Stability of hepatitis E virus at different pH values

Area of Science:

• Food Microbiology
• Virology
• Public Health

Background:

• Hepatitis E virus (HEV) causes acute and chronic hepatitis.
• Zoonotic HEV genotype 3 is transmitted via raw/fermented meat from pigs/boars.
• pH reduction is a food processing hurdle, but HEV pH stability is unknown.

Purpose of the Study:

• To determine the pH stability of HEV genotype 3.
• To assess HEV infectivity under simulated food processing conditions.

Main Methods:

• Cell culture-adapted HEV strain 47832c was treated in phosphate-buffered saline (PBS) at various pH levels (1-10).
• Virus infectivity was measured by focus forming units.
• Simulated meat curing conditions (pH 4.5-6.5) were tested at 4°C and room temperature for 7 days.

Main Results:

• HEV showed minimal infectivity loss between pH 2-9 after 3 hours at room temperature.
• Significant infectivity loss occurred at pH 10 (3 log10) and complete loss at pH 1 (<3.5 log10).
• No significant HEV infectivity difference was observed under simulated curing conditions (pH 4.5-6.5, 4°C, 7 days) compared to neutral pH.

Conclusions:

• HEV genotype 3 exhibits remarkable stability across a wide pH range relevant to food processing.
• Fermented meat products may contain infectious HEV if made from contaminated raw materials.
• Further studies should investigate the impact of salt concentration and water activity on HEV inactivation.