Evaluation of the Presence of ASFV in Wolf Feces Collected from Areas in Poland with ASFV Persistence.

Maciej Szewczyk,Sabina Nowak,Bogusław Szewczyk,Korneliusz Kurek,Małgorzata Witek,Robert W Mysłajek,Przemysław Stachyra,Anna Bajcarczyk,Krzysztof Łepek

doi:10.3390/v13102062

Maciej Szewczyk, Sabina Nowak + Show 7 more

Open Access

https://doi.org/10.3390/v13102062

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Abstract

African swine fever (ASF), caused by a DNA virus (ASFV) belonging to genus Asfivirus of the Asfarviridae family, is one of the most threatening diseases of suids. During last few years, it has spread among populations of wild boars and pigs in countries of Eastern and Central Europe, causing huge economical losses. While local ASF occurrence is positively correlated with wild boar density, ecology of this species (social structure, movement behavior) constrains long-range disease transmission. Thus, it has been speculated that carnivores known for high daily movement and long-range dispersal ability, such as the wolf (Canis lupus), may be indirect ASFV vectors. To test this, we analyzed 62 wolf fecal samples for the presence of ASFV DNA, collected mostly in parts of Poland declared as ASF zones. This dataset included 20 samples confirmed to contain wild boar remains, 13 of which were collected near places where GPS-collared wolves fed on dead wild boars. All analyzed fecal samples were ASFV-negative. On the other hand, eight out of nine wild boar carcasses that were fed on by telemetrically studied wolves were positive. Thus, our results suggest that when wolves consume meat of ASFV-positive wild boars, the virus does not survive the passage through intestinal tract. Additionally, wolves may limit ASFV transmission by removing infectious carrion. We speculate that in areas where telemetric studies on large carnivores are performed, data from GPS collars could be used to enhance efficiency of carcass search, which is one of the main preventive measures to constrain ASF spread.

Highlights

African swine fever (ASF) is a viral disease of suids that causes high mortality [1]
Taking an advantage of GPS-GSM telemetry, we localized carcasses of wild boars that likely died of ASF and were subsequently consumed by wolves, and we analyzed wolf fecal samples collected in the vicinity of the carcasses
Our field study mimics such an experiment, as telemetric data and snow tracking clearly indicated that both monitored wolves consumed wild boar carcasses that were confirmed as African swine fever virus (ASFV)-positive

Summary

Introduction

African swine fever (ASF) is a viral disease of suids that causes high mortality In 2007, it was introduced to the Caucasus and subsequently expanded through the Russian Federation, Ukraine, and Belarus until it eventually entered the European Union in 2014, where it has been spreading throughout Poland and the Baltic countries [4] It was detected west of the Polish border, e.g., in eastern Germany [5]. While a recent study indicated that scavengers represent a minor risk factor for spreading ASF [18], numerous articles in Polish popular and agricultural press suggest a role of wolves in the long-range disease spread (e.g., [19]) Such undocumented speculations could affect public attitude towards wolves and have negative effect on wolf conservation in Poland. Taking an advantage of GPS-GSM telemetry, we localized carcasses of wild boars that likely died of ASF and were subsequently consumed by wolves, and we analyzed wolf fecal samples collected in the vicinity of the carcasses

Wolf Telemetry and Sample Collection

Laboratory Analyses

Findings

Discussion