Volume 10, Number 12—December 2004
Alligators as West Nile Virus Amplifiers
|Tank||Status||No. with WNV- positive swabs||Mean first day viral sheddingb||Mean duration viral shedding (d)||Mean maximum viral load and range (log10 PFU/swab)|
|32°C parenteral||Infected (n = 6)||6||2||≥12||4.4 (3.5–4.9)|
|Tankmate (n = 2)||2||12||≥9||5.9 (4.9–6.2)|
|32°C oral||Infected (n = 2)||2||6||≥8||4.9 (3.3–5.2)|
|Tankmate (n = 6)c||4*||15||≥3||4.3 (2.0–4.8)|
|27°C parenteral||Infected (n = 6)||6||2||≥9||4.0 (1.9–4.4)|
|Tankmate (n = 2)||0||NA||NA||NA|
|27°C oral||Infected (n = 6)||5||6||≥10||4.2 (1.9–4.7)|
|Tankmate (n = 2)||1*||7||≥9||2.6 (NA)|
aFor some alligators (*), daily swabbing had stopped before or immediately after infection, so positive cloacal swabs were not detected.
bDays after injection or oral infection of the alligators; NA, not applicable.
cFour of six alligators were fed WNV-infected mice, but most likely became infected by tankmate transmission rather than oral transmission.
1 USDA National Wildlife Research Center, Fort Collins, Colorado.
2 Of alligators infected by tankmate transmission, the death rate is 20% (2/10). Of alligators held at 32°C, the death rate is 13% (2/16).