Molecular Characterization Of African Swine Fever Virus In Selected Areas Of Northern And Southern Tanzania During 2014 Outbreaks

ABSTRACT

African swine fever virus (ASFV) is a large double-stranded DNA virus of the Asfarviridae family that causes African swine fever (ASF), a highly contagious and fatal hemorrhagic disease of domestic pigs. African swine fever presents a serious threat to the food security and livelihoods of pig-keeping farmers. The aim of this study was to diagnose and genotype ASFV in domestic pigs following reports of ASF outbreaks in northern and southern Tanzania during 2014. Fifteen tissue samples were collected from domestic pigs that died of hemorrhagic disease in Arusha, Makambako, Sumbawanga and Nkasi. Diagnosis of ASF was done by polymerase chain reaction (PCR) using PPA1/PPA2 primers while genotyping was done by amplification, nucleotide sequencing and phylogenetic analysis of the variable part of B646L gene and complete E183L gene using primers p72U/p72D and PPA89/PPA889, respectively. African swine fever virus was confirmed in domestic pigs that died of hemorrhagic disease in study areas. Phylogenetic analysis clustered ASFV from northern and southern Tanzania into genotypes X and II, respectively. Genotype X ASFV identified in present study in northern Tanzania was similar to previously reported ASFV in Moshi and Arusha during 2009 and 2013 outbreaks. Genotype II ASFV identified in southern Tanzania was 100% similar to other ASFV previously reported in southern Tanzania between 2010 and 2013, and to ASFV reported in Madagascar, Russia and other European countries. The present study shows persistence and geographical restriction of ASFV within Tanzania. It is recommended that quarantine and restriction of pig movement be strictly imposed, to prevent further spread of ASF within Tanzania.