Genomic epidemiology is the process of monitoring the genetic makeup of pathogens (germs) that cause disease. This helps scientists understand how similar or different two or more pathogens are on a genetic level.
Epidemiologists at the Virginia Department of Health work with public health laboratory scientists to monitor genomic data for pathogens that cause certain reportable diseases. Laboratory procedures called genomic sequencing help us do this. When two or more people are infected with closely related pathogens, this might mean that they shared a common exposure to that pathogen. This helps us detect outbreaks sooner and improves our public health responses to infectious diseases.
Public Health Applications
- Early Outbreak Detection and Investigation. Genomic data help detect disease outbreaks. If infecting pathogens are closely related, this suggests that cases are likely to be part of the same outbreak. Outbreak responses and investigations might begin earlier using this information.
- Identify Transmission Links. Genomic data provide information about how similar or different infecting pathogens are. This can help public health understand if two or more cases of disease might share a common pathway of spread called a transmission link.
- Identify or Confirm Sources of Exposure. Genomic data provide detailed information about pathogens that are causing illness. If infecting pathogens are closely related, this suggests that cases might have shared a common source of exposure. This might include identifying a common food or environmental exposure that is making people sick.
- Improve Understanding of Disease Location and Spatial Distribution. Genomic data can provide important information about how diseases spread geographically. This can help link cases or outbreaks that occur in different locations.
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Last Updated: August 14, 2025