Hostname: page-component-8448b6f56d-42gr6 Total loading time: 0 Render date: 2024-04-19T03:46:15.528Z Has data issue: false hasContentIssue false

Tick-borne viruses

Published online by Cambridge University Press:  19 April 2005

M. LABUDA
Affiliation:
Institute of Zoology, Slovak Academy of Sciences, Dubravska cesta 9, 845 06 Bratislava, Slovakia
P. A. NUTTALL
Affiliation:
Centre for Ecology & Hydrology, Mansfield Rd., Oxford, OX1 3SR, UK

Abstract

At least 38 viral species are transmitted by ticks. Virus–tick–vertebrate host relationships are highly specific and less than 10% of all tick species (Argasidae and Ixodidae) are known to play a role as vectors of arboviruses. However, a few tick species transmit several (e.g. Ixodes ricinus, Amblyomma variegatum) or many (I. uriae) tick-borne viruses. Tick-borne viruses are found in six different virus families (Asfarviridae, Reoviridae, Rhabdoviridae, Orthomyxoviridae, Bunyaviridae, Flaviviridae) and at least 9 genera. Some as yet unassigned tick-borne viruses may belong to a seventh family, the Arenaviridae. With only one exception (African swine fever virus, family Asfarviridae) all tick-borne viruses (as well as all other arboviruses) are RNA viruses. Tick-borne viruses are found in all the RNA virus families in which insect-borne members are found, with the exception of the family Togaviridae. Some tick-borne viruses pose a significant threat to the health of humans (Tick-borne encephalitis virus, Crimean-Congo haemorrhagic fever virus) or livestock (African swine fever virus, Nairobi sheep disease virus). Key challenges are to determine the molecular adaptations that allow tick-borne viruses to infect and replicate in both tick and vertebrate cells, and to identify the principal ecological determinants of tick-borne virus survival.

Type
Research Article
Copyright
© 2004 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

ARTHUR, D. R. ( 1963). British Ticks. London, Butterworths.
ARTSOB, H. ( 1988). Powassan encephalitis. In The Arboviruses: Epidemiology and Ecology, Vol. IV ( ed. Monath, T. P.), pp. 2949. Boca Raton, CRC Press.
BALASHOV, J. C. ( 1998). Ixodid ticks – parasites and vectors of diseases. Sankt-Peterburg, Nauka.
BANERJEE, K. ( 1988). Kyasanur Forest Disease. In The Arboviruses: Epidemiology and Ecology, Vol. III ( ed. Monath, T. P.), pp. 93116. Boca Raton, CRC Press.
BLASKOVIC, D. & NOSEK, J. ( 1972). The ecological approach to the study of tick-borne encephalitis. Progress in Medical Virology 14, 275320.Google Scholar
BOOTH, T. F., DAVIES, C. R., JONES, L. D., STAUNTON, D. & NUTTALL, P. A. ( 1989). Anatomical basis of Thogoto virus infection in BHK cell culture and in the ixodid tick vector, Rhipicephalus appendiculatus. Journal of General Virology 70, 10931104.CrossRefGoogle Scholar
BOOTH, T. F., STEELE, G. M., MARRIOTT, A. C. & NUTTALL, P. A. ( 1991). Dissemination, replication, and trans-stadial persistence of Dugbe virus (Nairovirus, Bunyaviridae) in the tick vector Amblyomma variegatum. American Journal of Tropical Medicine and Hygiene 45, 146157.CrossRefGoogle Scholar
BROWN, S. E., GORMAN, B. M., TESH, R. B. & KNUDSON, D. L. ( 1993). Coltiviruses isolated from mosquitoes collected in Indonesia. Virology 196, 363367.CrossRefGoogle Scholar
BURGDORFER, W. ( 1977). Tick-borne diseases in the United States: Rocky Mountain spotted fever and Colorado tick fever. Acta Tropica 34, 103112.Google Scholar
BURGDORFER, W. & VARMA, M. G. R. ( 1967). Trans-stadial and transovarial development of disease agents in arthropods. Annual Revue of Entomology 12, 347376.CrossRefGoogle Scholar
CALISHER, C. H. ( 1996). In The Bunyaviridae (ed. Elliott, R. M.). New York, Plenum Press.
CALISHER, C. H. ( 2001). Colorado tick fever. In The Encyclopedia of Arthropod-transmitted Infections (ed. Service, M. W.), pp. 121126. Wallingford, CABI Publishing.
CHARREL, R. N., ZAKI, A. M., ATTOUI, H., FAKEEH, M., BILLOIR, F., YOUSEF, A. I., CHESSE, R. DE, MICCO, P. DE, GOULD, E. A. & LAMBALLERIE, X. DE ( 2001). Complete coding sequence of the Alkhurma virus, a tick-borne flavivirus causing severe haemorrhagic fever in humans in Saudi Arabia. Biochemical and Biophysical Research Communications 287, 455461.CrossRefGoogle Scholar
CHASTEL, C. ( 1988). Tick-borne virus infections of marine birds. Advances in Disease Vector Research 5, 2560.Google Scholar
CHERNESKY, M. A. & McLEAN, D. M. ( 1969). Localization of Powassan virus in Dermacentor andersoni ticks by immunofluorescence. Canadian Journal of Microbiology 15, 13991408.CrossRefGoogle Scholar
CLERX, J. P. M., CASALS, J. & BISHOP, D. H. L. ( 1981). Structural characteristics of nairoviruses (genus Nairovirus, Bunyaviridae). Journal of General Virology 55, 165178.CrossRefGoogle Scholar
DANIELOVA, V., HOLUBOVA, J., PEJCOCH, M. & DANIEL, M. ( 2002). Potential significance of transovarial transmission in the circulation of tick-borne encephalitis virus. Folia Parasitologica 49, 323325.CrossRefGoogle Scholar
DARWISH, M. & HOOGSTRAAL, H. ( 1981). Arboviruses infecting humans and lower animals in Egypt: a review of thirty years of research. Journal of the Egyptian Public Health Association 61, 1112.Google Scholar
DAUBNEY, R. & HUDSON, J. R. ( 1931). Nairobi sheep disease. Parasitology 23, 507524.CrossRefGoogle Scholar
DAVIES, C. R., JONES, L. D., GREEN, B. M. & NUTTALL, P. A. ( 1987). In vivo reassortment of Thogoto virus (a tick-borne influenza-like virus) following oral infection of Rhipicephalus appendiculatus ticks. Journal of General Virology 68, 23312338.CrossRefGoogle Scholar
DAVIES, C. R., JONES, L. D. & NUTTALL, P. A. ( 1986). Experimental studies on the transmission cycle of Thogoto virus, a candidate orthomyxovirus, in Rhipicephalus appendiculatus ticks. American Journal of Tropical Medicine and Hygiene 35, 12561262.CrossRefGoogle Scholar
DIXON, L. K., COSTA, J. V., ESCRIBANO, J. M., ROCK, D. L., VINUELA, E. & WILKINSON, P. J. ( 2000). Family Asfarviridae. In Virus Taxonomy, 7th Report of the International Committee on Taxonomy of Viruses (ed. van Regenmortel et al.), pp. 159165. San Diego, San Francisco, New York, Boston, London, Sydney, Tokyo, Academic Press.
EMMONS, R. W., OSHIRO, L. S., JOHNSON, H. N. & LENNETTE, E. H. ( 1972). Intraerythrocytic location of Colorado tick fever. Journal of General Virology 17, 185195.CrossRefGoogle Scholar
ELLIOTT, R. M. (ed.) ( 1996). The Bunyaviridae. New York, Plenum Press.CrossRef
FREEDMAN-FAULSTICH, E. Z. & FULLER, F. J. ( 1990). Nucleotide sequence of the tick-borne, orthomyxo-like Dhori/Indian/1313/61 virus envelope gene. Virology 175, 1018.CrossRefGoogle Scholar
FRESE, M., WEEBER, M., WEBER, F., SPETH, V. & HALLER, O. ( 1997). MX1 sensitivity: Batken virus is an orthomyxovirus closely related to Dhori virus. Journal of General Virology 78, 24532458.CrossRefGoogle Scholar
GAO, G. F., HUSSAIN, M. H., REID, H. W. & GOULD, E. A. ( 1993). Classification of a new member of the TBE flavivirus subroup by its immunological, pathogenic and molecular characteristics: identification of subgroup-specific pentapeptides. Virus Research 30, 129144.CrossRefGoogle Scholar
GAUNT, M. W., SALL, A. A., LAMBALLERIE, X. DE, FALCONER, A. K. I., DZHIVANIAN, T. I. & GOULD, E. A. ( 2001). Phylogenetic relationships of flaviviruses correlate with their epidemiology, disease association and biogeography. Journal of General Virology 82, 18671876.CrossRefGoogle Scholar
GERMAIN, M., SALUZZO, J. F., CORNET, J. P., HERVE, J. P., SUREAU, P., CAMICAS, J. L., ROBIN, Y., SALAUN, J. J. & HEME, G. ( 1979). Isolement du virus de la fievre jaune a partir de la ponte et de larves d'une tique Amblyomma variegatum. Comptes Rendus des Seances de l'Academie des Sciences Serie D 289, 635637.Google Scholar
GIBBS, E. P. J. ( 2001). African swine fever. In The Encyclopedia of Arthropod-transmitted Infections (ed. Service, M. W.), pp. 713. Wallingford, CABI Publishing.
GORDON, S. W., LINTHICUM, K. J. & MOULTON, J. R. ( 1993). Transmission of Crimean-Congo hemorrhagic fever virus in two species of Hyalomma ticks from infected adults to cofeeding immature forms. American Journal of Tropical Medicine and Hygiene 48, 576580.CrossRefGoogle Scholar
GOULD, E. A., ZANOTTO, P. M. A. DE & HOLMES, E. C. ( 1997). The genetic evolution of flaviviruses. In Factors in the Emergence of Arbovirus Diseases (ed. Saluzzo, J. F. & Dodet, B.), pp. 5163. Paris, Elsevier.
GRESÍKOVÁ, M. & CALISHER, C. H. ( 1988). Tick-borne encephalitis. In The Arboviruses: Epidemiology and Ecology, Vol. IV ( ed. Monath, T. P.), pp. 177202. Boca Raton, CRC Press.
GRESÍKOVÁ, M., NOSEK, J., KOZUCH, O., ERNEK, E. & LICHARD, M. ( 1965). Study on the ecology of Tribeč virus. Acta Virologica 9, 8389.Google Scholar
GRESÍKOVÁ, M., SEKEYOVA, M., TEMPERA, G., GUGLIELMINO, S. & CASTRO, A. ( 1978). Identification of Sindbis virus strain isolated from Hyalomma marginatum ticks in Sicily. Acta virologica 22, 231232.Google Scholar
HOOGSTRAAL, H. ( 1973). Viruses and ticks. In Viruses and Invertebrates (ed. Gibbs, A. J.). North-Holland Research Monographs Frontiers of Biology. Vol. 31, pp. 349390. Amsterdam, North-Holland Publishing Company.
HOOGSTRAAL, H. ( 1979). The epidemiology of tick-borne Crimean-Congo hemorrhagic fever in Asia, Europe, and Africa. Journal of Medical Entomology 15, 307417.CrossRefGoogle Scholar
HUGHES, L. E., CASPER, E. A. & CLIFFORD, C. M. ( 1974). Persistence of Colorado tick fever in red blood cells. American Journal of Tropical Medicine and Hygiene 23, 530532.CrossRefGoogle Scholar
IWATA, H., YAMAGAWA, M. & ROY, P. ( 1992). Evolutionary relationships among the gnat-transmitted orbiviruses that cause African horse sickness, bluetongue, and epizootic hemorrhagic disease as evidenced by their capsid protein sequences. Virology 191, 251261.CrossRefGoogle Scholar
JONES, L. D., DAVIES, C. R., GREEN, B. M. & NUTTALL, P. A. ( 1987). Reassortment of Thogoto virus (a tick-borne influenza-like virus) in a vertebrate host. Journal of General Virology 68, 12991306.CrossRefGoogle Scholar
KARABATSOS, N. ( 1985). International Catalogue of Arboviruses Including Certain Other Viruses of Vertebrates, Third edn. San Antonio, Texas, American Society of Tropical Medicine and Hygiene.
KAUFMAN, W. R., BOWMAN, A. S. & NUTTALL, P. A. ( 2002). Salivary fluid secretion in the ixodid tick Rhipicephalus appendiculatus is inhibited by Thogoto virus infection. Experimental and Applied Acarology 25, 661674.Google Scholar
KAUFMAN, W. R. & NUTTALL, P. A. ( 1996). Amblyomma variegatum (Acari: Ixodidae): mechanism and control of arbovirus secretion in tick saliva. Experimental Parasitology 82, 316323.CrossRefGoogle Scholar
KAUFMAN, W. R. & NUTTALL, P. A. ( 2004). Rhipicephalus appendiculatus (Acari: Ixodidae): dynamics of Thogoto virus infection in female ticks during feeding on guinea pigs. Experimental Parasitology 104, 2025.Google Scholar
KLEIBOEKER, S. B., SCOLES, G. A., BURRAGE, T. G. & SUR, J. H. ( 1999). African swine fever virus replication in the midgut epithelium is required for infection of Ornithodoros ticks. Journal of Virology 73, 85878598.Google Scholar
KOVAR, V., KOPACEK, P. & GRUBHOFFER, L. ( 2000). Isolation and characterization of Dorin M, a lectin from plasma of the soft tick Ornithodoros moubata. Insect Biochemistry and Molecular Biology 30, 195205.CrossRefGoogle Scholar
LABUDA, M., DANIELOVA, V., JONES, L. D. & NUTTALL, P. A. ( 1993). Amplification of tick-borne encephalitis virus infection during co-feeding of ticks. Medical and Veterinary Entomology 7, 339342.CrossRefGoogle Scholar
LAWRIE, C. H., UZCATEGUI, N. Y., GOULD, E. A. & NUTTALL, P. A. ( 2004). Ixodid and Argasid tick species and West Nile virus. Emerging Infectious Diseases 10 (in press).CrossRefGoogle Scholar
LEAHY, M. B., DESSENS, J. T. & NUTTALL, P. A. ( 1997). In vitro polymerase activity of Thogoto virus: evidence for a unique cap snatching mechanism in a tick-borne orthomyxovirus. Journal of Virology 71, 83478351.Google Scholar
LEE, V. H., KEMP, G. E., MADBOULY, M. H., MOORE, D. L., CAUSEY, O. R. & CASALS, J. ( 1974). Jos, a new tick-borne virus from Nigeria. American Journal of Veterinary Research 35, 11651167.Google Scholar
LIBIKOVA, H., MAYER, V., KOZUCH, O., REHACEK, J., ERNEK, E. & ALBRECHT, P. ( 1964). Isolation from Ixodes persulcatus ticks of cytopathic agents (Kemerovo virus) differing from tick-borne encephalitis virus and some of their properties. Acta Virologica 8, 289301.Google Scholar
LINDENBACH, B. D. & RICE, C. M. ( 2001). Flaviviridae: the viruses and their replication. In Fields' Virology, 4th edn. ( ed. Knipe, D. M., Howley, P. M. et al.), pp. 9911041. Philadelphia, Lippincott Williams & Wilkins.
LUDWIG, G. V., ISRAEL, B. A., CHRISTENSEN, B. M., YUILL, T. M. & SCHULTZ, K. T. ( 1991). Role of La Crosse virus glycoproteins in attachment of virus to host cells. Virology 181, 564571.CrossRefGoogle Scholar
LVOV, D. K. ( 1988). Omsk haemorrhagic fever. In The Arboviruses: Epidemiology and Ecology, Vol. III ( ed. Monath, T. P.), pp. 205216. Boca Raton, CRC Press.
LVOV, D. K., CHERVONSKI, V. I., GOSTINSHCHIKOVA, I. N., ZEMIT, A. S., GROMASHEVSKY, V. L., TSIRKIN, Y. M. & VESELOVKSKAYA, O. V. ( 1972). Isolation of Tyuleniy virus from ticks Ixodes (Ceratixodes) putus Pick.-Camb. 1878 collected on Commodore Islands. Archiv für gesamte Virusforschung 38, 139142.Google Scholar
LVOV, D. K., TIMOPHEEVA, A. A., SMIRNOV, V. A., GROMASHEVSKY, V. L., SIDOROVA, G. A., NIKIFOROV, L. P., SAZONOV, A. A., ANDREEV, A. P., SKVORTZOVA, T. M., BERESINA, L. K. & ARISTOVA, V. A. ( 1975). Ecology of tick-borne viruses in colonies of birds in the USSR. Medical Biology 53, 325330.Google Scholar
MAIN, A. J., DOWNS, W. G., SHOPE, R. E. & WALLIS, R. C. ( 1973). Great Island and Bauline: two new Kemerovo group orbiviruses from Ixodes uriae in eastern Canada. Journal of Medical Entomology 10, 229235.CrossRefGoogle Scholar
MANDL, C. W., KROSCHEWSKI, H., ALLISON, S. L., KOFLER, R., HOLZMANN, H., MEIXNER, T. & HEIZ, F. X. ( 2001). Adaptation of tick-borne encephalitis virus to BHK-21 cells results in the formation of multiple heparin sulfate binding sites in the envelope protein and attenuation in vivo. Journal of Virology 75, 56275637.CrossRefGoogle Scholar
MARIN, M. S., ZANOTTO, P. M. DE A., GRITSUN, T. S. & GOULD, E. A. ( 1995). Phylogeny of TYU, SRE and CFA virus: different evolutionary rates in the genus Flavivirus. Virology 206, 11331139.CrossRefGoogle Scholar
MARRIOTT, A. C. & NUTTALL, P. A. ( 1996). Large RNA segment of Dugbe nairovirus encodes the putative RNA polymerase. Journal of General Virology 77, 17751780.CrossRefGoogle Scholar
MEAD, D. G., RAMBERG, F. B., BESSELSEN, D. G. & MARE, C. J. ( 2000). Transmission of vesicular stomatitis virus from infected to noninfected black flies co-feeding on nonviremic deer mice. Science 287, 485487.CrossRefGoogle Scholar
MORSE, M. A., MARRIOTT, A. C. & NUTTALL, P. A. ( 1992). The glycoprotein of Thogoto virus (a tick-borne orthomyxo-like virus) is related to the baculovirus glycoprotein gp64. Virology 186, 640646.CrossRefGoogle Scholar
NUTTALL, P. A. ( 1984). Tick-borne viruses in seabird colonies. Seabird 7, 3141.Google Scholar
NUTTALL, P. A. ( 1993). Orbiviruses associated with birds. In Virus Infections of Birds (ed. McFerran J. B. & McNulty, M. S.). Virus Infections of Vertebrates, 4, pp. 195198. Amsterdam, Elsevier Science Publishers B.V.
NUTTALL, P. A. ( 1999). Pathogen–tick–host interactions: Borrelia burgdorferi and TBE virus. Zentralblatt für Bakteriologie 289, 492505.CrossRefGoogle Scholar
NUTTALL, P. A. ( 2001). Crimean-Congo haemorrhagic fever. In The Encyclopedia of Arthropod-transmitted Infections (ed. Service, M. W.), pp. 126132. Wallingford, CABI Publishing.
NUTTALL, P. A., JACOBS, S. C., JONES, L. D., CAREY, D. & MOSS, S. R. ( 1992). Enhanced neurovirulence of tick-borne orbiviruses resulting from genetic modulation. Virology 187, 407412.CrossRefGoogle Scholar
NUTTALL, P. A., MORSE, M. A., JONES, L. D. & PORTELA, A. ( 1995). Adaptation of members of the Orthomyxoviridae family to transmission by ticks. In Molecular Basis of Virus Evolution (ed. Gibbs, A. J., Calisher, C. H. & García-Arenal, F.), pp. 416425. Cambridge, Cambridge University Press.CrossRef
NUTTALL, P. A. & MOSS, S. R. ( 1989). Genetic reassortment indicates a new grouping for tick-borne orbiviruses. Virology 171, 156161.CrossRefGoogle Scholar
RAMPAS, J. & GALLIA, F. ( 1949). Isolation of encephalitis virus from Ixodes ricinus ticks. Casopis lekaru ceskych 88, 11791180 (in Czech).Google Scholar
RANDOLPH, S. E. ( 1998). Ticks are not insects: consequences of contrasting vector biology for transmission potential. Parasitology Today 14, 186192.CrossRefGoogle Scholar
RANDOLPH, S. E., MIKLISOVA, D., LYSY, J., ROGERS, D. J. & LABUDA, M. ( 1999). Incidence from coincidence: patterns of tick infestations on rodents facilitate transmission of tick-borne encephalitis virus. Parasitology 118, 177186.CrossRefGoogle Scholar
REHACEK, J. ( 1965). Development of animal viruses and rickettsiae in ticks and mites. Annual Revue of Entomology 10, 124.CrossRefGoogle Scholar
REHSE-KUPPER, B., CASALS, J., REHSE, E. & ACKERMANN, R. ( 1976). Eyach – an arthropod-borne virus related to Colorado tick fever virus in the Federal Republic of Germany. Acta Virologica 20, 339342.Google Scholar
REID, H. W. ( 1984). Epidemiology of louping-ill. In Vector Biology (ed. Mayo, M. A. & Harrap, K. A.), pp. 161178. London, Academic Press.
RENNIE, L., WILKINSON, P. J. & MELLOR, P. S. ( 2000). Effects of infection of the tick Ornithodoros moubata with African swine fever virus. Medical and Veterinary Entomology 14, 355360.CrossRefGoogle Scholar
RENNIE, L., WILKINSON, P. J. & MELLOR, P. S. ( 2001). Transovarial transmission of African swine fever virus in the argasid tick Ornithodoros moubata. Medical and Veterinary Entomology 15, 140146.CrossRefGoogle Scholar
REY, F. A., HEINZ, F. X., MANDL, C., KUNZ, C. & HARRISON, S. C. ( 1995). The envelope glycoprotein from tick-borne encephalitis virus at 2A resolution. Nature 375, 291298.CrossRefGoogle Scholar
ROY, P. ( 2001). Orbiviruses. In Fields’ Virology, 4th edn. ( ed. Knipe, D. M., Howley, P. M. et al.), pp. 18351869. Philadelphia, Lippincott Williams & Wilkins.
SALAS, M. L. ( 1994). African swine fever virus. In Encyclopedia of Virology, Vol. 1 ( ed. Webster, R. G. & Granoff, A.), pp. 129. London, Academic Press.
SCHMALJOHN, C. S. & HOOPER, J. W. ( 2001). Bunyaviridae: the viruses and their replication. In Fields' Virology, 4th edn. ( eds. Knipe, D. M., Howley, P. M. et al.), pp. 15811602. Philadelphia, Lippincott Williams & Wilkins.
SCHOEHN, G., MOSS, S. R., NUTTALL, P. A. & HEWAT, E. A. ( 1997). Structure of Broadhaven virus by cryo-electron microscopy: correlation of structural and phenotypic properties of Broadhaven virus and bluetongue virus outer capsid proteins. Virology 235, 191200.CrossRefGoogle Scholar
SHEPHERD, A. J., SWANEPOEL, R., CORNEL, A. J. & MATHEE, O. ( 1989). Experimental studies on the replication and transmission of Crimean-Congo hemorrhagic fever virus in some African tick species. American Journal of Tropical Medicine and Hygiene 40, 326331.CrossRefGoogle Scholar
SHIU, S. Y. W., AYRES, M. D. & GOULD, E. A. ( 1991). Genomic sequence of the structural proteins of LI virus: comparative analysis with tick-borne encephalitis virus. Virology 180, 411415.CrossRefGoogle Scholar
SIMONS, J. F., HELLMAN, U. & PETTERSSON, R. F. ( 1990). Uukuniemi virus S RNA segment: ambisense coding strategy, packaging of complementary strands into virions, and homology to members of the genus Phlebovirus. Journal of Virology 64, 247255.Google Scholar
SKOFERTSA, P. G., GAIDAMOVICH, S. I. A., OBUKHOVA, V. R., KORCHMAR' ND, I. A. & ROVOI, P. I. ( 1972). Isolation of Kemerovo group Kharagysh virus on the territory of the Moldavian SSR. Voprosy Virusologii 17, 709711.Google Scholar
SMITH, C. E. G. & VARMA, M. G. R. ( 1981). Louping ill. Vol. 1. In CRC Handbook Series of Zoonoses, Section B (ed. Beran, G. W.), pp. 191200. Boca Raton, CRC Press, Inc.
SONENSHINE, D. E. ( 1991). Biology of Ticks, First edn. New York, Oxford, Oxford University Press.
SREENIVASAN, M. A., BHAT, H. R. & RAJAGOPALAN, P. K. ( 1979). Studies on the transmission of Kyasanur forest disease virus by partly fed ixodid ticks. Indian Journal of Medical Research 69, 708713.Google Scholar
STEELE, G. M. & NUTTALL, P. A. ( 1989). Difference in vector competence of two species of sympatric ticks, Amblyomma variegatum and Rhipicephalus appendiculatus for Dugbe virus (Nairovirus: Bunyaviridae). Virus Research 14, 7384.CrossRefGoogle Scholar
SWANEPOEL, R., SHEPHERD, A. J., LEMAN, P. A., SHEPHERD, S. P., McGILLIVRAY, G. M., ERASMUS, M. J., SEARLE, L. A. & GILL, D. E. ( 1987). Epidemiological and clinical features of Crimean-Congo hemorrhagic fever in southern Africa. American Journal of Tropical Medicine and Hygiene 36, 120132.CrossRefGoogle Scholar
TAYLOR, R. M., HURLBUT, H. S., WORK, T. H. & KINGSTON, J. R. ( 1966). Arboviruses isolated from Argas ticks in Epypt: Quaranfil, Chenuda and Nyaminini. American Journal of Tropical Medicine and Hygiene 15, 7686.CrossRefGoogle Scholar
TELFORD, S. R., ARMSTRONG, P., KATAVOLOS, P., FOPPA, I., OLMEDA GARCIA, A. S., WILSON, M. L. & SPIELMAN, A. ( 1997). A new tick-borne encephalitis-like virus infecting new England deer ticks, Ixodes dammini. Emerging Infectious Diseases 3, 165170.CrossRefGoogle Scholar
THOMAS, L. A., KENNEDY, R. C. & EKLUND, C. M. ( 1960). Isolation of a virus closely related to Powassan virus from Dermacentor andersoni collected along north Cache la Poudre River, Colo. Proceedings of the Society of Experimental Biology and Medicine 104, 355359.CrossRefGoogle Scholar
TITUS, R. G. & RIBEIRO, J. M. C. ( 1990). The role of vector saliva in transmission of arthropod-borne diseases. Parasitology Today 6, 157160.CrossRefGoogle Scholar
TRAAVIK, T. ( 1979). Arboviruses in Norway. In Arctic and Tropical Arboviruses (ed. Kurstak, E.), pp. 6781. New York, Academic Press.CrossRef
TURELL, M. J. ( 1988). Horizontal and vertical transmission of viruses by insect and tick vectors. In The Arboviruses: Ecology and Epidemiology, Vol. I ( ed. Monath, T. P.), pp. 127152. Boca Raton, CRC Press.
VAN REGENMORTEL, M. H. V., FAUQUET, C. M., BISHOP, D. H. L., CARSTENS, E. B., ESTES, M. K., LEMON, S. M., MANILOFF, J., MAYO, M. A., McGEOCH, D. J., PRINGLE, C. R. & WICKNER, R. B. ( 2000). Virus Taxonomy, 7th Report of the International Committee on Taxonomy of Viruses, pp. 1162. San Diego, San Francisco, New York, Boston, London, Sydney, Tokyo, Academic Press.
VARMA, M. G. R. & SMITH, C. E. G. ( 1972). Multiplication of Langat virus in the tick Ixodes ricinus. Acta Virologica 16, 159167.Google Scholar
VERMEIL, C., LAVILLAUREIX, J. & REEB, E. ( 1959). Infection et transmission expérimentales du virus West Nile par Ornithodoros coniceps (Canestrini) de souche Tunisienne. Bulletin de Société Pathologie Exotique 53, 489495.Google Scholar
VINUELA, E. ( 1985). African swine fever. Current Topics in Microbiology and Immunology 116, 151170.Google Scholar
WANG, H. & NUTTALL, P. A. ( 2001). Intra-stadial tick-borne Thogoto virus (Orthomyxoviridae) transmission: accelerated arbovirus transmission triggered by host death. Parasitology 122, 439446.CrossRefGoogle Scholar
WATTS, D. M., KSIAZEK, T. G., LITHICUM, K. J. & HOOGSTRAAL, H. ( 1989). Crimean-Congo hemorrhagic fever. In The Arboviruses: Epidemiology and Ecology, Vol. II ( ed. Monath, T. P.), pp. 177260. Boca Raton, CRC Press.
WEBER, F., JAMBRINA, E., GONZALEZ, S., DESSENS, J. T., LEAHY, M., KOCHS, G., PORTELA, A., NUTTALL, P. A., HALLER, O., ORTIN, J. & ZURCHER, T. ( 1998). In vivo reconstitution of active Thogoto virus polymerase: assays for the compatibility with other orthomyxovirus core proteins and template RNAs. Virus Research 58, 1320.CrossRefGoogle Scholar
WIKEL, S. K. & BERGMAN, D. ( 1997). Tick–host immunology: significant advances and challenging opportunities. Parasitology Today 13, 383389.CrossRefGoogle Scholar
WOODALL, J. ( 2001). Thogoto virus. In The Encyclopedia of Arthropod-transmitted Infections (ed. Service, M. W.), pp. 504506. Wallingford, CABI Publishing.
YANEZ, R. J., RODRIGUEZ, J. M., NOGAL, M. L., YUSTE, L., ENRIQUEZ, C., RODRIGUEZ, J. F. & VINUELA, E. ( 1995). Analysis of the complete nucleotide sequence of African swine fever virus. Virology 208, 249278.CrossRefGoogle Scholar
YOZAWA, T., KUTISH, G. F., AFONSO, C. L., LU, Z. & ROCK, D. L. ( 1994). Two novel multigene families, 530 and 300, in the terminal variable regions of African swine fever virus genome. Virology 202, 9971002.CrossRefGoogle Scholar
YUNKER, C. E. ( 1975). Tick-borne viruses associated with seabirds in North America and related islands. Medical Biology 53, 302311.Google Scholar
ZAKI, A. M. ( 1997). Isolation of a flavivirus related to the tick-borne encephalitis complex from human cases in Saudi Arabia. Transactions of the Royal Society of Tropical Medicine and Hygiene 91, 179181.CrossRefGoogle Scholar
ZANOTTO, P. M. DE A., GAO, G. F., GRITSUN, T., MARIN, M. S., JIANG, W. R., VENUGOPAL, K., REID, H. W. & GOULD, E. A. ( 1995). An arbovirus cline across the northern hemisphere. Virology 210, 152159.CrossRefGoogle Scholar
ZELLER, H. G., KARABATSOS, N., CALISHER, C. H., DIGOUTTE, J.-P., MURPHY, F. A. & SHOPE, R. E. ( 1989 a). Electron microscopic and antigenic studies of uncharacterized viruses. I. Evidence suggesting placement of viruses in the families Arenaviridae, Paramyxoviridae, or Poxviridae. Archives of Virology 108, 191209.Google Scholar
ZELLER, H. G., KARABATSOS, N., CALISHER, C. H., DIGOUTTE, J.-P., CROPP, C. B., MURPHY, F. A. & SHOPE, R. E. ( 1989 b). Electron microscopic and antigenic studies of uncharacterized viruses. II. Evidence suggesting placement of viruses in the family Bunyaviridae. Archives of Virology 108, 211227.Google Scholar
ZILBER, L. A. & SOLOVIEV, V. D. ( 1946). Far Eastern tick-borne spring-summer (spring) encephalitis, pp. 180. American Review of Soviet Medicine (Special Suppl.).