Lyme Disease: Data and Statistics
From 2019 to 2023, over 1,500 cases of Lyme disease were reported in Delaware. In 2023, 349 cases of Lyme disease were reported in Delaware for an incidence rate of 34 cases per 100,000 population.
Lyme Disease Case Counts and Incidence Rates by Year and County, Delaware, 2019-2023
| CASE COUNTS | INCIDENT RATE PER 100,000 POPULATION | ||||
| YEAR | NEW CASTLE COUNTY | KENT
COUNTY | SUSSEX
COUNTY | DELAWARE | DELAWARE |
| 2023 | 213 | 53 | 83 | 349 | 33.8 |
| 2022 | 192 | 54 | 52 | 298 | 29.3 |
| 2021 | 97 | 18 | 25 | 140 | 14.0 |
| 2020 | 250 | 43 | 61 | 354 | 35.8 |
| 2019 | 439 | 84 | 135 | 658 | 67.6 |
| * These data include confirmed and probable cases according to national surveillance case definitions adopted by the Council of State and Territorial Epidemiologists (CSTE). The Lyme disease case definition, which was changed in 2022, may be found here. All rates are calculated per 100,000 population based on the U.S. Census Bureau’s population estimates (Current year incidence rates and case count subject to change when new population estimates are published, and data is finalized). | |||||
Source: Delaware Department of Health and Social Services, Division of Public Health, Office of Infectious Disease Epidemiology, Delaware Electronic Reporting and Surveillance System
Spotted Fever Group Rickettsiosis
Data and Statistics
From 2019 to 2023, over 75 cases of Spotted Fever Group Rickettsiosis (SFGR) were reported in Delaware. In 2023, 5 cases of SFGR were reported in Delaware for an incidence rate of 0.5 cases per 100,000 population.
Spotted Fever Group Rickettsiosis Case Count and Incidence Rates by Year and County, Delaware, 2019-2023
| CASE COUNTS | INCIDENT RATE PER 100,000 POPULATION* | ||||
| YEAR | NEW CASTLE COUNTY | KENT COUNTY | SUSSEX COUNTY | STATE | |
| 2023 | 1 | 0 | 4 | 5 | 0.5 |
| 2022 | 4 | 0 | 0 | 4 | 0.4 |
| 2021 | 7 | 1 | 11 | 19 | 1.9 |
| 2020 | 4 | 5 | 10 | 19 | 1.9 |
| 2019 | 18 | 5 | 13 | 36 | 3.7 |
| * Rates based on small numbers (less than 20) result in a large relative standard error, indicating an imprecise estimate that is unstable and unreliable. + These data include confirmed and probable cases according to national surveillance case definitions adopted by the Council of State and Territorial Epidemiologists (CSTE). The Spotted Fever Group Rickettsiosis (SFGR) case definition may be found here. Spotted Fever Group Rickettsiosis was previously called Rocky Mountain Spotted Fever. All rates are calculated per 100,000 population based on the U.S. Census Bureau’s population estimates (Current year incidence rates and case count subject to change when new population estimates are published, and data is finalized). | |||||
Source: Delaware Department of Health and Social Services, Division of Public Health, Office of Infectious Disease Epidemiology, Delaware Electronic Reporting and Surveillance System
Office of Infectious Disease Epidemiology
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