Pneumococcal vaccination encouraged among high-risk patients

In Singapore, invasive pneumococcal disease (IPD) tends to occur more frequently in relatively younger adults and those with fewer comorbidities and is associated with poorer outcomes and higher mortality risk, as described in a study. But such a hazard may be thwarted by pneumococcal vaccination, which has about 80-percent effectiveness at preventing infection.

“Our findings are useful to guide the identification of patients at high risk of in-hospital mortality from the disease. They also support current recommendations to vaccinate at-risk individuals to prevent IPD,” according to researchers.

In the study, the researchers reviewed the medical records of 9,677 patients who had undergone streptococcal urinary antigen testing and at least one sterile site culture during their admission to Tan Tock Seng Hospital over a 2-year period. A total of 496 patients (mean age, 69.1 years; 65.5 percent male; 72.4 percent Chinese) tested positive for pneumococcal disease, among whom 92 (18.5 percent) had IPD.

The most common comorbidities among patients with pneumococcal disease overall were chronic pulmonary disease (30.0 percent), diabetes mellitus (29.6 percent), myocardial infarction/congestive cardiac failure (28.8 percent), and renal disease (18.8 percent). Most patients had pneumonia as their primary diagnosis (70.0 percent), and 80 (16.1 percent) had received pneumococcal vaccination (PCV13 and/or PPSV23) at any time prior to admission. [BMC Infect Dis 2020;20:423]

When compared with non-IPD patients (n=404) and non-pneumococcal disease controls (n=9,181), those with IPD were the youngest (mean age, 70.8 and 72.2 vs 61.5 years, respectively; p<0.001), had the fewest comorbid conditions (median Charlson's score, 2 and 3 vs 1; p<0.001), and were the least likely to have received pneumococcal vaccination prior to admission (19.1 percent and 18.5 percent vs 3.3 percent; p=0.001).

However, the IPD group had more severe clinical outcomes. They had the highest intensive care unit (ICU) admission frequency (20.7 percent vs 8.7 percent in non-IPD and 6.3 percent in the control group; p<0.001) and inpatient mortality rate (26.1 percent vs 11.4 percent and 9.1 percent, respectively; p<0.001), as well as the longest duration of hospital stay (median, 9 vs 8 days in both groups; p=0.003).

Multivariable regression analysis revealed that prior pneumococcal vaccination conferred significant protection against the risk of developing IPD (adjusted relative risk ratio, 0.20, 95 percent CI, 0.06–0.69; p=0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission (adjusted odds ratio [aOR], 23.22; p<0.001), diagnosis of IPD (aOR, 3.19; p=0.002), age ≥85 years (vs <65 years: aOR, 10.78; p<0.001), and Charlson's score >3 (aOR, 1.93; p=0.042).

“[The finding] reflects the virulence of the disease and highlights the importance of early recognition, treatment, and prevention where possible,” according to the authors.

“Currently, our hospital has ongoing vaccination programmes to identify and opportunistically vaccinate high-risk groups according to standardized protocols,” they said.

The authors pointed out that high-risk inpatients are counselled on and given vaccination prior to discharge. Outpatients, on the other hand, are served by selected specialist clinics that have a nurse-led programme for counselling and vaccination administration for those at high risk, in conjunction with the medical consultation.

“Vaccination should also be provided by primary care practitioners as part of chronic disease management and alongside other preventive services such as health screening,” they added.