The Infection Chain™ Concept

Piglet Approach System Approach

Looking for the root of a problem

Chain of the infection in Epidemiology field: Individual (host)approach

13 April 2023

4Image courtesy of: http://www.cetl.org.uk/learning/img1/chain-infection.jpg

The pig production cycle or “chain”

13 April 20235

Production Chain / Infection Chain

13 April 20236

Sow Herd

Nursery

Finishing

GDU

Multiplier

Production Chain "Infection Chain"

Sow Herd

Nursery

Finishing

GDU

Multiplier

Production Chain "Infection Chain"

“Infection Chain” of swine pathogens

13 April 2023

7

SOW TO PIGLET

TRANSMISSION

PIGLET TO PIGLET

TRANSMISSION

EARLY OR LATE COLONIZATION

AGENT’S SPREAD

NURSERY OR FINISHING

GILT DEVELOPMENT

PROCESS

GILT TO SOW OR SOW TO SOW

TRANSMISSION (SOW HERD INFECTION

DYNAMICS)

Production flow / infection / prevention“Chain”

13 April 20238

Sow Herd

Nursery

Finishing

GDU

Multiplier

Production Chain "Infection Chain" "Prevention Chain"

PRRS…the example

13 April 20239

Role of Vaccine – Immunity for Control PRRSv in Growing Pigs

• Vaccine provides protective immunity that can mitigate the consequences of PRRSv infection

• The common benefit of vaccines is to improve herd health, which in turn improves economic return

• Meta-Analysis of 16 Modified Live PRRS Vaccination Challenge Studies; M.Roof et. al., Emerg Swine Dis Symp, 2007

• Growth Performance Improvement and Mortality Reductions Derived from a PRRS Large-Scale Control Project in the U.S.; J. Angulo, et.al., IPVS, 2012

Statement of the Problem:

•PRRS instability in the breeding herd

• Defined as evidence of PRRSv circulation and transmission vertically and/or horizontally

• Can cause reproductive problems w/ biologic & economic impact

• Can lead to weaning of PRRSv positive piglets w/ biologic & economic impact

• PRRSv Control or Elimination; D.Holtkamp, George Young Conf., 2012

• Assessment of economic impact of PRRSv on U.S. pork producers; D. Holtkamp et.al., JSHAP, 2013

Production flow / infection / prevention“Chain”

13 April 202312

Sow Herd

Nursery

Finishing

GDU

Multiplier

Production Chain "Infection Chain" "Prevention Chain"

Chain Thinking

Production Chain

Infection Chain™

Prevention Chain™

13 April 202313

Chain Thinking