[Respiratory infections and bacteremia caused by Neisseria meningitidis serogroup W]. / Infecciones respiratorias bacteriémicas por Neisseria meningitidis serogrupo W.

N. meningitidis serogroup W has recently been introduced into Chile. This serogroup has been associated with hypervirulent strains capable of causing outbreaks. Furthermore, there is data suggesting that the spectrum of clinical manifestations varies among different serogroups. Here we describe three cases of community acquired respiratory infections caused by N. meningitidis W, which were diagnosed by blood culture during 2013 in our hospital.

[Clinical characterization of cases with meningococcal disease by W135 group in Chile, 2012]. / Caracterización clínica de los casos de enfermedad meningocóccica por serogrupo W135 confirmados durante el año 2012 en Chile.

BACKGROUND: During 2012 in Chile, there were 60 cases of serogroup W135 meningococcal disease, which accounts for 57.7% of identified serogroup cases. AIM: To describe main clinical features of patients with serogroup W135 meningococcal disease confirmed in 2012. MATERIAL AND METHODS: Descriptive study of case series based on retrospective review of medical records. RESULTS: Male patients represented 61.7% and 46.7% were children under 5 years. At first clinical attention, 3.4% of patients were suspected of meningococcal disease, while 83.3% had meningococcemia as final diagnosis. Also at first attention, the most common symptoms or clinical signs were fever ≥ 38.0° C (60.3%), cold symptoms (52.5%), and nausea or vomiting (46.7%). Meningeal signs had a low frequency (8.7%). Diarrhea was the second most common symptom found among deceased patients (55.6%) and statistically higher than survivors (26.8%; p = 0.034). Six cases reported with sequelae: limb amputation, hearing loss or neurological damage, and mortality was 31.7%. DISCUSSION: In 2012, serogroup W135 meningococcal disease reported high mortality, atypical clinical presentation, low initial meningococcal disease diagnosis, and a high number of cases with poor clinical course.

Phenotypic and molecular characterization of invasive serogroup W135 Neisseria meningitidis strains from 1990 to 2005 in Brazil.

OBJECTIVE: Neisseria meningitidis serogroup W135 has been associated with global outbreaks since the 2000 Hajj. Considering that N. meningitidis serogroup W135 is the third most prevalent serogroup isolated in Brazil in the last 10 years, and the possibility that the Hajj-related N. meningitidis serogroup W135 clone has been causing disease in Brazil, the present study characterized invasive N. meningitidis serogroup W135 isolates recovered in Brazil from 1990 to 2005. METHODS: The isolates were characterized by serotyping, PorA and PorB VR typing, FetA and 16S rRNA typing, multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). RESULTS: Based on MLST, 73% of the isolates were clustered in one major clone of ST-11 complex/ET37 complex. Strains of this clone had the same STs, serotypes and PorA VR types as found in Hajj-related N. meningitidis serogroup W135 clone. One of these strains had the Hajj-2000 outbreak strain genotype, including 16S rRNA gene sequence 31 and 84% relatedness by PFGE. CONCLUSION: Taken together, these data suggest that the Hajj-related N. meningitidis serogroup W135 clone is present in Brazil but has not yet caused a substantial number of infections. Given the emergence of N. meningitidis serogroup W135 globally and the unpredictability of meningococcal disease epidemiology, continued surveillance for this invasive N. meningitidis serogroup W135 clone is needed for control and prevention strategies.

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

OBJECTIVES: The aim of this study was to characterize Neisseria meningitidis strains causing invasive disease in Rio Grande do Sul (RS), during 2003-2005, monitoring the occurrence of hypervirulent lineages, as well as to determine the diversity of PorA VR types for the corresponding isolates and clinical specimens. METHODS: Isolates and clinical specimens were characterized by MLST and PorA VR typing. RESULTS: This study demonstrated high prevalence of some hypervirulent lineages and emergence of new ones, including the emergence of lineages W135:P1.5,2:ST-11 complex, and C:P1.22,14-6:ST-103 complex. These lineages are probably responsible for the increasing incidence of serogroups C and W135, despite the overall decrease in serogroup B cases during the period. The most prevalent complex was serogroup B ST-32/ET-5 complex. The most prevalent PorA types found for serogroup B were P1.19,15, P1.7,16, and P1.18-1,3, representing a different distribution of PorA types compared to other states of Brazil. CONCLUSIONS: This study highlights the importance of monitoring each population, even within the same country. The different distribution of PorA VR types in RS has implications in vaccine design and efficacy. Detailed and accurate meningococcal characterization is an important element in studies of meningococcal epidemiology, population biology, and evolution and provides information for the design of control strategies.