Bartonella Infection in Fruit Bats and Bat Flies, Bangladesh.

Bats harbor diverse intracellular Bartonella bacteria, but there is limited understanding of the factors that influence transmission over time. Investigation of Bartonella dynamics in bats could reveal general factors that control transmission of multiple bat-borne pathogens, including viruses. We used molecular methods to detect Bartonella DNA in paired bat (Pteropus medius) blood and bat flies in the family Nycteribiidae collected from a roost in Faridpur, Bangladesh between September 2020 and January 2021. We detected high prevalence of Bartonella DNA in bat blood (35/55, 64%) and bat flies (59/60, 98%), with sequences grouping into three phylogenetic clades. Prevalence in bat blood increased over the study period (33% to 90%), reflecting an influx of juvenile bats in the population and an increase in the prevalence of bat flies. Discordance between infection status and the clade/genotype of detected Bartonella was also observed in pairs of bats and their flies, providing evidence that bat flies take blood meals from multiple bat hosts. This evidence of bat fly transfer between hosts and the changes in Bartonella prevalence during a period of increasing nycteribiid density support the role of bat flies as vectors of bartonellae. The study provides novel information on comparative prevalence and genetic diversity of Bartonella in pteropodid bats and their ectoparasites, as well as demographic factors that affect Bartonella transmission and potentially other bat-borne pathogens.

New species in the Basilia ferruginea group (Diptera: Nycteribiidae) from Mexico, with additional records of Basilia rondanii.

A new species of Basilia Miranda-Ribeiro, 1903 (Diptera: Nycteribiidae) belonging to the ferruginea group from Mexico is described and additional geographic records of Basilia rondanii Guimarães & D´Andretta, 1956 are presented. The type-specimens of the species were collected on an endemic Mexican vespertilionid bat, Myotis carteri La Val (Chiroptera: Vespertilionidae) in the State of Jalisco. Photographs in dorsal and ventral views and distribution maps of the new species and Basilia rondanii are presented.

Culiseta annulata: A New Mosquito For Kuwait.

We report new records for Culiseta annulata from Kuwait. Prior to our records, Culiseta longiareolata was the only Culiseta sp. known from Kuwait. Culiseta annulata is a vector of Tahyna virus (Bunyaviridae) to humans throughout Asia. We tested a limited number of mosquitoes for Tahyna virus and other viruses. Tahyna virus was not detected, but we did discover a mosquito Densovirus in a pool of Cs. annulata using next generation sequencing.

Phylogeography of Rhipicephalus sanguineus sensu lato and its relationships with climatic factors.

Brown dog ticks morphologically identifiable as Rhipicephalus sanguineus sensu lato, are distributed world-wide and their systematics is controversial. Results of genetic and reproductive compatibility studies of geographically distinct populations of R. sanguineus s.l. indicate that the R. sanguineus complex is paraphyletic. To further elucidate systematic relationships within R. sanguineus s.l. and geographic boundaries of its lineages, we conducted a phylogeographical study of 136 tick specimens from 23 countries. Voucher specimens were morphologically identified. A phylogenetic tree was constructed using concatenated partial mitochondrial 12S and 16S rDNA gene sequences and analyzed by the Neighbor-Joining method. A set of 19 bioclimatic variables within the WorldClim dataset were extracted and analyzed to assess correlations between distribution of R. sanguineus s.l. lineages and climatic variables. The following four branches are clearly recognized on the phylogenetic tree: R. sanguineus s.l.-tropical and temperate clades, R. leporis, and R. turanicus. DNA sequences of Rhipicephalus ticks from Israel differ from those of other groups. Strong association between geographical locations of major clades of R. sanguineus s.l. and temperature was identified. The tropical clade of R. sanguineus s.l. occupies areas with the annual mean temperature >20 °C, whereas the temperate clade is present in areas with the annual mean temperature <20 °C. Our results indicate that ticks in two closely related phylogenetic clades are adapted to different environmental conditions and support proposals for re-classification of R. sanguineus complex. Differences in R. sanguineus s.l. ecology and human/animal pathogens transmitted by different taxa of brown dog tick need to be studied.

Laboratory Validation of the Sand Fly Fever Virus Antigen Assay.

Sandfly fever group viruses in the genus Phlebovirus (family Bunyaviridae) are widely distributed across the globe and are a cause of disease in military troops and indigenous peoples. We assessed the laboratory sensitivity and specificity of the Sand Fly Fever Virus Antigen Assay, a rapid dipstick assay designed to detect sandfly fever Naples virus (SFNV) and Toscana virus (TOSV) against a panel of phleboviruses. The assay detected SFNV and TOSV, as well as other phleboviruses including Aguacate, Anahanga, Arumowot, Chagres, and Punta Toro viruses. It did not detect sandfly fever Sicilian, Heartland, Rio Grande, or Rift Valley fever viruses. It did not produce false positive results in the presence of uninfected sand flies (Lutzomyia longipalpis) or Cache Valley virus, a distantly related bunyavirus. Results from this laboratory evaluation suggest that this assay may be used as a rapid field-deployable assay to detect sand flies infected with TOSV and SFNV, as well as an assortment of other phleboviruses.

Culicoides sonorensis (Diptera: Ceratopogonidae) is not a competent vector of Cache Valley virus (family Bunyaviridae, genus Orthobunyavirus).

We investigated the susceptibility of Culicoides sonorensis to Cache Valley virus (CVV) (family Bunyaviridae, genus Orthobunyavirus) infection and the potential that it could be a vector or site of virus reassortment. CVV is native to the New World and causes disease in livestock. Infected blood meals were fed to both a competent vector, Anopheles quadrimaculatus, and Culicoides sonorensis. All Anopheles mosquitoes were infected as expected, but only 21 % of the C. sonorensis insects were susceptible to infection. These appeared to present a midgut barrier, because virus persisted but did not disseminate. This means Culicoides sonorensis is not likely to be a vector of CVV but could be involved in viral reassortment. Schmallenberg virus (SBV) (family Bunyaviridae, genus Orthobunyavirus) was recently discovered in Europe and probably is a novel virus resulting from a reassortment of two orthobunyaviruses, and an ongoing epizootic in cattle and small ruminants has caused significant economic damage.

Mosquitoes of Thule Air Base, Greenland.

Thule Air Base in western Greenland had a previously uncharacterized mosquito pest problem. Swarms of bloodfeeding mosquitoes have been reported from June to late August, but the species were unknown. We conducted a base-wide mosquito vector survey from June to July 2012. One species of mosquito, Aedes impiger, was collected and > 3,000 were processed for polymerase chain reaction-based virus surveillance. Active mosquito breeding sites were located throughout the base and surrounding valley. Two pools of mosquitoes from Thule Air Base tested positive for an Orthobunyavirus; however, DNA sequencing of the viral amplicons was not complete enough to fully identify the agent.

New records for Micronesian mosquitoes.

The mosquito fauna of Micronesia is diverse and subject to introductions of exotic species and local extinctions. We report on 2 recently identified populations of exotic mosquitoes, Aedes albopictus and Anopheles campestris, to the Republic of the Marshall Islands and Guam.

Further Characterization of Rio Grande Virus and Potential for Cross Reactivity with Rift Valley Fever Virus Assays.

Phleboviruses (genus Phlebovirus, family Phenuiviridae) are emerging pathogens of humans and animals. Sand-fly-transmitted phleboviruses are found in Europe, Africa, the Middle East, and the Americas, and are responsible for febrile illness and nervous system infections in humans. Rio Grande virus (RGV) is the only reported phlebovirus in the United States. Isolated in Texas from southern plains woodrats, RGV is not known to be pathogenic to humans or domestic animals, but serologic evidence suggests that sheep (Ovis aries) and horses (Equus caballus) in this region have been infected. Rift Valley fever virus (RVFV), a phlebovirus of Africa, is an important pathogen of wild and domestic ruminants, and can also infect humans with the potential to cause severe disease. The introduction of RVFV into North America could greatly impact U.S. livestock and human health, and the development of vaccines and countermeasures is a focus of both the CDC and USDA. We investigated the potential for serologic reagents used in RVFV diagnostic assays to also detect cells infected with RGV. Western blots and immunocytochemistry assays were used to compare the antibody detection of RGV, RVFV, and two other New World phlebovirus, Punta Toro virus (South and Central America) and Anhanga virus (Brazil). Antigenic cross-reactions were found using published RVFV diagnostic reagents. These findings will help to inform test interpretation to avoid false positive RVFV diagnoses that could lead to public health concerns and economically costly agriculture regulatory responses, including quarantine and trade restrictions.

Identical Viral Genetic Sequence Found in Black Flies (Simulium bivittatum) and the Equine Index Case of the 2006 U.S. Vesicular Stomatitis Outbreak.

In 2006, vesicular stomatitis New Jersey virus (VSNJV) caused outbreaks in Wyoming (WY) horses and cattle after overwintering in 2004 and 2005. Within two weeks of the outbreak onset, 12,203 biting flies and 194 grasshoppers were collected near three equine-positive premises in Natrona County, WY. Insects were identified to the species level and tested by RT-qPCR for VSNJV polymerase (L) and phosphoprotein (P) gene RNA. Collected dipterans known to be competent for VSV transmission included Simulium black flies and Culicoides biting midges. VSNJV L and P RNA was detected in two pools of female Simulium bivittatum and subjected to partial genome sequencing. Phylogenetic analysis based on the hypervariable region of the P gene from black flies showed 100% identity to the isolate obtained from the index horse case on the same premises. This is the first report of VSNJV in S. bivittatum in WY and the first field evidence of possible VSV maintenance in black fly populations during an outbreak.

Nuclear (18S-28S rRNA) and mitochondrial genome markers of Carios (Carios) vespertilionis (Argasidae) support Carios Latreille, 1796 as a lineage embedded in the Ornithodorinae: re-classification of the Carios sensu Klompen and Oliver (1993) clade into its respective subgenera.

Argasid systematics remains controversial with widespread adherence to the Hoogstraal (1985) classification scheme, even though it does not reflect evolutionary relationships and results in paraphyly for the main genera of soft ticks (Argasidae), namely Argas and Ornithodoros. The alternative classification scheme, proposed by Klompen and Oliver (1993), has problems of its own: most notably paraphyly of the subgenus Pavlovskyella and the controversial grouping together of the subgenera Alectorobius, Antricola, Carios, Chiropterargas, Nothoaspis, Parantricola, Reticulinasus and Subparmatus into the genus Carios. Recent phylogenetic analyses of 18S/28S rRNA sequences and mitochondrial genomes agree with the scheme of Klompen and Oliver (1993), with regard to the paraphyly of Pavlovskyella, placement of Alveonasus, Ogadenus, Proknekalia and Secretargas in the Argasinae and placement of Carios and Chiropterargas in the Ornithodorinae (Mans et al., 2019). The Carios clade and its constituent subgenera remain controversial, since the phylogenetic position of its type species Carios (Carios) vespertilionis Latreille, 1796 (formerly Argas vespertilionis) has not been determined with confidence. The current study aimed to resolve Carios sensu lato Klompen and Oliver, 1993, and Carios sensu stricto Hoogstraal, 1985, by determining and analysing phylogenetic nuclear and mitochondrial markers for C. (C.) vespertilionis. Both the nuclear and mitochondrial markers support placement of Carios s.s. within the subfamily Ornithodorinae, but to the exclusion of the clade that includes the 6 other subgenera that are part of Carios s.l. Klompen and Oliver (1993), namely Alectorobius, Antricola, Nothoaspis, Parantricola, Reticulinasus and Subparmatus. These 6 subgenera form a monophyletic clade that might be placed as new subgenera within the genus Alectorobius, or elevated to genera. Given the substantial differences in biology among these subgenera, we propose that these 6 subgenera be elevated to genera. Thus, we propose to modify the classification scheme of Mans et al. (2019) so that the subfamily Argasinae now has six genera, Alveonasus, Argas (subgenera Argas and Persicargas), Navis, Ogadenus, Proknekalia and Secretargas, and the subfamily Ornithodorinae has nine genera, Alectorobius, Antricola (subgenera Antricola and Parantricola), Carios, Chiropterargas, Nothoaspis, Ornithodoros (subgenera Microargas, Ornamentum, Ornithodoros, Pavlovskyella and Theriodoros), Otobius, Reticulinasus and Subparmatus (genera indicated in bold).

Investigation of a bluetongue disease epizootic caused by bluetongue virus serotype 17 in sheep in Wyoming.

OBJECTIVE: To characterize a 2007 bluetongue disease (BT) epizootic caused by bluetongue virus (BTV) serotype 17 in sheep in the Big Horn Basin of Wyoming. DESIGN: Cross-sectional study. ANIMALS: 1,359 sheep from ranches in Wyoming and Montana. PROCEDURES: Information on clinical signs and history of BT in sheep was obtained from ranchers and attending veterinarians. At 3 to 6 months after the 2007 BT epizootic, blood samples were collected from rams, ewes, and lambs within and outside the Big Horn Basin; blood samples were also collected from lambs born in the spring of 2008. Sera were tested for anti-BTV antibodies by use of a competitive ELISA to determine the seroprevalence of BTV in sheep and to measure antibody titers. Virus isolation and reverse transcriptase PCR assays were used to determine long-term presence of the infectious virus or viral genetic material in RBCs of sheep. RESULTS: The percentage of sheep seropositive for BTV closely matched morbidity of sheep within flocks, indicating few subclinical infections. Flocks separated by as little as 1 mile had substantial variation in infection rate. Rams were infected at a higher rate than ewes. There was no evidence of BTV successfully overwintering in the area. CONCLUSIONS AND CLINICAL RELEVANCE: This epizootic appears to be a new intrusion of BTV into a naïve population of sheep previously protected geographically by the mountains surrounding the Big Horn Basin. Rams may have a higher infection rate as a result of increased vector biting opportunity because of the large surface area of the scrotum.

Aqueous 2% geraniol as a mosquito repellent failed against Aedes aegypti on ponies.

Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol, is naturally produced by a wide range of plants and is a US Environmental Protection Agency minimum risk pesticide. Previous studies have shown various concentrations of geraniol repel or kill mosquitoes; however, geraniol might cause allergic contact dermatitis in humans or animals. We tested a commercially available 2% aqueous solution of geraniol on ponies as a mosquito repellent. Five trials were conducted on ponies treated with a 60-ml aerosol mist (30 ml per side) of 2% geraniol or as untreated controls. Animals were observed 3 h postapplication to check for skin irritation. Aedes aegypti, in feeding tubes, were held on the ponies for 7 min. The average percent of biting on control animals was 56%, with a range of 16-90%, and the average for the treatments was 13%, with a range of 0-86%. Based on statistical models, there was no significant difference (P = 0.081) in the percent bites between treated and untreated animals after 3 h. Based on our data, 2% geraniol was not an adequate mosquito repellent for horses. We did not observe any skin irritation on the animals treated with 2% geraniol.

Epizootic hemorrhagic disease outbreak in a captive facility housing white-tailed deer (Odocoileus virginianus), bison (Bison bison), elk (Cervus elaphus), cattle (Bos taurus), and goats (Capra hircus) in Colorado, U.S.A.

An ungulate research facility in Fort Collins, Colorado, U.S.A., experienced mortality in white-tailed deer (Odocoileus virginianus) because of epizootic hemorrhagic disease virus (EHDV) infection from 20 August 2007 through 26 September 2007. Epizootic hemorrhagic disease virus (EHDV) was detected by reverse transcriptase polymerase chain reaction and virus isolation from the spleen and lung tissues of two white-tailed deer. Virus neutralization tests were performed on pre- and postoutbreak sera from other species maintained in the same facility, including bison (Bison bison), elk (Cervus elaphus), domestic cattle (Bos taurus), and domestic goats (Capra hircus), as well as postoutbreak sera from the surviving white-tailed deer. Serum samples that represented all species in the facility neutralized EHDV-1 and EHDV-2 either before or after the outbreak. The animals that neutralized EHDV-1 did not neutralize EHDV-2. No clinical signs attributable to EHDV infection were noted in any of the species other than the deer during the outbreak. Although experimental EHDV infections have been reported in bison and elk, natural exposures have not been previously documented in these species in North America. The roles that elk, bison, cattle, and goats might play in the epidemiology of EHDV in a close-contact multispecies situation remain unknown.

Nighttime Aerial Sprays for Control of Crepuscular Biting Midges in South Carolina.

Nighttime aerial spray applications with naled were conducted to evaluate their efficacy in controlling crepuscular biting midges (Culicoides spp.) in South Carolina, using a US Air Force C-130. Local populations of Culicoides spp. were monitored before and after the sprays with Mosquito Magnet traps to assess the efficacy of postsunset applications. Biting midge populations were consistently decreased by the aerial spray applications in this study. This indicates that nighttime sprays can be used to control these pests, even when their peak flight activity is focused around sunset.

Rickettsia hoogstraalii and a Rickettsiella from the Bat Tick Argas transgariepinus, in Namibia.

Ectoparasites were collected from Eptesicus hottentotus, the long-tailed serotine bat, caught in Namibia as part of an ecological study. Larvae of Argas transgariepinus, a blood-feeding ectoparasite of bats in Africa, were removed from 3 of 18 bats. We present scanning electron microscope images of unengorged larvae. As with other ectoparasites, this bat tick might transmit pathogens such as Borrelia and Rickettsia to their hosts as has been reported for bat ticks in Europe and North America. We screened 3 pools (25 total) of larvae of A. transgariepinus removed from the long-tailed serotine bat Eptesicus hottentotus caught in Namibia. Two microbes of unknown pathogenicity, including Rickettsia hoogstraalii, a spotted fever group pathogen, and a Rickettsiella sp. were detected by molecular techniques.

The first finding of parasitic mite, Parasteatonyssus nyctinomi (Mesostigmata: Gamasina: Macronyssidae), in Namibia.

Sixty-four individuals of a macronyssid mite, Parasteatonyssus nyctinomi (Zumpt, Patterson 1951), were identified from Egyptian free-tailed bats Tadarida aegyptiaca (É. Geoffroy 1818) (Chiroptera: Molossidae) captured in the Kunene region of Namibia (southern Africa). This is the first report on P. nyctinomi in the country.

Revision of Simulium rufibasis (Diptera: Simuliidae) in Japan and Korea: Chromosomes, DNA, and Morphology.

The widespread nominal black fly Simulium (Simulium) rufibasis Brunetti was reexamined morphologically, chromosomally, and molecularly to determine the status of populations in Japan and Korea with respect to S. rufibasis from the type locality in India and to all other known species in the S. (S.) tuberosum species-group. Morphological comparisons established that the species previously known as S. rufibasis in Japan and Korea is distinct from all other species. Consequently, it was described and illustrated as a new species, Simulium (S.) yamatoense. Simulium yokotense Shiraki, formerly a synonym of S. rufibasis, was morphologically reevaluated and considered a species unplaced to species-group in the subgenus Simulium. Chromosomal analyses of S. yamatoense sp. nov. demonstrated that it is unique among all cytologically known species of the S. tuberosum group and is the sister species of the Taiwanese species tentatively known as S. (S.) arisanum Shiraki. Populations of S. yamatoense sp. nov. included two cytoforms, based on the sex chromosomes. Cytoform A, including topotypical representatives, was found in Kyushu, Japan, whereas cytoform B was found in Korea and Honshu, Japan. Molecular analysis based on the COI mitochondrial gene generally corroborated morphological and chromosomal data that S. yamatoense sp. nov. is a distinct species and, like the chromosomal data, indicate that it is most closely related to S. arisanum, with interspecific genetic distance of 2.92-4.63%.

Management Strategies for Reducing the Risk of Equines Contracting Vesicular Stomatitis Virus (VSV) in the Western United States.

Vesicular stomatitis viruses (VSVs) cause a condition known as vesicular stomatitis (VS), which results in painful lesions in equines, cattle, swine, and camelids, and when transmitted to humans, can cause flu-like symptoms. When animal premises are affected by VS, they are subject to a quarantine. The equine industry more broadly may incur economic losses due to interruptions of animal trade and transportation to shows, competitions, and other events. Equine owners, barn managers, and veterinarians can take proactive measures to reduce the risk of equines contracting VS. To identify appropriate risk management strategies, it helps to understand which biting insects are capable of transmitting the virus to animals, and to identify these insect vectors' preferred habitats and behaviors. We make this area of science more accessible to equine owners, barn managers, and veterinarians, by (1) translating the most relevant scientific information about biting insect vectors of VSV and (2) identifying practical management strategies that might reduce the risk of equines contracting VSV from infectious biting insects or from other equines already infected with VSV. We address transmission risk at four different spatial scales-the animal, the barn/shelter, the barnyard/premises, and the surrounding environment/neighborhood-noting that a multiscale and spatially collaborative strategy may be needed to reduce the risk of VS.

New National Record for Culex perexiguus from Kuwait.

Mosquitoes can transmit a wide variety of viral and parasitic pathogens. Several species have recently been reported in new locations throughout the Arabian Peninsula as a result of entomological surveillance by the US military. We report a new national record for Culex perexiguus from Kuwait based on morphologic and molecular identification of captured samples. This mosquito might pose a public health threat to local populations and to military personnel as a potential vector of both Sindbis and West Nile viruses.