Diagnostic specificity of the African swine fever virus antibody detection enzyme‐linked immunosorbent assay in feral and domestic pigs in the United States

Abstract

African swine fever (ASF) is a highly contagious haemorrhagic disease of pigs that has the potential to cause mortality nearing 100% in naïve animals. While an outbreak of ASF in the United States' pig population (domestic and feral) has never been reported, an introduction of the disease has the potential to cause devastation to the pork industry and food security. During the recovery phase of an outbreak, an antibody detection diagnostic assay would be required to prove freedom of disease within the previously infected zone and eventually nationwide. Animals surviving an ASF infection would be considered carriers and could be identified through the persistence of ASF viral antibodies. These antibodies would demonstrate exposure to the disease and not vaccination, as there is no ASF vaccine available. A well-established commercial enzyme-linked immunosorbent assay (ELISA) detects antibodies against ASF virus (ASFV), but the diagnostic specificity of the assay had not been determined using serum samples from the pig population of the United States. This study describes an evaluation of the World Organization for Animal Health (OIE)-recommended Ingezim PPA COMPAC ELISA using a comprehensive cohort (n = 1791) of samples collected in the United States. The diagnostic specificity of the assay was determined to be 99.4% (95% confidence interval (CI): [98.9, 99.7]). The result of this study fills a gap in understanding the performance of the Ingezim PPA COMPAC ELISA in the ASF naïve pig population of the United States.

Development of a Potential Penside Colorimetric LAMP Assay Using Neutral Red for Detection of African Swine Fever Virus

“…Therefore, the most effective means to control the disease relies on early and sensitive detection, followed by strict biosafety measures. The main methods for diagnosis of ASF include virus isolation (Gonzague et al, 2001), haemadsorption (Rowlands et al, 2009), antibody-based tests such as enzyme-linked immunosorbent assay (ELISA) (Hutchings and Ferris, 2006;Cubillos et al, 2013;Bergeron et al, 2017), indirect fluorescent antibody assay (IFA), immunochromatography test strip (ICTS) and molecular diagnosis (Notomi, 2000;Agüero et al, 2003;King et al, 2003;Basto et al, 2006;Giammarioli et al, 2008;Haines et al, 2013). Despite its good accuracy, virus isolation assay requires a good laboratory, well-trained personnel and is time consuming.…”

Characterization of Anti-p54 Monoclonal Antibodies and Their Potential Use for African Swine Fever Virus Diagnosis

“…Similarly, a commercially available blocking ELISA kit (Ingezim PPA COMPAC) for ASFV antibody detection were used as a standard evaluating method. The ASFV Ingezim PPA COMPAC is OIE recommended commercially available blocking ELISA [32] and is one of the three commercial ELISA kits in use by the Foreign Animal Disease Diagnostic Laboratory (FADDL) [11]. Initially, serum samples were classified as ASFV-seronegative and ASFV-seropositive based on their origin and their result on Ingezim PPA COMPAC and later all the samples were tested by the newly developed cELISA.…”

Rapid and sensitive RPA-Cas12a-fluorescence assay for point-of-care detection of African swine fever virus

“…Recently, a variety of laboratory tools has emerged to solve the immediate problems for better detection of ASFV, such as serodiagnosis (immunoelectroosmophoresis, IEOP) test [21], antigen ELISA [22], fluorescent antibody test (FAT) [23], immunochromatography test strip (ICTS) [24]) and molecular tools (PCR, RPA [25], multiplex RT-PCR [26] and qPCR [27,28]). The OIE has recommended several ASFV detection methods, including virus isolation, fluorescence antibody test (FAT) and conventional PCR or real-time PCR [29] in 2018.…”