African Swine Fever Virus, Tanzania, 2010–2012

al. Multicentre survey of incidence and public health impact of leptospirosis in the western Pacifi c. comparative accuracy of 8 commercial rapid immunochromatographic assays for the diagnosis of acute dengue virus infection. To the Editor: African swine fever (ASF) is a highly contagious and deadly hemorrhagic disease of domestic pigs caused by African swine fever virus (ASFV), a double-strand DNA virus of the family Asfarviridae and genus Asfi virus (1). Twenty-two ASFV genotypes (I–XXII) have been identifi ed on the basis of nucleotide sequencing of the variable 3′-end of the B646L gene encoding the major capsid protein p72 (2,3). Historically, all ASFV p72 genotypes have been circulating in eastern and southern Africa, and genotype I has been circulating in Europe, South America, the Caribbean, and western Africa (2,3). Spread of ASFV beyond traditional geographic boundaries occurred with incursion of p72 genotype II into the Republic of Georgia and its subsequent spread into Armenia, Azerbaijan, and Russia (4,5) and incursion of genotype IX into western Africa (6). ASFV circulating in Tanzania has p72 genotypes X, XV, and XVI (7–10). We describe incursion and persistent circulation in Tanzania of a highly virulent p72 genotype II ASFV that is identical to the Georgia 2007/1 isolate in the 3′-end of the B646L gene. An outbreak of ASF in domestic pigs occurred in November 2010 in the Kyela District of the Mbeya region in southwestern Tanzania, which coincided with another outbreak in a neighboring district of Karonga in northern Malawi (Figure, panel A). ASF continued to spread from Mbeya and ultimately reached the neighboring region of Iringa (Ludewa District) in February 2011 through feeding of pigs with swill from Mbeya. spread within the region because of the lack of zoosanitary measures and illegal movement of animals despite the quarantine in place. An outbreak on 1 farm in the Temeke District of the Dar es Salaam region in eastern Tanzania occurred in March 2011 after a farmer obtained pig stock from Mbeya. No further spread of the disease in Dar es Salaam was observed after early diagnosis, removal of affected pigs, and zoosanitary measures. In October 2011, the disease spread to the Sumbawanga District of the Rukwa region through feeding of swill and illegal movement of animals. ASF was reported in February 2012 in Ifakara in the Kilombero District in the Morogoro region, and in July 2012 in the Kilosa District within this region. The disease …