***Adapted from the CDC***

What is HIV?

  • HIV (human immunodeficiency virus) is a virus that attacks the body’s immune system. If HIV is not treated, it can lead to AIDS (acquired immunodeficiency syndrome).
  • There is currently no effective cure. Once people get HIV, they have it for life.
  • But with proper medical care, HIV can be controlled. People with HIV who get effective HIV treatment can live long, healthy lives and protect their partners.
  1. Health_Red_Black

    Andrea Alvare

    Director/Health Officer

Where did HIV come from?

  • HIV infection in humans came from a type of chimpanzee in Central Africa. Studies show that HIV may have jumped from chimpanzees to humans as far back as the late 1800s.
  • The chimpanzee version of the virus is called simian immunodeficiency virus. It was probably passed to humans when humans hunted these chimpanzees for meat and came in contact with their infected blood.
  • Over decades, HIV slowly spread across Africa and later into other parts of the world. The virus has existed in the United States since at least the mid to late 1970s.

HIV Transmission

Most people who get HIV get it through anal or vaginal sex, or sharing needles, syringes, or other drug injection equipment (for example, cookers). But there are powerful tools that can help prevent HIV transmission.

This section answers some of the most common questions about the risk of HIV transmission for different types of sex, injection drug use, and other activities. You can also download materials about HIV transmission.

HIV Consultation and Referral Services


CDC’s national health information hotline, providing answers to your questions
 regarding HIV, how to protect yourself, and where to get an HIV test.

1-800-CDC-INFO (232-4636) | 1-888-232-6348 TTY HIV In English, en Español, 8 am to 8 pm EST, Monday through Friday

HIV Info 

A service of the United States Department of Health and Human Services (HHS), offers access to the latest, federally approved HIV/AIDS medical practice guidelines, HIV treatment and prevention clinical trials, and other research information for health care providers, researchers, people affected by HIV/AIDS, and the
 general public.

1-800-HIV-0440 (448-0440) | 1-888-480-3739 TTY
 1-301-315-2816 (Outside the US)
In English, en Español, 1 pm to 4 pm EST, Monday through Friday | 

The Clinician Consultation Center 

Clinicians’ Warmline 

Provides health care providers with expert clinical advice on preventing and treating HIV. 1-800-933-3413 | 9 am to 8 pm EST, Monday through Friday 


Provides expert guidance in managing health care worker exposures to HIV and hepatitis B and C. Clinicians receive immediate post-exposure prophylaxis (PEP) recommendations.
1-888-448-4911 | Occupational PEP: 11 am to 8 pm EST, seven days a week | Non-occupational PEP: 9 am to 8 pm EST, Monday through Friday; 11 am to 8 pm EST, weekends and holidays 

Perinatal HIV Hotline 

Provides clinicians with around-the-clock advice on indications and interpretations of HIV testing in pregnancy, and consultation on antiretroviral use during pregnancy, labor and delivery, and the postpartum period. 1-888-448-8765 | 24 hours, seven days a week 

Substance Use Management 

Peer-to-peer consultation from physicians, clinical pharmacists, and nurses with special expertise in substance use evaluation and management.
1-855-300-3595 | 9 am to 8 pm EST, Monday through Friday 


Provides expert guidance on considerations for providing pre-exposure prophylaxis (PrEP) to people who don’t have HIV as part of an HIV prevention program.
1-855-448-7737 | 9 am to 8 pm EST, Monday through Friday 

Injection Drug Use (Adapted from the CDC)

Sharing needles, syringes, or other equipment (works) to inject drugs puts people at high risk for getting or transmitting HIV and other infections. People who inject drugs account for about 1 in 10 HIV diagnoses in the United States. Syringe services programs (SSPs) can play a role in preventing HIV and other health problems among PWID, by providing access to sterile syringes. These programs can also provide comprehensive services such as help with stopping substance misuse; testing and linkage to treatment for HIV, hepatitis B, and hepatitis C; education on what to do for an overdose; and other prevention services.


For more information, please go to 

Pre-Exposure Prophylaxis (PrEP)

Is PEP Right for You?

If you don’t have HIV or don’t know your HIV status, and in the last 72 hours you 

• May have been exposed to HIV during sex (for example, if the condom broke), • Shared needles, syringes, or other equipment to inject drugs, or
 • Were sexually assaulted

Talk to your health care provider, an emergency room doctor, or an urgent care provider about PEP right away. 

Pre-exposure prophylaxis (or PrEP) is medicine taken to prevent getting HIV. PrEP is highly effective for preventing HIV when taken as prescribed.

  • PrEP reduces the risk of getting HIV from sex by about 99%.
  • PrEP reduces the risk of getting HIV from injection drug use by at least 74%.


PrEP is less effective when not taken as prescribed. Since PrEP only protects against HIV, condom use is still important for the protection against other STDs. Condom use is also important to help prevent HIV if PrEP is not taken as prescribed.


For more information, please go to

Post-Exposure Prophylaxis (PEP)

PEP is the use of antiretroviral drugs after a single high-risk event to stop HIV seroconversion. PEP must be started as soon as possible to be effective—and always within 72 hours of a possible exposure.