Quantitative differential analysis of norovirus outbreak samples using RT-ddPCR.

Area of Science:

• Public Health
• Infectious Diseases
• Molecular Diagnostics

Background:

• Noroviruses are highly infectious agents causing acute gastroenteritis, leading to frequent outbreaks.
• Rapid identification and isolation of contamination sources are crucial for outbreak prevention.
• Understanding norovirus transmission routes is essential for effective control strategies.

Purpose of the Study:

• To investigate the prevalence of norovirus GII genotypes in various sample types from outbreaks.
• To compare the sensitivity of real-time PCR and reverse transcription droplet digital PCR (RT-dPCR) for norovirus detection.

Main Methods:

• Collection and categorization of 376 samples from nine norovirus outbreaks (patient, asymptomatic, cook, environmental).
• Detection of norovirus GII using real-time PCR and sequencing.
• Quantification of norovirus in sample categories using RT-dPCR, focusing on limit of blank and detection limit.

Main Results:

• Norovirus GII was detected in 34.9% of patient samples and 19.2% of asymptomatic individual samples.
• Lower detection rates were observed in environmental (2.4%) and cook (1.4%) samples.
• RT-dPCR revealed contrasting results compared to real-time PCR, highlighting its superior sensitivity.

Conclusions:

• Norovirus GII is frequently detected in patients and asymptomatic individuals during outbreaks.
• RT-dPCR demonstrates higher sensitivity for norovirus detection compared to real-time PCR.
• Sensitive diagnostic methods are vital for accurate norovirus surveillance and outbreak management.