Table 1.

Surveys for SFG Rickettsia in adult Dermacentor variabilis east of the Mississippi since 2000

State	Number tested	Rickettsia rickettsii	Rickettsia amblyommatis	Rickettsia parkeri	Rickettsia montanensis	Total % SFG Rickettsia	Reference
MD	392	0	0	0	3.8	6.1	41
TN	548	0	2.5	NT	10	15	42
KY	179	0	1.1	0.5	4.4	5	43
US	1,400	0.07	0.1	0	3.8	4	37*
VA	522†	0	0	0	1.7	1.7	44
VA	2,276	0	0.04	0.75	0.18	0.96	45
KY, TN	299	0	0	0	3.3	3.3	46
US	4,792	NT	NT	NT	2.8	2.8	47‡
TN	2,515	0	0	0	1.2	3.6	48§
NC	532	0.9	11.8	0.6	2	54.7‖	14‖
12 states	284	0	3.5	0	2.1	5.3	49*
Mean#	–	0.10 ± 0.55	1.90 ± 7.24	0.21 ± 0.62	3.21 ± 5.06	–	–

NT = not tested; SFG = spotted fever group. For each Rickettsia species, numbers in columns represent per cent prevalence. Rickettsia other than those listed are included under Total % SFG Rickettsia. We only included studies with a minimum of 100 field-collected ticks and excluded studies focusing on nonhuman host-associated ticks.

^*Used the data from mid-Atlantic states only.

^†Tested in 153 pools.

^‡Only looked for R. montanensis.

^§Only sequenced 31.

^‖This includes all Rickettsia (SFG and typhus group as well as several candidate Rickettsia).

^¶Prevalence of each Rickettsia species was calculated based on total number of ticks tested.

^#Means ± 1.96 × SD (95% CI).