Volume 32, Number 3—March 2026
CME ACTIVITY - Research
Blastomyces Urine Antigen Testing for Active Case Identification During a Blastomycosis Outbreak
, Jean Cox-Ganser, and Stella E. Hines
Table 2
Clinical factors by UAT result among employees from a medical survey conducted in a study of Blastomyces urine antigen testing for active case identification during a blastomycosis outbreak, United States*
| Clinical factor | All employees |
Employees with recent blastomycosis diagnosis‡ |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Total, n = 573 | Positive UAT, n = 52 | Negative UAT, n = 521 | p value† | Total, n = 71 | Positive UAT, n = 27 | Negative UAT, n = 44 | p value† | ||
| No. symptoms potentially related to blastomycosis | |||||||||
| 0 | 184 (32) | 5 (10) | 179 (34) | <0.001 | 4 (6) | 1 (4) | 3 (7) | 0.75 | |
| 1 | 156 (27) | 5 (10) | 151 (29) | 5 (7) | 1 (4) | 4 (9) | |||
| >2 |
231 (40) |
42 (81) |
189 (36) |
62 (87) |
25 (93) |
37 (84) |
|||
| No. medical findings potentially related to blastomycosis | |||||||||
| 0 | 479 (84) | 28 (54) | 451 (87) | <0.001 | 16 (23) | 6 (22) | 10 (23) | 0.96 | |
| >1 |
92 (16) |
24 (46) |
68 (13) |
55 (77) |
21 (78) |
34 (77) |
|||
| Days from symptom onset to test, median (IQR)§ |
NA |
NA |
NA |
NA |
48 (39–69) |
47 (31–70) |
52 (40–69) |
0.32 |
|
| Potentially immunocompromised¶ | |||||||||
| Yes | 64 (11) | 7 (13) | 57 (11) | 0.58 | 13 (18) | 6 (22) | 7 (16) | 0.54 | |
| No |
509 (89) |
45 (87) |
464 (89) |
58 (82) |
21 (78) |
37 (84) |
|||
| Pneumonia diagnosis | |||||||||
| Yes | 26 (5) | 8 (15) | 18 (3) | 0.001 | 17 (24) | 7 (26) | 10 (23) | 0.76 | |
| No |
543 (95) |
44 (85) |
499 (97) |
54 (76) |
20 (74) |
34 (77) |
|||
| Hospitalized for blastomycosis§ | |||||||||
| Yes | NA | NA | NA | 11 (16) | 8 (31) | 3 (7) | 0.02 | ||
| No |
NA |
NA |
NA |
58 (84) |
18 (69) |
40 (93) |
|||
| Antifungal drugs initiated§ | |||||||||
| Yes | NA | NA | NA | 65 (93) | 25 (96) | 40 (91) | 0.64 | ||
| No |
NA |
NA |
NA |
5 (7) |
1 (4) |
4 (9) |
|||
| Days from antifungal drug initiation to antigen test, median (IQR)§ | NA | NA | NA | 31 (18–41) | 29 (13–41) | 33 (22–40) | 0.36 | ||
*Values are no. (%) except as indicated. Numbers might not reach column total because of missing responses. UAT, urine antigen test; IQR, interquartile range; NA, not applicable. †Wilcoxon rank sum tests for continuous variables and Pearson χ2 tests or Fisher exact tests for categorical variables were used to test differences by urine antigen test result. ‡Recent diagnosis of blastomycosis included employees the Michigan Department of Health and Human Services identified as having confirmed or probable blastomycosis during the paper mill outbreak as of April 21, 2023, or self-reported healthcare provider-diagnosed blastomycosis on the NIOSH medical survey questionnaire. §Data were only collected for employees with a recent diagnosis of blastomycosis (n = 71) during the outbreak and thus not available for all employees. ¶Potentially immunocompromised was defined as reporting diabetes, an autoimmune disease, taking immunosuppressive medication, or an organ transplant.
1These first authors contributed equally to this article.