Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

State Laboratory Reporting Laws: Viral Load and CD4 Requirements

Data on viral load and CD4 counts for persons who are HIV-infected can provide information about the effectiveness of prevention and treatment programs.

Viral load measurements indicate the number of copies of the HIV-1 virus that are in a milliliter of a person’s blood.  CD4 results provide a measure of a person’s immune function and give information about a person’s white blood cells.  Among people with HIV, CD4 results are often used to monitor disease progression, determine the stage of HIV infection, and make decisions about when particular treatments are appropriate.  In addition, both viral load and CD4 data are used to assess whether patients are responding to treatment: when treatment is successful, CD4 counts rise and viral loads fall. Current HIV clinical management guidelines call for CD4 and viral load testing at the time of diagnosis and regularly thereafter. When all CD4 and viral load results are reported, public health agencies can determine access to care and treatment outcomes.

While all states in the United States have enacted laws or regulations requiring laboratory reporting, not all of the laws require reporting of all CD4 and viral load results. Currently, 42 states plus D.C. have enacted laws, regulations, or directives that specifically require laboratory reporting of all levels of CD4 and both detectable and undetectable viral loads of all HIV-positive individuals (click here to find out about specific states). For more information concerning the importance of CD4 and Viral Load reporting, see Dear Colleague Letter from Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, to HIV Surveillance coordinators, AIDS Directors, State Epidemiologists, State Health Officers, and State Public Health Lab Directors about laboratory reporting of HIV-related tests, including all CD4+ T-lymphocyte (CD4) results and all viral load test results. CDC 2013.


The information presented here does not constitute legal advice and does not represent the legal views of the Centers for Disease Control and Prevention or the Department of Health and Human Services, nor is it a comprehensive analysis of all legal provisions relevant to HIV. This information is subject to change and does not contain measures implemented by counties, cities, or other localities. Use of any provision herein should be contemplated only in conjunction with advice from legal counsel.