Genetic characterization of clade B measles viruses isolated in Tunisia and Libya 2002-2009 and a proposed new subtype within the B3 genotype.

Original article


Haddad-Boubaker S 1, Rezq M 2, Smeo MN 2, Ben Yahia A 1, Abudher A 2, Slim A 3, Ben Ghorbel M 4, Ahmed H 5, Rota P 6, Triki H 1.

1-Laboratory of Clinical Virology and WHO Regional Reference Laboratory for Poliomyelitis and Measles in Eastern Mediterranean Region, Institut Pasteur, Tunis, Tunisia 2-National Center for Infectious Diseases Prevention and Control, Libya 3-Laboratory of Microbiology, National Laboratory of Measles–Charles Nicolle Hospital, Tunis, Tunisia 4-National Program of Immunization, Basic Health Care Division, Ministry of Health, Tunisia 5-World Health Organization, Eastern Mediterranean Region, Vaccine

Virus Res. 2010 Nov;153(2):258-64


Genetic characterization was conducted on 18 wild-type measles viruses, detected in Tunisia and Libya from 2002 to 2009. Sequence analysis of the 456 nucleotides in the carboxy terminus of the nucleoprotein (N) gene and the entire hemagglutinin (H) gene indicated that all isolates were in genotype B3. All of the viruses from 2002 to 2007 and some of the isolates from 2009 belonged to subtype B3.1. In contrast, 7 of the viruses isolated during 2008 and 2009 were quite divergent from all B3 isolates. The nucleotide sequences of the N gene of these 7 isolates differed from the sequences of the Ibadan and New York reference strain by an average of 3.1 and 4.4%, respectively. The H gene sequences differed by 1.1 and 2.6% with the same reference strains. This is the first report describing the genetic characteristics of measles viruses from clade B isolated in North Africa; the results suggest that these viruses represent a new subtype of genotype B3.

Keywords: Measles virus; Genotype B3; Nucleoprotein gene; Hemagglutinin gene; Tunisia; Libya