Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo

antigenic drift
when viruses undergo minor mutations each year, such as the influenza A viruses
antigenic shift
when viruses undergo a major mutation; has occurred with flu viruses four times over the past 100 years
case definition
a set of criteria used to define a disease for the purpose of public health surveillance
case surveillance
when public health agencies collect information about an individual diagnosed with a health condition that could potentially pose a health threat to others
emerging infectious diseases (EIDs)
diseases that are newly affecting populations or diseases that have existed previously but only caused isolated disease that are now increasing in incidence and geographic range
erythema migrans (EM)
also known as the “bull’s eye” rash of Lyme disease; is erythematous, annular, and homogenous at the site of the actual tick bite and expands over several days to sizes greater than 5 centimeters in diameter with a central clearing as the rash expands
easily transmitted between individuals
infectious disease
disease caused by pathogenic microorganisms such as bacteria, viruses, parasites, or fungi; enters a human host, multiplies, and causes infection that can spread to others
condition where a baby’s head is smaller than expected, impacting brain development
nationally notifiable condition
a disease required by law to be reported to government authorities, allowing for case surveillance to assess transmission patterns and determine interventions to control outbreaks
an epidemic that spreads worldwide
the potential ability to cause disease; the more pathogenic an agent is, the greater the ability it has to cause disease in a susceptible host
public health surveillance
the ongoing, systematic collection, analysis, and interpretation of health-related data essential to planning, implementation, and evaluation of public health practice
living organisms, such as ticks and mosquitoes, that can transmit infectious pathogens to humans

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at
Citation information

© Apr 26, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.