Genotypes I, II and GIII-a subpopulations comprise of Asian strains whereas GIII-c comprises of American strains.
Scientists think they have evidence of this already happening in the arrival of Asian strains of waterborne bacteria, known as Vibrios, in Peru, Dr. Jaime Maresearcheraza, researcher in the department of biology and biochemistry at the University of Bath in England and lead author of the study, told The Huffington Post.
Using full-length G protein sequences of Asian strains, a phylogenetic tree was constructed to determine the relationship of Asian isolates with the other isolates (Fig. 2).
In fact, the strain recovered from Hawaii presents phenotypic characteristics typical of Asian strains (Gottschalk M, unpublished data, 2014).
It has been reported that large sequence differences distinguish the CagA function of Asian strains from other strains [ 11, 19].
Genetic variations of Asian strains were significantly lower compared to African and American strains, which were attributed to historical absences of YF in Asia [ 65].
Our analysis indicates that the two Asian phylotypes (nos. 2866 and 3321, total coverage of 96%) originated in southern Central Africa (phylotype no. 1), which differs from the origin predicted for India (97% of Asian strains) by (Shen et al., 2011), suggesting South Africa instead.
Also, its gene content is almost identical to that of a pandemic Asian strain (RIMD2210633) isolated at the same time, which supports the idea that the pandemic strain spread from Asia to South America very soon after it emerged.
Genetic admixture is predominantly observed in Sri Lankan strains of genotype III and all strains of genotype V. Inter-genotype recombination was observed to occur in non-structural region of several Asian strains whereas extent of recombination was limited in American strains.
However, in 1977, based on serological evidence [ 117] it was estimated that up to 44.5% of all Cubans became infected by an introduced Asian strain of DENV-1.
