Investigating Outbreaks in Health Care Settings: Step 1

Purpose

This page outlines how to verify a patient’s hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, as well as why it is crucial to do so as the first step in investigating an outbreak in a health care setting.

Step one: Verify the infection

Verify the HBV or HCV infection by reviewing medical records and interviewing the physician and the index patient.

Sample questionnaire available

CDC provides a sample questionnaire for interviewing the physician and index patient.
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The form captures information on exposure occurring before symptoms typically begin to show. Usually this is 6 weeks to 6 months for acute HBV infections and 2 weeks to 6 months for acute HCV infections.

In certain instances, this time period may need to be extended. For example, in the case of a documented seroconversion (e.g., anti-HCV negative to anti-HCV positive), the time period should include the 6 months prior to the most recent negative test result up until the time of the first positive test result.

Acute HBV infection

Most patients with acute hepatitis B are asymptomatic. When symptoms do develop, they can include:

  • Abdominal pain, nausea, and/or vomiting
  • Dark urine or clay-colored stools
  • Fatigue
  • Fever
  • Jaundice
  • Joint pain
  • Loss of appetite

To determine if a hepatitis B case is acute, review the person's medical history, information obtained from case investigation, and serologic findings. Markers indicating acute infection:

  • Positive hepatitis B surface antigen (HBsAg), and
  • Positive immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc).

Acute HCV infection

Most patients with acute hepatitis C are asymptomatic. When symptoms do develop, they can include:

  • Abdominal pain, nausea, and/or vomiting
  • Dark urine or clay-colored stools
  • Fatigue
  • Fever
  • Jaundice
  • Joint pain
  • Loss of appetite

To determine if a hepatitis C case is acute, review the person's medical history and information obtained from case investigation. Test for hepatitis C antibody with reflex to HCV RNA if antibody is reactive. To evaluate whether an infection could be recent, assess the following:

  • Medical history
  • Information from case investigation
  • New finding of hepatitis C antibody or RNA positivity in a person not previously known positive (whether or not symptoms or alanine aminotransferase [ALT] elevation are present).
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Content Source:
Division of Viral Hepatitis