Molecular epidemiology of African swine fever and peste des petits ruminants

African Swine Fever (ASF) and Peste des Petits Ruminants (PPR) are two highly contagious and fatal diseases of domestic pigs and small ruminants, respectively. For the control and eradication of these diseases, it is helpful to find out their origin and their mode of propagation. One of the options is the molecular tracing of the isolates based on partial genome sequencing and phylogenetic analysis. We thus performed a molecular epidemiology study on ASFV using five different genes. All of them allowed the segregation of the isolates in large regional groups, but none of them were able to discriminate at a local level. Two genes (p. 22 and p. 32) were however found to be the most variable. They were concatenated to increase distinction between local isolates. The occurrence of PPR outbreaks in three districts of Tajikistan allowed us to genetically characterize the causal strain. Partial sequence of its N protein gene was compared with the one of 43 other strains isolated since 1968 in Africa, the Middle East and Asia. The study demonstrated the value of the partial sequence of the N gene for the comparison of isolates obtained over an extended period of time and from various geographical origins