Table 1. Characteristics for patients with acute Q fever and control group with negative serologic results for Q fever, the Netherlands*.
| Characteristic | Study group | Control group | p value |
|---|---|---|---|
| No. patients | 82 | 52 | NS† |
| Male sex, no. (%) | 53 (65) | 38 (73) | NS‡ |
| Mean ± SD age, y (range) | 52 ± 16 (23–91) | 59 ± 16 (19–85) | 0.027† |
| Mean no. days between first day of sickness and presentation | 5.5 | 5.4 | NS† |
| History of lung disease | 8/78 (10) | 18/51 (35) | 0.001‡ |
| Immunocompromised§ | 5/81 (6) | 13/51 (25) | 0.002‡ |
| Valvular dysfunction | 8/82 (10) | 3/52 (6) | NS‡ |
| Valve prosthesis | 3/82 (4) | 0/52 (0) | NS‡ |
| Aneurysm | 2/82 (2) | 3/52 (6) | NS‡ |
| Vascular prosthesis | 3/82 (4) | 3/52 (6) | NS‡ |
| Liver disease | 1/82 (1) | 1/52 (2) | NS‡ |
| Malignancy | 2/82 (2) | 9/52 (17) | 0.002‡ |
| Diabetes | 9/82 (11) | 7/52 (13) | NS‡ |
| Contact with cattle | 29/47 (62) | 8/20 (40) | NS‡ |
| History of smoking | 58/74 (78) | 25/44 (57) | 0.013‡ |
| Alcohol use | 17/44 (39) | 12/27 (44) | NS‡ |
| Illicit drugs | 4/35 (11) | 0/18 (0) | NS‡ |
| Proton pump inhibitors¶ | 13/82 (16) | 22/52 (42) | 0.001‡ |
| Corticosteroids¶ | 5/82 (6) | 10/51 (20) | 0.017‡ |
*Values are no. positive/no. tested (%) unless otherwise indicated. NS, not significant. †By Student t-test. ‡By χ2 test. §Also includes patients using corticosteroids. ¶Only medications that differed significantly between groups is shown.