Porras González, NéstorSánchez-Vizcaíno Rodríguez, José ManuelBarasona García-Arévalo, José ÁngelGómez Buendía, AlbertoCadenas Fernández, EstefaníaRodríguez Bertos, Antonio Manuel2024-08-072024-08-072024-07-30Sanchez-Vizcaino JM, Barasona JA*, Gómez-Buendía A, Cadenas-Fernández E and Rodriguez-Bertos A. Histopathologic evaluation system of African swine fever in wild boar infected with high (Arm07) and low virulence (Lv17/WB/Riel) isolates. Veterinary Pathology, 3009858241266944. 2024. (A). ISSN: 0300-9858. Impact factor 2022: 0.960. Category: Veterinary Sciences, Quartile: 1, Position: 29 of 144. DOI: 10.1177/030098582412669440300-98581544-221710.1177/03009858241266944https://hdl.handle.net/20.500.14352/107430To understand the clinicopathological forms of African swine fever (ASF) in wild boar, it is crucial to possess a basic knowledge of the biological characteristics of the currently circulating ASF virus isolates. The aim of this work is to establish an accurate and comprehensive histopathologic grading system to standardize the assessment of the ASF lesions in wild boar. The study evaluated the differences between animals infected with a high virulence genotype II isolate (Arm07) (HVI) through intramuscular (IM) (n = 6) and contact-infected (n = 12) routes, alongside those orally infected with a low virulence isolate (Lv17/WB/Riel) (LVI) (n = 6). The assessment included clinical (CS), macroscopic (MS), and histopathologic (HS) scores, as well as viral loads in blood and tissues by real-time quantitative polymerase chain reaction (qPCR). Tissues examined included skin, lymph nodes, bone marrow, palatine tonsil, lungs, spleen, liver, kidneys, thymus, heart, adrenal glands, pancreas, urinary bladder, brain, and gastrointestinal and reproductive tracts. The HVI group exhibited a 100% mortality rate with elevated CS, MS, and HS values. Animals infected by contact (CS = 12; MS = 58.5; HS = 112) and those intramuscularly infected (CS = 14.8; MS = 47; HS = 104) demonstrated similar values, indicating that the route of infection does not decisively influence the severity of clinical and pathological signs. The LVI group showed a 0% mortality rate, an inconspicuous clinical form, minimal lesions (CS = 0; MS = 12; HS = 29), and a lower viral load. Histopathologic evaluation has proven valuable in advancing our comprehension of ASF pathogenesis in wild boar and paves the groundwork for further research investigating protective mechanisms in vaccinated animals.engAttribution 4.0 Internationaljournal articlehttps://doi.org/10.1177/03009858241266944open access636.09African swine fever virushigh virulence isolatehistopathologic evaluationlow virulence isolatescoring systemvaccinewild boarVeterinaria3109 Ciencias Veterinarias