Improved method for avian influenza virus isolation from environmental water samples

Area of Science:

• Veterinary Virology
• Ecology of Infectious Diseases
• Wildlife Epidemiology

Background:

• Environmental surveillance of migratory birds is crucial for understanding avian influenza virus (AIV) ecology.
• Existing AIV isolation methods from water samples have limitations in recovery efficiency.

Purpose of the Study:

• To improve the methodology for isolating AIV from environmental water samples.
• To enhance the efficiency of AIV detection in migratory bird overwintering sites.

Main Methods:

• Modification of a previously reported AIV isolation process from environmental water.
• Experimental validation of the improved method's recovery efficiency.
• Application of the enhanced method to water samples from a Japanese overwintering site (2018/2019).

Main Results:

• The modified AIV isolation method demonstrated a 10-100-fold higher recovery efficiency compared to the original method.
• A significantly larger number of AIV isolates were obtained using the improved method during the 2018/2019 season.
• Genetic and phylogenetic analyses revealed diverse AIV subtypes and genetic constellations circulating concurrently.

Conclusions:

• The improved AIV isolation method significantly enhances environmental surveillance capabilities.
• This advancement facilitates a deeper understanding of AIV ecology and circulation in migratory aquatic birds.
• Effective monitoring of AIV in overwintering sites is critical for disease control and prevention.