Epidemiology of invasive pneumococcal disease and vaccine provision in a tertiary referral center

Invasive pneumococcal disease (IPD) has an all-cause mortality of 5-35 % in the developed world. Pneumococcal vaccination is recommended for at-risk groups, including those infected with human immunodeficiency virus (HIV) and those over 65 years of age. However, adherence to vaccination guidelines is low. We reviewed all cases of IPD in our tertiary referral hospital from 2006 to 2010. IPD was defined as the isolation of Streptococcus pneumoniae from a normally sterile site with a compatible clinical syndrome. Demographics, risk factors, susceptibilities, pneumococcal serotype, mortality, and vaccination status for each patient were analyzed. There were 127 IPD episodes in 122 patients. The overall case fatality rate was 21.2 %. Seventy-two percent of the patients had two or more risk factors that should have prompted pneumococcal vaccination. However, the overall pneumococcal vaccination provision was only 9 %: 64.6 % of all typed isolates were contained in the pneumococcal polysaccharides vaccine 23 (PPV23), 48.8 % in the 7-valent pneumococcal conjugate vaccine (PCV7), and 60.1 % in PCV13. All isolates were fully sensitive to penicillin and cefotaxime. Recurrent IPD was seen in 11 % of the HIV-infected patients, highlighting a particular at-risk group. IPD has a high mortality rate. There is low vaccine provision in our study, although most IPD patients had risk factors that should have prompted vaccination. HIV-positive people are particularly at risk; vaccinating those with persisting CD4 counts less than 200 cells/mm³ and the use of "prime-boost" strategies may decrease incidence in the future. Newer models of care such as a dedicated vaccine clinic as described in this study may help increase vaccine provision and uptake.