Investigation of Rotavirus Survival in Different Soil Fractions and Temperature Conditions

Rotavirus is a leading cause of gastrointestinal illness worldwide. Rotavirus transmission occurs fecalorally, and becomes a critical water quality issue when soil and water resources are contaminated with feces. Transport of pathogens to surface water sources depends on their survival in the soil, especially considering the fact that large amounts of fecal material are often applied to agricultural lands as fertilizer. In this study, rotavirus survival was investigated in three different soil fractions and at three different temperatures (4℃, 25℃ and 37℃). A rotavirus suspension was mixed with whole soil, sand, and clay and allowed to incubate for up to 18 days. Samples were collected daily to investigate virus survival over time, which was quantified using a tissue-culture infectivity assay. Results indicated, in the absence of any soil particles, rotavirus survival was highest at 4℃, with survival decreasing as temperature increased. These data also indicated whole soil had some protective effect, allowing rotavirus to survive better in soil for the entire range of temperatures and for more than a week at 37℃. The results also showed that sand fractions were the most effective media for reducing rotavirus recovery at all temperature conditions tested. Although the mechanism responsible for the low recovery from sand is unknown, there is little or no infective rotavirus extracted from sand fractions. This finding strongly supports the use of sand as a filtering material to remove rotavirus from both point and nonpoint sources of water pollution.