Streptococcus pneumoniae Invasive Disease, 2017

In 2017, 482 (8.7 per 100,000) cases of invasive pneumococcal disease (IPD) were reported. By age group, annual incidence rates per 100,000 were 8.5 cases among children aged ≤4 years,
1.6 cases among children and adults aged 5-39 years, 10.4 cases among adults 40-64 years, and 26.9 cases among adults aged ≥65 years.

Pneumonia occurred most frequently (53% of infections), followed by bacteremia without another focus of infection (23%), septic shock (9%), and meningitis (6%). Forty-seven (10%) cases died. Health histories were available for 44 of these deaths; of these, 37 had an underlying health condition reported. The conditions most frequently reported were chronic kidney disease (8), atherosclerotic cardiovascular disease (8), emphysema/chronic obstructive pulmonary disease (7), diabetes (7), cardiac failure (6), current smoker (6), and solid organ malignancy (6).

In 1999, the year before the pediatric pneumococcal conjugate vaccine (Prevnar [PCV-7]) was licensed; the rate of IPD among children <5 years of age in the metropolitan area was 111.7 cases/100,000. Over the years 2000-2002 there was a major downward trend in incidence in this age group (Figure 6). Rates in each of the subsequent 8 years were level or somewhat higher. Based on the distribution of serotypes among isolates from these cases, this increase was limited to disease caused by non- vaccine serotypes (i.e. serotypes other than the 7 included in PCV-7) (Figure 6).

In March 2010, the U.S. Food and Drug Administration approved a 13-valent pediatric pneumococcal conjugate vaccine (PCV-13 [Prevnar 13]) which replaced PCV-7. This vaccine provides protection against the same serotypes in PCV-7, plus 6 additional serotypes (serotypes 1, 3, 5, 6A, 7F, and 19A). From 2007 to 2010, the majority of IPD cases among children <5 years of age has been caused by the 6 new serotypes included in PCV-13 (Figure 6). Since 2011, the majority of IPD cases among children <5 years of age has been caused by serotypes not included in PCV-13. In 2017, 19% of cases with isolates available for testing were caused by 6 of the PCV-13-included serotypes: 3 (10%), 19F (4%), 19A (2%), 7F (2%), 9V (<1%), and 18C (<1%).

In August 2014, the Advisory Committee on Immunization Practices (ACIP) recommended that all adults ≥65 years receive 1 dose of PCV- 13 followed by 1 dose of 23-valent pneumococcal polysaccharide vaccine 6 to 12 months later. Among adults ≥65 years, 14% of cases in 2017 had PCV-13 serotypes.

Of the 455 isolates submitted for 2017 cases, 81 (18%) isolates were resistant to penicillin using meningitis breakpoints. Using non-meningitis breakpoints, 2 (<1%) of 455 isolates were resistant to penicillin. (Note: CLSI penicillin breakpoints changed in 2008). Multi-drug resistance (i.e., high-level resistance to two or more antibiotic classes) was exhibited in 69 (15%) isolates.

• For up to date information see>> Streptococcus pneumoniae (Pneumococcal Disease)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2017