Published Date: 2017-07-24 12:24:49
Subject: PRO/AH/EDR> Bluetongue - USA: (MO) cervid, susp
Archive Number: 20170724.5200294
BLUETONGUE - USA: (MISSOURI) CERVID, SUSPECTED
A ProMED-mail post http://www.promedmail.org
ProMED-mail is a program of the International Society for Infectious Diseases http://www.isid.org
Date: Sat 22 Jul 2017 6:24 pm EDT
Source: KFVS 12 [edited]
A buck was pulled from a pond in Sainte Genevieve County and it died from bluetongue disease. According to the Missouri Department of Conservation, it has not been confirmed that the deer had, in fact, the disease, although it displayed signs of the illness.
"We're getting reports of some deer getting hemorrhagic disease because of the time of year is when we usually see disease show up," said Matt Bowyer with the Missouri Department of Conservation. "We have not taken the sample from a deer to confirm it yet."
According to Bowyer, it is common to see deer contract bluetongue. He said the disease is spread by a small type of fly [actually gnats, not flies. - Mod.MHJ] that is found around small bodies of water. Bowyer said the disease poses no threat to humans or their pets, and will not affect the deer population or the upcoming deer season.
[Byline: Marc Thomas]
[The state of Missouri can be located on the HealthMap/ProMED-mail interactive map at http://healthmap.org/promed/p/32397. St Genevieve County in southeast Missouri can be seen on the map at http://geology.com/county-map/missouri-county-map.gif.
This report is not as yet backed up by a news release on the Missouri Department of Conservation website (https://mdc.mo.gov/).
While epizootic hemorrhagic disease virus (EHD or EHDV) is closely related to bluetongue virus, the viruses are antigenically very different. EHD more often affects cervids. Bluetongue virus more often affects cattle. While either virus can and occasionally does cross into the other species, it is much more likely that EHD is the cause of these animals dying. We would appreciate receiving some testing information. Dr William Wilson has developed a PCR test that clearly demonstrates the differences between these 2 viruses.
Hemorrhagic disease (HD), caused by viruses in either the EHDV or bluetongue virus (BTV) groups (Reoviridae: Orbivirus), is the most important viral disease affecting white-tailed deer (Odocoileus virginianus) in the United States. In North America there are 3 subtypes of EHD virus (EHDV 1, 2, and 6), and 5 subtypes of BT virus (BTV 2, 10, 11, 13, and 17). Isolated cases of BT viruses from infected deer were first reported in 1968, although white-tailed deer mortalities consistent with EHD/BT disease were noted as early as 1886.
Bluetongue is an insect-transmitted, viral disease of sheep, cattle, goats, and other ruminants, such as white-tailed deer and pronghorn. It is particularly damaging in sheep; half the sheep in an infected flock may die. In cattle and goats, however, bluetongue viruses cause very mild, self-limiting infections with only minor clinical consequences. A bluetongue virus infection causes inflammation, swelling, and hemorrhage of the mucous membranes of the mouth, nose, and tongue. Inflammation and soreness of the feet also are associated with bluetongue. In sheep, the tongue and mucous membranes of the mouth become swollen, hemorrhagic, and may look red or dirty blue in color, thus giving the disease its name: bluetongue.
Bluetongue is a seasonal disease generally observed in the late summer and early fall in the United States. Virus transmission begins in the early spring with the onset of insect flight activity and continues until the 1st hard frosts.
Bluetongue viruses are spread from animal to animal by biting gnats. In the United States, the disease is most prevalent in the southern and south western states. It is almost non-existent in the upper north-central and north eastern states, where biting flies do not appear able to transmit the viruses.
Animals cannot directly contract the disease from other animals. For more information go to https://www.aphis.usda.gov/import_export/animals/oie/downloads/tahc_feb11/tahc_bluetongue_79_feb11_cmt.pdf.
This suspect report has been posted more because it provides a warning to other states to expect to see such cases in deer from now on. Usually EHD precedes BT outbreaks which are delayed by a measure of cross immunity from EHDv infections. Bluetongue may appear mild in livestock but it regularly results in pregnant cattle losing their embryos/foetuses and returning to service. In Louisiana we find teratogenic BTV infections related to 'dummy calves' which are unable to suckle. So be alert. - Mod.MHJ]