Culicoides sonorensis

[farmers_son]

Biting midge harbors livestock disease virus
April 19, 2005
ARS News Service
A small, hardy fly called a biting midge may play an important role in spreading vesicular stomatitis virus (VSV), which infects cattle, horses and swine, according to Agricultural Research Service (ARS) microbiologist Barbara Drolet.
VSV causes significant economic losses to the livestock industry from sickened animals, quarantines and subsequent export/import restrictions. Drolet, at the ARS Arthropod-Borne Animal Diseases Research Laboratory in Laramie, Wyo., and colleagues now have proof that VSV is capable of surviving and spreading throughout the blood-sucking midge, Culicoides sonorensis. To verify that Culicoides propagated VSV, the scientists had to find a way to show, without killing the midge, that virus ingested in a blood meal could survive the insect's midgut, then replicate and escape from the midgut to infect other organs.
Using an artificial feeding system, Drolet fed midges a viral meal and tracked the ensuing infections over time to show that VSV infects the midge's salivary glands and eggs and is shed in the midge's droppings. Drolet used a genetic technique to verify that the virus is able to replicate within the insect. Read more about the research in the April 2005 issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/apr05/midge0405.htm ARS is the U.S. Department of Agriculture's chief scientific research agency.

[farmers_son]

A better title for this thread might have been Vesicular stomatitis. I just wanted to point out that this biting midge Culicoides sonorensis is the same critter that spreads bluetongue and that the midge is known to be in Alberta.

Vesicular stomatitis (VS) is a vesicular disease of horses, cattle and pigs that is indistinguishable from Foot and Mouth Disease. Unlike FMD, humans are also susceptible. Although the infection is transmitted directly by the transcutaneous or transmucosal route, VSV has been isolated from sandflies and mosquitoes, suggesting that it could be insect-borne.

[pandiana]

Interesting paper, but if Culicoides sonorensis is not a competent vector in most parts of Canada for bluetongue, it would seem the vesicular stomatitis via this vector would also not be a problem.

[farmers_son]

I do not think we can make that assumption. The science is still out on whether the biting midge is a competent vector for bluetongue in Alberta and Canada as the survey will be complete in September 2005. I would imagine that the environmental requirements for the culicoides midge to spread VSV could well be different. Again no science. Since the insect is present in this province and if live cattle are or will be imported from infected areas of the U.S. during the vector season, the probability is there that the disease will spread.

Bottom line, herd health is priority one or should be if a country needs to export either live cattle or beef. Any disease that mimics Foot and Mouth Disease gets my attention real fast. Both Bluetongue and VSV mimic the symptoms of FMD.

In case anyone forgets, Canada had an outbreak of FMD in the 1950s. In my opinion FMD is far, far worse than BSE. Certainly would take care of our over population of cows. Forget about live cattle or beef exports for a while though.

We just do not need these kinds of problems.