Inactivation of poliovirus in digested sludge.

Area of Science:

• Environmental Virology
• Microbiology
• Public Health

Background:

• Understanding virus inactivation in wastewater treatment is crucial for public health.
• Anaerobically digested sludge is a common byproduct of wastewater treatment.
• The potential impact of digested sludge on viral pathogens requires investigation.

Purpose of the Study:

• To investigate the effect of anaerobically digested sludge on poliovirus infectivity.
• To determine the influence of temperature and incubation time on virus inactivation.
• To elucidate the mechanism of poliovirus inactivation by digested sludge.

Main Methods:

• Poliovirus was incubated in anaerobically digested sludge at temperatures ranging from 4°C to 28°C.
• Virus infectivity was measured over time.
• Sedimentation analysis of viral particles and their ribonucleic acid (RNA) was performed.
• Viral proteins were analyzed for breakdown.

Main Results:

• Poliovirus infectivity decreased in proportion to incubation time and temperature.
• Inactivation rates were higher at warmer temperatures (e.g., >1 log/day at 28°C).
• Inactivated virus particles showed nicked RNA (approx. 70% sedimentation value) and some viral protein breakdown.
• Loss of infectivity correlated with RNA inactivation.

Conclusions:

• Anaerobically digested sludge inactivates poliovirus, with temperature and time being key factors.
• The primary mechanism involves damage to the viral RNA, possibly preceded by protein cleavage.
• This virucidal activity appears to be a result of the anaerobic digestion process, not present in raw sludge.