Lab-based Surveillance

Lab-based surveillance refers to the systematic collection, analysis, and interpretation of data generated from clinical and public health laboratories to monitor infectious diseases.

It plays a crucial role in confirming diagnoses, identifying pathogens, tracking antimicrobial resistance, detecting outbreaks, and characterizing circulating strains or variants.

Unlike syndromic surveillance, which relies on symptoms, lab-based surveillance provides microbiologic or molecular confirmation of disease.

How lab-based surveillance works

It can be passive, where labs routinely report test results for notifiable diseases, or active, where specimens are deliberately collected and tested as part of a specific surveillance effort.

Types of lab-based surveillance

Various approaches support pathogen identification and monitoring across populations.

Core components of lab-based surveillance

• Routine diagnostic reporting (passive surveillance)
• Targeted specimen collection for specific pathogens (active surveillance)
• Reference lab functions like sequencing and subtyping
• Antimicrobial susceptibility testing
• Whole genome sequencing for outbreak detection
• Electronic laboratory reporting (ELR) systems

High-priority settings for lab surveillance

• Sexual health clinics
• Hospitals and emergency departments
• State and local public health labs
• Food safety and environmental testing labs
• Reference labs for rare or emerging pathogens

These settings serve as critical nodes for pathogen detection, confirmation, and characterization.

Key lab-based surveillance systems

• GISP (Gonococcal Isolate Surveillance Project)
• PulseNet for enteric pathogens
• National Respiratory and Enteric Virus Surveillance System (NREVSS)

Applications of lab surveillance data

• Monitoring antibiotic resistance trends
• Identifying genetic clusters of outbreaks
• Informing treatment guidelines and vaccine design

Case studies in lab-based surveillance

GISP and gonorrhea resistance

Clinics across the U.S. submit gonorrhea isolates for susceptibility testing to detect emerging resistance.

• Tracks resistance to cephalosporins and azithromycin
• Informs national STD treatment guidelines
• Supports timely updates to clinical practice

PulseNet and enteric pathogen detection

PulseNet uses whole genome sequencing to identify clusters of foodborne illness.

• Detects outbreaks of Salmonella, Listeria, and E. coli
• Links genetically related cases across states
• Supports source tracing and food recalls

Sequencing in respiratory virus surveillance

During COVID-19, sequencing allowed identification of new variants like Delta and Omicron.

• Used to monitor variant spread
• Guided vaccine updates and public health messaging
• Enabled international comparisons and alerts

AMR monitoring and global relevance

Lab-based resistance surveillance is essential to combat antimicrobial resistance (AMR).

• Tracks resistance in hospitals and communities
• Supports stewardship programs and policy decisions
• Feeds into WHO’s GLASS (Global Antimicrobial Resistance Surveillance System)

Real-time data for public health response

Sequencing and digital reporting have improved outbreak detection and response timeframes.

Strengths of lab-based surveillance

• High specificity and pathogen-level resolution
• Supports early detection of novel or resistant strains
• Enables confirmation of syndromic or clinical diagnoses

Challenges to maintaining strong lab systems

• Underutilization of diagnostic testing
• Delays in specimen transport or processing
• Limited sequencing capacity in some regions

Future directions in lab surveillance

Expanding lab capacity and technology integration

• Increase access to molecular diagnostics and sequencing
• Integrate lab and epidemiologic data systems
• Automate reporting through electronic lab interfaces
• Train the workforce in bioinformatics and data analysis
• Ensure equity in lab infrastructure globally