TABLE 1.
Detection of influenza A in pasteurized retail dairy products by quantitative real-time RT-PCRa
| Product | No. positive/total tested (% positive) | Mean qrRT-PCR-based quantity estimate (non-infectious) (±standard deviation) |
|---|---|---|
| Whole milk | 16/68 (23.5) | 3.0 ± 1.1 |
| 2% reduced fat milk | 16/58 (27.6) | 3.1 ± 1.2 |
| 1% low fat milk | 9/28 (32.1) | 3.1 ± 1.2 |
| Skim milk | 4/36 (11.1) | 3.3 ± 0.7 |
| Half and half | 6/25 (24.0) | 2.3 ± 1.0 |
| Yogurt | 0/14 (0) | Not applicable |
| Cream | 3/17 (17.6) | 2.3 ± 0.9 |
| Cottage cheese | 1/21 (4.8) | 2.6 ± 0.0 |
| Sour cream | 5/30 (16.7) | 3.4 ± 1.2 |
| Total | 60/297 (20.2) | 3.1 ± 1.1 |
a
Non-infectious qrRT-PCR-based quantity estimates are expressed as log10 50% egg infectious doses determined by a standard curve using quantified virus. No infectious virus was detected in any of the qrRT-PCR-positive samples.