
Background: VA conducts ongoing surveillance for seasonal influenza, which is associated with significant morbidity and mortality, putting VAs large elderly population at risk. Herein we report 2015-16 VA national influenza activity and vaccination data.
Methods: Influenza-like illness (ILI); hospitalizations; outpatient visits; telephone triage (TT); antivirals; and influenza testing were obtained from VA data sources (10/4/15-4/30/16) and compared to 3 prior seasons. Vaccinations were captured from 8/1/2015. We calculated Spearman correlation coefficients for ILI visits, hospitalizations, and influenza testing with national CDC FluView data.
Results: Surveillance metrics are reported in Table 1 and Figs. 1 and 2. ILI visits ranged from 1.1-2.8% this season. Flu activity peaked later (Week 10) and fewer vaccinations were recorded. CA (556), FL (536), TX (411) and IL (300) had the highest number of lab-confirmed cases. Correlation between VA and CDC %ILI visits (.81), hospitalizations (.92), tests performed (.97), and positive tests (.99) was strong (p<.0001).
Conclusion: The 2015-16 season was mild compared to 2014-15, with fewer admissions, TT calls, influenza tests and antivirals. This and a late peak may have contributed to fewer vaccinations. Percentage of hospitalizations with an ICU stay or death was stable across seasons. VA influenza data continues to align well with CDC data.
Table 1
| 2012-13 N (%) | 2013-14 N (%) | 2014-15 N (%) | 2015-16 N (%) |
Influenza Vaccinations | 1890006 | 1940361 | 1799580 | 1749915 |
Influenza-coded Hospitalizations Unique Patients ICU Admit Death Positive Influenza Test | 2524 | 2405 | 3704 | 1819 |
2490 | 2366 | 3637 | 1795 | |
391 (16) | 491 (20) | 620 (17) | 296 (16) | |
71 (3) | 74 (3) | 117 (3) | 58 (3) | |
1492 (60) | 1654 (70) | 2869 (77) | 1378 (76) | |
Influenza-coded TT Calls | 9503 | 8423 | 10234 | 5970 |
Influenza Tests Total Positive A B Both A & B or Not Specified | 30205 | 42623 | 66113 | 49367 |
5208 (20) | 6095 (14) | 11459 (17) | 5735 (12) | |
4642 (79) | 4985 (82) | 9029 (79) | 4102 (72) | |
1147 (19) | 1060 (17) | 2340 (20) | 1570 (27) | |
119 (2) | 50 (1) | 90 (1) | 63 (1) | |
Antiviral Prescriptions Inpatient Outpatient | 21117 | 16758 | 32400 | 15496 |
6207 | 4335 | 7490 | 3605 | |
14910 | 12418 | 24910 | 11891 |
Figure 1
Figure 2

C. Lucero-Obusan,
None
A. Wendelboe, None
M. Holodniy, None