Human Immunodeficiency Virus / HIV

CDC Yellow Book 2024

Travel-Associated Infections & Diseases

Author(s): Robyn Neblett Fanfair, Katarzyna (Kate) Buchacz, Philip  Peters

INFECTIOUS AGENT: Human immunodeficiency virus




Immigrants and refugees who come from environments with high rates of HIV in their cohorts or who have been abused
Travelers who have cosmetic or medical procedures using contaminated needles, syringes, or other items
Travelers who inject drugs using nonsterile equipment
Travelers who have unprotected sex


Avoid invasive procedures in locations where proper sterilization of instruments might not be used

Avoid nonsterile injection use

Practice safe sex

Take preexposure prophylaxis (for some travelers)


A clinical laboratory certified in moderate complexity testing; self-tests are also available

Infectious Agent

HIV is an enveloped positive-strand RNA virus in the family Retroviridae.


HIV is transmitted through sexual contact, needle or syringe sharing, unsafe medical injection or blood transfusion, and organ or tissue transplantation. It can also be transmitted from mother to child during pregnancy, at birth, and postpartum through breastfeeding.


HIV infection occurs worldwide. In 2000, an estimated 37.7 million people were living with HIV infection globally. Sub-Saharan Africa is the most affected part of the world (25.4 million cases, or 67% of all people living with HIV infection); central Asia and eastern Europe have experienced the largest increases in new HIV infections (47% increase from 2010 to 2020). Although the reported adult HIV prevalence in many regions of the world is low, certain populations are disproportionately affected (e.g., sex workers, people who inject drugs, men who have sex with men, transgender people, and incarcerated people). People with HIV face an intersection of stigma, discrimination, violence, and criminalization that causes health inequities; international travelers should be aware of how their travel affects local communities, including people with HIV.

The risk for HIV infection is generally low for international travelers. Risk for HIV exposure and infection is determined less by a traveler’s geographic destination and more by the behaviors in which they engage while traveling (e.g., sex without a condom, nonsterile injection drug use). Travelers who might undergo scheduled or emergency medical procedures should be aware that HIV can be transmitted by unsafe nonsterile medical injection practices (e.g., reusing needles, syringes, or single-dose medication vials). Unsafe medical practices might be greater in low-income countries where the blood supply and organs and tissues used for transplantation might not be screened properly for HIV.

Clinical Presentation

As many as 90% of infected people will recall experiencing symptoms during the acute phase of HIV infection. Acute HIV infection can present as an infectious mononucleosis-like or influenza-like syndrome, but the clinical features are highly variable. Symptoms typically begin a median of 10 days after infection and can include arthralgias and myalgias, fatigue, fever, headache, lymphadenopathy, maculopapular rash, malaise, oral ulcers, pharyngitis, and weight loss. Although none of these symptoms are specific for acute HIV infection, certain features (e.g., oral ulcers), suggest the diagnosis.


HIV can be diagnosed with laboratory-based or point-of-care assays that detect HIV antibodies, HIV p24 antigen, or HIV-1 RNA. In the United States, the recommended laboratory-based screening test for HIV is a combination antigen/antibody assay that detects antibodies against HIV, and the p24 antigen. The combination antigen/antibody assay becomes reactive approximately 2–3 weeks after HIV infection. Estimates suggest that 99% of people will develop a reactive combination antigen/antibody result within 6 weeks of infection, but in rare cases, it can take up to 6 months to develop a reactive test result.

HIV self-tests also are available for retail purchase in the United States, including an HIV antibody test performed on oral fluid instead of blood. Although oral swab HIV tests have a lower sensitivity for detecting recent HIV infection, these can be an important testing method for people and their partners who would not otherwise get an HIV test (see Sec. 11, Ch. 2, Rapid Diagnostic Tests for Infectious Diseases). Acute HIV infection is characterized by markedly elevated HIV RNA levels; perform an HIV RNA viral load test if acute infection is suspected. Travelers with potential HIV exposures abroad, including those with symptoms consistent with acute HIV infection, should consider testing for HIV during travel or upon return to the United States. Travelers can find detailed information on HIV testing locations.


With timely diagnosis, prompt medical care, and daily antiretroviral therapy (ART), people with HIV can now live longer, healthier lives. Owing to the advances of ART, people with HIV who start treatment can have close to the same life expectancy as people of the same age without HIV. Effective treatment also substantially reduces the risk of transmitting HIV to others. People with HIV who achieve and maintain an undetectable viral load by taking ART daily as prescribed cannot sexually transmit the virus to others (undetectable = untransmittable [U = U]).

Detailed information on specific treatments is available from the Department of Health and Human Services HIVinfo website. Travelers can contact HIVinfo toll free at 800-448-0440 (English or Spanish) or 888-480-3739 (TTY).


Travelers can reduce their risk for HIV infection by avoiding sexual encounters with people whose HIV status is unknown, using condoms consistently and correctly with all partners who have HIV or whose HIV status is unknown, and using HIV prophylaxis when indicated. Travelers going abroad for medical procedures should try to ensure in advance that all blood or blood products at the facility have been screened for bloodborne pathogens (including HIV) and that all invasive medical equipment is sterilized between uses or is sterile and single use only (see Sec. 6, Ch. 2, Obtaining Health Care Abroad, and Sec. 6, Ch. 4, Medical Tourism). Travelers who inject drugs should avoid sharing needles or other injection equipment and use only sterile, single-use syringes and needles that are safely disposed of after every injection.

Preexposure Prophylaxis

Preexposure prophylaxis (PrEP) is a highly effective method to prevent HIV acquisition and is used by people without HIV who are at risk of being exposed to HIV. Two medications have been approved by the US Food and Drug Administration for use as PrEP; each consists of 2 drugs combined in a single oral tablet taken daily. F/TDF (brand name Truvada) combines 200 mg emtricitabine with 300 mg tenofovir disoproxil fumarate. F/TAF (brand name Descovy) combines 200 mg emtricitabine with 25 mg tenofovir alafenamide.

People already on PrEP should continue its use during international travel. Travel medicine providers can consider initiating PrEP for people who have a greater risk for HIV acquisition [PDF] during international travel. A comprehensive prevention plan includes not only prescribing (or considering prescribing) PrEP, but also reinforcing careful adherence to the PrEP regimen, educating travelers on the importance of consistent condom use to protect against HIV as well other sexually transmitted infections, and discussing other HIV prevention methods.

Travelers taking PrEP should carry proper documentation and be aware that some countries (see below for further information) deny entry to people with evidence of HIV infection, which PrEP medications might mistakenly indicate to customs officials. Free, expert PrEP advice is available to health care professionals through the National Clinician Consultation Center’s PrEPline (855-448-7737).

Postexposure Prophylaxis

Postexposure prophylaxis (PEP) with antiretroviral medications is another method to prevent HIV infection. PEP is recommended as a prevention option after a single high-risk exposure to HIV during sex, through sharing needles or syringes, through a needlestick, or from a sexual assault. PEP must be started within 72 hours of a possible exposure. Travelers who will be working in medical settings (e.g., nurse volunteers drawing blood, medical missionaries performing surgeries) could have contact with HIV-infected or potentially infected biological materials.

Under certain conditions, a clinician can prescribe PEP medications for travelers to use in emergency situations. Free, expert PEP advice is available to health care professionals through the National Clinician Consultation Center’s PEPline (888-448-4911). See Sec. 9, Ch. 4, Health Care Workers, Including Public Health Researchers & Medical Laboratorians, for detailed advice regarding management of postexposure prophylaxis in occupational settings.

HIV Testing Requirements for US Travelers Entering Foreign Countries

Advise international travelers that some countries screen incoming travelers for HIV (usually those with an extended stay) and might deny entry to people with evidence of HIV infection. People intending to visit a country for an extended stay should review that country’s policies and requirements. This information is usually available from the consular officials of the individual nations. The US Department of State has compiled a list of entry, exit, and visa requirements by country.

CDC website:

The following authors contributed to the previous version of this chapter: Philip J. Peters, John T. Brooks

Brett-Major DM, Scott PT, Crowell TA, Polyak CS, Modjarrad K, Robb ML, et al. Are you PEPped and PrEPped for travel? Risk mitigation of HIV infection for travelers. Trop Dis Travel Med Vaccines. 2016;2:25.

Centers for Disease Control and Prevention. Preexposure prophylaxis for the prevention of HIV in the United States–2017 update: a clinical practice guideline. Atlanta: The Centers; 2018. Available from: [PDF].

Centers for Disease Control and Prevention. Preexposure prophylaxis for the prevention of HIV in the United States–2017 update: clinical providers’ supplement. Atlanta: The Centers; 2018. Available from: [PDF]

Centers for Disease Control and Prevention. HIV and COVID-19 Basics. Available from:

Joint United Nations Programme on HIV/AIDS (UNAIDS). UNAIDS data 2020. Geneva: UNAIDS; 2020. Available from:  [PDF].

Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in adults and adolescents with HIV. Washington, DC: Department of Health and Human Services; 2021. Available from [PDF].

Patel P, Borkowf CB, Brooks JT, Lasry A, Lansky A, Mermin J. Estimating per-act HIV transmission risk: a systematic review. AIDS. 2014;28(10):1509–19.

World Health Organization. Coronavirus disease (COVID-19): COVID-19 vaccines and people living with HIV. Available from: