| Autor: |
Kabuuka T; Infectious Animal Diseases Laboratory, National Livestock Resources Research Institute (NaLIRRI), National Agricultural Research Organisation (NARO), Totoro 21403, Uganda.; Department of Production Animal Studies (DPAS), Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa., Mulindwa H; Infectious Animal Diseases Laboratory, National Livestock Resources Research Institute (NaLIRRI), National Agricultural Research Organisation (NARO), Totoro 21403, Uganda., Bastos ADS; Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield 0028, South Africa.; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa., van Heerden J; Transboundary Animal Diseases Programme, Agricultural Research Centre-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa., Heath L; Transboundary Animal Diseases Programme, Agricultural Research Centre-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa., Fasina FO; Department of Production Animal Studies (DPAS), Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.; Food and Agriculture Organization of the United Nations (FAO), I-00100 Rome, Italy. |
| Abstrakt: |
African swine fever (ASF) is a haemorrhagic fever of swine that severely constrains pig production, globally. In Uganda, at least 388 outbreaks of ASF were documented from 2001 to 2012. We undertook a retrospective serological and molecular survey of ASF virus (ASFV) using banked samples collected from seven districts (Pallisa, Lira, Abim, Nebbi, Kabarole, Kibaale, and Mukono) of Uganda. Six assays (ELISA for antibody detection, diagnostic p72 gene PCR and genomic amplification, and sequencing of four gene regions ( p72 [P], p54 [A], CVR of the 9RL -ORF [C], and TK [T]), hereinafter referred to as P-A-C-T (PACT)) were evaluated. Antibodies to ASFV were detected in the Abim district (6/25; 24.0%), and the remainder of the serum samples were negative (187/193; 96.9%). For the tissue samples, ASFV detection by assay was 8.47% for P, 6.78% for A, 8.47% for C, and 16.95% for T. The diagnostic PCR ( p72 gene) detected seven positive animals from four districts, whereas the TK assay detected ten positives from all seven districts. In addition to the superior detection capability of TK, two virus variants were discernible, whereas CVR recovered three variants, and p72 and p54 sequencing each identified a single variant belonging to genotype IX. Our results indicate that dependence on serology alone underestimates ASF positivity in any infected region, that multi-locus sequence analysis provides better estimates of outbreak strain diversity, and that the TK assay is superior to the WOAH-prescribed conventional p72 diagnostic PCR, and warrants further investigation. |
