Scientific Abstract
African swine fever virus (ASFV) has spread globally at unprecedented rates over the last decade and is the most significant threat to worldwide pork production. High stability of ASFV makes indirect transmission through consumption of contaminated feed or exposure through contaminated fomites a likely route of transoceanic spread. Currently approved antemortem (whole blood) and postmortem (spleen, tonsil, certain lymph nodes) sample types have limitations due to being infrequently collected on commercial swine farms or requiring specialized training in necropsy. The objective of this study was to investigate novel antemortem and postmortem sample types for qPCR detection of ASFV in pigs infected through natural consumption of ASFV-contaminated liquid. Inoculated pigs (n = 10) naturally consumed ASFV-contaminated media while control pigs (n = 2) naturally consumed sterile media through gravity-fed nipple drinkers. Novel antemortem sample types were collected daily and included serum as well as rectal, oral, and nasal swabs. Novel postmortem sample types were collected upon death or euthanasia and included conjunctiva (and swab), aqueous humor, urine, hanging tender (and swab), diaphragm, feces, bone marrow, preputial swab, peritoneal swab, ear notch, tail, and unapproved lymph nodes. ASFV DNA was detected first in oral swabs at 2 days post-inoculation (dpi) and for the longest duration (mean 4 days) of the antemortem sample types. At postmortem between 5 – 7 dpi, submandibular lymph nodes had the same quantity of ASFV DNA detected as spleen (mean 6.9 log10 copies/µL). Overall, this study provides data on novel diagnostic sample types in a unique natural consumption model with potential benefits towards enhanced surveillance and early ASFV detection.
