Epidemiology and Infection

Molecular epidemiology of African and Asian Crimean-Congo haemorrhagic fever isolates

F. J. BURT a1c1 and R. SWANEPOEL a1
a1 Special Pathogens Unit, National Institute for Communicable Diseases, Sandringham, South Africa

Article author query
burt fj   [PubMed][Google Scholar] 
swanepoel r   [PubMed][Google Scholar] 


Phylogenetic relationships were examined for 70 Crimean-Congo haemorrhagic fever (CCHF) isolates from southern, central and West Africa, the Middle East and Greece using sequence data determined for a region of the S segment of the genome. Analysis revealed up to 18% genetic differences. Tree topology supports previous evidence for the existence of three groups of genetically related isolates, A, B and C. Within group A there are two clades: an African clade and a predominantly Asian clade comprising isolates from Pakistan, China, Iran, Russia and Madagascar. Group B includes isolates from southern and West Africa and Iran, and group C includes a single isolate from Greece. Despite the potential which exists for dispersal of the virus between Africa and Eurasia, it appears that circulation of the virus is largely compartmentalized within the two land masses, and the inference is that the geographic distribution of phylogenetic groups is related to the distribution and dispersal of tick vectors of the virus.

(Accepted December 20 2004)

c1 Special Pathogens Unit, National Institute for Communicable Diseases, Private Bag X4, Sandringham 2131, Johannesburg, South Africa. (Email: felicityb@nicd.ac.za)