Which technique is used in avian influenza surveillance?

Which technique is used in avian influenza surveillance?

• A. Visual inspection of feed troughs
• B. DNA sequencing of pathogens in market samples
• C. Environmental fecal sampling year-round, targeted
• D. Monitoring morbidity/mortality year-round, across all species

Answer: (C)

Systematic environmental sampling of feces from bird habitats is a cornerstone of avian influenza surveillance because it detects virus that birds shed into their environment, including from animals that appear healthy. Conducting this work year-round and targeting high-risk sites—such as migratory bird stopovers, wetlands with large bird concentrations, and live bird markets—captures evidence of virus circulation across species and settings without relying on sick birds or visible disease signs. This approach provides timely, broad-based data, supports early warning, and is more efficient for monitoring across large areas than trying to sample every individual bird. Visual inspection of feed troughs only gauges general health or management conditions and does not reliably reveal influenza presence. Sequencing pathogens in market samples is a valuable laboratory tool for confirming and characterizing viruses, but as a primary surveillance technique it is more resource-intensive and limited to collected samples, whereas environmental fecal sampling can detect circulation more broadly and routinely. Monitoring morbidity and mortality across all species can indicate problems but may miss asymptomatic circulation or early introductions, making it less sensitive for proactive surveillance.

Systematic environmental sampling of feces from bird habitats is a cornerstone of avian influenza surveillance because it detects virus that birds shed into their environment, including from animals that appear healthy. Conducting this work year-round and targeting high-risk sites—such as migratory bird stopovers, wetlands with large bird concentrations, and live bird markets—captures evidence of virus circulation across species and settings without relying on sick birds or visible disease signs. This approach provides timely, broad-based data, supports early warning, and is more efficient for monitoring across large areas than trying to sample every individual bird.

Visual inspection of feed troughs only gauges general health or management conditions and does not reliably reveal influenza presence. Sequencing pathogens in market samples is a valuable laboratory tool for confirming and characterizing viruses, but as a primary surveillance technique it is more resource-intensive and limited to collected samples, whereas environmental fecal sampling can detect circulation more broadly and routinely. Monitoring morbidity and mortality across all species can indicate problems but may miss asymptomatic circulation or early introductions, making it less sensitive for proactive surveillance.