Re-emergence of genotype I of African swine fever virus in Ivory Coast

Abstract

In July 2014, an outbreak of severe haemorrhagic disease in a domestic pig population, was reported in San-Pedro, the second seaport city of Ivory Coast. Animals of all age groups developed clinical signs consistent with African swine fever (ASF). Tissue and serum samples from dead pigs were sent to the laboratory for diagnostic confirmation and molecular characterization based on the partial B646L (p72), the full E183L (p54) gene and the central variable region of the B602L gene. The PCR results confirmed the outbreak of ASF. Phylogenetic analyses based on p72 and p54 sequences showed that the San-Pedro 2014 outbreak virus strain belongs to p72 genotype I. The Analysis of the tetrameric amino acid repeat regions of the B602L gene showed two repeat signatures which differ by an extra A = CAST in the second signature. The ASFV sequence of the San-Pedro 2014 outbreak strain is closely related to historical and recent ASFV strains collected in Angola and Cameroon whose ships have repeatedly visited the seaport of San-Pedro from March to June 2014. The 2014 viruses are distinct from the strains involved in the previous ASF wave in 1996 in Ivory Coast.

Keywords: African swine fever; Ivory Coast; San-Pedro; domestic pigs; genotyping; phylogenetic analysis.