TABLE 1.
Detection of equine influenza virus by virus isolation, antigen detection, and RT-PCR in foals infected experimentally with A/Equi/2/Kildare/89a
| Horse and day postchallenge | VI | EID50/ml | TCID50/ml | DFAb | PCR O | PCR I | PCR M |
|---|---|---|---|---|---|---|---|
| Horse 1 | |||||||
| 1 | − | − | − | − | − | ||
| 2 | + | 101.5 | 101.25 | − | − | + | + |
| 3 | + | 101.5 | 100.75 | − | − | + | + |
| 4 | + | 101.1 | 101.75 | − | − | + | + |
| 5 | + | 101.2 | 102.5 | − | − | + | + |
| 6 | + | − | − | − | − | − | + |
| 7 | − | − | − | − | + | ||
| 8 | − | − | − | − | − | ||
| 9 | − | − | − | − | − | ||
| 10 | − | − | − | − | − | ||
| Horse 2 | |||||||
| 1 | − | − | − | − | − | ||
| 2 | + | 101 | − | − | − | − | + |
| 3 | + | 101.8 | 103 | + | + | + | NAc |
| 4 | + | 101.7 | 102.25 | ++ | − | + | + |
| 5 | + | 101.8 | 103.25 | +++ | + | + | + |
| 6 | + | 102.2 | 102.25 | +++ | − | + | + |
| 7 | + | 100.8 | − | − | − | − | + |
| 8 | − | − | − | − | − | ||
| 9 | − | − | − | − | − | ||
| 10 | − | − | − | − | − | ||
| Horse 3 | |||||||
| 1 | − | − | − | − | − | ||
| 2 | + | 101.2 | 101.5 | + | − | + | + |
| 3 | + | 101.3 | 102.75 | ++ | − | + | + |
| 4 | + | 102 | 102.25 | − | − | + | + |
| 5 | + | 102.2 | 104 | − | + | + | + |
| 6 | + | 101.8 | 102.25 | ++ | + | + | + |
| 7 | + | 101.2 | 101.75 | − | − | + | + |
| 8 | − | − | − | − | − | ||
| 9 | − | − | − | − | − | ||
| 10 | − | − | − | − | − | ||
| Horse 4 | |||||||
| 1 | − | − | − | − | + | ||
| 2 | + | − | − | − | − | − | + |
| 3 | + | 100.6 | − | − | − | − | + |
| 4 | + | 101 | 101.5 | − | + | + | + |
| 5 | + | 102.3 | 102.25 | − | + | + | + |
| 6 | + | 102.8 | 102 | − | − | + | + |
| 7 | − | − | − | − | − | ||
| 8 | − | − | − | − | − | ||
| 9 | − | − | − | − | − | ||
| 10 | − | − | − | − | − |
a
VI, virus isolation (in embryonated eggs) from the nasal secretions prior to freezing; PCR O, PCR using the NPF and NPR primers; PCR 1, nested PCR using NPF, NPR, NPFI, and NPRI; PCR M, PCR using M52C and M253R. All aliquots assayed by EID50, TCID50, DFA, and PCR had undergone a single freeze-thaw cycle.
b
For DFA scores, see Materials and Methods.
c
NA, not applicable.