Emergencia de la cepa W135 causante de enfermedad meningocócica invasora en Chile 2012 / Emergence of W135 meningococcal serogroup in Chile during 2012

The epidemiologic behavior of the Invasive Meningococcal Disease (IMD) in Chile has changed. At the end of 2011, the W135 serogroup belonging to the hypervirulent clone ST-11 emerged. It affected diverse countries of the world, after the Mecca pilgrimage in 2000. In Chile, there have been 133 IMD cases during 2012. These figures represent an incidence of 0.7 per 100,000 inhabitants, which is 30% higher than expected. Eighty eight percent of cases were confirmed by the National Reference Laboratory at the Chilean Public Health Institute. The serogroup was determined in 103 strains and 58% belonged to the W135 serogroup, surpassing for the first time the B serogroup (37%). The Metropolitan Region concentrated 80% of these cases, and the remaining 20% affected other seven regions of the country. Forty seven percent of cases corresponded to children less than 5 years of age. The predominant clinical presentation of the W135 serogroup was a sepsis in 67% of cases. The fatality ratio of IDM during 2012 was 27%, the highest in the past 20 years. With this information, the Chilean Ministry of Health decreed a sanitary alert and implemented an integrated approach to control and prevent W-135 IDM, denominated "W-135 Action Plan".

Immunogenicity and hereditary stability of Neisseria meningitidis serogroup W135/Y strains used in conjugate vaccine production / 中华微生物学和免疫学杂志

Objective To evaluate the immunogenic stability and hereditary stability of Neisseria meningitides serogroup W135/Y[CMCC(B)29037/CMCC(B)29028]within all the passages,which isolated from china.Methods The toxicity of the 3rd,5th,10th,15th,20th,25th and 30th passage of the Neisseria meningitidis was assayed in mice.Serological detection and biochemical detection were measured,and immunized mice subcutaneously.The antigeeicity of each passage of Neisseria meningitides serogroup W135/Y were measured by serum bactericidal test and the indirect ELISA.With the 30 passage of Neisseria meningitides serogroup W135/Y,the effect to the encephalic tissue was measured in mice.Fermented the Neisseria meningitides serogroup W135/Y with 30 passage and purified the capsular polysaccharide,then analyzed the quality respectively.Results The LD50 of the strains CMCC(B)29037/29028 of each passage was low(LD50 ≥ 109),and all the 30logical detection and all the 30 passage of the two strains were half in the tube agglutination.Glucose and maltose fermentation test were positive.Fructose,sucrose and lactose fermentation test were negative.The GMT of immunogenicity were 1114 and 2229 respectively and all the 30 passage were more than 640 and 1040 respectively.After Immunization with individual 30 passage of the Neisseria meningitides,the titer in serum bactericidal assay(SBA)and indirect ELISA were no difference.The capsular polysaccharide purified from Neisseria meningitides serogroup W135/Y met the quality standard.Conclusion Neisseria meningitides serogroup W135/Y,CMCC(B)29037/29028,used in the manufacture of the meningococcal conjugate vaccine,are stable in the toxicity,antigenicity,immunogenicity.Serological detection and biochemical detection are qulified,and the capsular polysaccharide has met the quality standard.

Meningococcal Disease in the Republic of Korea Army: Incidence and Serogroups Determined by PCR

This study was performed to determine the incidence and serogroups of meningococcal disease in the Korean Army. From August 2000 to July 2001, we identified prospective cases in the Korean Army. Meningococcal disease was confirmed by isolation of Neisseria meningitidis or detection of its antigen by latex agglutination from cerebrospinal fluid (CSF) or blood. Polymerase chain reactions (PCRs) were performed in the crgA gene to identify N. meningitidis regardless of its serogroup, and then in orf-2 (serogroup A) and siaD (serogroups B, C, Y, and W135) respectively for serogroup prediction. During the study period, twelve patients (four meningitis and eight septicaemia) were identified. The annual incidence was 2.2 per 100,000 (95% confidence interval, 1.3-3.8) among 550,000 private soldiers. Latex agglutinations were positive to A/C/Y/W135 polyvalent latex, but not to B latex in all patients. PCRs of crgA gene were positive in ten patients, whose samples (2 isolates from CSF, 2 CSFs, and 6 sera) were stored. In PCRs for serogroup prediction, one isolate was serogroup A, and one isolate and two sera were serogroup C. The need for meningococcal vaccination would be considered in the Korean Army through the cost-benefit analysis based on the result of this study.