Molecular characterisation and assessment of epidemiological risk factors of African swine fever virus in Iringa Region, Tanzania
Sokoine University of Agriculture
A cross sectional study was carried out in Iringa Region involving two Districts of Kilolo and Iringa Municipal to determine the epidemiological risk factors of the African swine fever (ASF) outbreak and genotyping the circulating African swine fever virus (ASFV) during a hemorrhagic disease outbreak in 2012 in Iringa. A structured questionnaire was used to collect epidemiological risk factors from pig keepers. Eighty households that kept pigs and that experienced the disease in 2012 were involved. The epidemiological risk factors found were introduction of pigs into the herd before disease outbreak (OR=12.2578, CI95%=108.6596, P=0.0244), feeding of kitchen leftovers and consumption of pig meat (OR=35.6117, CI95% =300.2233, P=0.001), duration of disease outbreak CI95%=14 -19 days, failure of the pig keepers and other stakeholders to adhere to quarantine condition and treatment of sick pigs during outbreak. Tissue samples were obtained from a total of 20 pigs. DNA extraction was done before performing polymerase chain reaction (PCR). Three sets of primers were used in this study to diagnose and genotype the ASFV. PCR of ASFV using diagnostic primers PPA1/PPA2 confirmed the disease outbreak to be ASF. Characterization of the virus was done by amplifying the variable part of B646L gene using primers p72U/p72D which showed that the circulating ASFV belonged to genotype II and 100% identical to the Georgia 2007/1 isolate and other Tanzanian ASFV that circulated in 2010 and 2011. Similarly, complete amplification of E183L gene using primers PPA89 and PPA722 showed that ASFV circulating in Iringa in 2012 belonged to group II of p54 genotypes clustering together with Georgia 2007/1 isolate. The results from the present study indicate that the ASFV isolate that was introduced into Tanzania in 2010 is still circulating in Iringa. Deliberate efforts have to be taken in order to save the pig industry from ASF devastation.
Epidemiological risks, Molecular characterisation, Iringa Region, Tanzania, African swine fever virus (ASFV), African swine fever (ASF), Pig industry