Decreasing case fatality rate following invasive pneumococcal disease, North East England, 2006-2016

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health

Background:

• Effective pneumococcal conjugate vaccines have reduced invasive pneumococcal disease (IPD) incidence and mortality.
• IPD incidence is now increasing due to serotype replacement, posing a renewed public health challenge.

Purpose of the Study:

• To statistically analyze the trend in the 30-day all-cause case fatality rate (CFR) for IPD in North East England (NEE).
• To identify factors associated with increased CFR in IPD patients.
• To assess changes in IPD mortality over time despite vaccination efforts.

Main Methods:

• A statistical analysis was conducted on clinical, microbiological, and demographic data from laboratory-confirmed IPD cases between April 2006 and March 2016.
• Logistic regression was used to estimate the adjusted association between CFR and epidemiological year.
• Factors associated with CFR were identified, including age, sex, comorbidities, and specific serotypes.

Main Results:

• The overall 30-day CFR for IPD was 19% (486 deaths out of 2510 episodes).
• Increasing age, male sex, septicaemia, clinical risk groups, alcohol abuse, and specific serotypes were independently associated with higher CFR.
• A significant decline in CFR over time was observed after adjusting for these predictors (adjusted odds ratio 0.93, P = 0.003).

Conclusions:

• A small but significant decline in 30-day all-cause CFR following IPD was observed in NEE.
• Certain population groups remain at increased risk of mortality from IPD.
• Despite vaccine introduction, further strategies are required to mitigate the ongoing mortality burden of IPD.