Epidemiology of meningococcal disease in southern Brazil from 1995 to 2003, and molecular characterization of Neisseria meningitidis using multilocus sequence typing

Abstract

Summaryobjective To describe the epidemiology of meningococcal disease (MD) in southern Brazil. methods Retrospective cohort study among 2215 MD cases reported from 1995 to 2003 in Rio Grande do Sul (RS) State.results The overall incidence fell by 50%; the case-fatality rate during this period was 22%. Even so, the incidence of MD remained high after the epidemic period ended in 1999. Together, the age groups of 1-4 years and infants accounted for 54.1% of reported cases with incidences of 11.3 ⁄ 100 000 and 31.3 ⁄ 100 000, respectively; 69.8% of cases were caused by Neisseria meningitidis serogroup B, which increased significantly. There was a significant decrease in serogroup C cases in the whole period. The phenotypes B:4,7:P1.19,15, B:15:P1.7,16 and B:NT:P1.3 caused almost 50% of all serotyped cases. Fifty-six isolates obtained from RS patients during the first non-epidemic year 2000 plus 20 isolates from other southern Brazilian states (Santa Catarina and Paraná ), Denmark and France were typed by multilocus sequence typing. Twenty sequence types (STs) were identified, eight of them found only in RS. ST-33 (27%) and ST-259 (18%) were the most frequent; both belong to the ST-32 ⁄ ET-5 complex. ST-259 cases showed a trend towards higher risk of fatal outcome. ST-259 isolates were not detected among geographic controls or in other studies in Brazil.conclusion Our data suggest that ST-33 and ST-259 clones and the emergence of the ST-103 isolates contributed to the continued high incidence of MD in RS.

Clonal Distribution of Disease-Associated and Healthy Carrier Isolates ofNeisseria meningitidisbetween 1983 and 2005 in Cuba

“…Importantly, most of the small number of cases that occurred after vaccination were caused by ST-33 strains (13 of 20 strains) with the same phenotype (B:4:P1.19,15) as the VA-MENGOC-BC vaccine strain. The prevalence of this phenotype after the introduction of the Cuban vaccine has previously been reported in Cuba (40) and Brazil (3,13). However, in Cuba, where VA-MENGOC-BC is used systematically, the vaccine has had a dramatic impact on the morbidity and mortality from the disease (41).…”

High prevalence of Neisseria meningitidis hypervirulent lineages and emergence of W135:P1.5,2:ST-11 clone in Southern Brazil

“…These were previously found in other states of Brazil, but not in RS. 2,24,25 These hypervirulent clones have been reported to cause outbreaks and epidemics worldwide, reinforcing the importance of molecular characterization of MD cases in order to monitor the spread of these lineages and to establish control measures for the disease. 26e28 There was a higher genetic diversity in isolates within the ST-32 complex than was seen between 1995 and 2003, with 18 different STs, 8 of them novel.…”

“…Baethgen et al 2 characterized about 70% of isolates identified in 2000 from RS as belonging to the hypervirulent lineage ST-32/ET-5 clonal complex. In this study, 57 (74%) isolates and specimens belonged to 3 hypervirulent lineages.…”

“…There was an epidemic period between years 1995 and 2000, and the pattern of disease became endemic again after 2000. 2 In the last years, several advances have been made in our understanding of meningococcal biology and pathogenesis, global epidemiology, transmission, carriage, host susceptibility and pathophysiology. 5 Although there is high genetic variability of Neisseria meningitidis, only some 'hypervirulent lineages', composed by a minority of genotypes and antigenic types, account for the majority of the cases of invasive disease.…”

Enfermedad meningocóccica en la Región Metropolitana de Chile y su correlación con factores ambientales

“…Estudios de series temporales en diferentes latitudes muestran un patrón estacional similar al de la RM; por ej. ; en el sur de Brasil la mayor cantidad de casos se produce cada año entre junio y agosto 12 , en España la …”