Related Experiment Videos
Meningococcal infections in England and Wales: 1994
1Meningococcal Reference Unit, Manchester Public Health Laboratory.
Abstract:
One thousand one hundred and twenty-nine isolates of Neisseria meningitidis from cases of invasive disease were submitted to the PHLS Meningococcal Reference Unit in 1994, a fall of 13% from the total of 1297 in 1993. One hundred and seventy-four cases were diagnosed serologically, making 1303 laboratory ascertained cases, compared with 1368 in 1993. The overall fall of 4% was similar to the 5% fall in notifications to the Office of Population Censuses and Surveys. The seasonal increase between the third and fourth quarters of the year was less apparent than usual in 1994, when a higher proportion of cases occurred during the summer months. Regional rates of infection varied, notably in the proportions of group C infections, which were highest in the south east. DNA based typing techniques have clarified the characterisation of previously non-typable organisms. B4PI.4 has been identified as a recently emergent strain, which is now responsible for a quarter of all group B infections. Considerable regional variation was observed in the use of serodiagnosis. The monthly distribution of cases diagnosed serologically was similar to that of cases confirmed by isolation, but the age profile was skewed towards older patients.
Insights
Invasive meningococcal disease cases decreased in 1994, with fewer seasonal peaks. New DNA typing identified an emergent Neisseria meningitidis strain, B4PI.4, causing a quarter of group B infections.
Area of Science:
- Microbiology
- Epidemiology
- Genetics
Background:
- In 1994, the PHLS Meningococcal Reference Unit received 1129 Neisseria meningitidis isolates from invasive disease cases.
- This represented a 13% decrease from 1297 isolates in 1993, with laboratory-ascertained cases falling by 4%.
Purpose of the Study:
- To analyze trends in invasive meningococcal disease (IMD) in 1994.
- To characterize Neisseria meningitidis strains using advanced typing techniques.
- To investigate regional variations in IMD and serodiagnosis.
Main Methods:
- Analysis of 1129 Neisseria meningitidis isolates from invasive cases.
- Comparison of 1994 data with 1993 data, including laboratory diagnoses and Office of Population Censuses and Surveys notifications.
- Application of DNA-based typing techniques for strain characterization.
- Examination of regional and seasonal distribution of cases.
Main Results:
- A 4% overall fall in laboratory-ascertained cases compared to 1993.
- A less pronounced seasonal increase, with more cases in summer months.
- Identification of B4PI.4 as an emergent strain responsible for 25% of group B infections.
- Regional variations in group C infections, highest in the South East.
- Age profile of serologically diagnosed cases skewed towards older patients.
Conclusions:
- Neisseria meningitidis infections showed a declining trend in 1994.
- Emergence of the B4PI.4 strain significantly impacts group B meningococcal disease epidemiology.
- DNA typing is crucial for characterizing meningococcal strains and understanding disease dynamics.