Estimating the impact of low temperature on African swine fever virus transmission through contaminated environments

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Dokumenter

  • Fulltext

    Forlagets udgivne version, 1,29 MB, PDF-dokument

African Swine Fever Virus (ASFV) is the cause of an infectious disease in pigs, which is difficult to control. Long viability of ASFV has been shown for several contaminated materials, especially under low temperature. Therefore, when pigs are exposed to a contaminated environment, new infections could occur without the presence of infectious individuals. For example, a contaminated, poorly washed, empty livestock vehicle poses a risk to the next load of pigs. A quantitative stochastic environmental transmission model was applied to simulate the change in environmental contamination levels over time and calculate the epidemic parameters through exposure-based estimation. Due to the lack of experimental data on environmental transmission at low temperatures, we performed a non-linear fit of the decay rate parameter with temperature based on a literature review. Eventually, 16 scenarios were constructed for different temperature (at 20 °C, 10 °C, 0 °C, or −10 °C) and duration of empty periods (1, 3, 5, or 7 days) after the environment had been contaminated. We quantified the variation in the contamination level of the environment over time and the probability of newly added recipients getting infected when exposed to the environment after the empty period. As a result, the transmission rate parameter for ASFV in pigs was estimated to be 1.53 (0.90, 2.45) day-1, the decay rate parameter to be 1.02 (0.73, 1.47) day-1 (at 21 °C), and the excretion rate parameter to be 2.70 (2.51, 3.02) day-1. Without washing and disinfecting, the environment required 9, 14, 24, 54 days to reach a low probability of causing at least one new case (<0.005) at 20 °C, 10 °C, 0 °C, −10 °C, respectively. In addition, the method proposed in this paper enables assessment of the effect of washing and disinfecting on ASFV environmental transmission. We conducted this study to better understand how the viability of ASFV at different temperatures could affect the infectivity in environmental transmission and to improve risk assessment and disease control strategies

OriginalsprogEngelsk
Artikelnummer105991
TidsskriftPreventive Veterinary Medicine
Vol/bind219
ISSN0167-5877
DOI
StatusUdgivet - 2023

Bibliografisk note

Funding Information:
The authors would like to express their most sincere appreciation to Ann Sofie Olesen and her team for their far-reaching and inspiring experiments. Besides, the authors wish to thank the experts from the Danish Veterinary and Food Administration, Sten Mortensen, Sisse Berg Wulff and Francisco Calvo Artavia, as well as Jan Dahl from the Danish Agriculture & Food Council, for valuable comments and input to this paper. The paper forms part of a thesis submitted by the first author for the requirements of the Quantitative Veterinary Epidemiology specialisation for MSc Animal Sciences at Wageningen University & Research.

Funding Information:
The authors would like to express appreciation for the financial support from the Danish Agriculture & Food Council, for their generous support in accommodation, transportation, participation in a conference, and investigation during the first author's internships in Denmark.

Publisher Copyright:
© 2023 The Authors

ID: 367292256