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*
Table 2
Univariate odds ratio (OR) associated with any Rickettsia organism and with R. montanensis
| Variable | Rickettsia genus–positive |
R. montanensis–positive |
||||
|---|---|---|---|---|---|---|
| OR | 95% CIa | p value | OR | 95% CI | p value | |
| Sex |
||||||
| Female |
1.0 |
reference |
1.0 |
reference |
||
| Male |
0.94 |
0.41–2.16 |
0.890 |
0.98 |
0.35–2.75 |
0.967 |
| County of collection |
||||||
| Baltimore |
1.02 |
0.29–3.57 |
0.969 |
0.57 |
0.16–2.09 |
0.397 |
| All other counties |
1 |
reference |
1.0 |
reference |
||
| Month collected: |
||||||
| April |
1.0 |
reference |
1.0 |
reference |
||
| May |
0.96 |
0.30–3.12 |
0.951 |
0.37 |
0.08–1.84 |
0.227 |
| June |
0.52 |
0.11–2.58 |
0.425 |
0.26 |
0.03–2.13 |
0.209 |
| July/August | 4.14 | 1.49–11.47 | 0.006 | 1.87 | 0.57–6.16 | 0.301 |
aCI, confidence interval.
