Lone star tick
Lone Star Tick

Behaviors of Ticks that Carry It

Ehrlichiosis is transmitted by lone star ticks.

Where They are Most Often Found

The range of lone star ticks has increased and they are now found in Wisconsin, the Middle Atlantic states, up the coastline to Maine and even into Canada.


Ehrlichiosis incidence map


The American Journal of Tropical Medicine and Hygiene Increasing Incidence of Ehrlichiosis in the United States: A Summary of National Surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii Infections in the United States, 2008–2012 Jan 6, 2016 During 2008–2012, 4,613 cases of E. chaffeensis infections were reported  …The hospitalization rate (HR) was 57% and the case fatality rate (CFR) was 1%. Children aged < 5 years had the highest case fatality rate of 4%. During 2008–2012, 55 cases of E. ewingii infection were reported…. The HR was 77%; no deaths were reported. Immunosuppressive conditions were reported by 26% of cases. The overall rate for ehrlichiosis has increased 4-fold since 2000. Although previous literature suggests E. ewingii primarily affects those who are immunocompromised, this report shows most cases occurred among immunocompetent patients. This is the first report to show children aged < 5 years with ehrlichiosis have an increased CFR, relative to older patients. Ongoing surveillance and reporting of tick-borne diseases are critical to inform public health practice and guide disease treatment and prevention efforts. https://www.ajtmh.org/content/journals/10.4269/ajtmh.15-0540

CDC Emerging Infectious Diseases Ehrlichia Infections, North Carolina, USA, 2016 Nov, 2018 Nearly two thirds of persons suspected of having tickborne illness in central North Carolina, USA, were not tested for Ehrlichia. Failure to test may have resulted in a missed diagnosis for ≈13% of these persons, who were therefore substantially less likely to receive antimicrobial treatment and to have follow-up testing performed. https://wwwnc.cdc.gov/eid/article/24/11/18-0496_article