Rate of invasive pneumococcal disease increases with age
Very elderly adults have the highest rate of invasive pneumococcal diseases, according to a recent study, suggesting that age influences manifestations of this illness.
Increasing age heightened the rate of invasive pneumococcal disease per 100,000. Some 27.3 percent of these cases were in those aged ≥65 years, but they were responsible for 48 percent of deaths. Case fatality rate rose with increasing age, from 9.6 percent in the 17‒54-year age group to 31.7 percent in the ≥75-year age group. [Am J Med 2018;131:100.e1-100.e7]
On the other hand, the rate of meningitis, admission to intensive care and use of mechanical ventilation decreased with increasing age.
A substantial reduction in the rate of invasive pneumococcal disease was observed due to protein conjugate vaccine 7 and protein conjugate vaccine 13 serotypes in those aged ≥55 years; however, the decline in rates for those in the 17‒54-year age group was much smaller. About 50 percent of the cases had replacement with nonvaccine serotypes.
“It has been known for some time that the incidence of all-cause pneumonia and invasive pneumococcal disease increases with advancing age,” researchers said. [Can Respir J 2005;13:139-142; J Infect Dis 2016;214:792-796]
“Although there has been a decline in the rate of invasive pneumococcal disease among those aged ≥75 years in the postpneumococcal conjugate vaccine 13 era, the rate still remains higher than for those in the 17‒54-year age group,” they added.
Data from the investigators’ surveillance study supported this finding. In 2014, males in the ≥75-year age group had 3.7-times higher rate than those in the 17‒54-year age group, while the corresponding figure was 6.4 times for females.
“We found no difference in overall incidence rates between 55‒64 and 65‒74 year olds or for males vs females in our survey,” researchers said. “De St. Maurice [and colleagues] also found no gender differences in rates for the 65‒74-year-old patients in the postpneumococcal conjugate vaccine 13 era.” [J Infect Dis 2016;214:792–796]
Furthermore, researchers showed 10 factors correlated with increased 30-days mortality and two with lower 30-day mortality. [Medicine (Baltimore) 2011;90:171-179]
The 10 factors were as follows: cancer within 5 years, cirrhosis, diabetes, requirement for oxygen supplementation, mechanical ventilation, altered mental status, cardiac arrest, infection with high or intermediated mortality serotypes, and treatment with a single antibiotic. Factors linked to lower mortality were age 18‒40 years and treatment with two antibiotics.
In a subset of the present study population, the following factors predicted increased mortality: age per decade (adjusted odds ratio [aOR], 1.42), nursing home residence (aOR, 3.34), dementia (aOR, 3.27), alcoholism (aOR, 2.32), multilobe pneumonia (aOR, 2.53) and guideline discordant antibiotic therapy (aOR, 3.24). On the other hand, smoking (aOR, 0.52) and infection with low case fatality rate serotypes (aOR, 0.54) correlated with reduced mortality.
In this prospective observational study of all cases (2,435) of invasive pneumococcal disease in adults in Northern Alberta from 2000 to 2014, researchers compared the rates of the disease per 100,000, sociodemographic variables, clinical characteristics, and invasive pneumococcal disease-related outcomes for the following age groups: 17‒54, 55‒64, 65‒74 and ≥75 years.