FAQs

  1. About AIDSVu
  2. Interpreting AIDSVu Data
  3. About HIV Diagnoses and Treatment
  4. AIDSVu and Your HIV Risk
  5. Technical Questions

About AIDSVu

Q. Where do the data on AIDSVu come from?
A. State- and county-level AIDSVu data are obtained from CDC’s national HIV surveillance programs in accordance with each state’s HIV/AIDS data re-release agreement and compiled by researchers at the Rollins School of Public Health at Emory University. ZIP code and census tract data are obtained directly from state and local health departments. All data received by Emory are anonymous, meaning that no names or other personally identifying information are provided. Strict rules are applied to the mapping process to protect the privacy of those living with HIV.

Q. How often is AIDSVu updated?
A. AIDSVu is updated on an ongoing basis with new data and additional information as it becomes available. See the Data Methods (State/County and ZIP Code/Census Tract) page for more information about the frequency with which different data elements on AIDSVu are updated.

Q. Who is AIDSVu intended for?
A. AIDSVu is intended to be used by public health officials, health care providers, researchers, policymakers, advocates and the general public. The detailed, yet easily accessible, information on AIDSVu can help communities plan where HIV prevention, testing and treatment services are needed most; provide important visuals and data for grants, policy reports, and advocacy efforts; and give health care providers and the general public a tool for better understanding how HIV impacts their communities.

Interpreting AIDSVu Data

Q. What does AIDSVu tell us about the U.S. HIV epidemic?
A. AIDSVu provides a visualization of the HIV epidemic across the United States. The interactive maps on the website illustrate how the HIV epidemic affects communities differently, and that epidemic severity can differ from state to state and across county and city lines. In large metropolitan areas, the epidemic differs by ZIP code and census tract. This information is important for individuals to understand how common HIV is in their communities, and for health officials and policymakers to see where prevention and care programs are needed most.

Q. What is the difference between the number of HIV cases in an area and the HIV prevalence rate?
A. The number of HIV cases in a geographic area is the number of people living with an HIV infection diagnosis in that geographic region (e.g., state, county, ZIP code, census tract). The number of cases can be useful for identifying areas where the greatest or fewest number of individuals living with an HIV infection diagnosis reside. This can help inform decisions about how and where to provide services, such as HIV education, testing, prevention and linkage to care programs.

The HIV prevalence rate displayed on AIDSVu refers to the relative concentration of people in an area living with an HIV infection diagnosis, and is usually expressed as the number of individuals living with an HIV diagnosis (including those with an AIDS diagnosis) per 100,000 people in the population. The prevalence rate can be useful for comparing the severity of the HIV epidemic in areas with different population sizes – for example, in a densely populated area and in a more sparsely populated one.

AIDSVu features both HIV prevalence case counts and rates to fully depict the HIV epidemic in the United States. Rates and case counts displayed on AIDSVu’s state and county maps are estimated (see Data Methods State/County) and rates and case counts displayed on AIDSVu’s ZIP code and census tract maps are reported data (see Data Methods ZIP Code/Census Tract).

Q. Why are HIV rates higher in some parts of the country than others?
A. There are a number of factors affecting HIV rates. For example, HIV rates in the United States are higher among certain demographic groups – including African Americans and men who have sex with men – and, therefore, HIV rates are on average higher in geographic areas where individuals in these communities live. In addition, high HIV rates have been associated with areas that have high rates of poverty. Visit AIDSVu’s interactive map to view overall HIV rates next to poverty rates.

Q. What does HIV prevalence mean?
A. HIV prevalence refers to the number of people living with an HIV infection diagnosis. Prevalence figures on AIDSVu’s state- and county-level maps are estimated, just like national HIV prevalence estimates released from CDC, which means that the figures have been adjusted to account for reporting delays. An explanation of how CDC estimates HIV prevalence data is available here. ZIP code and census tract data presented on AIDSVu only represent persons tested, diagnosed and reported to the state or local health department.

Q. What do the different color shadings on the AIDSVu map mean?
A. Different color shadings are used to indicate the relative severity of the HIV epidemic across states, counties, ZIP codes and census tracts. On all maps, lighter colors (e.g., beige and yellows) indicate HIV is less prevalent and darker colors (e.g., dark red and magenta) indicate higher prevalence. Specific breakdowns are listed in the legend box on the map.

Q. Why are data not shown or not available for some areas?
A. For all geographic areas, AIDSVu does not display HIV data if the area has less than five persons living with an HIV diagnosis. Additionally, AIDSVu does not display HIV data for areas with a population less than 100 persons for state and counties, less than 1,000 persons for ZIP codes and less than 500 persons for census tracts. These suppression rules help protect the privacy of individuals with HIV who live in these areas. In addition, data are not available for some areas because the state health department chose not to have them displayed or because estimated data could not be calculated for a state. See the Data Methods (State/County and ZIP Code/Census Tract) page for more information about the data presented on AIDSVu.

Q. How do the state and county data on AIDSVu compare with national data?
A. The national data released by CDC in their annual HIV Surveillance Report and AIDSVu’s state- and county-level data all come from the national HIV surveillance database housed at CDC. While CDC does not release county-level HIV prevalence data in the HIV Surveillance Report, state data contained in this report matches what is displayed on AIDSVu.

Q. How did AIDSVu select the cities displaying ZIP code and census tract data?
A. AIDSVu invited cities with highest rates of HIV diagnoses, according to CDC’s recent HIV surveillance report, to provide data. AIDSVu’s resources and capacity determine the number of new cities invited each year.

Q. What does it mean that county-level surveillance figures might be “inflated” by state and federal correctional facilities?
A. Some counties are home to state and federal correctional facilities where inmates have been diagnosed with HIV. Because the data displayed on AIDSVu count these inmates, and because the “persons living with an HIV diagnosis” data on AIDSVu are analyzed by residence at earliest HIV infection diagnosis, inmates diagnosed in correctional facilities may artificially inflate the rate and case count of persons living with an HIV diagnosis in the county. It is “artificial” in the sense that the rate and case count would not be that high in the county if the incarcerated cases were removed from the figures. See the Data Methods State/County page for more information about how AIDSVu determines the counties in which potential inflation may be occurring.

Q. Why aren’t data for Asians, American Indians/Alaskan Natives, and Native Hawaiians/Other Pacific Islanders displayed at the county level?
A. Race-specific county-level HIV prevalence data for Asians, American Indians/Alaska Natives, and Native Hawaiians are not provided because these data do not meet CDC’s criteria for statistical reliability, data quality, or confidentiality due to small population denominators and HIV case counts by county.

About HIV Diagnoses and Treatment

Q. For the purposes of AIDSVu, what does “rate/number of persons living with an HIV diagnosis” mean? Does AIDSVu include people with HIV who don’t know it because they haven’t been tested?
A. On AIDSVu, the HIV prevalence rate or number of cases represent data, adjusted for reporting delays, for people living with an HIV diagnosis. An explanation of how CDC estimates HIV prevalence data is available here (PDF). AIDSVu’s data do not include estimates of people who have not been diagnosed.

CDC estimates that more than one million people in the United States are living with HIV. These national statistics count both people who have been diagnosed with HIV (i.e., who have had a positive test for HIV), and an estimate of other people who are living with HIV, but who have not been diagnosed. CDC estimates that that as many as one in five people in the United States who are living with HIV don’t know it.

Q. What is a late HIV diagnosis, and why is this important to understanding the U.S. epidemic?
A. An HIV diagnosis is considered late if it is made within 12 months of the infection progressing to AIDS, a late stage of the disease. Even though fewer people with HIV are being diagnosed late, CDC estimates that one-third of HIV infection diagnoses are still made late. People with late HIV diagnoses miss opportunities to start treatment earlier, when it can be more effective. Clinical trials have also shown that people with HIV who are not receiving treatment are more likely to transmit the virus to other people. State information on late diagnoses can be found on the state profile pages.

Q. What are ADAPs, and why are there waiting lists in some states?
A. The AIDS Drug Assistance Program, or ADAP, is a government program that provides HIV treatment medications to low-income individuals who do not have health insurance, or who do not have health insurance that covers HIV medications. An estimated one in four people with HIV in the United States receives treatment through an ADAP. An ADAP is administered by the state with both state and federal money. Because of the budget shortfalls facing many state governments and the federal government, some states have had to establish waiting lists for persons to receive HIV medications through the ADAP.

Q. If someone with HIV is tested multiple times, are they double-counted?
A. CDC works with state and local health departments to “de-duplicate” HIV case reports, so that individuals with HIV are not double-counted both within, and across, jurisdictions.

AIDSVu and Your HIV Risk

Q. What can AIDSVu tell me about my personal risk for HIV?
A. In the early years of the epidemic, individual risk for HIV infection was dependent on one’s personal behaviors, such a sexual and drug use behavior. That’s still true today, but the state of the epidemic in one’s community is also a factor. The HIV epidemic has grown from its start in big cities to affect nearly every part of the United States, and so it is important to understand how HIV is affecting your community. AIDSVu helps make that information easy to understand.

Q. Where can I go to get an HIV test?
A. AIDSVu includes links to HIV testing sites across the country. Visit the HIV Testing Locator to find the testing sites closest to you.

Q. How often should I be tested for HIV?
A. If a health care provider doesn’t offer you an HIV test, ask to be tested. CDC recommends that everyone in the Unites States between 13 and 64 years old be routinely tested for HIV. However, it is important to know that despite the CDC recommendations, HIV testing may not be done automatically when you see a health care provider, even if blood is drawn. The only way to know for sure you are being tested for HIV is to ask to be tested.

If you engage in behavior that puts you at high risk for HIV infection – for example, if you are a man who has sex with other men – CDC recommends that you be tested for HIV at least once a year, and more often if you have reason to believe that you’ve been exposed to the virus.

Q. If I am HIV positive, where can I go to get care and treatment?
A. AIDSVu includes an HIV Care Services Locator to help you identify Ryan White HIV/AIDS Medical Care Provider clinics in your community where you can go to receive HIV care and treatment. This is not an exhaustive list of sites, and other health care providers, such as your primary care doctor, can also help by referring you to an HIV medical care provider.

Q. What should I do if I live in a high prevalence (i.e., darkly shaded) area?
A. It’s important to remember that even if you live in a county, ZIP code or census tract where HIV is more common, you’re still in control of your personal risk for getting HIV. You can’t get HIV from casual contact, like from coughing or sneezing, and you can make choices about sex and needle sharing that can greatly reduce your risk. If you want more information about how to protect yourself, you can find more information here. Also, CDC recommends that everyone between the ages of 13 and 64 in the United States be routinely tested for HIV. This is especially important if you are living in a place where HIV infection is more common.

Q. What should I do if I live in a lower prevalence (i.e., lightly shaded) area?
A. It’s important to remember that just because you live in a county, ZIP code or census tract where HIV is less common doesn’t mean you are protected from HIV. As AIDSVu shows, HIV impacts nearly every part of the United States. CDC recommends that everyone between the ages of 13 and 64 in the United States be routinely tested for HIV. If you’re HIV-positive, it’s important to get into medical care as soon as possible. If you’re negative, you can make choices about sex and needle sharing that can greatly reduce your risk and help you stay negative. If you want more information about how to protect yourself, you can find more information here.

Technical Questions

Q. What browsers does AIDSVu work with?
A. The following browsers are supported: Internet Explorer versions 7, 8 and 9, Mozilla Firefox, Chrome and Safari.

Q. How does AIDSVu determine my location?
A. AIDSVu estimates your location from the Internet Protocol (IP) address assigned to your computer. An IP address is assigned to your computer by your Internet Service Provider each time you access the Internet. Depending on the type of connection you have, your IP address may change. AIDSVu does not link your IP address with any personal information about you.

Q. Can I print or download an AIDSVu map?
A. A variety of AIDSVu maps are available for download and printing on our Downloadable Maps and Resources page. Additionally, you can print your current map view by clicking on the print icon on the control bar.