Influenza Cases Data - 2025-2026 Season for Delaware

Influenza Positive Cases

Showing data for

Data are current as of 12/20/2025

Most recent dashboard update: 12/24/2025

Key Case Indicators

Delaware

New Flu Cases

Week 51 (12/14/2025 - 12/20/2025)

894

cases

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Delaware

Total Flu Cases

Week 40 to 51 (9/28/2025 - 12/20/2025)

1,670

cases

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Cumulative Flu Cases

Total Flu Cases for Delaware

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Total Flu Cases by County (Cumulative)

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New Cases (Current Season)

New Flu Cases for Delaware

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Confirmed Flu Cases (State and County)

Influenza Cases are confirmed via PCR testing

2025 - 2026Influenza Season (Current)¹

Location	Week 51 12/21/2026 - 12/27/2026	Year to Date2
Delaware	894	1,670
New Castle County	413	804
Sussex County	230	447
Kent County	247	406

2024 - 2025Influenza Season

Location	Week 51 12/14/2025 - 12/20/2025	Year to Date2
Delaware	237	634
New Castle County	143	332
Sussex County	36	102
Kent County	58	200

2023 - 2024Influenza Season

Location	Week 51 12/15/2024 - 12/21/2024	Year to Date2
Delaware	511	1,527
New Castle County	236	735
Sussex County	137	379
Kent County	138	413

2022 - 2023Influenza Season

Location	Week 51 12/17/2023 - 12/23/2023	Year to Date2
Delaware	891	7,788
New Castle County	373	3,528
Sussex County	306	2,258
Kent County	212	2,003

Footnotes:
1. There may be technical discrepancies of reporting numbers week to week due to retroactive reporting or reclassification of cases.
2. YTD stands for “Year to Date” and represents the cumulative number of cases through the current MMWR Week being assessed for the current flu season.
3. Percentage of cases for the cumulative count of confirmed cases through the influenza season to the current MMWR Week.

Confirmed Flu Cases by Age Group (Delaware)

Cell counts with less than 10 cases are suppressed for smaller age groups.

2025 - 2026Influenza Season (Current)¹

Age	Week 51 12/21/2026 - 12/27/2026	Year to Date2
0 - 4	152	301
5 - 11	231	412
12 - 17	153	239
18 - 34	167	297
35 - 49	52	105
50 - 64	54	118
65+	85	198

2024 - 2025Influenza Season

Age	Week 51 12/14/2025 - 12/20/2025	Year to Date2
0 - 4	35	112
5 - 11	46	124
12 - 17	21	52
18 - 34	50	110
35 - 49	20	81
50 - 64	26	67
65+	39	88

2023 - 2024Influenza Season

Age	Week 51 12/15/2024 - 12/21/2024	Year to Date2
0 - 4	53	197
5 - 11	85	265
12 - 17	35	113
18 - 34	87	239
35 - 49	79	232
50 - 64	86	243
65+	86	238

2022 - 2023Influenza Season

Age	Week 51 12/17/2023 - 12/23/2023	Year to Date2
0 - 4	138	1,301
5 - 11	151	1,952
12 - 17	94	953
18 - 34	154	1,329
35 - 49	92	693
50 - 64	110	717
65+	152	843

Confirmed Cases of Influenza by Type and Subtype/Lineage

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Sections in Influenza Dashboard

Overview Cases Hospitalizations Vaccinations

Location

Week 51

12/21/2026 - 12/27/2026

Year to Date2

Delaware

894

1,670

New Castle County

413

804

Sussex County

230

447

Kent County

247

406

Location

Week 51

12/14/2025 - 12/20/2025

Year to Date2

Delaware

237

634

New Castle County

143

332

Sussex County

102

Kent County

200

Location

Week 51

12/15/2024 - 12/21/2024

Year to Date2

Delaware

511

1,527

New Castle County

236

735

Sussex County

137

379

Kent County

138

413

Location

Week 51

12/17/2023 - 12/23/2023

Year to Date2

Delaware

891

7,788

New Castle County

373

3,528

Sussex County

306

2,258

Kent County

212

2,003

Age

Week 51

12/21/2026 - 12/27/2026

Year to Date2

0 - 4

152

301

5 - 11

231

412

12 - 17

153

239

18 - 34

167

297

35 - 49

105

50 - 64

118

65+

198

Age

Week 51

12/14/2025 - 12/20/2025

Year to Date2

0 - 4

112

5 - 11

124

12 - 17

18 - 34

110

35 - 49

50 - 64

65+

Age

Week 51

12/15/2024 - 12/21/2024

Year to Date2

0 - 4

197

5 - 11

265

12 - 17

113

18 - 34

239

35 - 49

232

50 - 64

243

65+

238

Age

Week 51

12/17/2023 - 12/23/2023

Year to Date2

0 - 4

138

1,301

5 - 11

151

1,952

12 - 17

953

18 - 34

154

1,329

35 - 49

693

50 - 64

110

717

65+

152

843