The nucleotide sequence analysis identified circulation of a single strain on each affected farm (Table 2). Serotype O was detected from 11/15 (73.3%) herds and serotype A was detected from 4/15 (26.7%) herds. The percentage of identity of the characterized O and A strains from the different farms in this investigation were 97.6-100% and 99.5-100%, respectively. We detected serotype O strains only from animals that suffered from the severe clinical form. In contrast, the FMDV serotype A strains were found only in animals that showed the mild clinical form. The phylogenetic tree constructed with serotype O strains placed these newly detected strains in the East Africa 3 (EA-3) topotype (Figure 2). These new serotype O…show more content… Previous reports suggested that animal movement increases the spread of FMDV originating from clinically infected or carrier animals (15,16). Moreover, animal movement poses a risk for increasing seropositivity to FMDV (17).
Egypt has a unique transcontinental location in northeast Africa and Southwest Asia. Consequently, this location makes Egypt vulnerable to incursion of FMDV strains circulating in both African and Asian countries. Previous studies highlighted the threat of incursion of exotic FMDV strains that predominate in sub-Saharan Africa to North Africa (8). The two groups of strains characterized in this study clustered into distinct clades, differing from the previously circulating strains in Egypt and Sudan associated with these topotypes. Based on the history of introduction of new animals into the herds in association with the outbreaks, these finding suggest new incursions of FMDV strains into Egypt and indicates separate introductions. While the source of these new strains is not clear, the percentages of identity with other strains in these topotypes suggest that Sudanese viruses are the most closely related to the characterized strains. Egypt suffers from a shortage in meat production. Therefore, the authorities import low priced livestock from Sudan and sub-Saharan countries to meet the demand (18). Moreover, the animal movement that occurs between Egypt and neighboring countries such as Sudan is uncontrolled