No abstract

A record linkage study was done to provide comprehensive data on the epidemiologic characteristics of invasive pneumococcal disease (IPD) in Scotland. The overall incidence of IPD was 11 cases/10(5) persons and 21 cases/10(5) persons <1 year of age, 51 cases/10(5) persons 1 year of age, 45 cases/10(5) elderly persons (age > or =65 years), 176-483 cases/10(5) persons with chronic medical conditions, and 562-2031 cases/10(5) persons with severe immunosuppression. The case-fatality rate was 11% among elderly persons and ranged from 3% to 13% among persons with underlying medical conditions. The most common pneumococcal serogroups associated with IPD were 14, 9, 6, 19, 23, 8, and 4. Serogroups included in the 23-valent polysaccharide vaccine caused the majority of cases of IPD. The proportion of IPD due to the 7-, 9-, and 11-valent conjugate vaccine serogroups was lower among older people and persons with underlying medical conditions.

John Snow was a genius in epidemiology. His achievement was to evolve an elegant, internally and externally consistent theory which concerned the mechanisms and processes involved in every aspect of the subject he had chosen to study. In order to do this he did not restrict himself to any method. He used all skills available to himself and his colleagues. He published his theory, and practical suggestions for the prevention of cholera arising out it, both internally in medical meetings and to the medical press, and to the public in the form of pamphlets and in reports addressed to the appropriate authority. This surely should be the objective of all epidemiological work.

No abstract

We reviewed population-based laboratory reports of invasive meningococcal, pneumococcal, Haemophilus influenzae, Group B Streptococcus (GBS) and Listeria monocytogenes isolates in order to examine the changing epidemiology of meningitis and invasive non-meningitic disease (INMD) caused by these 5 pathogens in the 2 periods before (1983-91) and after (1992-99) routine use of H. influenzae type B conjugate vaccine (Hib) in Scotland. Neissieria meningitidis was the most common cause of meningitis, accounting for 39.2% of cases of meningitis in 1983-91 and 47% of cases in 1992-99, followed by H. influenzae (31%), Streptococcus pneumoniae (22.4%), GBS (3.9%) and L. monocytogenes (3.5%) in 1983-91 and S. pneumoniae (36.3%), H. influenzae (7.8%), GBS (6.1%) and L. monocytogenes (2.8%) in 1992-99. The important epidemiological features of meningitis and INMD caused by these 5 pathogens between 1983-91 and 1992-99 include: 1. The incidence of bacterial meningitis due to S. pneumoniae and GBS was stable; 2. S. pneumoniae was the predominant cause of INMD in both periods; 3. The incidences of INMD caused by N. meningitidis, GBS and S. pneumoniae increased, by 27%, 55% and 56%, respectively; 4. Decreases in the incidences of bacterial meningitis (by 50%) and INMD (by 50%) due to L. monocytogenes were detected; and 5. There were dramatic reductions in the proportions of bacterial meningitis (by 92%) and INMD (by 56%) due to H. influenzae in vaccinated and non-vaccinated individuals. Continued surveillance is necessary to monitor the disease trend, population at risk, serotype distribution and antimicrobial susceptibility in order to implement appropriate public health interventions against invasive bacterial disease.