Featured Research

from universities, journals, and other organizations

Predicting Outbreaks Of Plague With The Help Of Satellite Images

Date:
August 4, 2008
Source:
Utrecht University
Summary:
Normally percolation theory is used to describe the movement of liquid through porous material. A good example of percolation is when hot water is forced through ground coffee in an espresso machine. By moving through the coffee via the empty spaces between the ground coffee particles, the water picks up the flavor of the coffee. Scientists now report in Nature that the spread of the bubonic plague bacteria in Central Asia by gerbils, works much the same way.

Normally percolation theory is used to describe the movement of liquid through porous material. A good example of percolation is when hot water is forced through ground coffee in an espresso or Senseo machine.

By moving through the coffee via the empty spaces between the ground coffee particles, the water picks up the flavour of the coffee. Stephen Davis and colleagues at the Faculty of Veterinary Medicine, Utrecht University, report in Nature their discovery that the spread of the bubonic plague bacteria in Central Asia by gerbils, works much the same way.

Plague bacteria percolate through the landscape transmitted by fleas from one great gerbil family to the next, from burrow system to burrow system. It’s the first time percolation theory is used to accurately describe the natural dynamics of an infectious disease. The discovery might be helpful to understand how outbreaks of disease occur in other populations. It may, for example, shed new light on spread of bovine tuberculosis in badgers, and spread of viral diseases in populations of African lions.

Spread of infection predictable

Like making a good cup of coffee, there are conditions for successful percolation of the plague through gerbils. In the case of coffee, if you pack it too tightly the water will not move through and the coffee just burns.

In the case of plague, if there are too few gerbils, the fleas won’t be able to move from one burrow to another, and the spread halts. The use of percolation theory by Davis can predict the final size of an outbreak of plague, starting with one infected family group. It has also determined the so called ‘abundance threshold’ necessary to be exceeded before percolation occurs, in this case the percentage of available burrows populated by gerbils.

Russian ‘Plague Archives’ show plague dynamics

In Kazakhstan and elsewhere in central Asia, the plague bacterium Yersinia pestis, source of human cases of bubonic plague, still circulates in wild populations of gerbils and other small mammals. Intensive surveillance systems established by Soviet scientists in Kazakhstan at the end of World War II appear to have successfully reduced human cases. These programs also resulted in vast amounts of data, referred to as ‘The Plague Archives’, recording the dynamics of plague in wild animals.

The data for the research done by Davis comes from one of the desert plague foci in Kazakhstan where great gerbils play a central role as a plague host. A remarkable feature of these gerbils is their complex burrow systems that create discs of bare earth, typically 30 metres in diameter and visible from space on satellite images like the ones from Google Earth. The vast tracts of land inhabited by connecting burrows of great gerbils contrast starkly with the relatively short distances of about 200 metres travelled by fleas responsible for transmission of plague. This difference in scales means that connectivity of the population is key.


Story Source:

The above story is based on materials provided by Utrecht University. Note: Materials may be edited for content and length.


Cite This Page:

Utrecht University. "Predicting Outbreaks Of Plague With The Help Of Satellite Images." ScienceDaily. ScienceDaily, 4 August 2008. <www.sciencedaily.com/releases/2008/08/080801074728.htm>.
Utrecht University. (2008, August 4). Predicting Outbreaks Of Plague With The Help Of Satellite Images. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2008/08/080801074728.htm
Utrecht University. "Predicting Outbreaks Of Plague With The Help Of Satellite Images." ScienceDaily. www.sciencedaily.com/releases/2008/08/080801074728.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 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