthermore, R. felis was identified in one CSF sample from AES patients and three flea samples from Xenopsylla cheopis. Rickettsia spp. was also confirmed in one Ornithonyssus bacoti mite sample. The results of this investigation concluded the presence of spotted fever group Rickettsia spp. among AES identified cases as well as in the mite and flea vectors that infest rodents., (© 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Background: Understanding the geographic distribution of Rickettsia montanensis infections in Dermacentor variabilis is important for tick-borne disease management in the United States, as both a tick-borne agent of interest and a potential confounder in surveillance of other rickettsial diseases. Two previous studies modeled niche suitability for D. variabilis with and without R. montanensis , from 2002 to 2012, indicating that the D. variabilis niche overestimates the infected niche. This study updates these, adding data since 2012. Methods: Newer surveillance and testing data were used to update Species Distribution Models (SDMs) of D. variabilis , and R. montanensis -infected D. variabilis , in the United States. Using random forest models, found to perform best in previous work, we updated the SDMs and compared them with prior results. Warren's I niche overlap metric was used to compare between predicted suitability for all ticks and " R. montanensis -positive niche" models across datasets. Results: Warren's I indicated <2% change in predicted niche, and there was no change in order of importance of environmental predictors, for D. variabilis or R. montanensis -positive niche. The updated D. variabilis niche model overpredicted suitability compared with the updated R. montanensis -positive niche in key peripheral parts of the range, but slightly underpredicted through the northern and midwestern parts of the range. This reinforces previous findings of a more constrained R. montanensis -positive niche than predicted by D. variabilis records alone. Conclusions: The consistency of predicted niche suitability for D. variabilis in the United States, with the addition of nearly a decade of new data, corroborates this is a species with generalist habitat requirements. Yet a slight shift in updated niche distribution, even of low suitability, included more southern areas, pointing to a need for continued and extended monitoring and surveillance. This further underscores the importance of revisiting vector and vector-borne disease distribution maps.

Rickettsia felis is an emerging rickettsial agent principally associated with cat fleas (Ctenocephalides felis), formerly discovered in 1990. Since then, clinical cases of R. felis infection have been identified globally by specific DNA sequences in patients with undifferentiated febrile illness, including in Taiwan, but such evidence is limited. R. felis rickettsiosis is self-limiting and easily treated with doxycycline, but its diagnosis remains a challenge. Environmental risk factors for R. felis rickettsiosis have yet to be clearly demonstrated, and its transmission biology is incompletely understood. Cat fleas are naturally infected with R. felis at varying rates, and vector competence in the transmission of R. felis has been demonstrated in animal models, including dogs, which may serve as reservoir hosts. In northern Taiwan, despite ∼20% of cat fleas infesting companion animals consistently found to be infected with R. felis, only a few cases of potential R. felis infection have been identified through a retrospective serological investigation, though without molecular confirmation. Ecological studies have identified divergent R. felis-like organisms in different arthropod hosts, but these strains appear to serve as nonpathogenic endosymbionts. Although its association with disease is limited, we believe cat flea-borne R. felis warrants increased recognition in an aging population due to immunosenescence and the proximity of companion animals to the elderly. Adopting a One Health approach involving collaboration and communication between clinicians, veterinarians, public health practitioners, and environmental scientists will improve our knowledge about this neglected pathogen and promote the prevention and control of vector-borne diseases., (Copyright © 2022. Published by Elsevier B.V.)

Rickettsia rickettsii is the etiological agent of Rocky Mountain spotted fever, which is an important tick-borne zoonosis and, in Brazil, it causes Brazilian spotted fever, which has high lethality rate. This study aimed to evaluate a synthetic peptide corresponding to a segment of the outer membrane protein A (OmpA) as an antigen in a serological test for the diagnosis of rickettsial infections. The amino acid sequence of the peptide was selected by predicting B cell epitopes using B Cell Epitope Prediction (Immune Epitope Database and Analysis Resource) and Epitopia and OmpA sequences of Rickettsia rickettsii strain 'Brazil' and Rickettsia parkeri strains 'Maculatum 20' and 'Portsmouth'. A peptide with amino acid sequence common to both Rickettsia species was synthesized and arbitrarily named OmpA-pLMC. To evaluate this peptide in enzyme-linked immunosorbent assay (ELISA), serum samples of capybara (Hydrochoerus hydrochaeris), horse (Equus caballus), and opossum (Didelphis albiventris) that had been previously tested by indirect immunofluorescence assay (IFA) for rickettsial infection were separated into IFA-positive and IFA-negative groups and used in the assay. There were no significant differences in ELISA optical density (OD) values between IFA-positive and IFA-negative groups with horse samples. The mean OD values were significantly higher in the IFA-positive capybara serum samples (IFA-pos vs. IFA-neg = 2.389 ± 0.761 vs. 1.760 ± 0.840). However, receiver operating characteristic (ROC) curve analysis did not show significant diagnostic parameters. On the other hand, 12 out of 14 (85.7%) opossum samples of the IFA-positive group showed reactivity in ELISA, and this was significantly higher than of the IFA-negative group (0.7196 ± 0.440 vs. 0.2318 ± 0.098, respectively; 85.7% sensitivity, 100% specificity). Therefore, our results show that OmpA-pLMC has a potential to be used in immunodiagnostic assays to detect spotted fever group rickettsial infections., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Tick-borne diseases (TBDs) pose a significant risk to humans and represent one of the major factors influencing readiness within the United States' military worldwide. Additionally, ticks and TBDs constitute major animal health problems leading to economic losses at multiple levels affecting low- and middle-income countries the hardest. Tick control is frequently hampered by issues ranging from acaricide resistance to lack of data on tick distribution and infection rates. We conducted a cross-sectional study to assess tick species distribution, host use, and rickettsial pathogen infection rate of ticks in different areas of the Uganda Cattle Corridor. We identified 4,425 hard ticks (Ixodida: Ixodidae) comprised of seven species by morphological characters with 3,315 ticks collected from four locations during the dry season and 1,110 ticks from one location during the wet season. Rickettsial pathogen prevalence was assessed in ticks collected from two districts to determine the minimum infection rate compared across seasons, village location, and tick species. We found statistically significant differences in the abundance and distribution of tick species among districts in the dry season, host animal species, and the proportion of rickettsial positive pools between villages. Seasonality, village location, and tick species do not affect the minimum infection rate of rickettsial pathogens of ticks in Uganda, but village location affects the proportion of positive tick pools. These results indicate geographical and seasonal differences among pathogen-harboring ticks contributing to our understanding of the current distribution of ticks and TBDs in Uganda., (Published by Oxford University Press on behalf of Entomological Society of America 2022.)

Rickettsia felis is an obligate intracellular gra m-negative bacterium that belongs to the family of Rickettsiaceae. Ctenocephalides felis, cat flea, is the primary vector of the bacteria. The flea is the most common ectoparasite in dogs and associated with flea-borne spotted fever in humans. Information on R. felis and flea species parasitizing on dogs in Vietnam is limited. This study aimed to identify the species of fleas collected from dogs in the Central Highlands of Vietnam and detected the existence of R. felis in these fleas utilizing molecular tools. Morphological identification of 1618 fleas and molecular confirmation revealed the predominance of C. felis orientis parasitizing on dogs in the Central Highlands of Vietnam. Sixty-eight out of 100 fleas collected from household dogs were positive for spotted fever group rickettsiae; whilst R. felis was detected in 97.06 % (66/68) of C. felis orientis and C. felis felis. The results of this study indicate the potentially high risk of R. felis infection to humans and animals., Competing Interests: Conflict of interest The authors declare no conflicts of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Spotted fever rickettsioses are important causes of emerging infectious disease in the United States and elsewhere. Rocky Mountain Spotted Fever, caused by R. rickettsii causes a febrile, acute illness in dogs. Because it circulates in peripheral blood in low copy number and because of the acute nature of the disease, dogs may test PCR and seronegative at the time of presentation. Therefore, therapy with doxycycline must be initiated and continued based on the clinician's index of suspicion. Combining PCR with serologic testing, repeat testing of the same pre-antimicrobial blood sample, and testing convalescent samples for seroconversion facilitates diagnosis. The prognosis can be excellent if appropriate antimicrobial therapy is begun in a timely fashion. It is well established that dogs are sentinels for infection in people in households and communities. Whether R. rickettsii causes illness in cats is not well established. The role of other spotted fever group rickettsia in causing illness in dogs and cats is being elucidated. Veterinarians should keep in mind that novel and well characterized species of SFG Rickettsia are important causes of emerging infectious disease. Veterinarians can play an important role in detecting, defining, and preventing illness in their canine patients and their human companions., Competing Interests: Disclosure Paid speaker and consultant for Zoetis and IDEXX laboratories. Currently employed at Zoetis., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Non-fatal cases of rickettsial infection with different clinical features than the classic BSF (Brazilian Spotted Fever) have been reported in seashore areas of Paraná state, southern Brazil. In addition, Amblyomma ovale tick infected by Rickettsia parkeri strain Atlantic rainforest has been also described in this area. Accordingly, the aim of this study was to investigate the occurrence of anti-Rickettsia spp. antibodies in human and dog populations, and Rickettsia spp. infection in ticks from oceanic islands and seashore mainland cities of southern Brazil. Serum samples were collected from 328 persons and their 282 dogs from three islands and two seashore mainland cities. A total of 211 ticks were collected from dogs, identified as A. ovale and R. sanguineus. In overall, 40 of 328 (12.2%) human samples were seropositive for Rickettsia spp., including 21 of 190 (11.1%) on islands and 19 of 138 (13.7%) on seashore mainland, and 62 of 282 (22.0%) dog samples, including 31 of 153 (20.3%) on islands and 31 of 129 (24.0%) in seashore mainland areas. In overall, nine of 82 (11.0%) ticks were positive to real-time PCR assay targeting a fragment of the rickettsial gltA gene, including two of 64 (3.1%) Rickettsia sanguineus and seven of 18 (38.9%) A. ovale, of which four were infected with the R. parkeri strain Atlantic rainforest. Despite no association between risk factors and Rickettsia spp. seropositivity was found in human beings, access to natural areas (p = .011) and tick infestation (p = .004) was significantly associated to dog seropositivity. The serological and molecular findings herein have confirmed previous tick and clinical case reports and enlarged the geographical occurrence of A. ovale infected by R. parkeri strain Atlantic rainforest in oceanic islands and seashore mainland cities of Paraná State, indicating a new likely transmission area of this new rickettsial infection in human beings and dogs of southern Brazil., (© 2022 Wiley-VCH GmbH.)

Although ticks are known vectors of pathogens across a range of hosts, there is limited research on emerging tick-borne diseases of horses in the United States. Tick surveys from other regions suggest Rickettsia spp. and Ehrlichia spp. may be clinically relevant in horses. To better understand the transmission risk of these tick-borne rickettsial disease agents to horses, ticks were collected from horses in Oklahoma. Ticks for the current study (306 Amblyomma americanum, 20 Dermacentor albipictus, 19 D. variabilis, and 7 A. maculatum) were evaluated for Rickettsia spp. and Ehrlichia spp. using polymerase chain reaction and sequence analysis. Serum samples from infested and noninfested horses were evaluated for antibodies to R. rickettsii using indirect fluorescence antibody testing and Ehrlichia spp. and Anaplasma spp. using a commercial enzyme-linked immunoassay. Of the horses with tick infestations, 71.4% hosted at least one tick with a rickettsial agent detected. Rickettsia spp. were identified in 25.9% (91/352) of the ticks tested with R. amblyommatis (80.2%; 73/91) most often detected. Ehrlichia spp. were identified in 2.8% (10/352) of the ticks tested with E. ewingii most often identified. Serologic screening revealed no horses with antibodies to R. rickettsii or Anaplasma spp., but 29.6% of the examined horses had circulating antibodies to Ehrlichia spp. Together, these results demonstrate the presence of Rickettsia spp. and Ehrlichia spp. in equine ticks and evidence of past or current infection with Ehrlichia spp. in Oklahoma horses which strongly suggests there is a need to explore the relationship between these agents and equine health., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Rickettsioses is a group of emerging infectious diseases in Southeast Asia caused by Gram-negative obligate intracellular bacteria in the Rickettsiae tribe. However, there is limited information regarding the vertebrate hosts of Rickettsia spp. in this region. This study aims to detect and identify Rickettsia agents present in wildlife and domesticated animals in Malaysia using Polymerase Chain Reaction (PCR) and sequencing of citrate synthase gene (gltA), followed by genotyping and phylogenetic analysis. Rickettsia sp. was detected in 2 (0.67%) of 300 wildlife and domesticated animal blood samples. The positive samples were derived from a goat (5.56% of 18) and a sheep (2.22% of 45). Both sequences demonstrated 99.64% sequence similarity to Rickettsia asembonensis, a species that is known to infect humans and macaques. This study reported for the first time the detection of R. asembonensis in sheep and goats in Malaysian farms, suggesting this species may be adapting to a wider range of animals, specifically farm animals. Therefore, this bacterium may pose a zoonotic threat to the local community particularly to the farmworkers or animal handlers. The low infection rate of this pathogen across different animals highlighted the need of continuous surveillance of emerging and reemerging pathogens among animal populations., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Rickettsial diseases are recognized as one of the most important vector-borne infectious diseases for humans all over the world. Dogs and their ticks are considered the most important reservoirs for Rickettsia spp., especially in spotted fever group rickettsioses. The aim of the study was to investigate Rickettsia infections in ticks collected from stray dogs in southeastern Iran. In this study, 50 stray dogs in Kerman city were randomly selected, of 68% and 52% of which were above 8 months age and male, respectively. Ticks were collected from the dog skins. After identification of collected ticks, genomic DNA of all ticks was extracted. DNA samples were tested using real-time PCR for Rickettsia spp. infections. The species of Rickettsia in positive samples were determined using gltA gene amplification and sequencing. A total of 250 ticks were collected from 50 stray dogs and all of them belonged to Rhipicephalus sanguineus sensu lato. Totally, 10 pooled of 50 pooled ticks were positive for Rickettsia spp. in real-time PCR and the minimal Rickettsial infection rate was 4% in this study. The identified Rickettsia spp. included R. massiliae (n = 5), R. rhipicephali (n = 1), and R. sibirica (n = 1). In this study, molecular evidence of Rickettsia spp. infection was observed in collected ticks from stray dogs in southeast Iran. More sensitivity to human and animal health care systems in southeastern Iran is essential to the diagnosis of suspected clinical cases that are related to rickettsiosis., (Copyright © 2022. Published by Elsevier GmbH.)

The genus Rickettsia encompasses several species grouped into two main clusters, Typhus and the Transitional groups. The latter group contains Rickettsia felis, an endosymbiont of several arthropods with an uncertain human pathogenicity and whose most efficient transmission mechanism described thus far is transovarial. The aim of this study was to evaluate whether this pathway exists using phylogenetic analysis and partial sequences of the 17kDa and gltA genes and comparing them with host phylogeny using the cytb region. This is the first study that evaluates the vertical transmission of R. felis. In general, both phylogenies of R. felis showed no polytomies, as suspected if this pathway was the only pathway occurring. When phylogenies of the invertebrates and the gltA of R. felis were compared for strong coevolutionary insight, intricate relationships were observed, suggesting that other transmission pathways must occur, such as horizontal transmission. Further studies are needed to determine which other transmission routes occur in hematophagous arthropods., (© 2022 Wiley-VCH GmbH.)

Spotted fever group Rickettsia species are intracellular bacteria transmitted by tick or mite vectors and that cause human diseases referred to as spotted fever group rickettsioses, or spotted fevers. In the United States, the most recognized and commonly reported spotted fevers are Rocky Mountain spotted fever (RMSF) ( Rickettsia rickettsii ), Rickettsia parkeri rickettsiosis, Pacific Coast tick fever ( Rickettsia species 364D), and rickettsialpox ( Rickettsia akari ). In this study, we summarize and evaluate surveillance data on spotted fever cases reported to the Centers for Disease Control and Prevention (CDC) through the National Notifiable Diseases Surveillance System from 2010 to 2018. During this period, there were 36,632 reported cases of spotted fevers with 95.83% ( N  = 35,104) reported as meeting the case definition as probable and 4.17% ( N  = 1528) reported as meeting the case definition as confirmed. The average national incidence of total cases, both probable and confirmed, was 12.77 cases per million persons per year. The highest statewide incidence was in Arkansas, with 256.84 per million per year, whereas the lowest incidence occurred in California, with 0.32 per million per year (note that spotted fevers were not notifiable in Hawaii and Alaska). Cases of spotted fevers were reported more frequently among males by gender, White by race, and non-Hispanic by ethnicity. The incidence of spotted fevers increased significantly from 2010 to 2018, but it is uncertain how many of the reported cases were RMSF and how many developed from more moderate spotted fevers. Improvement of the ability to differentiate between spotted fever group Rickettsia species is needed.

Tick-borne pathogens (TBPs) pose an increased health and productivity risk to livestock in sub-Saharan Africa. Information regarding TBPs infecting small ruminants in Kano metropolis is scarce. Therefore, we investigated the molecular epidemiology of tick-borne pathogens of economic importance from sheep and goats in Kano, Nigeria using Polymerase chain reaction (PCR). A total of 346 blood DNA samples were collected from small ruminants and analyzed for TBPs using PCR and sequencing. Risk of infection was determined for age, sex, breed and animal species. Our results indicate the absence of piroplasmids (Babesia/Theileria) and Rickettsia spp. infections. The overall prevalence for Anaplasma spp. was 9.25% (32/346) with a higher prevalence in goats 13.59% (25/184) compared with sheep 4.32% (7/162). With respect to age of animals, goats >4 years had the highest prevalence of 32.45% (11/37) which differs significantly (P = 0.0059) compared with other age categories. Cross breed goats had a prevalence of 15.63% (5/32) compared with Kano brown breed 14.08 (20/142). Sex significant difference (P = 0.029) was observed in the goats with females having the highest prevalence 20.89% (14/67) compared with males 9.40% (11/117). Furthermore, with regards to sheep, no significant difference (P > 0.05) was observed with respect to age and breed. Finally, no significant difference (P > 0.05) was observed with the prevalence of Anaplasma spp. due to Body condition score (BCS) in both sheep and goats. Conclusively, the occurrence of TBPs in small ruminants is low. Continuous efforts in tick control must be sustained to ensure high productive yield and reduced disease burden associated with TBPs of sheep and goats in Kano metropolis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Host feeding patterns and the prevalence of infection with Rickettsia parkeri were determined for the primary vector, Amblyomma maculatum Koch as well as sympatric tick species A. americanum (Linnaeus) and Dermacentor variabilis (Say) collected from a reconstructed prairie in the Piedmont region of North Carolina during 2011 and 2012. The occurrence of R. parkeri among A. maculatum adults and nymphs was 36.9% (45/122) and 33.3% (2/6), respectively. Rickettsia parkeri was detected in a single male A. americanum 2.3% (1/43). A PCR-reverse line blot hybridization assay of a 12S rDNA fragment amplified from remnant larval and nymphal bloodmeals of host-seeking ticks was used to identify bloodmeal hosts. Of the tick samples tested, bloodmeal host identification was successful for 29.3% (12/41) of adult A. americanum and 39.2% (20/51) of adult D. variabilis. For A. maculatum, bloodmeal host identification was successful for 50% (61/122) of adults collected from vegetation and 100% (4/4) of nymphs removed from cotton rats (Sigmodon hispidus Say and Ord). The cotton rat was the most common bloodmeal host with 59.0% (36/61) identified for adult A. maculatum. No statistically significant association was observed, however, between bloodmeal host and pathogen prevalence for any tick species. While the cotton rat was an important bloodmeal host for A. maculatum nymphs, this vertebrate did not appear to be the primary source of R. parkeri infection for A. maculatum., (© The Author(s) 2022. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Rickettsiosis is considered an emerging/re-emerging vector-borne disease that causes significant public health threats. Ticks are reservoirs and vectors of Rickettsia having a significant role in the transmission of rickettsiae. In Portugal, little is known about tick-borne Rickettsia species in sheep. Therefore, this study aimed to investigate rickettsiae infection in ticks and their sheep host from 27 farms in four districts of central Portugal, to clarify the role of the sheep host in the circulation of this zoonotic agent. Between March and May 2021, EDTA blood samples (n = 100) of healthy grazing sheep and their ticks (n = 100, one tick per animal) were collected during a herd health program in central Portugal. Obtained ticks were identified as Rhipicephalus sanguineus sensu lato by PCR targeting a partial sequence of 16S rRNA gene followed by sequence analysis. Rhipicephalus sanguineus s.l. and host sheep blood were tested for the presence of Rickettsia spp. by PCR targeting a partial sequence of ompB and ompA genes. From a total of 100 paired R. sanguineus s.l. and host sheep, Rickettsia massiliae was detected in 62 ticks and 35 grazing sheep blood samples, collected in central Portugal, 2021. All 35 positive sheep had attached positive R. sanguineus s.l., with matching nucleotidic sequences. These findings suggest that sheep may develop rickettsiemia and are likely capable of transmitting and amplifying the infection to uninfected ticks maintaining rickettsiae in circulation in the domestic cycle., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Human tick-borne rickettsioses are caused by Rickettsia africae, Rickettsia massiliae, Rickettsia parkeri, Rickettsia philipi and Rickettsia rickettsii in the American continent. Rickettsia parkeri represents the second most important agent of eschar-associated spotted fever throughout the American continent. In Mexico, the presence of three strains of this bacterium (Black Gap, Maculatum and Atlantic Rainforest) has recently been reported in four species of ticks from five states (Baja California, Campeche, Sonora, Tabasco and Veracruz) and rickettsaemia was demonstrated in a dog from the state of Yucatán. We report two human cases of R. parkeri-rickettsiosis from Yucatan, Mexico. These findings have increased the interest in R. parkeri surveillance in the human population, due to the fluctuating regional Spotted Fever morbidity and mortality in the country., (© 2022 Wiley-VCH GmbH.)

Ticks are considered as the reservoirs for pathogenic Rickettsia for humans and domestic animals. Recently, clinical cases of rickettsiosis have been reported from Iran and its surrounding countries. This study was aimed at investigating the prevalence of Rickettsia spp. in ticks in Southeastern Iran.All ticks were collected April to September 2019 from the domestic animals and stray dogs from different villages of Kerman province. For the primary detection of Rickettsia spp., Real-Time PCR was carried out on extracted DNA from ticks by targeting the 16 S rRNA gene. From the PCR-sequencing method of 16 S rRNA, citrate synthase (gltA), antigen 17 kDa, and ompA genes were used for identification of Rickettsia spp. in Real-Time PCR positive samples. A total of 185 ticks were examined and belonged to the genus Hyaloma and Rhipicephallus. Ticks with most frequencies included Rhipicephallus sanguineous (30.9%). In total, six samples (3.24%) were positive for Rickettsia spp. using the Real-Time PCR. According to the results of sequencing and phylogeny, samples were closely related to R. rhipicephali (2 samples) and R. massiliae (four samples). These results are important in the detection and epidemiology of Rickettsia spp. in Iran and indicate the necessity of detection and prevention approaches for rickettsiosis., (Copyright © 2022. Published by Elsevier Ltd.)

Background: Flea-borne rickettsioses have been limitedly explored in the Indian sub-Himalayan belt, including the North Eastern Region (NER) of India. This study investigates the presence of rickettsiae hosts and their probable pathogens in the disease-endemic hilly state of the NER of India., Methods: Entomological surveys were carried out in disease-reporting localities in a hilly state in India. Fleas collected from domesticated animals were processed for detection of a Rickettsia-specific 17-kDa gene., Results: Sequence analysis revealed Rickettsia felis in six flea pools (40%), Candidatus Rickettsia senegalensis in two pools (13.3%) and Rickettsia asembonensis in one pool (6.6%)., Conclusions: Our findings suggest Ctenocephalides felis, Ctenocephalides canis and Pulex irritans as potential carriers of R. felis and R. felis-like organisms in India., (© The Author(s) 2022. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)

Background: Rickettsia spp. are important tick-borne pathogens that cause various human and animal diseases worldwide. A tool for rapid and accurate detection of the pathogens from its vectors is necessary for prevention of Rickettsioses propagation in humans and animals, which are infested by ticks. Therefore, this study was conducted to evaluate a molecular tool, ultra-rapid real-time PCR (UR-qPCR), for rapid and accurate detection of Rickettsia spp. from 5644 ticks in 408 pools collected from livestock and their surrounding environments in Gangwon and Jeju province in South Korea., Results: The UR-qPCR of Rickettsia DNA showed a limit of detection of 2.72 × 10 1 copies of Rickettsia DNA and no cross reaction with other tick-borne pathogens, namely Anaplasma phagocytophilum, Ehrlichia chaffeensis, E. canis, Toxoplasma gondii, and Borrelia burgdorferi. In addition, the PCR assay also showed possibility of various Rickettsia species detection including R. monacensis, "Candidatus R. longicornii", R. japonica, R. roultii, and R. tamurae. The collected ticks were identified with major species belonged to Haemaphysalis longicornis (81.62%), followed by H. flava (15.19%), and Ixodes nipponensis (3.19%). Rickettsia detection from tick samples using the UR-qPCR showed that the minimum infection rate (MIR) of Rickettsia in collected ticks was 1.24‰ and that all positive pools contained H. longicornis, equal to the MIR of 1.39‰ of this species. Additionally, MIR of Rickettsia spp. detected in ticks collected in Gangwon and Jeju was 1.53‰ and 0.84‰, respectively. Furthermore, the sequencing results of the 17 kDa protein antigen gene and ompA gene showed that Rickettsia spp. sequences from all pools were related to "Candidatus R. longicornii" and "Candidatus R. jingxinensis"., Conclusions: The UR-qPCR system was demonstrated to be useful tool for accurate and rapid detection of Rickettsia from its vector, ixodid ticks, within 20 min. The data on Rickettsia spp. in ticks detected in this study provide useful information on the distribution of Rickettsia in previously unstudied Korean provinces, which are important for the prevention and control of the spread of rickettsioses in both animals and humans in the country., (© 2022. The Author(s).)

Wild birds have an important role as hosts of ticks infected by rickettsiae. However, the role of birds as reservoirs of tick-borne rickettsiae is unknown and poorly understood. This is particularly relevant in several tropical and subtropical areas, where migration influences the global spread of ectoparasites and pathogens of public health importance. This research aimed to detect and evaluate the exposure to spotted fever group rickettsiae in wild birds that could represent reservoirs in the Department of Arauca in the Colombian Orinoquia region. Sampling was conducted in three municipalities of the Department of Arauca (Colombia). Blood samples were collected from 255 birds and processed to obtain serum (n = 155) and DNA (n = 255) samples. The serum samples were processed for indirect immunofluorescence assays (IFA) for the detection of antibodies to Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Rickettsia rhipicephali, and Rickettsia bellii. Additionally, we investigated rickettsiae DNA in blood samples by amplification of the citrate synthase gene (gltA). The IFA results revealed seropositivity in 97 samples from 54 species of resident and migratory birds. No sample was positive for rickettsial DNA. The presence of antibodies in 62.5% of the sera indicates previous exposure of these birds to rickettsiae. The null detection of rickettsiae in the blood of seropositive birds is possibly due to a short period of bacteremia. Experimental studies are required to improve our understanding of the role of wild birds as sources of rickettsial infections in ticks., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Dogs are important in the epidemiology of tick-borne diseases, playing a significant role mainly in endemic areas of rickettsiosis and borreliosis, and serving as sentinels in epidemiological surveys. We analyzed the distribution of Rickettsia and Borrelia spp. in dogs and their ticks in the municipalities of Guaxupé, Minas Gerais, and Tapiratiba, São Paulo, Brazil, two areas non-endemic for Baggio-Yoshinari Syndrome (BYS) and rickettsiosis. Serum from 242 dogs of different ages (>12 months) and breeds were tested by the Indirect Immunofluorescence Assay (IFA) using specific antigens for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Rickettsia rhipicephali, and Rickettsia bellii, and by an indirect Enzyme Linked Immunosorbent Assay (ELISA) for the detection of homologous IgG antibodies against Borrelia burgdorferi American strain G39/40. Ticks were collected from the animals and subjected to PCR and nested PCR for detection of Rickettsia spp. (synthase citrate gene) and Borrelia spp. (flagellin gene). Serological data showed that 7.85% (19/242) of the analyzed dogs were seropositive for at least one of the five Rickettsia antigens tested; one (0.41%) was considered seropositive for R. parkeri (1:64) and one (0.41%) for R. rickettsii (1:256). Nine (3.72%) were considered seropositive for R. bellii and one (0.41%) for R. amblyommatis; a seroprevalence of 13.64% (33/242) for IgG class immunoreactive antibodies against B. burgdorferi was observed. A total of 148 ticks were collected from the dogs; among these 3.40% were identified as larvae of the genus Rhipicephalus and 0.70% of the genus Amblyomma; 89.8% were identified as Rhipicephalus sanguineus, 4.70% Amblyomma sculptum and 1.40% Amblyomma ovale; all negative for PCR of Rickettsia spp. and nested PCR for Borrelia spp.. The serological findings of this study suggest the circulation of Rickettsiae associated with the spotted fever group and vector ticks, just like Borrelia spp. in a non-endemic Brazilian area, drawing attention to the possibility of a zoonotic cycle in the region., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The redclaw crayfish (Cherax quadricarinatus) is a freshwater decapod crustacean, cultured in numerous countries worldwide for both food and ornamental purposes. Redclaw crayfish has become an important aquaculture species due to its physical and biological traits, relatively easy breeding, and a short growing-out period to reach commercial size. Bacterial infections are the second-most studied pathogens of freshwater crayfish. However, redclaw crayfish rickettsiosis, caused by Coxiella cheraxi, was reported in only a few scientific papers in the early 2000s, in Australia and Ecuador. Coxiella cheraxi is a rod-shaped intracellular bacterium that can cause mortality of 22%-80% in naturally infected crayfish. In experimental infections, mortality rates may be even higher (40%-90%). Coxiella cheraxi is closely related to Coxiella burnetii, the agent of Q-fever, which affects ruminants (goats, sheep, and cattle) and occasionally may cause zoonotic infections. According to the scientific knowledge available, C. cheraxi is a species-specific pathogen because it has been only detected in Cherax quadricarinatus and thus far, there is no evidence of a zoonotic potential. In this study, we describe an outbreak of rickettsiosis in a batch of redclaw crayfish imported to Israel from an Australian hatchery, observed 2 months after introduction in a quarantine facility. Initial mortality was evaluated through histopathology, revealing infection by rickettsia-like organisms (RLO) that were subsequently investigated by molecular analysis and transmission electron microscopy examination. Phylogenetic analysis revealed that the detected RLO were closely related to C. cheraxi from a single source (Australian strain TO98), available in free publicly accessible databases. After 5 months in quarantine, almost 99% of the crayfish population had died. Our findings raise valuable questions related to aquatic animal trade and the importance of mitigation measures, such as quarantine and routine diagnostic procedures, to limit the spread of infectious diseases., (© 2021 Wiley-VCH GmbH.)

Objectives: We sought to determine the habitat associations and pathogen status of Amblyomma maculatum ticks in New York City (NYC), New York, USA, a newly expanded portion of their range. Methods: We collected 88 ticks from two NYC parks on Staten Island, one of the five boroughs of NYC, and compared our findings with similar habitat in Brooklyn, New York during the same time period (April 30-September 1). We tested 76 for pathogens. Results: We found adult and immature ticks in native and invasive grasses at Freshkills and Brookfield parks on Staten Island. No A. maculatum ticks were found in Brooklyn. 52.6% of ticks tested were infected with Rickettsia parkeri -the etiological agent of R. parkeri rickettsiosis. Conclusions: This high rate of R. parkeri in a dense urban center is of concern to the medical community, who should be aware of this species' presence and the symptoms of R. parkeri rickettsiosis.

The prevalence and genetic identity of Rickettsia infection in Rhipicephalus sanguineus sensu lato (s.l.) ticks were determined in Taiwan. In total 1153 ticks were examined for Rickettsia infection by PCR assay targeting the citrate synthase gene (gltA) of Rickettsia. The prevalence of Rickettsia infection in R. sanguineus s.l. ticks with a general infection rate of 2.2%, and was detected in nymph, male and female stages of R. sanguineus s.l. ticks with an infection rate of 3.1, 2.0 and 1.1%, respectively. Phylogenetic relationships were analyzed by comparing the gltA sequences obtained from four Taiwan strains and 16 other strains representing 13 genospecies of Rickettsia. Phylogenetic analyses reveal that one Taiwan strain was genetically affiliated with the Japan isolate (GRA-1 strain) which belongs to the spotted fever group (R. parkeri/R. honei) and three Taiwan strains were genetically affiliated with the transitional group of Rickettsia (R. felis). Intra- and inter-species analysis also indicated the genetic distance (GD) of the Taiwan strains with a lower level of GD < 0.011, 0.023 and 0.003 as compared with the type strains of R. parkeri, R. honei and R. felis, respectively. Our findings reveal the first detection of Rickettsia infections (R. parkeri/R. honei and R. felis) in R. sanguineus s.l. ticks of Taiwan. These results also highlight the epidemiological significance of diverse Rickettsia species existed in R. sanguineus s.l. ticks and the potential threat for the geographical transmission of Rickettsia infection in Taiwan., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Brazilian spotted fever (BSF) is an acute infectious disease caused by the bacterium Rickettsia rickettsii, which is transmitted by different tick species. Due to deleterious effects caused on ticks, the horizontal transmission of R. rickettsii through amplifying hosts is crucial for its maintenance in tick populations among BSF-endemic areas. The tick Amblyomma aureolatum is the main vector of R. rickettsii in the São Paulo metropolitan area; nevertheless, it is not known which vertebrate could act as an amplifying host for this tick species. Herein, we evaluated the potential of domestic dogs - primary hosts for A. aureolatum adults in BSF-endemic areas - to act as amplifying hosts. For this purpose, A. aureolatum non-infected adults were allowed to feed on two groups of dogs: the control group (G1), composed of one dog not exposed to R. rickettsii; and, the infected group (G2), composed of three dogs infected with R. rickettsii via tick parasitism. All G2-dogs became ill, seroconverted to R. rickettsii, and rickettsial DNA was detected in 87% of the engorged females that fed on them. Transovarial transmission rate was estimated to be 25% and infected larvae successfully transmitted R. rickettsii to guinea-pigs, confirming transovarial transmission and vector competence. No rickettsial DNA was detected in individual samples of eggs or larvae, which precluded the estimation of filial infection rate, but implies that it was low. Our results suggest that domestic dogs act as amplifying hosts of R. rickettsii for A. aureolatum ticks in BSF-endemic areas in Brazil., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

The objective of this work was to evaluate the relationship between the populations of the ticks Amblyomma triste Koch, 1844, Rhipicephalus microplus (Canestrini, 1888), Amblyomma sculptum Berlese, 1888, the pathogenic bacteria Rickettsia parkeri and a marsh deer (Blastocerus dichotomus) population after its removal from a pristine environment. For this purpose, ticks were collected from the cervical region of deer at the Marsh Deer Conservation Center in Promissão, São Paulo State, Brazil for nine consecutive years (2000 - 2008). Deer in captivity at the Center were kept in 2,000 m² paddocks surrounded by two-meter-high fences in the Tiete-river marsh. In total, 1,012 ticks of 26 deer were collected. Prevalence of the species A. triste among tick-infested hosts was the highest in the first triennium but decreased to the second and further to the third triennium. In contrast, the R. microplus prevalence amidst infested host population, increased from the first to the third triennium and was the species that attained the highest infestation intensity. Amblyomma sculptum was the tick with the lowest infestation prevalence and intensity throughout the period. The change in the proportion between the two most prevalent species was attributed to the new environment, specifically its restricted size and within it a dry area more suitable for R. microplus. DNA of 424 ticks processed in 276 pools was tested for Rickettsia genetic material by polymerase chain reactions (PCR). Twenty samples of the study were positive for the rickettsial gltA gene. Of these, 18 were from A. triste ticks and revealed the presence of the ompA spotted fever group gene as well. Eleven samples were sequenced and showed 100% identity with R. parkeri sensu stricto. Two samples from R. microplus did not amplify ompA gene neither yielded product in a PCR specific for Rickettsia bellii. Sequencing of the gltA gene in the DNA of these two ticks was also 100% identical with R. parkeri s.s. In conclusion, the changes in the deer environment modified the tick populations but maintained, at least temporary, R. parkeri bacteria in A. triste ticks. Rhipicephalus microplus was refractory to the R. parkeri infection and bacterial DNA in this tick species indicated DNA spill over from other tick species. It was demonstrated that captive marsh deer may sustain cattle tick populations on its own. This would hardly occur under pristine conditions because of the inadequacy the marsh deer´s naturally humid habitat for the cattle tick. However, deer transportations of R. microplus ticks from one farm to another may occur whenever habitat loss pushes this wild animal towards farms., (Copyright © 2021. Published by Elsevier GmbH.)

Wild rodents are considered as potential carriers of several zoonotic vector-borne bacteria but their epidemiology is poorly understood in Tunisia. A total of 305 biological samples (100 spleens, 100 livers, 100 kidneys, and 5 pooled ectoparasites (Xenopsylla cheopis, Laelaps echidninus, Ornithonyssus sp., Hoplopleura sp. and eggs of the rat fleas)) were collected from 100 wild rodents from three Tunisian governorates. Molecular screening was performed to reveal infections with main vector-borne bacteria. Captured rodents belonged to three rodent genera and species including Rattus rattus (n = 51, 51%), Meriones shawi (n = 24, 24%) and Mus musculus (n = 25, 25%). Examined rodents were found to be heavily infested by the rat flea X. cheopis (n = 32, 47%) and the rat mite L. echidninus (n = 22, 32.3%). However, the rat mite Ornithonyssus sp. (n = 13, 19.1%) and the rat lice Hoplopleura sp. (n = 1, 1.5%) were rarely identified. Based on 16S rRNA and msp4 genes, infection with Anaplasmataceae bacteria was detected in six specimens of R. rattus and one M. shawi. Pathogenic A. phagocytophilum (n = 1), A. phagocytophilum-like 1 (Anaplasma sp. Japan) (n = 1), and A. ovis (n = 5) were identified. On the basis of ompB, ompA and gltA genes, infection with Rickettsia spp. was identified in three specimens of R. rattus and one of M. shawi. Five Rickettsia species of the spotted fever group, corresponding to R. monacensis, R. helvetica, R. massiliae, R. africae, and R. aeschlimannii, were detected in mixed infections. Bartonella henselae DNA was also found in two R. rattus, based on rpoB partial sequences. All revealed Anaplasma, Rickettsia and Bartonella bacteria were detected in spleen samples. Ehrlichia, Coxiella and Borrelia spp. were not identified in any of the tested samples. In Tunisia, this is the first report indicating infections with Anaplasma, Rickettsia and Bartonella spp. in wild rodents, particularly present alongside domestic livestock and human. This represents a serious risk of potential bacterial transmission. Thus, controlling rodent population in animal herds, residential areas and sensitizing local people to this risk seem absolutely necessary., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study aimed to analyze epidemiological indicators related to seroprevalent and seroincident cases of spotted fever group rickettsiae (SFGR) and to identify housing conditions related to tick infestation. A prospective study (2016-2018) was conducted to examine rickettsial seropositivity in humans, domestic animals, and wild mammals in the municipality of Uramita, Antioquia, Colombia, where a previous Rickettsia rickettsii outbreak was reported from 2014 to 2015. The seroprevalence and its associated factors were estimated at baseline, and the seroincidence and its risk factors for humans were estimated 20 months later. A cross-sectional analysis was performed to evaluate the housing conditions linked to tick infestation. The SFGR seroprevalence was 26.70% (95% confidence interval [CI], 20.79-31.37), and the factors associated with SFGR seropositivity were male sex (adjusted prevalence ratio [PRa], 1.67; 95% CI, 1.19-2.32), age (evaluated in 5-year increments) (PRa, 1.05; 95% CI, 1.01-1.09), and household proximity (PRascattered vs. very near=3.87; 95% CI, 1.12-8.66). The overall seroincidence was 7.40% (95% CI, 4.71-11.06), and the factors associated with SFGR seroincident cases were the presence of wild animals (adjusted relative risk [RRa], 2.46; 95% CI, 1.06-4.72) and the presence of trees in the peri-domiciliary area (RRa, 0.47; 95% CI, 0.23-0.94). The prevalence of house tick infestation was 27.81% (95% CI, 21.93-34.80), and the factors associated with infestation were dirt floors (PRa, 5.88; 95% CI, 2.28-10.31), fiber cement roofs (PRa, 1.76; 95% CI, 1.07-2.83), and the presence of canines in peri-domiciliary or intra-domiciliary areas (PRa, 5.05; 95% CI, 3.31-7.19). Seropositivity rates for canines and opossums were 35.62% (26/73) and 100% (6/6), respectively. Identification of these factors will help to implement efficient surveillance programs in Colombia.