How will public and animal health interventions drive life-history evolution in parasitic nematodes?

Penelope A. Lynch, Uwe Grimm, Andrew Fraser Read

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Infection caused by parasitic nematodes of humans and livestock can have significant health and economic costs. Treatments aimed at alleviating these costs, such as chemotherapy and vaccination, alter parasite survival and reproduction, the main selective pressures shaping life-history traits such as age to maturity, size and fecundity. Most authors have argued that the life-history evolution prompted by animal and public health programmes would be clinically beneficial, generating smaller, less fecund worms, and several mathematical models support this view. However, using mathematical models of long-lasting interventions, such as vaccination, and regularly repeated short interventions, such as drenching, we show here that the expected outcome actually depends on how mortality rates vary as a function of worm size and developmental status. Interventions which change mortality functions can exert selection pressure to either shorten or extend the time to maturity, and thus increase or decrease worm fecundity and size. The evolutionary trajectory depends critically on the details of the mortality functions with and without the intervention. Earlier optimism that health interventions would always prompt the evolution of smaller, less fecund and hence clinically less damaging worms is premature.

Original languageEnglish (US)
Pages (from-to)1599-1611
Number of pages13
JournalParasitology
Volume135
Issue number13
DOIs
StatePublished - Nov 1 2008

Fingerprint

animal parasitic nematodes
animal health
public health
Public Health
life history
Fertility
Mortality
Vaccination
Theoretical Models
fecundity
mathematical models
vaccination
Parasitic Diseases
economic costs
Livestock
Health Care Costs
drug therapy
trajectories
Reproduction
Parasites

All Science Journal Classification (ASJC) codes

  • Parasitology
  • Animal Science and Zoology
  • Infectious Diseases

Cite this

@article{4d2e113dcf0b4f65b27a4b809fb62dbd,
title = "How will public and animal health interventions drive life-history evolution in parasitic nematodes?",
abstract = "Infection caused by parasitic nematodes of humans and livestock can have significant health and economic costs. Treatments aimed at alleviating these costs, such as chemotherapy and vaccination, alter parasite survival and reproduction, the main selective pressures shaping life-history traits such as age to maturity, size and fecundity. Most authors have argued that the life-history evolution prompted by animal and public health programmes would be clinically beneficial, generating smaller, less fecund worms, and several mathematical models support this view. However, using mathematical models of long-lasting interventions, such as vaccination, and regularly repeated short interventions, such as drenching, we show here that the expected outcome actually depends on how mortality rates vary as a function of worm size and developmental status. Interventions which change mortality functions can exert selection pressure to either shorten or extend the time to maturity, and thus increase or decrease worm fecundity and size. The evolutionary trajectory depends critically on the details of the mortality functions with and without the intervention. Earlier optimism that health interventions would always prompt the evolution of smaller, less fecund and hence clinically less damaging worms is premature.",
author = "Lynch, {Penelope A.} and Uwe Grimm and Read, {Andrew Fraser}",
year = "2008",
month = "11",
day = "1",
doi = "10.1017/S0031182008000309",
language = "English (US)",
volume = "135",
pages = "1599--1611",
journal = "Parasitology",
issn = "0031-1820",
publisher = "Cambridge University Press",
number = "13",

}

How will public and animal health interventions drive life-history evolution in parasitic nematodes? / Lynch, Penelope A.; Grimm, Uwe; Read, Andrew Fraser.

In: Parasitology, Vol. 135, No. 13, 01.11.2008, p. 1599-1611.

Research output: Contribution to journalArticle

TY - JOUR

T1 - How will public and animal health interventions drive life-history evolution in parasitic nematodes?

AU - Lynch, Penelope A.

AU - Grimm, Uwe

AU - Read, Andrew Fraser

PY - 2008/11/1

Y1 - 2008/11/1

N2 - Infection caused by parasitic nematodes of humans and livestock can have significant health and economic costs. Treatments aimed at alleviating these costs, such as chemotherapy and vaccination, alter parasite survival and reproduction, the main selective pressures shaping life-history traits such as age to maturity, size and fecundity. Most authors have argued that the life-history evolution prompted by animal and public health programmes would be clinically beneficial, generating smaller, less fecund worms, and several mathematical models support this view. However, using mathematical models of long-lasting interventions, such as vaccination, and regularly repeated short interventions, such as drenching, we show here that the expected outcome actually depends on how mortality rates vary as a function of worm size and developmental status. Interventions which change mortality functions can exert selection pressure to either shorten or extend the time to maturity, and thus increase or decrease worm fecundity and size. The evolutionary trajectory depends critically on the details of the mortality functions with and without the intervention. Earlier optimism that health interventions would always prompt the evolution of smaller, less fecund and hence clinically less damaging worms is premature.

AB - Infection caused by parasitic nematodes of humans and livestock can have significant health and economic costs. Treatments aimed at alleviating these costs, such as chemotherapy and vaccination, alter parasite survival and reproduction, the main selective pressures shaping life-history traits such as age to maturity, size and fecundity. Most authors have argued that the life-history evolution prompted by animal and public health programmes would be clinically beneficial, generating smaller, less fecund worms, and several mathematical models support this view. However, using mathematical models of long-lasting interventions, such as vaccination, and regularly repeated short interventions, such as drenching, we show here that the expected outcome actually depends on how mortality rates vary as a function of worm size and developmental status. Interventions which change mortality functions can exert selection pressure to either shorten or extend the time to maturity, and thus increase or decrease worm fecundity and size. The evolutionary trajectory depends critically on the details of the mortality functions with and without the intervention. Earlier optimism that health interventions would always prompt the evolution of smaller, less fecund and hence clinically less damaging worms is premature.

UR - http://www.scopus.com/inward/record.url?scp=56249095167&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=56249095167&partnerID=8YFLogxK

U2 - 10.1017/S0031182008000309

DO - 10.1017/S0031182008000309

M3 - Article

VL - 135

SP - 1599

EP - 1611

JO - Parasitology

JF - Parasitology

SN - 0031-1820

IS - 13

ER -