Table 1.

Summary of major tick-borne diseases of humans in the United States and their etiological agents, primary vectors and vertebrate reservoirs

Disease	Etiological agent(s)	Primary vector(s)	Vertebrate reservoir(s)
Anaplasmosis	Anaplasma phagocytophilum	Ixodes scapularis	Peromyscus leucopus, Sciurus spp., Neotoma spp., Tamias spp., Blarina brevicauda1
		Ixodes pacificus
Babesiosis	Babesia microti	Ixodes scapularis	Peromyscus leucopus2
Borrelia miyamotoi disease	Borrelia miyamotoi	Ixodes scapularis, Ixodes pacificus	Peromyscus leucopus3/ not determined/ (transovarial transmission)
Colorado tick fever	Colorado tick fever virus (coltivirus)	Dermacentor andersoni	Spermophilus lateralis4
Ehrlichiosis	Ehrlichia muris eauclairensis	Ixodes scapularis	Not determined
	Ehrlichia chaffeensis	Amblyomma americanum	Odocoileus virginianus5
	Ehrlichia ewingii	Amblyomma americanum	Odocoileus virginianus6
Heartland virus disease	Heartland virus (phlebovirus)	Amblyomma americanum	Not determined
Lyme disease	Borrelia burgdorferi	Ixodes scapularis, Ixodes pacificus	Peromyscus leucopus, Sciurus griseus Tamias spp.7
	Borrelia mayonii	Ixodes scapularis	Not determined
Powassan encephalitis	Powassan virus (flavivirus)	Ixodes scapularis	Peromyscus leucopus8
Rickettsia parkeri rickettsiosis	Rickettsia parkeri	Amblyomma maculatum	Not determined9
Rocky Mountain spotted fever	Rickettsia rickettsii	Dermacentor variabilis, Dermacentor andersoni, Rhipicephalus sanguineus s. l.	(transovarial transmission), Microtus spp., Spermophilus spp., Sylvilagus Tamias spp.10
Pacific Coast tick fever	Rickettsia philipii	Dermacentor occidentalis	Not determined11
Tularemia	Francisella tularensis	Amblyomma americanum	Various terrestrial and aquatic mammals12
		Dermacentor variabilis
		Dermacentor andersoni

¹(Foley and others 2008; Keesing and others 2012; Nieto and Foley 2009; Telford and others 1996).

²(Telford and Spielman 1993).

³(Barbour et al. 2009; Castillo and others 2015).

⁴(Burgdorfer 1977).

⁵(Lockhart et al. 1997a).

⁶(Yabsley et al. 2002).

⁷(Lane et al. 2005; Mather et al. 1989).

⁸(Ebel 2010).

⁹(Paddock and Goddard 2015).

¹⁰(Burgdorfer 1977).

¹¹(Padgett et al. 2016).

¹²(WHO 2007).