A state-by-state survey of ticks recorded from humans in the United States
Merten, H.A.; Durden, L.A.
Journal of Vector Ecology Journal of the Society for Vector Ecology 25(1): 102-113
2000
ISSN/ISBN: 1081-1710 PMID: 10925803 Document Number: 512472
Based on tick specimens accessioned into the U.S. National Tick Collection, the species of ticks recorded as ectoparasites of humans are documented and compared for 49 U.S. states. A total of 44 tick species was recorded as parasites of humans, consisting of 11 species of Argasidae and 33 species of Ixodidae. Four of the hard tick species are not native to the U.S. and were removed from travelers returning from foreign destinations. Therefore, we record 40 of the 84 species of U.S. ticks as ectoparasites of humans. Predictably, in the southern U.S. and Atlantic states, all active stages of Amblyomma americanum were common ectoparasites of humans. Also, in the eastern U.S., adults of Dermacentor variabilis, and all active stages (especially adults) of Ixodes scapularis, were commonly recorded. In certain Rocky Mountain and western states, all active stages of D. andersoni predominated, whereas, in most far western states, adults of I. pacificus were relatively common parasites of humans. Parasitism by Ornithodoros spp. was mainly recorded in the western U.S. These findings, together with records of human parasitism by other tick species in the U.S., are briefly discussed with respect to tickborne disease risk.