Featured Research

from universities, journals, and other organizations

How Does Bluetongue Virus Survive Through The Winter?

Date:
August 27, 2008
Source:
Public Library of Science
Summary:
In 2006, Bluetongue virus -- which infects livestock -- reached Northern Europe for the first time. Some people thought that the outbreak would be limited to that particular year, as winter was expected to kill off the midges that host and spread the disease, bringing the threat of infection to an end. In actuality, the disease escalated in the following year, spreading to the UK. So, how did the virus survive the winter?

In 2006, Bluetongue virus – which infects livestock – reached Northern Europe for the first time. Some people thought that the outbreak would be limited to that particular year, as winter was expected to kill off the midges that host and spread the disease, bringing the threat of infection to an end. In actuality, the disease escalated in the following year, spreading to the UK. So, how did the virus survive the winter?

Drs Anthony Wilson, Karin Darpel and Philip Mellor of the Institute for Animal Health have discussed this puzzling question in an Unsolved Mystery article, published in the open access journal PLoS Biology, freely available to read from publication on the 26th of August.

The answer to this question is of great practical importance, as it will affect both national and international trade of Ruminants, the livestock susceptible to infection, and will dictate trade rules for a long time even after the infection has passed. The answer is also relevant to how we can deal with bluetongue and other unpleasant midge-transmitted diseases in the future.

Dr Mellor said: "Although the major mechanism of bluetongue virus spread is undoubtedly that of Culicoides midges feeding on infected ruminants, growing the virus and then transmitting it to further susceptible animals, other mechanisms may also be at work. These may assume greater importance during the midge-free season (winter), such as we in northern latitudes experience."

Wilson and colleagues point out that evidence to date does not support the winter survival of bluetongue virus in the eggs of Culicoides midges. An alternative hypothesis is that, in mild winters such as that of 2006-07 in northern Europe, sufficient infected midges might survive until they become active again in spring. The midges may enter livestock barns to overwinter. Two other possibilities for disease endurance during winter are that bluetongue is spread by some susceptible species of long-lived ticks and/or by simple mechanical transmission by Melophagus ovinus, a wingless parasite that lives in the fleece of sheep.

Additionally, there is evidence from Australia that bluetongue virus can survive in midges and in a small proportion of infected cattle for three to four months, which would be long enough for winter to come and go without killing the virus.

Closer to home, the recent outbreaks of bluetongue in northern Europe have provided evidence for a different overwinter route—transplacental infections; the virus spreading from an infected pregnant animal to its fetus, a phenomenon also demonstrated by experiment. This phenomenon might be particularly important in cattle, where the long gestation period of nine months (four for sheep) means that the virus can grow and survive within a fetus, at just the right temperature, throughout the coldest of winters. There is also circumstantial evidence that cattle could become infected orally if they eat the afterbirth of an infected offspring from another cow.

As Dr. Mellor summarizes, "Experiments have revealed a toolbox of possible mechanisms, with the potential to interact with and complement one another."


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Anthony Wilson, Karin Darpel, Philip Scott Mellor. Where Does Bluetongue Virus Sleep in the Winter? PLoS Biology, 2008; 6 (8): e210 DOI: 10.1371/journal.pbio.0060210

Cite This Page:

Public Library of Science. "How Does Bluetongue Virus Survive Through The Winter?." ScienceDaily. ScienceDaily, 27 August 2008. <www.sciencedaily.com/releases/2008/08/080825203916.htm>.
Public Library of Science. (2008, August 27). How Does Bluetongue Virus Survive Through The Winter?. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2008/08/080825203916.htm
Public Library of Science. "How Does Bluetongue Virus Survive Through The Winter?." ScienceDaily. www.sciencedaily.com/releases/2008/08/080825203916.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins