Enterovirus inactivation in soil

Abstract

The inactivation of radioactively labeled poliovirus type 1 and coxsackievirus B 1 in soils saturated with surface water, groundwater, and septic tank liquor was directly proportional to temperature. Virus persistence was also related to soil type and the liquid amendment in which viruses were suspended. At 37°C, no infectivity was recovered from saturated soil after 12 days; at 4°C, viruses persisted for at least 180 days. No infectivity was recovered from dried soil regardless of temperature, soil type, or liquid amendment. Additional experiments showed that evaporation of soil water was largely responsible for the decreased recovery of infectivity from drying soil. Increased rates of virus inactivation at low soil moisture levels were also demonstrated. Increasing concern over efficient use of limited water resources has resulted in research on the possible use of sewage or sewage sludges for land reclamation and fertilizer (9, 14, 18). Viruses and other pathogens remaining in the sewage or sludge could contaminate crops, surface water, or groundwater. For viral contamination to occur, however, viruses must remain infectious after a period of association with soils. Knowledge of virus persistence and movement in soils is presently incomplete and sometimes contradictory. For example, Tierney et al. (19) have shown that viruses in sewage or sludge used to irrigate crops may persist for up to 11 days in soil at summer temperatures and for over 96 days under winter conditions. Wellings et al. (23) demonstrated that enteric viruses can survive irrigation and move at least 6 m vertically and 38 m laterally through soil to monitoring wells.

Pathogens in livestock waste, their potential for movement through soil and environmental pollution

“…Soil temperature may influence the transport of microorganisms through soil by its effect on dispersal, survival or adsorption (Kemp et al, 1992). In general, low temperatures favour survival of both viruses (Yeager and O'Brian, 1979;Hurst et al, 1980) and bacteria (Kibbey et al, 1978;Zibilske and Weaver, 1978). However, the majority of studies have compared survival at 37°C with those at lower (e.g.…”

Hepatitis viruses and emerging viruses

“…The poliovirus is inactivated more readily than the hepatitis A virus by heating and storage treatments used to prepare manure for spreading on lands (Stramer and Cliver, 1984;Deng and Cliver, 1992). However, once the environment is contaminated, the poliovirus survives for weeks to months in groundwater (Yates et al, 1985;Gordon and Toze, 2003) and in soil (Yeager and O'Brien, 1979;Hurst et al, 1980). This virus has also been shown to persist for weeks to months on vegetables irrigated by spraying or flooding with contaminated waters (Tierney et al, 1977).…”

Pathogen Removal from Wastewater during Groundwater Recharge

“…Although all enteric viruses possess outer capsids comprised of polypeptide subunits and generally behave as charged, amphoteric, colloidal particles, the surfaces of the virions differ in the details of their configura tion, charge density and distribution, and other features. In fact, even the same virus can display different surface properties that will influence its physicochemical behavior as a result of conformational changes brought about by pH effects and interactions with soluble chemicals and particulate surfaces [55].…”

“…Yaeger and O'Brien [55] compared the degree of poliovirus inactiva- ? tion in eight different soils saturated with riverwater, groundwater, or septic wastewater and in the same soils that were allowed to dry out during the course of the experiment.…”

“…The effects of both drying and aerobic microbial activity may contribute to virus inactivation under these conditions. In stud ies on the mechanisms of virus inactivation in soils, Yeager and O'Brien [55] found that the loss of poliovirus infectivity in moist and dried soils resulted from irreversible damage to the virus particles, including (1) dis sociation of viral genomes and capsids, and (2) degradation of viral RNA. In both moist and dried nonsterile soils, viral RNA was released from cap sids and found in a degraded form.…”