Natural mode of horizontal transmission of bovine leukemia virus (BLV): the potential role of tabanids ( Tabanus spp.)

• Published in: Veterinary immunology and immunopathology Vol. 22; no. 3; pp. 255 - 263
• Main Authors: Manet, G., Guilbert, X., Roux, A., Vuillaume, A., Parodi, A.L.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.1989
• Subjects: Animals; Cattle; Cattle Diseases - epidemiology; Cattle Diseases - transmission; Diptera - microbiology; France - epidemiology; Insect Vectors; Leukemia - epidemiology; Leukemia - veterinary; Leukemia Virus, Bovine; Retroviridae; Seasons; Seroepidemiologic Studies; Tabanus; France
• ISSN: 0165-2427; 1873-2534
• DOI: 10.1016/0165-2427(89)90012-3

In order to evaluate the potential role of hematophagous insects in the natural spreading of bovine leukemia virus (BLV) infection in cattle, a 2-year survey was carried out involving sequential serological tests on 3328 cattle in three different areas. A parallel entomological study was run over the same period, using continuous trapping, in order to determine both the density and variations of horsefly ( Tabanus spp.) populations in the close vicinity of the herds. After statistical analysis, this space-time study showed that: (1) There is a significant positive geographical correlation between the rate of incidence of BLV infection and the density of the horsefly population. (2) Seasonal variations in the incidence rate exist; the highest rates are generally observed during summer (from July of September), and the lowest during winter, spring and early summer (from November to mid-July). (3) There is a time link between the rate of sero-conversion and the variations in activity of the horsefly population. All these data combined would appear to indicate that tabanids play a considerable role in the spread of BLV under natural conditions.