Week ending 15 December 2018 (week 50)

The number of positive respiratory specimens in week 50 increased by 150% from the previous week, with 250 positive specimens in week 50 compared to 104 positive speci-mens in week 49. Influenza A accounted for 43% of the total respiratory specimen tests. The percentage of influenza-like illness visits in the Active Duty and non-AD popula-tions increased from week 49 by 4%. No influenza-associated hospitalizations were re-ported to DRSi in weeks 49 or 50. The peak of this influenza season has yet to hit, so it is strongly recommended to get an influenza vaccination to protect against respiratory illness and to follow appropriate hand hygiene practices at all times.

Additional Resources: Army Influenza Reports; ARD Reports; AFHSC Influenza Reports; NHRC FRI Reports; DoD Pandemic Influenza Watchboard; CDC Key: ILI -Influenza-Like Illness; DRSi- Disease Reporting System Internet; NHRC- Naval Health Research Center; ADV-Adenovirus; RSV-Respiratory Syncytial Virus; DED- Disease Epidemiology Division; SM-Service Member

Questions? Email APHC DEP 410-436-7605

*Data Source: MEDPROS, ASIMS, MRRS

INFLUENZA-ASSOCIATED HOSPITALIZATIONS

DEMOGRAPHICS

Influenza Vaccination Coverage*

As of 7 November 2018

N/A DoD

89% Army Active Duty

79% Army Guard

70% Army Reserve

SUMMARY

AD: In week 50, a total of 25 cases tested positive for a respiratory specimen in the AD population, an increase since week 49. The majority of them (40%) were in the 18-29 group, followed by 28% in the 30-39 and 40-49 age groups, and 4% in the 50-59 group. There were no AD cases in the 60+ group.

Non-AD: Of the 225 positive specimens among non -AD individuals, 85% (190) were among individuals less than 18 years old.

In the civilian population, the number of states reporting widespread influenza activity increased since last week from three to now six states and Guam. Regional influenza activity was reported to the CDC by 18 states, local activity was re-ported by 19 states, and sporadic activity was reported by the District of Columbia, Puerto Rico, the US Virgin Islands, and seven states.

No cases of influenza-associated hospitalization were report-ed to DRSi in weeks 49 or 50. In the same week last season, two non-AD cases had been reported. So far this season, seven cases of influenza-associated hospitalization have been reported to DRSi in non-AD patients; there have been no re-ported cases of influenza-associated hospitalizations reported this season in the AD population.

*DRSi does not capture cases older than 65 years old for influenza-associated hospitalizations.

Click to enlarge image GEOGRAPHIC SPREAD

Week ending 15 December 2018 (week 50) Army Influenza Activity Report U.S. Army Public Health Center

LABORATORY RESPIRATORY SPECIMEN TESTING

ILI ACTIVITY - ARMY ILI ACTIVITY - UNITED STATES

The number of positive specimens in week 50 increased by 140% from week 49, with 250 posi-tive specimens in week 50 compared to 104 posi-tive specimens in week 49. RSV accounted for 48% of the positive specimens. Influenza A and B accounted for 43% and 3.6% of the specimens, respectively. Parainfluenza accounted for <1% of positive specimens, and adenovirus accounted for 4% of positive specimens. The majority of posi-tive influenza A tests in week 50 were from rapid antigen tests (RATs), followed by PCR. There were no positive cultures in week 50.

Nationwide, 1,154 specimens were tested and submitted to CDC, of which 408 (35%) were positive. Influenza A ac-counted for 98% of the total positive specimens submitted to the CDC in week 50. In the Army population, 250 (8%) of 3118 specimens tested were positive for a respiratory illness; of that, 43% (108) tested positive for influenza A. 21 (20%) of the positive influenza A specimens were from Active Duty individuals. RHC-A and RHC-C reported the majority of positive influenza A specimens, with 65 (60%) and 27 (25%) of the total influenza A positive specimens, respectively.

Nationwide in week 50, incident ILI activity was 2.7%, above to the national baseline. Regionally, the percentage of ILI outpatient visits reported to the CDC ranged from 1.1% to 3.9%. At Army medical treatment facilities, incident ILI activi-ty increased from week 49 to week 50 by 4%, and was 26% lower than in the same week last year. The majority of ILI encounters (69%) were from non-AD patients.

Locations providing week 50 laboratory data as of 19 December 2018: Ft Belvoir, Ft Benning, Ft Bliss, Ft Bragg, Ft Campbell, Ft Carson, Ft Drum, Ft Eustis, Ft Gordon, Ft Hood, Ft Huachuca, Ft Irwin, Ft Jackson, Ft Knox, Ft Leavenworth, Ft Lee, Ft Leonard Wood, Ft Meade, Ft Polk, Ft Rucker, Ft Sam Houston, Ft Sill, Ft Stewart, Ft. Wainwright, Korea, Landstuhl, Redstone Arsenal, Tripler, West Point, and Walter Reed.

*NOTE: Madigan AMC data was not received due to the switch from AHLTA/CHCS to MHS Genesis

Week ending 15 December 2018 (week 50) Army Influenza Activity Report U.S. Army Public Health Center

LABORATORY RESPIRATORY SPECIMEN TESTING

No.: Number of specimens tested during MMWR week 50 2018.

% Pos.: Percentage of positive specimens reported during MMWR week 50, 2018.

Baseline % Pos.: Percentage of positive specimens reported in MMWR week 50 during influenza seasons from September 2012 - May 2018.

Missing values indicate that specimens were not tested for the disease during the week of interest.

Week ending 15 December 2018 (week 50) Army Influenza Activity Report U.S. Army Public Health Center

Regional Health Command - Atlantic (RHC-A)

Regional Health Command - Central (RHC-C)

Regional Health Command - Europe (RHC-E)

Regional Health Command - Pacific (RHC-P)

Proportion of Influenza A Positive Specimens by Week and Region, Army Medical Laboratories, 2018-2019 as Compared to 2014-2018

Age

GroupAD

Non-AD

Ben

Season

Total

< 18 0 0 4

18-29 0 0 3

30-39 0 0 5

40-49 0 0 0

50-59 0 0 1

60+ 0 0 0

Total 0 0 13

Week 50

Age

GroupAD

Non-AD

Ben

Season

Total

< 18 0 6 28

18-29 3 1 15

30-39 2 0 13

40-49 2 1 11

50-59 0 1 2

60+ 0 0 0

Total 7 9 69

Week 50

AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD

RHC-A 0 6 3 9 1 4 2 4 2 5 7 17 4 14 12 53

RHC-C 2 9 1 10 2 11 0 12 1 7 4 12 0 18 2 25

RHC-E 0 1 1 2 1 1 0 2 - - 2 1 - - - -

RHC-P 0 2 0 2 1 2 4 6 1 2 7 8 4 7 7 9

CENTCOM - - - - - - - - - - - - - - - -

Number of Positive Influenza A Specimens by Duty Status and Region

RegionWeek 43 Week 44 Week 45 Week 46 Week 47 Week 48 Week 49 Week 50

Age Group AD

Non-AD Ben

Season Total

< 18 0 190 20218-29 10 8 5330-39 7 4 4840-49 7 4 2650-59 1 7 2260+ 0 12 17

Total 25 225 368

Week 50

Note: Reportable influenza cases are defined as only cases that have been hospitalized and are under the age of 65. See Armed Forces Reportable Medical Events Guidelines and Case Definitions for more information.Data as of 19 December 2018.

Clinic visits for ILI are obtained from ESSENCE. Data as of 19 December 2018.

Week 47 Week 48 Week 49 Week 50 Season TotalRAT 15 41 38 84 275

Culture 1 2 0 0 17PCR 2 15 9 24 76

Influenza A 18 58 47 108 368Influenza B 16 11 13 9 110Adenovirus 13 11 10 11 114Enterovirus 1 0 0 0 4

Parainfluenza 24 21 7 2 179RSV 63 85 27 120 655

Negative 2284 2569 2805 2868 24905Total 2419 2755 2909 3118 26335

Test Types Among Positive Influenza A

Specimens

Army MTF Laboratory Results,

2018-19

AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD AD Non-AD

RHC-A 0 6 3 9 1 4 2 4 2 5 7 17 4 14 12 53

RHC-C 2 9 1 10 2 11 0 12 1 7 4 12 0 18 2 25

RHC-E 0 1 1 2 1 1 0 2 - - 2 1 - - - -

RHC-P 0 2 0 2 1 2 4 6 1 2 7 8 4 7 7 9

CENTCOM - - - - - - - - - - - - - - - -

Number of Positive Influenza A Specimens by Duty Status and Region

RegionWeek 43 Week 44 Week 45 Week 46 Week 47 Week 48 Week 49 Week 50