China ; epidemiology ; Humans ; Meningococcal Infections ; epidemiology

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.
Adult ; Human ; Korea/epidemiology ; Male ; Meningococcal Infections/epidemiology* ; Meningococcal Infections/physiopathology ; Military Personnel* ; Neisseria meningitidis/genetics ; Serotyping

OBJECTIVETo study the molecular subtypes and microflora structure of Neisseria meningitidis (Nm) strains isolated in Jiangxi province.

METHODSA total of 123 Nm strains separately isolated from patients, close contacts and health people in 1976-1987 and 2005-2008 were investigated by multilocus sequence typing (MLST) and PorA subtyping, to test the characteristics of gene Nm and sequence porA. Minimum spanning tree was constructed by using BioNumerics software based on data of MLST; and the microflora structure was then analyzed.

RESULTSThe serogroups of 67 Nm strains isolated in 1976-1987 included group A (43 strains), group B (18 strains), group C (1 strains) and group W135 (5 strains); while the serogroups of 56 Nm strains isolated in 2005-2008 included group A (3 strains), group B (7 strains), group C (45 strains) and 1 ungrouped strain. The total 123 Nm strains could be divided into 40 MLST types; while the 46 strains in group A could be divided into 14 MLST types, 29 out of which belonged to ST-3 type, accounting for 63.0% (29/46) as the dominant type. All of the 29 strains were isolated between 1976 and 1987, while 14 strains were isolated from patients, 9 were from close contacts and 6 were from health people. The 46 strains in group C could be divided into 5 MLST types, 41 out of which belonged to ST-4821 type, accounting for 89.1% (41/46). All of the strains were isolated between 2005 and 2008, 6 strains were isolated from patients, 6 were from close contacts and 29 were from health people. The porA gene of the total 123 Nm strains were classified to 32 different types, including 24 different VR1 types and 22 different VR2 types. The dominant PorA type of the prevalent strain (ST-3 type, group A) between 1976 and 1987 was P1.7-1, 10, accounting for 39.1% (18/46) of the strains in group A; while the 18 strains were isolated from 11 patients, 4 close contacts and 3 health people. The dominant PorA type of the prevalent strain (ST-4821 type, group C) between 2005 and 2008 was P1.20, 9, accounting for 46.3% (19/41) of the ST-4821 strains in group C; while the 19 strains were isolated from 1 close contacts and 18 health people. P1.7-2, 14 dominated since 2006, including 22 strains, accounting for 53.7% (22/41) of the ST-4821 strains in group C, isolated from 6 patients, 5 close contacts and 11 health people. There were no dominant PorA type found in group B and all the 5 strains in group W135 belonged to ST-174 and the PorA type was P1.21, 16, isolating from 3 close contacts and 2 health people between 1979 and 1980.

CONCLUSIONNm isolated in Jiangxi province showed significant gene polymorphism, as well as predominant lineages existing. In different periods, the prevalent lineages varied a lot, as translating from serogroup A: ST-3:P1.7-1, 10 to serogroup C: ST-4821:P1.7-2, 14 nowadays.

Bacterial Typing Techniques ; China ; epidemiology ; Genotype ; Humans ; Meningococcal Infections ; epidemiology ; microbiology ; Neisseria meningitidis ; classification ; genetics ; isolation & purification ; Serotyping

OBJECTIVETo study the characteristics of epidemiology and molecular typing on Neisseria meningitidis serogroup C strains associated with outbreaks of Anhui province and sporadic cases in China, using pulsed field gel electrophoresis (PFGE).

METHODS212 Neisseria meningitidis serogroup C strains were isolated from invasive meningococcal cases, close contacts and healthy carriers, including 48 strains from Anhui province with 38 strains associated with serogroup C outbreaks. PFGE were performed by genomic DNA digestion with Nhe I restriction enzyme. The results of PFGE were analyzed by BioNumerics software (Version 4.0, Applied Maths BVBA, Belgium).

RESULTSA total number of 212 Neisseria meningitidis serogroup C isolates were typed by 43 patterns, named AH1 to AH43. In China, AH1 pattern was the major PFGE pattern with 69.3% (n = 147) of all strains, distributed in 11 provinces. Three types of PFGE patterns (AH1 to AH3) were found in 48 strains from Anhui province, in which, 93.8% (n = 45) belonged to AH1. 97.4% (n = 37) of 38 strains associated with serogroup C outbreaks in Anhui province showed AH1 pattern. A total of 53 serogroup C strains were isolated from invasive meningococcal cases with 67.9% (36/53) of AH pattern. 71.9% (87/121) of serogroup C strains isolated from contacts of invasive meningococcal cases was AH1 pattern and 63.2% (24/38) of the strains from healthy carriers showed AH1 pattern.

CONCLUSIONBy PFGE typing and analysis, AH1 pattern of Neisseria meningitidis serogroup C strains was proved to be the main clone which causing the outbreaks in Anhui province and might be responsible for the sporadic serogroup C meningococcal disease epidemics else where in the country.

Bacterial Typing Techniques ; China ; epidemiology ; DNA, Bacterial ; genetics ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Meningococcal Infections ; epidemiology ; Neisseria meningitidis, Serogroup C ; classification ; genetics ; isolation & purification ; Sequence Analysis, DNA