62. Gender Differences in Invasive Pneumococcal Disease Rates
Session: Oral Abstract Session: Bacterial Diseases
Thursday, October 8, 2015: 8:30 AM
Room: 25--ABC

Background:

Children seem to be the natural reservoir for pneumococcal infections in adults. Exposure to colonized children, derived immunity and related adult pneumococcal diseases may vary by age and gender. Invasive pneumococcal disease (IPD) rates in adults, particularly those >64, decreased after PCV7 and PCV13 introduction in children. The study objective was to determine if adult IPD rates vary by age and gender and if PCV7 and PCV13, introduced in 2000 and 2010 respectively, impacted age and gender-specific IPD rates in adults.

Methods:

We used population and laboratory-based IPD surveillance data from the CDC Active Bacterial Core Surveillance program (1998-2013) for Tennessee (TN). Data were divided into 4 eras: Pre-PCV7 (1998-1999), Early-PCV7 (2001-2004), Late-PCV7 (2005-2009), and Post-PCV13 (2011-2013); and age-stratified into 18-39, 40-64 and >64 years. The transitional years 2000 and 2010 were excluded. Population based rates were calculated using census data and rates were compared using incidence rate ratios (IRR).

Results:

IPD rates were consistently higher among males than females in all age groups; however this was most pronounced among adults 18-39 and 40-64 (Figure). When rates were stratified by race, these differences persisted. Overall IPD rates declined in both males and females after PCV7 and PCV13 introduction. Interestingly, after PCV13 introduction gender differences were eliminated in adults 18-39, but persisted in adults 40-64 and were present in adults >64.

Table shows annualized IPD rates per 100,000 population, stratified by age, gender and vaccine era.

Age 18-39

Age 40-64

Age >64

Vaccine Era

Male Rate

Female

Rate

IRR

(95% CI)

Male

Rate

Female

Rate

IRR

(95% CI)

Male

Rate

Female

Rate

IRR

(95% CI)

Pre-PCV7

33

22

1.5

(1.3-1.8)*

23

14

1.6

(1.3-2.0)*

63

55

1.2

(0.94-1.4)

Early-PCV7

8

5

1.5

(1.2-1.9)*

25

14

1.7

(1.5-2.0)*

46

47

0.98

(0.83-2.3)

Late-PCV7

8

7

1.2

(0.94-1.4)

27

22

1.2

(1.1-1.4)*

49

45

1.1

(0.95-1.3)

Post-PCV13

5

5

1

(0.76-1.4)

21

16

1.3

(1.1-1.6)*

43

32

1.4

(1.1-1.6)*

*indicates statistical significance

Description: 1 - Layout 1.pdf

Conclusion:

We observed age and gender differences in adult IPD in TN. Gender differences were more pronounced among younger adults. Additional study is needed to understand the reasons for these differences and their potential implications in vaccine-derived indirect protection.

Annabelle De St. Maurice, MD, MPH, Pediatric Infectious Diseases, Vanderbilt University, Nashville, TN, Natasha Halasa, MD, MPH, FPIDS, School of Medicine, Vanderbilt University, Nashville, TN, William Schaffner, MD, FIDSA, FSHEA, Department of Health Policy, Vanderbilt University School of Medicine, Nashville, TN and Carlos G. Grijalva, MD, MPH, Department of Health Policy, Vanderbilt University Medical Center, Nashville, TN

Disclosures:

A. De St. Maurice, Pfizer: Grant Investigator , Grant recipient , Research grant and Research support

N. Halasa, Sanofi Pasteur: Grant Investigator , Grant recipient , Research grant and Research support
Gilead: Grant Investigator , Research support
Pfizer: Grant Investigator , Grant recipient , Research grant and Research support
Baxter: Grant Investigator , Grant recipient , Research grant and Research support
Biocryst: Grant Investigator , Research support

W. Schaffner, None

C. G. Grijalva, GSK, Pfizer: Consultant , Consulting fee

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