Persistence of poliovirus 1 in soil and on vegetables grown in soil previously flooded with inoculated sewage sludge or effluent

Abstract

Land disposal of sewage sludge and effluent is becoming a common practice in the United States. The fertilizer content and humus value of such wastes are useful for agricultural purposes, and the recycling of sewage onto the land eliminates many of our stream pollution problems. The potential exists for crops grown in such irrigated soil to be contaminated by viruses that may be present in the sewage. Studies were initiated to determine viral persistence in soil and on crops grown under natural conditions in field plots that had been flooded to a depth of 1 inch (2.54 cm) with poliovirus 1-inoculated sewage wastes. Lettuce and radishes were planted in sludgeor effluent-flooded soil. In one study, the vegetables were planted 1 day before flooding, and in another they were planted 3 days after the plots were flooded. Survival of poliovirus 1 in soil irrigated with inoculated sewage sludge and effluent was determined during two summer growing seasons and one winter period. The longest period of survival was during the winter, when virus was detected after 96 days. During the summer, the longest survival period was 11 days. Poliovirus 1 was recovered from the mature vegetables 23 days after flooding of the plots had ceased. Lettuce and radishes are usually harvested 3 to 4 weeks after planting.

Sources and contamination routes of microbial pathogens to fresh produce during field cultivation: A review

“…This was done for 123 days spanning through spring, summer and winter seasons. Poliovirus survived best during winter (when it was detected after 96 days), but during summer, the longest survival period was 11 days (Tierney et al, 1977). Parasites seem to prefer warm temperature conditions.…”

Scientific Opinion on the risk posed by pathogens in food of non‐animal origin. Part 2 (Salmonella and Norovirus in leafy greens eaten raw as salads)

“…Among sewage-sludge treatments used in practice (6 days duration), only thermophilic processes inactivated pathogenic viruses other than Norovirus (Rotavirus and Enterovirus) (Spillmann et al, 1987). The fate of viruses from sewage sludge or sewage effluents after application to soil used for vegetable production was investigated for enteroviruses (Tierney et al, 1977) in outdoor experimental plots. The population of infectious enteroviruses declined in the soil but some samples of lettuce planted just after or just before sewage application, were contaminated with these viruses at harvest.…”

Hepatitis viruses and emerging viruses

“…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). It has also been demonstrated to survive for weeks to months on fresh and frozen produce, and simple washing does not appear to effectively eliminate poliovirus from food surfaces (Kurdziel et al, 2001;Lukasik et al, 2003).…”