Ongoing group B Neisseria meningitidis epidemic in São Paulo, Brazil, due to increased prevalence of a single clone of the ET-5 complex

Abstract

Beginning in 1988, the incidence of meningococcal disease in the area of greater São Paulo began to surpass the upper confidence limit of an 8-year average incidence (from 1979 to 1986), thus characterizing a new epidemic in the region of greater São Paulo. This epidemic, which extended to 1990, was different from previous epidemics in that it was caused by serogroup B. The increased incidence of meningococcal disease was paralleled by an increased prevalence of a single group B clone, B:4:P1.15, of the ET-5 complex. ET-5 strains have been present in the greater São Paulo area since 1979; however, they have been associated with a high percentage of the group B disease only from 1987 to the present. On the basis of the increased incidence of group B disease in São Paulo, a mass vaccination program with a serotype 4:P1.15 meningococcal protein vaccine was undertaken. The impact of this vaccination program is under analysis.

Molecular mimetics of polysaccharide epitopes as vaccine candidates for prevention of Neisseria meningitidis serogroup B disease

“…These epidemics can result in hundreds of thousands of cases in a single season, with tens of thousands of deaths. Outbreaks of serogroup C disease also have emerged as an important clinical problem in North America [11,12] and serogroup B epidemics have occurred periodically in Europe, the Americas and in New Zealand [3,10,13,14]. Given this large disease burden in the developed and developing world, an e¡ective vaccine for prevention of N. meningitidis disease remains an important public health priority.…”

Genetic diversity of Neisseria meningitidis strains isolated in Rio de Janeiro, Brazil, evaluated by multilocus enzyme electrophoresis

“…Meningococcal strains belonging to serogroup B, causing severe disease in different countries, had proved to be markedly heterogeneous (Caugant et al 1987b;Achtman 1991;Caugant 1998). Generally, populations of N. meningitidis specially from serogroup B, present a high linkage equilibrium contributing to its panmictic features, but sporadic propagation of clonal genotypes, may cause localized epidemic events tending to endemic, probably because of the fast genetic recombination occurring among isolates of particular serogroups (Crowe et al 1987;Sacchi et al 1992a;Smith et al 1993;Bart et al 2001). After cluster analysis by MEE, we confirmed the panmictic structure of N. meningitidis B isolated in Rio de Janeiro; strains from different serogroups isolated from different geographical areas, clustered at a higher similarity level, then strains of the same serogroup isolated within the same neighbourhood; the Cuba vaccine strain (B:4:P1.15), for example, showed 100% of similarity with a serogroup A strain isolated in Rio de Janeiro in 1990.…”

“…In Brazil, cases associated with MD have been described since 1970, but in 1974 an important outbreak occurred with the predominance of serogroup A strains followed by serogroup C, reaching 179AE4 cases per 100 000 inhabitants. However, during the 1980s, the incidence of serogroup A decreased and serogroup B emerged as the most isolated in the country so far (Sacchi et al 1992a;Noronha et al 1997;Milagres et al 2000). The incidence rate of MD between 1980 and 1986 was low (ca 1 case per 100 000 inhabitants) followed by an increase to 4AE5 cases per 100 000 inhabitants from 1993 to 1997, when the most affected region of Brazil was the southeast where the Rio de Janeiro state is located.…”

“…In Brazil this complex was detected during an outbreak in São Paulo and in some other Brazilian states (Caugant et al 1987a;Sacchi et al 1992aSacchi et al , 1994, but only three strains related to the ET-5 complex were reported as isolated in the State of Rio de Janeiro during the period of 1986-1989. From 1989 to date, detection of the ET-5 complex in this state, was not reported anymore.…”

Genetic and immunologic characterization of a novel serotype 4, 15 strain of Neisseria meningitidis

“…Biotinylated oligonucleotide probes have been used in hybridization assays to identify porB variable region (VR) genotypes [18]. Serotype 4 and serotype 15 strains of N. meningitidis are epidemiologically, serologically, and genetically di¡erent [14,18,20]. Studies were undertaken to characterize a disease isolate from Chile, Ch501, which unexpectedly reacted with both type 4 and type 15 serotyping monoclonal antibodies.…”