The burden of severe pneumococcal infection in Ireland: potential effectiveness and indirect benefits of the 7-valent pneumococcal conjugate vaccine.

This study attempts to overcome the problem of under-reporting of serious pneumococcal infection in the Republic of Ireland by adding a proportion of 'unspecified' disease to pneumococcal disease reports. ICD-9 data for all age groups was collected on meningitis (from the National Disease Surveillance Centre), and septicaemia and pneumonia (from the Hospital In-Patient Enquiry system) for the year 1999. A 7-valent pneumococcal conjugate vaccine (PCV) has been shown to have significant effectiveness in the target paediatric age group and also indirect herd effects on the US adult population. The implications of these direct and indirect effects were applied to the epidemiology of serious pneumococcal infection in Ireland. The annual reported incidence rates for laboratory confirmed severe pneumococcal disease in Ireland in 1999 may underestimate both the morbidity and mortality of disease by 21% and 28% respectively. In all age groups 1,183 cases and 132 deaths may be prevented annually by the introduction of the vaccine. In addition, the vaccine provides an effective new tool for reducing disease caused by antibiotic resistant pneumococci thus assisting in the control of anti-microbial resistance in humans.