Ehrlichiosis and Anaplasmosis: Data and Statistics

From 2019 to 2023, over 100 cases of ehrlichiosis were reported in Delaware (Table 1). In 2023, 18 cases of ehrlichiosis were reported in Delaware for an incidence rate of 1.8 cases per 100,000 population.

Table 1. Ehrlichiosis Case Counts and Incidence Rates by Year and County, Delaware, 2019-2023

CASE COUNTS				INCIDENT RATE PER 100,000 POPULATION*
NEW CASTLE COUNTY	KENT COUNTY	SUSSEX COUNTY	DELAWARE	DELAWARE
2	4	12	18	1.8
5	2	9	16	1.6
6	3	19	28	2.8
7	1	21	29	2.9
8	5	28	41	4.2
5	5	16	26	2.7
* 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 Ehrlichiosis and Anaplasmosis case definition 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

From 2018 to 2023, close to 50 cases of Anaplasmosis were reported in Delaware (Table 2). In 2022, 9 cases of Anaplasmosis were reported in Delaware for an incidence rate of 0.9 cases per 100,000 population.

Table 2. Anaplasmosis Case Counts and Incidence Rates by Year and County, Delaware, 2019-2023

From 2019 to 2023, close to 40 cases of anaplasmosis were reported in Delaware (Table 2). In 2023, 5 cases of anaplasmosis were reported in Delaware for an incidence rate of 0.5 cases per 100,000 population.

	CASE COUNTS				INCIDENT RATE PER 100,000 POPULATION*
YEAR	NEW CASTLE COUNTY	KENT COUNTY	SUSSEX COUNTY	STATE	STATE
2023	2	1	2	5	0.5
2022	5	1	3	9	0.9
2021	3	0	5	8	0.8
2020	1	0	4	5	0.5
2019	3	1	3	7	0.7
* 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 Ehrlichiosis and Anaplasmosis case definition 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

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Ehrlichiosis and Anaplasmosis: Data and Statistics

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