Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 10, Number 8—August 2004

Dispatch

Spotted-Fever Group Rickettsia in Dermacentor variabilis, Maryland

Nicole C. Ammerman*, Katherine I. Swanson*, Jennifer M. Anderson*, Timothy R. Schwartz*, Eric C. Seaberg*, Gregory E. Glass*, and Douglas E. Norris*Comments to Author 
Author affiliations: *Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA

Main Article

Table 1

Characteristics of Dermacentor variabilis collected in Maryland, 2002a

Characteristic N % infection with any Rickettsia organisms (95% CI) % infection with SFG Rickettsia (%) (95% CI)
All ticks
392
6.1 (4.0–9.0)
3.8 (2.2–6.3)
Sex

pb = 1.000
p = 1.000
Male
185
5.9 (3.0–10.4)
3.8 (1.5–7.6)
Female
207
6.3 (3.3–10.5)
3.9 (1.7–7.4)
County of collection

p = 0.052
p = 0.024
Anne Arundel
1
0 (0–97.5)
0 (0–97.5)
Baltimore
342
6.1 (3.8–9.2)
3.5 (1.8–6.0)
Calvert
17
0 (0–19.5)
0 (0–19.5)
Charles
18
0 (0–18.5)
0 (0–18.5)
Prince George’s
1
100 (2.5–100)
100 (2.5–100)
Saint Mary’s
13
15.4 (1.9–45.4)
15.4 (1.9–45.4)
Month collected

p = 0.007
p = 0.101
April
146
4.8 (1.9–9.6)
4.8 (1.9–9.6)
May
108
4.6 (1.5–10.5)
1.9 (0.2–6.5)
June
78
2.6 (0.3–9.0)
1.3 (0.03–6.9)
July/August
58
17.2 (8.6–29.4)
8.6 (2.9–19.0)
Unknownc 2 0 0

aCI, confidence interval; SFG, spotted fever group.
bFisher exact p values.
cTicks with unknown month of collection were excluded from the statistical analyses for this characteristic.

Main Article

TOP