Volume 18, Number 9—September 2012
Letter
Contaminated Soil and Transmission of Influenza Virus (H5N1)
Table
Clinical, virologic, and serologic results obtained from chickens exposed to soils experimentally contaminated with influenza virus (H5N1)*
| Protocol | Sandy topsoil (rice fields) | Building sand | Soil-based compost |
|---|---|---|---|
| Low-dose contamination | |||
|
Clinical signs |
None | None | None |
|
Mortality rate |
None | None | None |
|
Virus in postmortem samples |
NA | NA | NA |
|
Seroconversion rate |
None | 33% at day 24 | 50% at day 24 |
| High-dose contamination | |||
|
Clinical signs |
None | None | None |
|
Mortality rate |
None | 100% by day 4 | 100% by day 4 |
|
Virus in postmortem samples |
NA | Yes | Yes |
|
Seroconversion rate |
None | NA | NA |
*Low-dose contamination protocol, exposure of the chickens to soil inoculated with 1 infectious unit on day 0, 2 on day 6, 4 on day 12, and 8 on day 18. High-dose contamination protocol, exposure of the chickens to soil inoculated with 8 infectious units on day 0, 12 on day 6, 16 on day 12, and 20 on day 18. In each experiment, 10–20 chickens were exposed to contaminated soils. Each experiment was repeated twice. For each experiment, a control group was established (same number of chickens exposed to noncontaminated soils; no deaths were observed in control groups). NA, not applicable.