Table 2 Test prevalence of infection with D. immitis by diagnostic test and shelter location
Diagnostic test | Brisbane dogs (n = 174) | Townsville dogs (n = 209) | All dogs (n = 383) | Prevalence difference (95% CI)a | P value b | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Positive | Prevalence (95% CI) | Age (years), median (IQR) | Positive | Prevalence (95% CI) | Age (yrs), median (IQR) | Positive | Prevalence (95% CI) | Age (yrs), median (IQR) | |||
Conventional antigen testing | 2 | 1.1% (0.1, 4.1) | 6.5 (5.0, 8.0) | 46 | 22.0% (16.6, 28.2) | 5.0 (2.0, 5.0) | 48 | 12.5% (9.4, 16.3) | 5.0 (2.0, 5.0) | 20.9% (15.0, 26.7) |  < 0.001 |
Modified Knott’s test | 2 | 1.1% (0.1, 4.1) | 6.5 (5.0, 8.0) | 35 | 16.7% (12.0, 22.5) | 4.5 (2.0, 5.0) | 37 | 9.7% (6.9, 13.1) | 4.7 (2.3, 5.0) | 15.6% (10.3, 20.9) |  < 0.001 |
Conventional antigen testing and modified Knott’s test combined | 2 | 1.1% (0.1, 4.1) | 6.5 (5.0, 8.0) | 54 | 25.8% (20.0, 32.3) | 3.0 (2.0–5.0) | 56 | 14.6% (11.2, 18.6) | 4.5 (2.0, 5.0) | 24.7% (18.5, 30.8) |  < 0.001 |
Antigen testing after heat treatment | 3 | 1.7% (0.1, 5.0) | 5.0 (2.2, 8.0) | 67 | 32.1% (25.8, 38.8) | 4 (2.0, 5.0) | 70 | 18.3% (14.5, 22.5) | 4.0 (2.0, 5.0) | 30.3% (23.7, 36.9) |  < 0.001 |