Classical Swine Fever Antigen Rapid Test Card (Colloidal Gold Method)

Target and Hazard: Classical swine fever (CSF, hog cholera) is caused by classical swine fever virus (CSFV, genus Pestivirus, family Flaviviridae). A highly contagious acute febrile disease listed as a Class II animal disease in China, it presents with persistent high fever, anorexia, conjunctivitis, skin petechiae and gastrointestinal signs, with mortality reaching 80% in acute cases. Infection of pregnant sows causes transplacental transmission, leading to abortion, stillbirth, mummified fetuses and weak piglets, with persistent virus carriage and immunosuppression in the herd. It is one of the most economically devastating diseases of the swine industry.

Significance of Testing: The card detects CSFV antigen directly, enabling rapid identification of virus-carrying pigs during the early viraemic phase and overcoming the limitation of antibody assays in vaccinated herds, where vaccine-induced and field-virus antibodies cannot be distinguished. It is intended for rapid on-site screening of suspected outbreaks, quarantine testing of incoming animals, slaughterhouse inspection and immediate post-mortem diagnosis, providing direct evidence for isolation, culling and vaccination programme decisions.

Principle: Colloidal gold immunochromatographic assay (double-antibody sandwich): antigen in the sample binds to gold-labelled antibody, migrates along the nitrocellulose membrane and is captured by the specific monoclonal antibody coated on the test line (T), producing a visible line; development of the control line (C) confirms test and procedure validity.

Performance and Applications: Simple operation requiring no equipment; visual reading within 10–15 minutes; samples: whole blood, serum, plasma or spleen and tonsil homogenate; storage and shipment at 2–30 °C with an 18-month shelf life — suitable for point-of-care testing on pig farms, at primary veterinary stations, in slaughterhouse inspection and during field necropsy. Method: colloidal gold immunochromatographic assay (double-antibody sandwich) | Samples: whole blood, serum, plasma, spleen/tonsil homogenate | Time to result: 10–15 min | Reading: visual assessment of T/C lines — a coloured T line indicates a positive result, C line is the procedural control | Format: tests/box (as stated on the label) | Storage: 2–30 °C, cool and dry; shelf life 18 months | Note: sensitivity, specificity, limit of detection, intra-/inter-assay CV and agreement with RT-PCR/virus isolation are subject to our internal QC report.