Genetic Homogeneity of Measles Viruses Associated with a Measles Outbreak, São Paulo, Brazil, 1997

Update on the Global Distribution of Genotypes of Wild Type Measles Viruses

“…Laboratory studies have estimated that the mutation rate of measles virus is similar to those of other RNA viruses [23]. However, molecular epidemiologic studies of the measles resurgences in Brazil in 1997 [24] and in the United States in 1989-1991 [14] suggest that there is very little sequence variation in the N and H genes within a single chain of measles transmission. Nucleotide sequences from the N genes of viruses isolated during the large outbreak in São Paulo in 1997 were nearly identical to the sequences obtained from viruses that had spread to other states in Brazil as well as other South American countries during 1997 and 1998 [24].…”

“…However, molecular epidemiologic studies of the measles resurgences in Brazil in 1997 [24] and in the United States in 1989-1991 [14] suggest that there is very little sequence variation in the N and H genes within a single chain of measles transmission. Nucleotide sequences from the N genes of viruses isolated during the large outbreak in São Paulo in 1997 were nearly identical to the sequences obtained from viruses that had spread to other states in Brazil as well as other South American countries during 1997 and 1998 [24]. The genotype D3 viruses that were isolated during the resurgence of measles in the United States during 1989-1992 showed very little sequence variability in both the H and N genes, suggesting that 1 strain of virus had seeded the entire country [14].…”

“…However, recent molecular epidemiologic studies have demonstrated interruption of circulation of genotype D6 viruses that were responsible for the large measles outbreak in São Paulo in 1997 and subsequent outbreaks in Rio de Janeiro, Argentina, Chile, Bolivia, Haiti, and the Dominican Republic [24,[34][35][36][37]. The record low num- ber of cases and the identification of genotypes other than D6 in association with measles cases imported into South and Central America are consistent with regional elimination [38][39][40].…”

High Genetic Diversity of Measles Virus, World Health Organization European Region, 2005–2006

“…Genotype C2 has been continuously detected in the European Region since the early 1970s and is therefore considered to be the indigenous genotype of Europe (4,5). D6 viruses have been regularly reported from different countries of the European Region since the early 1990s (4)(5)(6)(7)(8)(9)(10)(11)(12), and genotype D6-associated outbreaks or sporadic cases on other continents were mostly due to MV importations from Europe (13)(14)(15) (Figure 1). These observations thus provide overwhelming evidence for the endemic circulation of genotype D6 in Europe at least during the past 15 years.…”

Resurgence of measles virus in São Paulo, Brazil

“…Due to good strategies for the close observation of measles virus, the circulation of indigenous cases was not registered for the mentioned period. However, in 2001, 2002 and 2005, cases of an imported virus belonging to the group D5 was registered 2,3,4 .…”