The efficiency of concentration methods used to detect enteric viruses in anaerobically digested sludge

Area of Science:

• Environmental microbiology
• Virology
• Wastewater treatment

Background:

• Biosolids can harbor enteric viruses, potentially underestimated by current recovery methods.
• Inefficient virus recovery impacts accurate risk assessment in wastewater treatment.

Purpose of the Study:

• To evaluate methods for recovering enteric viruses (adenoviruses, rotavirus, norovirus, hepatitis A) from biosolid samples.
• To assess the prevalence and resistance of these viruses post-anaerobic digestion in Brazil.

Main Methods:

• Spiking experiments using quantitative PCR to compare beef extract elution and ultracentrifugation.
• Inhibition level testing with bacteriophage PP7 as an internal control.
• Detection of adenoviruses (AdV), rotavirus A (RVA), norovirus GII (NoV GII), and hepatitis A virus (HAV).

Main Results:

• Beef extract elution proved suitable for enteric virus recovery, particularly adenoviruses.
• PCR inhibition was observed, necessitating internal controls.
• Detected viruses: AdV (90%), RVA (45%), NoV GII (45%), HAV (18%), indicating resistance to anaerobic treatment.

Conclusions:

• Enteric viruses persist after anaerobic digestion, posing potential risks.
• Beef extract elution is recommended for improved virus detection in biosolids.
• This study underscores the need for effective waste management in Brazil.