Frequently Asked Questions

About AIDSVu

Q. Where do the data on AIDSVu come from?
AIDSVu data were compiled by researchers at the Rollins School of Public Health at Emory University. State- and county-level data presented on AIDSVu were obtained from the U.S. Centers for Disease Control and Prevention's (CDC) national HIV surveillance database. Each state health department chose the levels of data they wanted displayed on the AIDSVu maps. Zip code-level data presented for New York City, Washington, DC, and Los Angeles County were obtained directly from the jurisdictions. See the Data Methods page for more information about data sources.

Q. How often is AIDSVu updated?
In general, information on AIDSVu will be updated on an ongoing basis as it becomes available. We will update state and local HIV surveillance data at least annually. See the Data Methods page for more information about the frequency with which different data elements on AIDSVu are updated.

Q. Who is AIDSVu intended for?
AIDSVu is intended to be used by public health officials, health care providers, researchers, policy makers, advocates and the general public. We hope that the detailed, yet easily accessible, information on AIDSVu helps communities accurately plan where HIV prevention, testing and treatment services are needed most, and gives 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?
AIDSVu provides a geographic picture of persons living with an HIV infection diagnosis in the United States. The website reflects how the HIV epidemic is one that affects communities and neighborhoods differently, and that its severity can differ from state to state and across county lines. In large metropolitan areas, the epidemic differs by zip code. This information is important for individuals to understand how common HIV is in their communities. Health officials and policymakers can use AIDSVu to help inform their decisions on 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 case rate?
The number of HIV cases in a geographic area on AIDSVu is the actual number of people living with an HIV infection diagnosis in that geographic region (state or county). 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 case 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 cases per 100,000 people in the population. The case 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 case counts and HIV case rates to fully depict the HIV epidemic in the United States.

Q. Why are HIV rates higher in some parts of the country than others?
There are a number of factors at play. 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 with high rates of poverty.

Q. What does HIV prevalence mean?
HIV prevalence refers to the number of people living with an HIV infection diagnosis. Prevalence figures may only include individuals who have been tested and diagnosed, as in the case of the state- and county-level data on AIDSVu, or they may also include an estimate of individuals who are HIV-positive but have not been tested and diagnosed, as in the case of national HIV prevalence estimates released from CDC.

Q. What do the different color shadings on the AIDSVu map mean?
Different color shadings are used to indicate the relative severity of the HIV epidemic across states and counties. Yellow indicates the lowest severity, and brown indicates the highest severity - specific breakdowns are listed in the legend box on the map. Gray shading indicates that data are not available, or are not shown for privacy reasons (in areas with a very small number of persons living with an HIV diagnosis and/or a small total population).

Q. Why are data not shown or not available for some areas?
AIDSVu does not display HIV data for areas with a very small number of persons living with an HIV infection diagnosis and/or a total population less than 1,000 persons. This helps 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 decided not to have them displayed. See the Data Methods page for more information about the data presented on AIDSVu.

Q. What does it mean that surveillance figures might be "inflated" in counties with correctional facilities?
Some counties have correctional facilities (i.e., prisons or jails) where a significant number of HIV-positive 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.

Q. How do the state data on AIDSVu compare with national statistics I have heard?
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 tested and diagnosed - CDC estimates that 21 percent of people in the United States who are living with HIV, don't know it. The state- and county-level data on AIDSVu only count people who have been diagnosed with HIV.

Nationally, CDC estimates that one-third of HIV infections are diagnosed late, that is, within one year of infection progressing to AIDS. People with late HIV diagnoses miss opportunities to start treatment earlier, when it can be more effective, and thus may have a shortened life expectancy. State information on late diagnoses can be found on the state profile pages on AIDSVu.

About HIV Diagnoses and Treatment

Q. For the purposes of AIDSVu, what does "persons living with an HIV diagnosis" mean? Does AIDSVu include people with HIV who don't know it because they haven't been tested?
On AIDSVu, an HIV diagnosis refers to a positive HIV test result reported to health officials. Because of this, the state- and county-level data on AIDSVu do not include people who have HIV but who have not been tested and diagnosed. They also do not include people who may have been diagnosed but not yet reported to health officials. CDC estimates that as many as one in five people who are infected with HIV nationwide do not know it because they have not been diagnosed.

Q. What is a late HIV diagnosis, and why is this important to understanding the U.S. epidemic?
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, nearly one-third of diagnoses in the United States are still made late. People with late HIV diagnoses miss opportunities to start treatment earlier, when it can be more effective, and thus may have a shortened life expectancy. Clinical trials have also shown that people with HIV who are not receiving treatment are more likely to transmit the virus to other people.

Q. What are ADAPs, and why are there waiting lists in some states?
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?
CDC works with state and local health departments to "de-duplicate" HIV case reports, so that individuals with HIV are not double-counted if they are tested multiple times or in different states.

AIDSVu and Your HIV Risk

Q. What can AIDSVu tell me about my personal risk for HIV?
In the early years of the epidemic, individual risk for HIV infection was dependent on one's personal behaviors. That's still true today, but the HIV epidemic has grown from its start in big cities to affect nearly every part of the United States. Your personal risk for HIV is impacted by your sexual and drug use behavior, and by the chance that your sex or drug using partners are living with HIV.

For more information about how individual risk behaviors are contributing to the epidemic in a particular state, choose a state from the list below: [ show list ] [ hide list ]

Q. Where can I go to get an HIV test?
AIDSVu includes links to HIV testing sites across the country. Visit the HIV Testing Sites page to find a testing site in your city, state or zip code.

Q. How often should I be tested for HIV?
If a health care provider doesn't offer you an HIV test, ask to be tested. CDC recommends that everyone between the ages of 13 and 64 in the United States be routinely tested for HIV but 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. What should I do if I live in a high prevalence (darkly shaded) county or state?
It's important to remember that even if you live in a county or state 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, and 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 (lightly shaded) county or state?
It's important to remember that just because you live in a county or state 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 in 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?
The following browsers are supported: Internet Explorer versions 7, 8, and 9, Mozilla Firefox, Chrome and Safari.

Q. How does AIDSVu determine my location?
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 series of AIDSVu maps are available for download and printing here.