Argasidae Research Articles

New records on autogenic behavior among populations of Ornithodoros fonsecai (Labruna and Venzal, 2009) (Ixodida: Argasidae) from northeastern Brazil.

Ornithodoros fonsecai is an argasid tick that is endemic to Brazil. The autogeny (the oviposition without a blood meal) can be facultative or obligatory in female ticks of the family Argasidae. The present study reports new records on the facultative autogeny among populations of O. fonsecai from the states of Ceará and Pernambuco, northeast Brazil. The specimens obtained were fed on rabbits and kept in a biological oxygen demand (BOD) at 25°C ± 1 ºC. All females obtained from both populations emerged from nymphs of third instar (N3) were autogenic, which were fed once before molting. Approximately 183 eggs were observed between 22 and 29 days (oviposition period), with a hatching rate of larvae of 52%, from two females of Ceará, and around 367 eggs between 20 and 35 days, with 92% of hatching of larvae, from three females of Pernambuco. Previously, this behavior has already been registered only in a population in the municipality of Nobres, state of Mato Grosso, Brazil. Thus, the present study reports facultative autogeny in females of O. fonsecai among populations from the states of Ceará and Pernambuco in northeastern Brazil.

First documentation of a jaguar (Panthera onca) with otitis caused by Otobius megnini (Dugés 1883).

Otobius megnini (spinose ear tick) is a cosmopolitan soft tick that parasitizes domestic and wild mammals, as well as humans. The larval and nymphal stages are common parasites that feed on blood inside the canal ears of hosts, while adults are nonfeeding and live off the host. Different nymphal stages of O. megnini were collected from a jaguar (Panthera onca) suffering from otitis in captive conditions from Guerrero, Mexico. This is the first documentation worldwide of O. megnini in a jaguar with otitis. The presence of this tick species represents a risk of transmission to animals and humans exposed to the nymphal stages of the tick.

Survey of mite lifespans: preface to part 3

This volume is part 3 of a series of surveys of mite lifespans and related life history data. The first part in 2021 covered the suborder Oribatida (excluding Astigmata), Winterschmidtiidae, Eriophyoidea, Tydeidae, Anystidae, Cheyletidae, and Blattisociidae (Zhang 2021). The second part (Zhang 2022) included reviews of life history data for three important families of economic importance: Tetranychidae (Li et al. 2022), Phytoseiidae (Han et al. 2022), and Laelapidae (Zhang et al. 2022). I am pleased to introduce Part 3 of this series, with three reviews for the superorder Parasitiformes: the order Ixodida, or the ticks (Chen et al. 2024), the family Parasitidae (Lewandowski & Pińkowska 2024), and the family Rhodacaridae (Momen et al. 2024). About 10% of the 960 tick species are of importance in animal and human health, and we have life history data reviewed for 12.2% of the species (Chen et al. 2024). It is noteworthy that the longest-living mite is a soft tick—Argas brumpti Neumann—which had survived for 27 years in the laboratory (Shepherd 2022).

New records of ticks (Acari: Ixodida) and Rickettsia species in El Salvador.

The tick fauna of El Salvador is currently represented by 10 species of hard ticks (family Ixodidae) and 2 species of soft ticks (family Argasidae). This study aimed to report new and additional records of ticks and rickettsiae in El Salvador. During 2019-2021, a total of 216 specimens of ticks were collected from eight host species (domestic and wild animals) and in the environment among 15 geographic localities of El Salvador. Combining morphological and molecular analyses, tick specimens were identified into the following 11 tick species: Amblyomma dissimile, Amblyomma longirostre, Amblyomma mixtum, Amblyomma ovale, Amblyomma cf. parvum, Amblyomma sabanerae, Amblyomma scutatum, Dermacentor panamensis, Ixodes boliviensis, Ornithodoros puertoricensis, and Otobius megnini. In addition, one free-living nymph was morphologically and molecularly identified as Ixodes sp., although closely related to Ixodes brunneus and Ixodes silvanus. Three rickettsial agents of the spotted fever group were identified: Rickettsia rhipicephali in D. panamensis; a Rickettsia endosymbiont in Ixodes boliviensis; and Rickettsia amblyommatis in A. cf. parvum. This study reports the first records of A. longirostre, D. panamensis, I. boliviensis, O. puertoricensis and O. megnini in El Salvador. In addition, the agents R. rhipicephali and Rickettsia sp. endosymbiont of I. boliviensis are also reported for the first time in the country. With the present study, the current tick fauna of El Salvador increases to 17 species, being 13 Ixodidae and 4 Argasidae, including the addition of one genus to each of these two families (Ixodes and Otobius, respectively).

New finding on a migratory bird, the fowl tick Argas (Persicargas) persicus (Oken, 1818), in Italy

Migratory birds reach Europe from sub-Saharan Africa, and some avian species may harbor and transport infected ectoparasites, mainly ticks, native to the territories of departure. In 2022, a project focused on identifying the introduction of pathogens in Italy from Africa via migratory birds represented an important opportunity to investigate this particular route of tick dispersal. Among ticks collected from migratory birds on the island of Ventotene, Latium Region, we found one larva of a soft tick on a common whitethroat (Curruca communis) that was morphologically and molecularly identified to the species level as Argas (Persicargas) persicus (Oken 1818). This study reports the fifth detection of this species in Italy; therefore, it is considered very rare. Further monitoring programmes should be implemented to better monitor the spread of this species and possibly update its distribution.

Ecology and phenology of the bat tick Argas (Carios) dewae (Acari: Argasidae).

Although 12 soft tick species (Argasidae) are native to Australia, the ecology of most is poorly known. Argas dewae parasitizes several insectivorous bat species and has been recorded on humans. Therefore, understanding its ecology is crucial for wildlife health management and public health preparedness. To address this knowledge gap, A. dewae populations were monitored from 2 bat hosts (Chalinolobus gouldii and Austronomus australis) using bat boxes at 3 sites in Victoria, Australia, for 28 months (July 2005–December 2007). A phenological profile undertaken for A. dewae revealed that tick load on bat hosts increased throughout winter and peaked in the first month of spring, before collapsing and remaining low throughout the drier late spring and summer periods. There was also further investigation of the relationship between 2 response variables (tick infestation risk and tick load) and a range of explanatory variables (body condition index, sex, age class, bioseason, site, bat density per nest box). In C. gouldii, site was the only significant predictor of A. dewae infestation risk, while load was correlated with several variables including age class, sex, bioseason, roost density and body condition index. This paper also reports the first records of A. dewae from 6 bat species in 3 bat families (Miniopteridae: Miniopterus australis; Molossidae: A. australis; Vespertilionidae: Chalinolobus morio, Myotis Macropus, Vespadelus darlingtonia, Vespadelus regulus) and a second record of A. dewae from a human. The first distribution records are presented for A. dewae in South Australia, the Australian Capital Territory and Queensland.

A higher infection rate of Toxoplasma gondii in soft ticks infesting domestic hens: A novel report from Pakistan

Ticks are the second most important hematophagous ectoparasites after mosquitoes and serve as vectors for various pathogens, transmitting them to wild and domestic animals, as well as humans. Argas persicus are the soft ticks that are known to parasitize domestic poultry. Hard ticks are known to be the reservoir of Toxoplasma (T.) gondii but limited such information is available for soft ticks. This study reports the molecular prevalence and phylogenetic analysis of T. gondii infecting Argas (A.) persicus ticks (N = 70), collected from four domestic poultry breeds in the Kurram District, Khyber Pakhtunkhwa, Pakistan, between June and August 2023. The results showed that 26 out of 70 (37 %) A. persicus samples tested positive for the ITS-1 gene of T. gondii. These findings were confirmed by the DNA sequencing and BLAST analysis of amplified amplicons. Phylogenetic analysis showed that Pakistani isolates were genetically diverse and clustered with isolates that were reported from birds and mammals from Pakistan, Tunisia, Malaysia, Brazil and Iraq.Risk factor analysis indicated that the prevalence of T. gondii was not associated with any specific poultry breed, sampling period, or the body temperature of the fowl hosts. Similarly parasite prevalence was not found associated with tick sex or their developmental stage but parasite infection rate varied with the feeding status of the ticks; highest T. gondii infection rate was observed in fully fed Argas persicus. In conclusion, this is the first report from Pakistan highlighting a high prevalence of T. gondii in A. persicus infesting domestic poultry suggesting a potential zoonotic risk to humans through the consumption of infected poultry. This data is confirming that in addition to oral ingestion of oocysts, T. gondii can be mechanically transmitted through soft ticks.

Identification and characterization of a novel Pavlovskyella (Acari: Argasidae) from Chile, parasite of the culpeo fox (Lycalopex culpaeus).

Soft ticks (Argasidae) of the subgenus Pavlovskyella Pospelova-Shtrom are worldwide distributed parasites of medical importance. However, the systematics of the subgenus are currently under debate because genetic data shows that the group is paraphyletic. Meanwhile, species of Pavlovskyella continue to be discovered. In this study a novel species of the subgenus is described from specimens collected on a fox in central Chile. The larva of this new species differentiates from other Pavlovskyella spp. by having the following combination of characters: subpyriform dorsal plate; 15 pairs of setae, 7 anterolateral, 3 central, and 5 posterolateral, and hypostome with denticles in the distal third. Nymphs and adults of the species lack cheeks, eyes or bulging structures on the flank, but exhibit dorsoventral grooves, and humps on tarsi I, II, and III. Moreover, a patch of glabrous integument appears on the distal portion of coxal folds. A phylogenetic analysis using the mitogenome indicates a monophyletic group composed by Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, Ornithodoros (Pavlovskyella) improvisus Muñoz-Leal & Venzal, and Ornithodoros (Pavlovskyella) rostratus Aragão. Interestingly, a phylogeny using 18S-28S rDNA sequences shows that South American Pavlovskyella spp. are paraphyletic, as depicted in previous studies. Adding species of the subgenus from the Neotropical region to phylogenetic analyses could aid to solve this paraphyly. Furthermore, this is the fifth species of Pavlovskyella described in South America, and the second in Chile.

Integrating Systematic Surveys With Historical Data to Model the Distribution of Ornithodoros turicata americanus, a Vector of Epidemiological Concern in North America.

Globally, vector-borne diseases are increasing in distribution and frequency, affecting humans, domestic animals, and wildlife. Science-based management and prevention of these diseases requires a sound understanding of the distribution and environmental requirements of the vectors and hosts involved in disease transmission. Integrated Species Distribution Models (ISDM) account for diverse data types through hierarchical modeling and represent a significant advancement in species distribution modeling. We assessed the distribution of the soft tick subspecies Ornithodoros turicata americanus. This tick species is a potential vector of African swine fever virus (ASFV), a pathogen responsible for an ongoing global epizootic that threatens agroindustry worldwide. Given the novelty of this method, we compared the results to a conventional Maxent SDM and validated the results through data partitioning. Our input for the model consisted of systematically collected detection data from 591 sampled field sites and 12 historical species records, as well as four variables describing climatic and soil characteristics. We found that a combination of climatic variables describing seasonality and temperature extremes, along with the amount of sand in the soil, determined the predicted intensity of occurrence of this tick species. When projected in geographic space, this distribution model predicted 62% of Florida as suitable habitat for this tick species. The ISDM presented a higher TSS and AUC than the Maxent conventional model, while sensitivity was similar between both models. Our case example shows the utility of ISDMs in disease ecology studies and highlights the broad range of geographic suitability for this important disease vector. These results provide important foundational information to inform future risk assessment work for tick-borne relapsing fever surveillance and potential ASF introduction and maintenance in the United States.

Associations between Ornithodoros spp. Ticks and Mojave Desert Tortoises (Gopherus agassizii) Obtained from Health Assessment Documents.

Soft ticks in the genus Ornithodoros occur throughout the Mojave Desert in southern Nevada, southeastern California, and parts of southwestern Utah and northwestern Arizona, USA, and are frequently observed parasitizing Mojave desert tortoises (Gopherus agassizii). However, limited research exists examining the relationship between ticks and desert tortoises. Mojave desert tortoises are listed as threatened by the US Fish and Wildlife Service, and as such, their populations are monitored and individual tortoise health is routinely assessed. These health assessments document the presence and abundance of ticks present on tortoises, but detailed examination of the relationship between ticks and tortoise health has been lacking. This study analyzed the relationship between tick presence and desert tortoise health assessments as a function of season, location, age (adult vs. juvenile), foraging behavior, evidence of clinical signs of disease, body condition score, and sex. Our results indicate that more ticks were found on tortoises in the summer than in any other season. Ticks were observed more frequently on captive tortoises versus wild tortoises, and more ticks were likely to be present on adult tortoises than on juveniles. Ticks were also more likely to be observed on tortoises that lacked evidence of foraging and on tortoises with observed clinical signs of disease. These findings provide valuable insights into the biology of ticks in relation to tortoises that may be useful for management of both captive and free-living threatened tortoise populations where ticks are detected. Our study also may improve understanding of potential tick-borne disease dynamics in the Mojave desert tortoise habitat, including Borrelia sp. carried by Ornithodoros ticks, which cause tick-borne relapsing fever in people.

Description of a new Ornithodoros (Pavlovskyella) (Ixodida: Argasidae) tick species from Pakistan.

The genus Ornithodoros is notably diverse within the family Argasidae, comprising approximately 134 species distributed among 4 subgenera, 1 of which is the subgenus Pavlovskyella. In an earlier study, we identified distinct soft ticks as Ornithodoros (Pavlovskyella) sp., which were collected from animal shelters in Khyber Pakhtunkhwa, Pakistan. Providing additional collections from that same locality and a comprehensive analysis involving detailed morphological and mitogenome-based comparisons with closely related species, this study formally designates a novel species for these specimens. Adults and late-instar nymphs of the new species display a dorsoventral groove, small cheeks not covering the capitulum, 5 small even humps on tarsus I and a transverse postanal groove intersecting the median postanal groove perpendicularly. It also lacks a tuft of setae on the ventral surface of the hood which separates the novel species from Ornithodoros papillipes. Ventral chaetotaxy of tarsus IV indicates 4–7 setal pairs in nymphs and 5–7 pairs in adults that separate the new species from Ornithodoros tholozani sensu stricto and Ornithodoros crossi, 2 morphologically closely related species that occur in geographical proximity. Phylogenetic analyses of the full-length mitochondrial genome and the 18S and 28S ribosomal RNA genes, combined with pairwise nucleotide comparisons of cox1, cox2, atp8, atp6, cox3, nad3, nad5, nad4, nad4L, nad6, cytb, nad1, nad2, 12S rDNA, 16S rDNA, 18S rDNA and 28S rDNA further support that the new species belongs to the Pavlovskyella subgenus, clustering with O. tholozani, Ornithodoros verrucosus and Ornithodoros tartakovskyi.

Development of a rapid and reliable surveillance method for Ornithodoros turicata americanus in gopher tortoise (Gopherus polyphemus) burrows in the southeastern United States.

The soft tick Ornithodoros turicata Duges (Acari: Argasidae) is a potential vector of African swine fever virus (ASFV). We evaluated the efficacy of two methods to collect soft ticks rapidly and efficiently from gopher tortoise (Gopherus polyphemus) burrows, which are ubiquitous throughout large regions of the southeastern United States and their burrows are a known microhabitat of O. turicata. Burrow vacuuming was an effective and efficient tick collection method; no tick was captured employing CO2 trapping. Using an occupancy modelling framework, we estimated that the probability of detecting ticks from an infested burrow each time a sample was taken with this method was 58% and increased with the average relative humidity. With the occupancy model, we estimated that 70% of the burrows in the study area were infested with O. turicata. Manual sifting of the burrow material yielded more ticks (6.6 individuals/sample) than using a set of three sieves (2.9 individuals/sample), yet the probability of detecting the species was not different between the two methods (Pval = 0.7). These methods can inform the development of ASF vector surveillance and outbreak response plans in areas of high risk for ASFV introduction in the region.

Molecular characterisation of Australasian Ixodiphagus (Hymenoptera; Encyrtidae; Encyrtinae) reveals unexpected diversity and a potential novel host switch

Ticks are important medical and veterinary parasites that represent a substantial health threat to humans, companion animals, and livestock. Ixodiphagus wasps (Hymenoptera; Encyrtidae) are known endoparasitoids of ixodid (hard) and argasid (soft) ticks, with potential utility as natural biocontrol agents. Two species, Ixodiphagus brunneus and Ixodiphagus mysorensis, are previously recorded from Australia, however, the genus lacks formal revisionary work in Australia, and the validity and host ranges of these species remain uncertain. This work aimed to investigate the diversity of Ixodiphagus in Australasia and provide a molecular data resource for future work on these understudied endoparasitoids. We extracted DNA from archival Ixodiphagus specimens from Australian and New Zealand insect collections and performed high-throughput sequencing which resulted in complete or mostly complete mitochondrial genome sequences from 11 specimens, including I. brunneus, Ixodiphagus taiaroaensis, and a novel Ixodiphagus sp. reared from Rhipicephalus linnaei from Townsville, Australia. In addition, approximately 70% of the genome of the Wolbachia endosymbiont of I. brunneus was recovered. Finally, we screened 178 recently collected pooled tick samples from southern New South Wales, Australia, for Ixodiphagus spp. using 28S rRNA and cytochrome c oxidase subunit 1(COI) gene PCR, and recovered 14 positive samples. Phylogenetic analysis of Australasian Ixodiphagus spp. based on 28S rRNA and complete mitochondrial genome sequences determined that members of the Australasian fauna are distinct from Ixodiphagus hookeri (the only other Ixodiphagus species for which genetic data exists), and that at least two distinct species are present in Australia; I. brunneus identified from Ixodes holocyclus and Haemaphysalis bancrofti ticks, and an uncharacterised Ixodiphagus sp. found in Rhipicephalus linnaei ticks from northern Queensland. Furthermore, there was substantial genetic diversity at the 28S rRNA loci among I. brunneus samples, which may represent normal genetic variability or a secondary cryptic species. The molecular data generated here represents the first known for the genus Ixodiphagus in Australasia, doubling that of the world fauna, and provides the first known complete mitochondrial genomes for these important tick parasitoids.

Description of Ornithodoros (Pavlovskyella) tartakovskyi using scanning electron microscopy, with notes on the morphology of Pavlovskyella sensu stricto and Theriodoros subgenera

Accumulation of DNA sequence data and its use in systematics of the family Argasidae reveals new incongruencies between genera and subgenera, since several groups defined by classical taxonomy appear to be paraphyletic, which is the case of the subgenus Pavlovskyella. In order to identify morphological characters unique to one of the monophyletic groupings within Pavlovskyella and improve its system, we describe all active stages of Ornithodoros (Pavlovskyella) tartakovskyi, a species with an incomplete original description. Larvae, nymphs, males and females from Iran were examined with scanning electron microscopy (SEM). The larva of O. (P.) tartakovskyi lacks dorsal plate, posteromedian seta, postcoxal setae and a spinose area in palpal article I; the dorsal surface has 13 pairs of setae and the hypostome has two short rows of denticles in the apex only. The first nymphal instar (N1) has a micromammillated body with faint dorsal and ventral disks. The second nymphal instar (N2) shows mammillated body with an incipient hood, and dorsal disks outlined as in subsequent instars. Both N1 and N2 have a small patch of glabrous surface in the anterior margin of preanal groove, absent in posterior stages. Third nymphal instar (N3) has a small hood and lack cheeks, which are incipient in the fourth nymphal instar (N4). The four nymphal instars (N1–N4) have blunt hypostomes, striated capitula, non-mammillated legs, and 3 humps on tarsi I. Females and males of O. (P.) tartakovskyi have mammillated bodies, small cheeks not covering the capitulum, the anteromedian disk is placed anteriorly to anterior central disks, and a posterior median file of disks is merged with the median disk. We describe all postembryonic stages of O. (P.) tartakovskyi providing morphological characters that define Pavlovskyella sensu stricto and Theriodoros, a sister subgenus that includes similarly shaped species.

Microbiota-driven vaccination in soft ticks: Implications for survival, fitness and reproductive capabilities in Ornithodoros moubata.

The Ornithodoros moubata (Om) soft tick, a vector for diseases like tick-borne human relapsing fever and African swine fever, poses challenges to conventional control methods. With diminishing insecticide efficacy, harnessing the tick's microbiota through innovative approaches like microbiota-driven vaccination emerges as a promising strategy for sustainable and targeted disease control. This study investigated the intricate relationship between Pseudomonas, a keystone taxon in the Om microbiome, and its impact on tick fitness, microbiome structure and network dynamics. Utilizing in silico analyses and empirical vaccination experiments, the role of Pseudomonas within microbial networks in the tick midguts (MG) and salivary glands (SG) of Om was studied. Additionally, the consequences of anti-microbiota vaccines targeting Pseudomonas and Lactobacillus on tick fitness, microbiome diversity and community assembly were explored. The result of the study shows that in Om, Pseudomonas plays a central role in microbial networks, influencing keystone species despite being categorized as peripheral (interacting with 47 different taxa, 13 of which are keystone species). Anti-microbiota vaccination targeting Pseudomonas and Lactobacillus yields distinct effects on tick fitness, with Pseudomonas vaccination significantly impacting female tick survival, while Lactobacillus significantly reduced oviposition and fertility. Microbiome changes post-vaccination reveal diversity alterations, emphasizing the impact of vaccine choice. Community assembly dynamics and network robustness analyses highlight Pseudomonas' pivotal role, in influencing topological features and network resilience. The findings of the study provide comprehensive insights into the intricate dynamics of Om microbial networks and the potential of targeted microbiota-driven vaccines for tick control.

Pathogen and Host Associations of Soft Ticks Collected in South Texas.

Background: Soft ticks (Family: Argasidae) are vectors of relapsing fever Borrelia in the United States and are potential vectors of African swine fever virus, a pathogen that could have a devastating effect on the U.S. swine industry if introduced to the U.S. mainland. Much of the tick-borne disease research in the U.S. focuses on hard ticks, and less is known about the ecology of soft ticks. Some soft tick species found in the southern U.S. have a wide host range and may feed on cattle, swine, native and exotic ungulates, small mammals, reptiles, and humans. Because the feeding habit of most soft tick species involves taking short, repeated blood meals that may include multiple host species, pathogen transmission among hosts is a concern both for human and animal health. Materials and Methods: Sampling was carried out at four locations in south Texas using dry ice traps placed in or near animal burrows and other sheltering cracks and crevasses that may provide refuge for soft ticks. Collected ticks were identified and subsequently screened for Rickettsia and Borrelia species and for host bloodmeal detection using conventional polymerase chain reaction and Sanger sequencing for pathogen and host species identification. Results: In total, 256 ticks of two Ornithodorinae species were screened. Borrelia species were identified in three samples. Bloodmeal detections were made in 22 tick specimens, representing eight vertebrate host species. Conclusions: Results demonstrate that the soft tick species detected herein feed on a range of wildlife hosts in south Texas and are associated with agents of human disease.

Chemical Synthesis and Structure-Activity Relationship Studies of the Coagulation Factor Xa Inhibitor Tick Anticoagulant Peptide from the Hematophagous Parasite Ornithodoros moubata.

Tick Anticoagulant Peptide (TAP), a 60-amino acid protein from the soft tick Ornithodoros moubata, inhibits activated coagulation factor X (fXa) with almost absolute specificity. Despite TAP and Bovine Pancreatic Trypsin Inhibitor (BPTI) (i.e., the prototype of the Kunitz-type protease inhibitors) sharing a similar 3D fold and disulphide bond topology, they have remarkably different amino acid sequence (only ~24% sequence identity), thermal stability, folding pathways, protease specificity, and even mechanism of protease inhibition. Here, fully active and correctly folded TAP was produced in reasonably high yields (~20%) by solid-phase peptide chemical synthesis and thoroughly characterised with respect to its chemical identity, disulphide pairing, folding kinetics, conformational dynamics, and fXa inhibition. The versatility of the chemical synthesis was exploited to perform structure-activity relationship studies on TAP by incorporating non-coded amino acids at positions 1 and 3 of the inhibitor. Using Hydrogen-Deuterium Exchange Mass Spectrometry, we found that TAP has a remarkably higher conformational flexibility compared to BPTI, and propose that these different dynamics could impact the different folding pathway and inhibition mechanisms of TAP and BPTI. Hence, the TAP/BPTI pair represents a nice example of divergent evolution, while the relative facility of TAP synthesis could represent a good starting point to design novel synthetic analogues with improved pharmacological profiles.

The role of gastropods in African swine fever virus ecology

The spread of the African swine fever virus (ASF virus) genotype ii in the Eurasian region has been very successful and often inexplicable. The virus spreads rapidly and persists in areas with wild boar populations, but areas without feral pig populations are also affected. The virus has shown the ability to survive for a long time in the environment without a population of susceptible hosts, both pigs and Ornithodoros soft ticks. Published data indicated that ASF viruses persist significantly longer in an environment with some freshwater snails (especially Pomacea bridgesii, Tarebia granifera, Asolene spixii, Melanoides tuberculate, and Physa fontinalis), compared to freshwater without snails. Data obtained in this study suggest that gastropods theoretically can be the hosts of the ASF virus. Also, we have proven the possibility of long-term existence of an infectious virus when infected in vitro.

Epidemiology and ecology of the sylvatic cycle of African Swine Fever Virus in Kenya

African Swine Fever (ASF) is caused by a DNA virus (AFSV) maintained and transmitted by the Argasid ticks. The re-emergence of the disease in Africa coupled with its rapid spread globally is a threat to the pig industry, food security and livelihoods. The ecology and epidemiology of the ASFV sylvatic cycle, especially in the face of changing land use and land cover, further compounds the menace and impacts of this disease in Kenya. The study aimed to determine the occurrence and distribution of ASFV seroprevalence in warthog populations, the tick vectors and extent of tick infestation of warthog burrows, and the genotypes of ASFV in soft ticks in Kenya. Warthogs from different parts of Kenya were captured and venous blood was centrifuged to harvest sera. Warthog burrows were examined for their conditions and to extract ticks. Sera were analyzed for antibodies against ASFV using a commercial ELISA kit coated with p32 ASFV recombinant protein. Ticks were pooled, DNA extracted and the p72 gene of the ASFV was amplified by qPCR and conventional PCR. The overall seroprevalence of ASFV in warthogs was 87.5 %. A total of 228 warthog burrows were examined and 2154 argasid ticks were extracted from the burrows. Tick pools from Kigio Farm and Lewa Wildlife Conservancies were ASFV-positive by qPCR and conventional PCR. ASFV was further confirmed by the Twist Comprehensive Viral Research Panel (TCVRP), which also identified the argasid ticks as Ornithodoros porcinus. The ticks were infected with virus genotype IX, and their occurrence overlaps with regions of previous ASF outbreaks in domestic pigs. Further, Viruses that could be tick endosymbionts/commensals or due to bloodmeal were detected in ticks by TCVRP; Porcine type-C oncovirus; Pandoravirus neocaledonia; Choristoneura fumiferana granulovirus; Enterobacteria phage p7; Leporid herpesvirus 4 isolate; 5; Human Lymphotropic virus; Human herpesvirus 5. In conclusion, our results suggest that infected Ornithodoros spp. seems to have a rich virome, which has not been explored but could be exploited to inform ASF control in Kenya. Further, the ecology of Ornithodoros spp. and burrow-use dynamics are complex and more studies are needed to understand these dynamics, specifically in the spread of ASFV at the interface of wild and domestic pigs. Further, our results provide evidence of genotype IX ASFV sylvatic cycle which through O. porcinus tick transmission has resulted in high exposure of adult common warthogs. Finally, the co-circulation of ASFV genotype IX in the same location with past ASF outbreaks in domestic pigs and presently in ticks brings to focus the role of the interface and ticks on virus transmission to pigs and warthogs.

Tick-Borne Relapsing Fever Infection from a Bunker, a Case Report on a "One Health" Approach.

Background: Tick-borne relapsing fever (TBRF) caused by Borrelia persica is an endemic disease in Israel and highly prevalent in military personnel. Prevention among the Israel Defense Force soldiers is based on increased awareness mainly in hyperendemic areas and selective postexposure prophylaxis with doxycycline. In this study, we report the presence of a suspected outbreak of TBRF in four soldiers who spent 30 h inside a deserted bunker. Materials and Methods: Clinical data on TBRF suspected cases were retrieved from clinical records, soft ticks were collected using carbon dioxide (CO2) traps and their DNA was extracted and analysed by PCR and nucleotide sequencing. Environmental conditions such as relative humidity, air temperature, wind speed, and type of soil, as well as presence or absence of animal traces inside the bunkers were documented. Results: TBRF-like clinical symptoms in the patients included: tick bite scars, fever (37.5-39.2°C), rash, tachycardia, hypotension, myalgia, cough, headache, cervical lymphadenopathy and nausea. Microscopic search for B. persica in blood smears was performed in three patients and was negative. Out of the 255 Ornithodoros tholozani ticks collected from the bunker, 198 were analyzed and 2 (1%) were infected with B. persica. To determine if tick infestation in military bunkers is a common phenomenon, we surveyed nine additional military bunkers located in four different geographical areas for the presence of soft ticks. Only one additional bunker was infested with two O. tholozani ticks, both negative for B. persica. Presence of earth that probably helped sustain a relatively big tick population was observed on the floor in the highly infested bunker. Environmental treatment with lambda-cyhalothrin at 9.7% was performed and showed efficacy with no ticks recovered in the infested bunker 124 days after intervention. Conclusion: This study shows that military bunkers may harbor soft ticks infected with B. persica and entrance into bunkers should be considered as a risk for acquiring this infection like entrance into natural caves and archeological ruins.