[Study on the immunity of diphtheria in children at county level with different 4-vaccine coverage rates based on the results from "National Immunization Program Review" in 2004].

OBJECTIVE: To investigate the immunity level of diphtheria antibody among children living in the areas where different coverage rates of 4-vaccines stratified by results of national immunization program (NIP) reviewed in 2004. METHODS: According to data from 4-vaccine coverage rates of NIP reviewed in 2004, 3 levels could be set. We randomly selected 2 counties at each level and then 10 villages from each county with 42 children involved who were born between 1992 and 2003. ELISA quantitative method was used to test IgG of diphtheria antitoxin. RESULTS: (1) The positive rate of diphtheria antitoxin was only 49.6% with the highest as 78.1% and lowest as 33.0%. There was a significant decreasing trend of this positive rate with the increase of age. The highest (61.2%) fell in the group that were born in 2003 and the lowest (37.6%) was seen among children born in 1992 to 1995. (2) Geometric mean concentrations (GMCs) was only 0.48 IU/ml with a trend of decrease when age was increasing. There was no GMCs peak seen in children who were at the age of boosting, as expected. (3) Positive rates of children born between 2001 and 2003 were lower than 62% while the diphtheria-pertussis-tetanus (DPT) vaccine coverage rates were all higher than 90%. (4) There was no significant difference of diphtheria antitoxin positive rates between children with eligible routine immunization (58.1%) and those were ineligible (59.6%). CONCLUSION: Other than some specific ones, children from most of the investigated counties had a low level of antibody against diphtheria. The coverage rate of DPT vaccine did not necessarily reflect the immunity against diphtheria, suggesting the increase of immunity against diphtheria an urgent task to be taken care of.

[Surveillance on pathogens of meningococcal meningitis in Beijing, 2005].

OBJECTIVE: To study the pathogens of meningococcal meningitis (MM) in Beijing, 2005. METHODS: Blood and cerebrospinal fluid specimens from MM patients were detected by polymerase chain reaction. Bacterial strains were analyzed by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS: 7 of the blood and 5 of cerebrospinal fluid specimens showed positive results. 105 of the Neisseria meningitides strains were isolated from the specimens of patients, close contacts and healthy carriers. Serogroup A and C Neisseria meningitides strains shared the same patterns of pulsed-fieldgel electrophoresis, respectively. The sequence type of serogroup A Neisseria meningitides belonged to ST7 while the sequence type of serogroup C Neisseria meningitides belonged to ST4821. CONCLUSION: Patients suffered from meningococcal meningitis were caused by serogroup A (ST7) and C (ST4821) Neisseria meningitides in Beijing, 2005.

Laboratory confirmation of a suspicious meningococcal meningitis death case.

A suspicious meningococcal meningitis death case was reported to the Beijing CDC. The blood specimen was analyzed via multi-PCR and MLST. 6 isolates from close contacts were analyzed via PFGE and MLST. According to the results of the above analyses, the cause of this case was identified as a serogroup A Neisseria meningitidis, which, in terms of sequence typing, belonged the ST7 group.

The molecular characterization of serogroup C Neisseria meningitidis strains circulating in Beijing.

The aim of this study was to characterize the molecular features of serogroup C Neisseria meningitidis strains circulating in Beijing, China. Twenty out of 23 strains belonged to ST 4821. The causative serosubtype for meningococcal meningitis was P1.12-1,16-8. All of the strains expressed class 3 PorB protein. Among the five pulsed-field gel electrophoresis patterns observed, pattern III predominated.