State Laboratory Reporting Laws: Viral Load and CD4 Requirements

HIV viral loads, CD4 cell counts, and HIV drug resistance testing are frequently conducted on samples from people with HIV for clinical purposes. Data collected from these tests can also be used to provide information about the effectiveness of and need for prevention and treatment programs.

HIV viral load measurements indicate the number of copies of the HIV that are in a milliliter of a person’s blood. HIV medicine, when taken as prescribed, reduces the amount of HIV in the body (viral load) to a very low level, which keeps the immune system working and prevents illness. This is called viral suppression. HIV viral loads are routinely monitored to detect drug resistant virus or potential issues with treatment adherence.

CD4 is a protein found on the surface of some white blood cells. Measuring white blood cells with CD4 (CD4 cell counts) provides a measure of a person’s immune function. Among people with HIV, CD4 counts are often used to monitor disease progression and determine the stage of HIV infection.

Current HIV clinical management guidelines recommend CD4 and viral load testing at the time of diagnosis and regularly thereafter.

HIV drug resistance testing, which generates HIV molecular data, is used when a person enters, or re-enters care to select an appropriate treatment regimen. HIV drug resistance testing helps determine if virologic failure is due to drug resistance and determine an appropriate change in treatment. HIV molecular data can also be used to identify drug resistance trends on the population level and can be used to identify a growing cluster of infections (i.e., an area or group of individuals) in which transmission is rapidly occurring.  When viral loads, CD4 counts and molecular data are reported, public health agencies can more effectively allocate resources for HIV prevention and care, monitor trends, identify and respond to HIV clusters, and ensure that people with HIV are and remain in care.

While all states in the United States (U.S.) have enacted statutes or regulations (laws) requiring laboratory reporting, not all laws require reporting of all viral load, CD4 count, and molecular data. As of 2020, 48 states, the District of Columbia, and Puerto Rico meet the criteria for requiring all CD4 and viral load data reported. Of these, 25 states and Puerto Rico, also required molecular data reporting. Two states and one U.S. territory do not meet the criteria for reporting all viral load, or CD4 count: Idaho, New Jersey, and the Virgin Islands.

Not all states with complete reporting laws have complete reporting of laboratory data to CDC. While all jurisdictions report some laboratory data to CDC, the following have incomplete reporting based on evaluation of their surveillance data: Arizona, Arkansas, Connecticut, Kansas, Kentucky, Vermont, and Puerto Rico.

US map showing HIV data laboratory reporting laws and practices.
Map legend (light blue)

Require the Reporting of All CD4 Counts, Viral Loads, and Molecular Data (n=21)

Map legend (teal)

Require the Reporting of All CD4 Counts, and Viral Loads (n=22)

Map legend (purple)

Do Not Require the Reporting of All CD4 Counts, Viral Loads, or Molecular Data (n=3)

Map legend (blue)

Require the Reporting of All CD4 Counts, Viral Loads, and Molecular Data, but Do Not Have Complete Reporting of Laboratory Data to CDC (n=6)

Map legend (gold)

Require the Reporting of All CD4 Counts, and Viral Loads, but Do Not Have Complete Reporting of Laboratory Data to CDC (n=1)

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.