| Periodically the African horse sickness virus
spreads out of its endemic zone and infects Culicoides vectors in other parts of
the world. A painful example is what happened in Spain in 1987-1990, when African
horse sickness was imported into Spain in a subclinically infected zebra (zebras do not
become ill when infected with the virus but can be viremic and infectious for the vector
for as long as 6 weeks!), and the Culicoides there became infected, and
effectively spread the disease. Here is a photo of the Culicoides insect -
feeding on the arm of a very dedicated entomologist. These insects have a variety of
other names - midges, no-see-ums, and gnats, among others. |
