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Table 1 Infection rates of Rickettsiales bacteria detected in nested PCR assays and identified by sequencing for tick species

From: Prevalence of Rickettsiales in ticks removed from the skin of outdoor workers in North Carolina

  

Number infected (% infected for each tick species)

Bacteria

Year

A. americanum

A. maculatum

D. variabilis

I .scapularis

All species

(n  = 821 [734])a

(n= 8)

(n  = 37)

(n  = 8)

(n  = 874 [787])a

Rickettsia

2011

257 (70.6)

4 (57.1)

2 (20.0)

4 (100.0)

267 (69.4)

 

2012

202 (54.6)

-b

8 (29.6)

2 (50.0)

212 (52.7)

 

Total

459 (62.5)

4 (50.0)

10 (27.0)

6 (75.0)

479 (60.9)

E. ewingii

2011

15 (4.1)

-

-

-

15 (3.9)

 

2012

37 (10.0)

-

3 (11.1)

-

40 (10.0)

 

Total

52 (7.1)

-

3 (8.1)

-

55 (7.0)

E. chaffeensis

2011

5 (1.4)

1 (14.3)

-

-

6 (1.6)

 

2012

8 (2.2)

-

-

-

8 (2.0)

 

Total

13 (1.8)

1 (12.5)

-

-

14 (1.8)

A. phagocytophilum

2011

-

-

-

-

-

 

2012

2 (0.5)

-

-

-

2 (0.5)

 

Total

2 (0.3)

-

-

-

2 (0.3)

  1. aNumbers in the brackets represent the number of DNA samples tested for Rickettsiales bacteria. DNA samples were extracted from individual ticks and pools of A. americanum larvae. In 2011, 48 larvae ticks were pooled (9 and 1 pools containing five and three larvae, respectively). In 2012, 63 ticks were pooled (11, 2 and 1 pools containing five, three and two larvae, respectively). The number of the DNA extractions was used as a denominator to calculate infection rates shown in the table.
  2. bThe minus symbol indicates that no positive specimens were found among the submitted specimens for this tick species.