Pathogens in ticks collected in Israel: I. Bacteria and protozoa in Hyalomma aegyptium and Hyalomma dromedarii collected from tortoises and camels

Ticks were collected from 30 Greek tortoise (Testudo graeca), and 10 Arabian camels (dromedary) (Camelus dromedarius) in Israel. All those collected from Greek tortoises belonged to Hyalomma aegyptium, while all specimens collected from the camels belonged to Hyalomma dromedarii. Out of 84 specimens of H. aegyptium, 31 pools were examined by PCR, while from 75 H. dromedarii specimens nine pools were studied. Out of 31 pools of H. aegyptium 26 were positive for pathogens or endosymbiont; 14 for one, 11 for two and one for three pathogens. Out of nine pools prepared from H. dromedarii, seven were positive for pathogens (two for C. burnetii and five for Leishmania infantum). In H. aegyptium, Rickettsia africae, Rickettsia aeschlimannii, Rickettsia endosymbiont, Coxiella burnetii, Hemolivia mauritanica, Babesia microti, Theileria sp., and Leishmania infantum was detected, while in H. dromedarii C. burnetii and L. infantum were found. None of the ticks were positive for Anaplasma/Ehrlichia, Listeria monocytogenes, Bartonella spp., Hepatozoon spp. and Toxoplasma gondii. H Rickettsia endosymbionts, C. burnetii, B. microti, Theileria sp. and L. infantum are reported for the first time in H. aegyptium, and C. burnetii and L. infantum for the first time in H. dromedarii.     

Molecular survey of bovine Babesia species in Bactrian camels (Camelus bactrianus) in Mongolia

Bovine babesiosis, which is caused by species of genus Babesia, is a leading cause of considerable economic losses to the cattle industry each year. Bovine Babesia species have frequently been detected in non-cattle hosts, such as water buffalo (Bubalus bubalis), from which the parasites can be transmitted by ticks to cattle. Therefore, Babesia infections should be minimized not only in cattle but also in non-cattle carriers. In the present study, we surveyed the Bactrian camels (Camelus bactrianus) in Mongolia for three clinically significant bovine Babesia species, including Babesia bovis, B. bigemina, and Babesia sp. Mymensingh, which had been detected previously in Mongolian cattle. We screened blood DNA samples from 305 Bactrian camels in six Mongolian provinces for these species, using parasite-specific PCR assays. Our findings showed that the Bactrian camels in Mongolia were infected with all three Babesia species surveyed. The overall positive rates of B. bovis, B. bigemina, and Babesia sp. Mymensingh were 32.1%, 21.6%, and 24.3%, respectively, whereas 52.5% of the surveyed animals were infected with at least one parasite species. We also found that the female Bactrian camels and the Mongolian native camel breed had significantly higher Babesia positive rates than the male Bactrian camels and the Hos Zogdort breed. In Mongolia, cattle and Bactrian camels usually share common pasture lands for grazing; furthermore, tick species infesting cattle also infest Bactrian camels. Our findings, together with these observations, suggest that the tick transmission of bovine Babesia species might be possible between cattle and Bactrian camels. Therefore, strategies for the control of bovine babesiosis in Mongolia should include methods to minimize bovine Babesia species infections in Bactrian camels.     

Molecular characterization of tick-borne bacteria and protozoans in yaks (Bos grunniens), Tibetan sheep (Ovis aries) and Bactrian camels (Camelus bactrianus) in the Qinghai-Tibetan Plateau Area,China

Due to the specific plateau climate, a variety of unique animals live in the Qinghai-Tibetan Plateau Area (QTPA) including yaks (Bos grunniens), Tibetan sheep (Ovis aries) and Bactrian camels (Camelus bactrianus). However, information on tick-borne diseases (TBDs) in the QTPA and on the molecular characteristics of tick-borne pathogens (TBPs) in the area is limited. Therefore, the aim of this study was to investigate Anaplasma spp., Babesia spp., Theileria spp., Borrelia burgdorferi sensu lato and Rickettsia spp. infecting yaks, Tibetan sheep and camels in this area. A total of 276 animals were screened. Overall, 84.5% (164/194) of yaks, 58% (23/40) of Tibetan sheep, and 38% (16/42) of camels tested positive for at least one pathogen. Theileria spp., Anaplasma ovis and spotted fever group (SFG) Rickettsia spp. were detected as TBPs in the current study with overall infection rates of 10.9% (30/276), 8.3% (23/276) and 62.9% (171/276), respectively. Further study revealed that 1.5% (3/194) of the yaks were infected with Theileria sp. OT3, 1.5% (3/194) with T. luwenshuni, 6.2% (12/194) with T. uilenbergi, 1.1% (2/194) with T. ovis and 82% (159/194) with SFG Rickettsia spp. It was also shown that 58% (23/40) of the Tibetan sheep were infected with A. ovis and 15% (6/40) with T. ovis. Among the camels, 10% (4/42) were infected with T. equi, while 29% (12/42) were positive for Rickettsia spp. Sequence analysis revealed that the Rickettsia spp. infecting yaks and camels were Rickettsia raoultii and Rickettsia slovaca. To the best of our knowledge, this study reports the first detection and characterization of these pathogens in yaks, Tibetan sheep and camels in the country, except for T. luwenshuni infections in yaks.     

Molecular and seroepidemiological investigation of Сoxiella burnetii and spotted fever group rickettsiae in the southern region of Kazakhstan

Ticks are involved in the circulation of a number of human pathogens, including spotted fever group (SFG) Rickettsia spp. and Coxiella burnetii. Little is known about the occurrence of these microorganisms in the southern region of Kazakhstan. In 2018–2022, a total of 726 ticks were collected from bitten humans, livestock, and vegetation in four oblasts of the southern region of Kazakhstan and subjected to DNA extraction. The overall infection rate of Coxiella spp. and Rickettsia spp. in the ticks was 3.3% (24/726) and 69.9% (300/429), respectively. Phylogenetic analysis of ompA and gltA genes revealed the presence of three pathogenic SFG rickettsiae: Candidatus R. tarasevichiae, R. aeschlimannii and R. raoultii in ticks collected from bitten humans. In addition, Candidatus R. barbariae was detected in six Rhipicephalus turanicus ticks for the first time in Kazakhstan. To determine the seroprevalence of C. burnetii infection, we performed a serological analysis of samples collected from 656 domestic ruminants (cattle, sheep, and goats) in the region. Overall, 23.5% (154/656) of the animals tested were positive for IgG against C. burnetii. Seroprevalence at the herd level was 54% (28/52). Goats (43%; 12/28; odds ratio (OD) = 28.9, p < 0.05) and sheep (31.9%; 137/430; OD = 18.1, p < 0.05) had higher seroprevalence than cattle (2.5%; 5/198). Among the risk factors considered in this study, age (p = 0.003) and the oblast in which the animals were sampled (p = 0.049) were statistically associated with seropostivity for Q fever in sheep, according to the results of multivariate logistic regression analysis. Seroprevalence ranged from 0% to 55.5% in animals in different districts of the southern region of Kazakhstan. Active C. burnetii bacteremia was detected in four of 154 (2.6%) seropositive animals. The data obtained provide strong evidence of the presence of pathogenic rickettsiae and C. burnetii in the southern region of Kazakhstan and emphasize the need to improve epidemiological surveillance in the region.     

Tick-borne pathogens in dogs,wild small mammals and their ectoparasites in the semi-arid Caatinga biome,northeastern Brazil

Caatinga is a biome exclusive to the semiarid zone of Brazil, where studies on ticks and tick-borne diseases are scarce. Herein, we investigated the occurrence of Rickettsia, Ehrlichia, and Coxiella in wild mammals, domestic dogs and their ectoparasites using molecular and serological techniques. During 2014–2016, blood samples and ectoparasites were collected from 70 small mammals (51 rodents, 18 marsupials, 1 wild canid) and 147 domestic dogs in three areas of the Caatinga. Through serological analyses of domestic dogs of the three areas, 8 to 11 % were seropositive for Rickettsia rickettsii, 9 to 37 % for Rickettsia amblyommatis, 61 to 75 % for Ehrlichia canis, and 0–5% for Coxiella burnetii. All wild mammals were seronegative for Rickettsia spp. and C. burnetii, except for one rodent (Wiedomys pyrrhorhinos) and one marsupial (Didelphis albiventris) that were seroreactive to C. burnetii, one wild canid (Cerdocyon thous) for R. amblyommatis, and two Rattus rattus for Rickettsia spp. Through PCR targeting DNA of Rickettsia, Ehrlichia or Coxiella, all blood samples were negative, except for the presence of Ehrlichia canis DNA in 8.8 % of the domestic dogs, and a recently reported novel agent, Ehrlichia sp. strain Natal, in one marsupial (Gracilinanus agilis). A total of 222 ticks, 84 fleas, and six lice were collected. Ticks were mostly Rhipicephalus sanguineus sensu lato, some Ixodes loricatus, Ornithodoros rietcorreai, Haemaphysalis sp., and Amblyomma spp.; fleas were Ctenocephalides felis felis, Pulex sp. and Polygenis (Polygenis) bohlsi jordani; and lice were Polyplax sp. and Gyropus sp. Through molecular detection of microorganisms, 9% of C. felis felis contained Rickettsia felis, 20 % of A. auricularium contained R. amblyommatis and 13 % of A. parvum contained ‘Candidatus Rickettsia andeanae’, whereas Ehrlichia canis DNA was detected in at least 6% of the R. sanguineus s.l. from one area. We report a variety of ectoparasites infesting small mammals and domestic dogs in the Caatinga biome, where these ectoparasites probably act as vectors of rickettsiae, ehrlichial agents (E. canis and Ehrlichia sp. strain Natal) and C. burnetii. Our results highlight to the potential risks of human infection by these tick-borne agents in the Caatinga biome.     

Prevalence of Coxiella burnetii and Rickettsia spp. in ticks and rodents in southern Germany

Coxiella burnetii, the causative agent of Q fever, and Rickettsia spp. are bacterial pathogens that can be transmitted by ticks of the genus Dermacentor (i.e., Dermacentor marginatus and D. reticulatus). In Germany, the occurrence of these ticks is currently limited to few areas. However, due to increasing temperatures, these vectors will likely extend their distribution in the future, and C. burnetii and Rickettsia spp. might spread with them. To assess the prospective risk of human infections by these agents, it is important to know their current distribution. We collected 666 adult Dermacentor spp. and 119 rodents, mainly Microtus arvalis, in 3 Q fever endemic areas in southern Germany. Ticks and rodent organ pools were screened by PCR for C. burnetii and Rickettsia spp. No evidence of C. burnetii infections could be found in ticks or rodents, suggesting that these animals do not play an essential role in the epidemiology of Q fever in Germany. Rickettsia raoultii and R. slovaca could be detected in 30.3% and 0.75% of all examined ticks, respectively. In contrast, no rickettsia infections could be found in any rodent samples. Both rickettsia species can cause tick-borne lymphadenopathy (TIBOLA), a usually mild human disease. Because of the possible transmission of these rickettsiae to humans, TIBOLA should be considered in the differential diagnosis of tick-borne diseases. Our data show that a spread of these rickettsiae is possible in Germany and that more studies on the distribution of these agents are necessary.     

Immunochemical and antigenic characterization ofCoxiella burnetii strains isolated in Europe and Mongolia

SDS-PAGE, immunoblotting and serological methods such as microimmunofluorescence (MIF) test and ELISA were used to compare protein and lipopolysaccharide (LPS) profiles and antigenicity of 12Coxiella burnetii strains isolated mostly from ticks in Europe and Mongolia with three referenceC. burnetii strains originating from USA, namelyNine Mile from tick,Priscilla from goat placenta and S from human heart valve. Among strains from Europe and Mongolia, no significant differences in protein and LPS profiles were observed, irrespective of their origin, i.e. the country and source of isolation. The LPS profiles of these strains appeared to be more related to those ofNine Mile strain associated with acute Q fever, than to those of strainsS andPriscilla associated with chronic Q fever. In immunoblots all strains isolated from Slovakia and Poland reacted more expressively with rabbit serum againstNine Mile than with serum againstPriscilla strain. In the MIF test and ELISA there were no substantial differences in antibody-binding capacity between the reference and newly isolatedC. burnetii strains, except for strainPriscilla reacting with homologous serum in lower antigenic concentration than other strains under study. However, in the MIF test much higher antigenic concentrations of eachC.burnetii strain was required to detect antibodies in thePriscilla serum than in theNine Mile, Luga andS sera.     

Serological examination of human and animal sera from six countries of three continents for the presence of rickettsial antibodies

Forty samples each of human sera collected in Guinea Bissau, Cape Verde, El Salvador and Iran, and animal sera (goat and cattle from Sri Lanka and sheep from Tanzania) were examined for the presence of antibodies to typhus group (TG) rickettsiae, spotted fever group (SFG) rickettsiae and Coxiella burnetii by enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody (IFA) test. Of human sera tested, a higher proportion of positive sera were found with ELISA and IFA test for TG, SFG rickettsiae and C. burnetii in El Salvador (42.5 vs 20.0%, 40.0 vs 32.5%, and 27.5 vs 27.5%, respectively) and in Iran (25.0 vs 15.0%, 45.0 vs 27.5%, and 27.5 vs 25.0%, respectively), than in Guinea Bissau and Cape Verde, where they were less than 20.0% except for antibodies to SFG rickettsiae in Guinea Bissau (25.0% with ELISA and 20.0% with IFA test). While all animal sera were negative for the presence of antibodies to TG rickettsiae, a high proportion of sera from Sri Lanka reacted in ELISA and IFA test with SFG rickettsiae and C. burnetii (37.5 vs 20.0% and 27.5 vs 25.0% for goat sera, and 40.0 vs 30.0%, and 17.5 vs 15.0% for cattle sera, respectively). The results obtained indicate that the studied rickettsial diseases can be spread in given territories and may pose a public health problem requiring greater attention than has been paid so far. The suitability of ELISA and IFA test for serological survey of rickettsial antibodies is discussed.     

Rickettsia parkeri strain Atlantic rainforest infecting Amblyomma ovale (Acari: Ixodidae) in the Amazon Biome (Acre state,Brazil)

There is a lack of studies regarding tick-associated Rickettsia in the Amazon biome. Aiming to contribute to this knowledge, our research group collected ticks in the Western Amazon to better understand the tick fauna and their associated Rickettsia. In this study, we detected Rickettsia parkeri strain Atlantic rainforest DNA in the tick Amblyomma ovale Koch, 1844 in Rio Branco municipality, Acre state, northern Brazil. This is the first time that the R. parkeri strain Atlantic rainforest has been reported in the Amazon biome and is the first evidence of the circulation of a pathogenic spotted fever group (SFG) Rickettsia in this biome. This finding provides substantial information to help public health authorities understand which species of Rickettsia may be related to Amazon spotted fever cases.     

Prevalence of Rickettsia spp., Anaplasma phagocytophilum,and Coxiella burnetii in adult Ixodes ricinus ticks from 29 study areas in central and southern Sweden

A total of 887 adult Ixodes ricinus ticks (469 females and 418 males) from 29 different localities in Sweden were screened for Rickettsia, Anaplasma, and Coxiella DNA using PCR and then subjected to gene sequencing. Rickettsial DNA was detected in 9.5–9.6% of the ticks. Most of the positive ticks were infected with Rickettsia helvetica. One tick harbored another spotted fever rickettsia, closely related to or identical with R. sibirica not previously found in I. ricinus nor in Sweden. Six of the ticks (0.7%) were infected with an Anaplasma sp., presumably A. phagocytophilum. Coxiella burnetii DNA was not detected in any of the ticks. The detection of R. helvetica and A. phagocytophilum in several of the localities sampled suggests that these potentially human-pathogenic agents are common in Sweden.     

Prevalence of antibodies to rickettsiae in the north-western part of Bosnia and Herzegovina

The prevalence of rickettsial antibodies in north-western part of Bosnia and Herzegovina was studied. Among 231 sera tested by complement fixation (CF) positive were: 61.5% forRickettsia typhi, 4.3% forR. prowazekii, 1.7% forR. conorii and 19.0% forCoxiella burnetii. Of 183 sera tested by indirect immunofluorescence assay (IFA) 37.7% reacted withR. typhi, 1.6% withR. conorii and 22.4% withC. burnetii. The results show that at leastR. typhi andC. burnetii are highly endemic in this area.Abbreviations CF complement fixation - IFA indirect immunofluorescence - SFG spotted fever group - TG typhus group     

Identification of Rickettsia spp., Anaplasma spp., and an Ehrlichia canis-like agent in Rhipicephalus microplus from Southwest and South-Central China

Rhipicephalus microplus is considered to be the most important tick infesting cattle, buffalo, horse, goats as well as other animals. They transmit diseases between domestic animals and act as vectors of a variety of zoonotic pathogens. Although pathogens harbored by R. microplus have been extensively studied, the Rickettsiales pathogens vectored by R. microplus in some areas of China remained largely unexplored. From August to October 2020, a total of 291 R. microplus ticks were collected from goats and cattle in three Southern China provinces, Guangxi (n = 138), Sichuan (n = 120) and Hubei (n = 33) provinces. Phylogenetic analysis based on COI gene sequences shows that these ticks are divided into three distinct clades, indicating the remarkable genetic diversity of R. microplus ticks in China. These samples were subsequently screened for the presence of Rickettsia, Anaplasma and Ehrlichia using conventional PCR and sequencing. Subsequently, five bacterial species were identified. Out of the 120 tick DNA samples from Sichuan province, 35.83% (43/120) were positive for Rickettsia sp. belonging to spotted fever group (SFG), 12.50% (15/120) were positive for Anaplasma marginale and 0.83% (1/120) was identified as A. platys. From the 138 DNA samples from Guangxi province, an Ehrlichia canis-like and Rickettsia sp. were detected, with a positive rate of 11.59% (16/138) and 2.17% (3/138), respectively. A. capra DNA was detected in 4 out of 33 (12.12%) samples from Hubei province. Notably, the 16S, gltA and groEL sequences of the E. canis-like are closely related to the E. canis strain previously identified from China, and form a distinct cluster in the phylogenetic trees. Collectively, our results expand the knowledge on tick-borne Rickettsiales pathogens in China. Because the state of engorgement of ticks was not recorded, it is not clear at this stage whether these pathogens are infecting the ticks or are simply present in the blood meal. Given the public health significance of SFG Rickettsia, A. capra, A. platys and E. canis, a thorough investigation of the diversity and presence of pathogens in R. microplus in areas with tick-associated diseases are needed.     

Rickettsiae of spotted fever group,Borrelia valaisiana,and Coxiella burnetii in ticks on passerine birds and mammals from the Camargue in the south of France

Ticks are obligate hematophagous arthropods that have a limited mobility, but can be transported over large geographical distances by wild and domestic mammals and birds. In this study, we analyze the presence of emerging zoonotic bacteria in ticks collected from passerine birds and mammals present in the Camargue, in the south of France, which is a major rallying point for birds migrating from Eurasia and Africa.The presence of Coxiella burnetii, Rickettsia, Borrelia, and Bartonella was examined by real-time PCR on DNA samples extracted from 118 ticks. Rickettsia massiliae was detected in ticks from Passer domesticus, Ri. aeschlimannii in ticks from Acrocephalus scirpaceus and Luscinia megarhynchos, and Borrelia valaisiana in one tick from Turdus merula. In addition, Ri. massiliae, Ri. slovaca, Candidatus Ri. barbariae, and C. burnetii were detected in ticks from dogs, horses, cats, and humans. No Bartonella DNA was detected in these samples.The migratory birds may play a role in the transmission of infectious diseases and contribute to the geographic distribution of Ri. aeschlimannii, Bo. valaisiana, and C. burnetii. The role of birds in spreading Rh. sanguineus ticks infected with Ri. massiliae needs to be clarified by complementary studies. This is the first detection of Candidatus Ri. barbariae in Rh. sanguineus from the south of France.     

Coxiella burnetii in 3 Species of Turtles in the Upper Midwest,United States

Coxiella burnetii, the causative bacterium of the zoonotic disease Q fever, has been documented in many different species. We describe documented turtles that were PCR positive for C. burnetii from multiple locations in Illinois and Wisconsin, USA. Assessing the conservation implications, reservoir potential, and zoonotic risk requires further research.     

Applying next generation sequencing to detect tick-pathogens in Dermacentor nuttalli,Ixodes persulcatus,and Hyalomma asiaticum collected from Mongolia

Ticks and tick-borne diseases represent major threats to the public health of the Mongolian population, of which an estimated 26% live a traditional nomadic pastoralist lifestyle that puts them at increased risk for exposure. Ticks were collected by dragging and removal from livestock in Khentii, Selenge, Tuv, and Umnugovi aimags (provinces) during March-May 2020. Using next-generation sequencing (NGS) with confirmatory PCR and DNA sequencing, we sought to characterize the microbial species present in Dermacentor nuttalli (n = 98), Hyalomma asiaticum (n = 38), and Ixodes persulcatus (n = 72) tick pools. Rickettsia spp. were detected in 90.4% of tick pools, with Khentii, Selenge, and Tuv tick pools all having 100% pool positivity. Coxiella spp. were detected at an overall pool positivity rate of 60%, while Francisella spp. were detected in 20% of pools and Borrelia spp. detected in 13% of pools. Additional confirmatory testing for Rickettsia-positive pools demonstrated Rickettsia raoultii (n = 105), Candidatus Rickettsia tarasevichiae (n = 65) and R. slovaca/R. sibirica (n = 2), as well as the first report of Candidatus Rickettsia jingxinensis (n = 1) in Mongolia. For Coxiella spp. reads, most samples were identified as a Coxiella endosymbiont (n = 117), although Coxiella burnetii was detected in eight pools collected in Umnugovi. Borrelia species that were identified include Borrelia burgdorferi sensu lato (n = 3), B. garinii (n = 2), B. miyamotoi (n = 16), and B. afzelii (n = 3). All Francisella spp. reads were identified as Francisella endosymbiont species. Our findings emphasize the utility of NGS to provide baseline data across multiple tick-borne pathogen groups, which in turn can be used to inform health policy, determine regions for expanded surveillance, and guide risk mitigation strategies.     

Rickettsioses studies. 3. Natural foci of rickettsioses in south Bohemia.

Antibodies against Coxiella burnetii and against rickettsiae of the spotted fever group were found in human sera and in sera from domestic and wild animals collected in south Bohemia. Spotted fever group rickettsiae were also discovered in the tick Ixodes ricinus. These results indicate the presence of both types of rickettsiae in this part of Czechoslovakia. As no epizootics or epidemics of Q fever have as yet been reported in the area, it can be assumed that C. burnetii occurs in the latent state. The occurrence of spotted fever group rickettsiae is probably endemic among I. ricinus ticks and among small and larger wild mammals.     

Isolation of Coxiella burnetii from bovines with history of reproductive disorders in India and phylogenetic inference based on the partial sequencing of IS1111 element

In the present study, a total of 158 blood samples from 148 bovines and 10 dogs having a history of reproductive disorders were screened for Coxiella burnetii by trans-PCR method. In case of bovines, 6.08% (9/148) blood samples comprised of 4.54% (4/88) cattle and 8.33% (5/60) buffaloes turned out to be positive for C. burnetii DNA while all the samples from dogs (10) were found negative. Of the 9 PCR-positive bovine blood samples, the organism could be isolated only from 3 cases of buffaloes by chick embryo inoculation method. Further, to predict the homology and genetic diversity, the recovered C. burnetii isolates designated as Y1, Y3 and Y7 were partially sequenced for IS1111 gene. On phylogenetic analysis, Y3 and Y7 isolates clustered to a common node away from Y1 isolate. This study may enlighten the nature of circulating C. burnetii isolates in different parts of the world. To the best of our knowledge, this appears to be the first report describing phylogenic analysis of C. burnetii isolates based on IS1111 gene sequence.     

Detection of Coxiella burnetii in ticks collected in Slovakia and Hungary

A total of 235 adult ticks collected from vegetation in Slovakia and Hungary in 1998–2000 were tested for Coxiella burnetii by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). C. burnetii was identified in six ticks of Ixodes ricinus, Dermacentor marginatus, and Haemaphysalis concinna species.     

Equine Influenza A(H3N8) Virus Isolated from Bactrian Camel,Mongolia

Because little is known about the ecology of influenza viruses in camels, 460 nasal swab specimens were collected from healthy (no overt illness) Bactrian camels in Mongolia during 2012. One specimen was positive for influenza A virus (A/camel/Mongolia/335/2012[H3N8]), which is phylogenetically related to equine influenza A(H3N8) viruses and probably represents natural horse-to-camel transmission.     

Prevalence of Coxiella-infections in ticks - review and meta-analysis

Q fever is a global zoonotic infection caused by the intracellular Gram-negative bacterium Coxiella burnetii. Historically, it is considered a vector-borne disease, but the role of ticks in transmission has not fully been elucidated yet. Excretion of C. burnetii in tick feces and saliva is well documented but the role of these findings or the epidemiological context is discussed controversially. Thus, the aim of this study was to determine the prevalence of C. burnetii DNA in ticks to clarify the potential role of tick species for maintenance of C. burnetii infection. A literature review was performed using Google scholar, Agora, Science Direct, PubMed and Scopus to identify original studies on C. burnetii DNA presence in ticks. The search was limited to literature published from 2009 to 2020 in English and French and focused on data obtained by molecular detection of C. burnetii DNA in ticks. Overall, the prevalence of C. burnetii in ticks collected in Africa varied from 2.91% to 13.97%, in Europe from 2.46% to 10.52% and the Middle East from 4.76% to 12.53%. Ticks collected from animals showed a prevalence of 8% (95% CI: 6%–10%), followed by ticks collected from the environment and animals of 7% (95% CI: 5%–10%). C. burnetii DNA has been found in samples of many tick species with the highest prevalence in Rhipicephalus evertsi and Amblyomma variegatum. However, most of these studies did not include a differentiation between C. burnetii and Coxiella-like endosymbionts making it finally difficult to estimate the potential role that ticks play in the epidemiology of Q fever. Therefore, it is necessary to analyze the vector competence of different tick species to transmit C. burnetii. Knowledge of the vector and reservoir competence of ticks is important for taking adequate preventive measures to limit infection risks.