Detection of African swine fever virus in free‐ranging wild boar in Southeast Asia

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission  such as free-ranging management systems and wild boar access  in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, correct waste disposal and swill feeding.

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The impact of African Swine Fever Virus on smallholder village pig production: an outbreak investigation in Lao PDR

10.22541/au.162105009.94756785/v1 ◽

2021 ◽

Author(s):

Nina Matsumoto ◽

J Siengsanan-Lamont ◽

Tariq Halasa ◽

James Young ◽

Michael Ward ◽

...

Keyword(s):

Risk Factors ◽

Wild Boar ◽

Spatial Clustering ◽

African Swine Fever Virus ◽

Lao Pdr ◽

Clinical Signs ◽

African Swine Fever ◽

Fever Virus ◽

Free Ranging ◽

The Impact

African Swine Fever Virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao Peoples Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (P < 0.001). Villagers reported known risk factors for ASFV transmission − such as free-ranging management systems and wild boar access − in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of 9 pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district’s population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, incorrect waste disposal and swill feeding.

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No evidence for African swine fever virus DNA in haematophagous arthropods collected at wild boar baiting sites in Estonia

Transboundary and Emerging Diseases ◽

10.1111/tbed.14013 ◽

2021 ◽

Author(s):

Reet Herm ◽

Heli Kirik ◽

Annika Vilem ◽

Laura Zani ◽

Jan Hendrik Forth ◽

...

Keyword(s):

Wild Boar ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Fever Virus

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The Role of Interleukine-10 and Interferon-γ as Potential Markers of the Evolution of African Swine Fever Virus Infection in Wild Boar

Pathogens ◽

10.3390/pathogens10060757 ◽

2021 ◽

Vol 10 (6) ◽

pp. 757

Author(s):

Sandra Barroso-Arévalo ◽

Jose A. Barasona ◽

Estefanía Cadenas-Fernández ◽

José M. Sánchez-Vizcaíno

Keyword(s):

Wild Boar ◽

Vaccine Candidate ◽

African Swine Fever Virus ◽

African Swine Fever ◽

Interferon Γ ◽

Fever Virus ◽

Control Group ◽

Challenge Virus ◽

Ifn Γ

African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.

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