Effect of Sodium Chloride, Sodium Nitrite and Sodium Nitrate on the Infectivity of Hepatitis E Virus

Abstract

Hepatitis E virus (HEV) infection can cause acute and chronic hepatitis in humans. The zoonotic HEV genotype 3, which is highly prevalent in Europe, is mainly transmitted by consumption of raw meat and raw meat products produced from infected pigs or wild boars. High salt concentrations represent an important measure to preserve meat products and to inactivate foodborne pathogens. Here, an HEV preparation in phosphate-buffered saline (PBS) was subjected to different salt concentrations and the remaining infectivity was measured in a cell culture assay. Treatments with up to 20% sodium chloride for 24 h at 23 °C, with and without addition of 0.015% sodium nitrite or 0.03% sodium nitrate, did not lead to virus inactivation as compared to PBS only. Conditions usually applied for short-term and long-term fermented raw sausages were simulated by incubation at 22 °C for up to 6 days and at 16 °C for up to 8 weeks, respectively. Only 2% sodium chloride with 0.015% sodium nitrite showed a weak (< 1 log 10), but significant, infectivity reduction after 2 and 4 days as compared to PBS only. Addition of 2% sodium chloride and 0.03% sodium nitrate showed a slight, but not significant, decrease in infectivity after 2 and 8 weeks as compared to PBS only. In conclusion, HEV is highly stable at high salt concentrations and at salt conditions usually applied to preserve raw meat products.

Hepatitis E: An update on One Health and clinical medicine

“…Other factors usually applied for conservation of food are lowering pH and increasing salt concentrations. However, recent investigations using a cell culture isolate indicate a very high stability of HEV against pH 2‐9 as well as against the highest salt concentrations usually applied during meat production 46,47 . Consumption of under‐cooked raw meat products, should therefore be avoided by individuals who are at high risk for development of severe hepatitis E.…”

Detection of Enteric Viruses and Core Microbiome Analysis in Artisanal Colonial Salami-Type Dry-Fermented Sausages from Santa Catarina, Brazil

“…High salt concentrations are also used to preserve meat products and to inactivate foodborne pathogens. Wolff et al [47] tested the effects of NaCl, sodium nitrite, and sodium nitrate concentrations on the infectivity of HEV. Conditions consistent with those in fermented sausages were simulated.…”

Stability of Hepatitis E Virus After Drying on Different Surfaces

“…Cell culture systems assessing the infectivity of HEV in solutions have been improved recently (Capelli et al, 2020;Meister et al, 2019;Schemmerer et al, 2016Schemmerer et al, , 2019Todt et al, 2020), but are still laborious and time-consuming compared to many other viruses. Recent stability studies using the cell culture-adapted HEV strain 47832c in phosphate-buffered saline (PBS) showed a very high resistance of HEV against a broad pH range and high salt concentrations (Wolff et al, 2020a(Wolff et al, , 2020b. Conditions prevailing in raw sausage production could not completely inactivate HEV, indicating that infectious virus can be expected in raw sausages if sufficiently contaminated starting material was used (Wolff et al, 2020a(Wolff et al, , 2020b.…”

“…Recent stability studies using the cell culture-adapted HEV strain 47832c in phosphate-buffered saline (PBS) showed a very high resistance of HEV against a broad pH range and high salt concentrations (Wolff et al, 2020a(Wolff et al, , 2020b. Conditions prevailing in raw sausage production could not completely inactivate HEV, indicating that infectious virus can be expected in raw sausages if sufficiently contaminated starting material was used (Wolff et al, 2020a(Wolff et al, , 2020b. Another scenario of food contamination could involve cross-contamination via surfaces used during food production and preparation.…”