Risk of introducing African horse sickness virus into the Netherlands by international equine movements

C.J. de Vos, C.A. Hoek, G. Nodelijk

Research output: Contribution to journalArticleAcademicpeer-review

18 Citations (Scopus)

Abstract

African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1 × 10-4/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31% and 53%, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46% if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input parameters. Sensitivity analysis indicated that uncertainty about the probability of non-notified presence of AHS in low and very low risk regions, the protective effect of quarantine and the vector–host ratio had most impact on the estimated risk. Furthermore, temperature values at the time of release of AHSV largely influenced the probability of onward spread of the virus by local vectors to local hosts.
LanguageEnglish
Pages108-122
JournalPreventive Veterinary Medicine
Volume106
Issue number2
DOIs
Publication statusPublished - 2012

Fingerprint

African Horse Sickness Virus
African horse sickness virus
Netherlands
Horses
African Horse Sickness
African horse sickness
horses
Virus Release
viruses
Ceratopogonidae
Viruses
Quarantine
Equidae
quarantine
Uncertainty

Keywords

  • zebra equus-burchelli
  • bluetongue virus
  • culicoides-sonorensis
  • oral-susceptibility
  • vaccine strains
  • europe
  • ceratopogonidae
  • horsesickness
  • transmission
  • diptera

Cite this

@article{36a99859e61e41129338208ae6335844,
title = "Risk of introducing African horse sickness virus into the Netherlands by international equine movements",
abstract = "African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1 × 10-4/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31{\%} and 53{\%}, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46{\%} if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input parameters. Sensitivity analysis indicated that uncertainty about the probability of non-notified presence of AHS in low and very low risk regions, the protective effect of quarantine and the vector–host ratio had most impact on the estimated risk. Furthermore, temperature values at the time of release of AHSV largely influenced the probability of onward spread of the virus by local vectors to local hosts.",
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author = "{de Vos}, C.J. and C.A. Hoek and G. Nodelijk",
year = "2012",
doi = "10.1016/j.prevetmed.2012.01.019",
language = "English",
volume = "106",
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Risk of introducing African horse sickness virus into the Netherlands by international equine movements. / de Vos, C.J.; Hoek, C.A.; Nodelijk, G.

In: Preventive Veterinary Medicine, Vol. 106, No. 2, 2012, p. 108-122.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Risk of introducing African horse sickness virus into the Netherlands by international equine movements

AU - de Vos, C.J.

AU - Hoek, C.A.

AU - Nodelijk, G.

PY - 2012

Y1 - 2012

N2 - African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1 × 10-4/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31% and 53%, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46% if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input parameters. Sensitivity analysis indicated that uncertainty about the probability of non-notified presence of AHS in low and very low risk regions, the protective effect of quarantine and the vector–host ratio had most impact on the estimated risk. Furthermore, temperature values at the time of release of AHSV largely influenced the probability of onward spread of the virus by local vectors to local hosts.

AB - African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1 × 10-4/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31% and 53%, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46% if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input parameters. Sensitivity analysis indicated that uncertainty about the probability of non-notified presence of AHS in low and very low risk regions, the protective effect of quarantine and the vector–host ratio had most impact on the estimated risk. Furthermore, temperature values at the time of release of AHSV largely influenced the probability of onward spread of the virus by local vectors to local hosts.

KW - zebra equus-burchelli

KW - bluetongue virus

KW - culicoides-sonorensis

KW - oral-susceptibility

KW - vaccine strains

KW - europe

KW - ceratopogonidae

KW - horsesickness

KW - transmission

KW - diptera

U2 - 10.1016/j.prevetmed.2012.01.019

DO - 10.1016/j.prevetmed.2012.01.019

M3 - Article

VL - 106

SP - 108

EP - 122

JO - Preventive Veterinary Medicine

T2 - Preventive Veterinary Medicine

JF - Preventive Veterinary Medicine

SN - 0167-5877

IS - 2

ER -