Cocirculation of measles virus genotype B2 and B3.1 in Central African Republic during the 2000 measles epidemic.

Many African countries have begun implementation of national programs to eliminate measles by the year 2015. However, measles continues to be endemic in Africa. This study describes the first molecular epidemiological study of measles virus circulating in Central African Republic. Two hundred and ten blood samples were tested for measles IgM. Sixty-seven urine samples were collected during measles outbreak in Bangui in 2000 and 2004 and used for genotyping studies. Two different methods were used to determine measles virus genotypes; the recently described real-time PCR-based method and the nucleotide sequencing and phylogenetic analysis methods. These tests revealed the cocirculation of two distinct viruses in Bangui. The proposed subgroup of the B3 genotype, B3.1 was found in 14 samples. This virus has been found in other neighboring countries. More surprising, genotype B2 was found in samples from four patients. The first measles genotype B2 viruses were isolated in Gabon in 1984, but have not been detected until recently when they were identified during a measles outbreak in 2003 in South Africa. This suggests that the circulation of measles genotype B2 has continued in Central Africa during the last 20 years. This study provides the baseline for genetic surveillance of measles virus in Central African Republic. Knowledge of currently circulating measles virus genotype in Central African Republic will help in monitoring the success of measles elimination program.