Systematic Veterinary Virology

TRANSMISSION

• BTV infection is transmitted in both wild and domestic ruminants/camelids from the bite of the vector midge of the genus Culicoides.  Culicoides act as biological vectors for BTV.
• Experimental studies have also demonstrated that ticks are also capable of mechanically or biologically transmitting BTV. The virus can also be transmitted sexually in infected semen, embryos (in embryo technology) and transplacentally from dam to offspring.
• Mechanical transmission also occurs in BT through use for contaminated needles and equipment contaminated with blood of infected animals. Transmission by Culicodes is the most common method in the spread of BT. The Culicoides vector infects animals mostly during mid-summer and rainy seasons, when it is most active.