Stability of hepatitis A virus.

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Hepatitis A virus (HAV) and poliovirus are significant human pathogens.
• Understanding viral stability is crucial for disinfection and prevention strategies.

Purpose of the Study:

• To compare the stability of Hepatitis A virus (HAV) and poliovirus type 2 under identical conditions.
• To investigate the impact of temperature, pH, and salt concentration on viral integrity.

Main Methods:

• Comparative stability assays at varying pH, temperature, and salt concentrations.
• Thermal inactivation studies measuring the temperature for 50% disintegration (T50,10).
• Analysis of viral RNA release and capsid structure changes upon heating.

Main Results:

• Both viruses showed similar resistance between pH 3 and 11.
• HAV demonstrated significantly higher thermal stability (T50,10 = 61°C) compared to poliovirus (T50,10 = 43°C) at pH 7.0.
• 1 M MgCl2 increased T50,10 for poliovirus to 61°C and for HAV to 81°C.
• Heating HAV led to RNA release and formation of empty capsids, which retained serological reactivity until further heating.

Conclusions:

• HAV is more thermostable than poliovirus.
• Magnesium ions significantly enhance the heat resistance of both viruses.
• HAV capsid dissociation products retain antigenicity, but this is lost upon excessive heating.