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Foot and Mouth Disease
Newsgroup uk.business.agriculture Reference Notes

Reference Note: Analysis of part data from "Science" Magazine.

Published 15th April 2001 Chart of Circles.
Revised 20th April 2001 Additional material faxed from author including author profile.
Revised 28th April 2001 Additional material faxed from author.
Revised 6th May 2001 Additional material faxed from author.

Chart of Circles.

Author: Peter N Allen, Cowcash-UK.

Date: 15th April 2001.

Purpose: Publish chart of circles of zones referred to in uk.business.agriculture article.

Text:

Extract from Message-ID: <tdhqm224032vdf@corp.supernews.co.uk> posted in uk.business.agriculture by "Peter N Allen" <petertdm@lineone.net> on Sun, 15 Apr 2001 01:26:23 +0100.

Re the paper[1] in "Science", kindly explained to me by Neil Ferguson via email. The most relevant part for me is the chart marked A. It has a Y axis marked "Probability" which for us ordinary mortals is percentages expressed as 0 to 1 instead of 0 to 100. The x axis indicates distance of new outbreaks from source confirmed FMD case. So this data and its interpretation is crucial to the validity and potential effectiveness of "contiguous" culling. That of course depends on the definition of "contiguous" as used by MAFF - rather than Oxford dictionary "adjoining to" or "adjacent".

I have converted Neil Ferguson's data into circles of zones, so that it becomes easier to see direct relevance to farm distances.

In brief:-

29% new cases are within a circle 2km diameter arround infection source; 48% new cases are within a zone from 1km to 3km away from infection source; that means within a band of inner diameter 2km, out to diameter 6km.

27% new cases are within the band outside this; that is they are within band of inner diameter 6km, out to 18km external diameter.

In livestock country, where farms are mostly smaller, most "contiguous" farms are within the inner most 2km diameter circle - the area where only 29% of new cases have arisen.

Chart:

Circles of Zones (thumbnail) Download 751 x 845 pixels jpeg image 72.24 KB (73976 Bytes)

References:

  1. The Foot-and-Mouth Epidemic in Great Britain: Pattern of Spread and Impact of Interventions. Neil Ferguson, Christl Donnelly, Roy Anderson. Department of Infectious Disease Epidemiology, Imperial College School of Medicine, St Mary's Campus, Norfolk Place, London W2 1PG, UK. Sciencexpress. www.sciencexpress.org 12 April 2001.

Further Analysis - 20th April 2001.

Q. What are the causes and mechanisms of virus transfer - apart from physical contact, which is now unlikely to be risked by any normal farmer?
A.
  • Aerosol plumes on moisture - from sheep flock breath;
  • gaseous outbursts from bursting carcasses, - vermin attacks;
  • rough handling on loading for late incineration or off-farm burial;
  • smoke plumes from uneven and slow burning, with ash & rising fragment;
  • wind-borne transportation on humid, cool air.

Any of these could apply to many of the "pods" of new outbreaks. All are documented in 1967 Report [the Northumberland Report of the 1967 outbreak published in 1969].

Church Stoke Outbreak
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The Church Stoke outbreak is an example of how the Imperial College data translates into the field situation - with neighbouring farm infection occurring as a MINORITY of actual new oubreaks.

Such “pods” or clusters of new infection are characteristic of the continuing spread and leap-frogging of the current outbreak.

Linking the Imperial College data with cases on the ground.

"WHERE the infections arise is likely to be related to or governed by HOW they became infected - the two aspects are inseparable." Linking the Imperial College data with cases on the ground
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Figures from MAFF website:

YOUR FIGURES
Wednesday 19 April.

(1.) 575,000 Animals awaiting slaughter
(2.) 35,000 Daily average of animals slaughtered

OUR SUMS

Divide (1.) by (2.) to give time lag to slaughter

575,000 / 35,000 = 16.5 days delay from decision to action

- this is in agreement with experience reported from the field, particularly for contiguous culls.

from MAFF website, Details of new cases:

average time lag from new focus:
  case 142 Church stoke date 11.03.01
spread to cases 255, 262, 345, 433, 469 dates 15-22.03.01
  time to new infections 5 -10 days
this is typical for most scenarios.

How many "contiguous"? Distance from 142=5 to 9 km.

From Ferguson/Imperial College data, ONLY 29% OF CONTIGUOUS FARMS WILL BE INFECTED - which matches the above scenario figures.

Prof King is HALF RIGHT 24hours INFECTED YES  
  48hours contiguous WRONG  

Peter N Allen, Cowcash-UK, 01939 270 788.

Further Analysis - 28th April 2001.

"Which ever way you look at it, the high risk zone was never in the 2km zone (1km radius." Whichever way you look at it, the high risk zone was never in the 2km zone.
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"Contiguous Killing Has Prolonged FMD" Contiguous Killing has Prolonged FMD
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Further Analysis - 6th May 2001.

FMD Epidemic profiles in relation to number of days from diagnosis to disposal
Per Howard & Donnelly, October 2000 and MAFF data per website.
FMD Epidemic profiles in relation to number of days from diagnosis to disposal
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Author Profile.

Peter N Allen first became known to dairy farmers as Prof John Owen’s associate in developing Complete Diets for Dairy Cows (Tech. Bulletin No.18, 1978) with the SAC at Aberdeen. Later as Head of the Livestock Dept. at Harper Adams College, he continued to write for the farming journals, specialising in Feed Management and the effects of feed combinations on ruminant feed efficiency. After sheep farming in Devon, and a spell in commerce, he returned to Cranfield University, developing interests in Human Resources, and computer applications for Business Management. His personal "vested interest" has been for many years the better use of scientific research to increase efficiency instead of output. To this end, he has committed his resources into the development of software innovation, to combine technical and financial efficiency.

PUBLICATIONS & PRESS COVERAGE.

1999, August "Farming Gazette" - Now dairy farmers can feed for EFFICIENCY
1998, August "Farming News" - Let the chips decide what to feed your cow
1996, November "RABDF News" - Managing for Margins *
1994, June "Science & Technology Now" - Nutrition or Feed Management? *
1993, August "Dairy Farmer" - Conference Preview
1992, April, "Farming News" - Feed formula for dairy margins
1992, May, June, July, August, "Dairy Farmer" - D/F lndex & the High Margin System *
1981, February, "Dairy Farmer" - Feeding for Fat or Yield? *
1981, March, "Dairy Farmer" - Feeding for Fat AND Yield *
1981, May, "Dairy Farmer" - More doubts about MOC’s *
1979, September, "Livestock Farming" - Digestible fibre demands attention *
1978, March, "Farmers Weekly" - Milk & Beef Suppl. Complete Feeding
1978, Winter, "Maize Dev. Assoc." - The Right Diet *
1978, December, "British Farmer & Stockbreeder" - MAFF criticise CDF
1977, Winter, "RASE/ADAS Conference" - CDF - Key Management Points *
1977, September, "SAC Technical No.18" - Complete diets for dairy cows *
1976, November, "Livestock Farming" - Complete Feeding conference report
1976, September, "MMB Conference Paper" - Complete Feeding *
1976, March, "Dairy Farmer" - Complete diets in practice *
* indicates personal authorship, other refererences are third party reporting.

Twenty five year track record of putting Science into Systems.

Do not let history repeat itself. From 1974 to 1978 we urged the adoption of "Complete Diet Feeding" (CDF), frequently against the criticism & opposition of MAFF/ADAS. Four years later, after repeating our Aberdeen trials, the 1982 ADAS Bridgets EHF Annual Report, page 30, endorsed our findings. MAFF/ADAS soon adopted the alternative American term Total Mixed Rations (TMR), and the system is now the system of choice.


© Original Content Copyright Peter N Allen 2001
© Web Presentation Copyright Chris Salter 2001

Document preparation: Chris Salter, Original Think-tank, Cornwall, United Kingdom.
Document Reference: <URL:http://www.originalthinktank.org.uk/fmd/contiguous.html>
Created: 15th April 2001
Last modification: 30th November 2001
Last information content change: 6th May 2001

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