HIV can be detected in several fluids and tissue of a person living with HIV. It is important to understand however, that finding a small amount of HIV in a body fluid or tissue does not mean that HIV is transmitted by that body fluid or tissue. Only specific fluids (blood, semen, vaginal secretions, and breast milk) from an HIV-infected person can transmit HIV. These specific fluids must come in contact with a mucous membrane or damaged tissue or be directly injected into the blood-stream (from a needle or syringe) for transmission to possibly occur.
In the United States, HIV is most commonly transmitted through specific sexual behaviors (anal or vaginal sex) or sharing needles with an infected person. It is less common for HIV to be transmitted through oral sex or for an HIV-infected woman to pass the virus to her baby before or during childbirth or after birth through breastfeeding or by prechewing food for her infant.
In the United States, it is also possible to acquire HIV through exposure to infected blood, transfusions of infected blood, blood products, or organ transplantation, though this risk is extremely remote due to rigorous testing of the U.S. blood supply and donated organs.
Some healthcare workers have become infected after being stuck with needles
containing HIV-infected blood or, less frequently, when infected blood comes
in contact with a worker's open cut or is splashed into a worker's eyes or
inside their nose. There has been only one instance of patients being infected
by an HIV-infected dentist.
Scientists and medical authorities agree
that HIV does not survive well outside the body, making the possibility
of environmental transmission remote. HIV is found in varying concentrations
or amounts in blood, semen, vaginal fluid, breast milk, saliva, and
tears. To obtain data on the survival of HIV, laboratory studies have
required the use of artificially high concentrations of laboratory-grown
virus. Although these unnatural concentrations of HIV can be kept alive
for days or even weeks under precisely controlled and limited laboratory
conditions, CDC studies have shown that drying of even these high concentrations
of HIV reduces the amount of infectious virus by 90 to 99 percent within
several hours. Since the HIV concentrations used in laboratory studies
are much higher than those actually found in blood or other specimens,
drying of HIV-infected human blood or other body fluids reduces the
theoretical risk of environmental transmission to that which has been
observed–essentially zero. Incorrect interpretations of conclusions
drawn from laboratory studies have in some instances caused unnecessary
Results from laboratory studies should not be used to assess
specific personal risk of infection because (1) the amount of virus
is not found in human specimens or elsewhere in nature, and (2) no
one has been identified as infected with HIV due to contact with
an environmental surface. Additionally, HIV is unable to reproduce
its living host (unlike many bacteria or fungi, which may do so under
suitable conditions), except under laboratory conditions; therefore,
it does not spread or maintain infectiousness outside its host.
Yes. In fact, unprotected (without a condom) anal sex (intercourse) is considered
to be very risky behavior. It is possible for either sex partner to become
infected with HIV during anal sex. HIV can be found in the blood, semen, pre-seminal
fluid, or vaginal fluid of a person infected with the virus. In general, the
person receiving the semen is at greater risk of getting HIV because the lining
of the rectum is thin and may allow the virus to enter the body during anal
sex. However, a person who inserts his penis into an infected partner also
is at risk because HIV can enter through the urethra (the opening at the tip
of the penis) or through small cuts, abrasions, or open sores on the penis.
Not having (abstaining
from) sex is the most effective way to avoid HIV. If people choose to have
anal sex, they should use a latex condom. Most of
the time, condoms
work well. However, condoms are more likely to break during anal sex than during
vaginal sex. Thus, even with a condom, anal sex can be risky. A person should
use generous amounts of water-based lubricant in addition to the condom to
reduce the chances of the condom breaking.
Yes, it is possible for either partner to become infected with HIV through
vaginal sex* (intercourse). In fact, it is the most common way the virus is
transmitted in much of the world. HIV can be found in the blood, semen (cum),
pre-seminal fluid (pre-cum) or vaginal fluid of a person infected with the
In women, the lining of the vagina can sometimes tear and possibly allow
HIV to enter the body. HIV can also be directly absorbed through the mucous
membranes that line the vagina and cervix.
In men, HIV can enter the body through the urethra (the opening at the
tip of the penis) or through small cuts or open sores on the penis.
Not having (abstaining from) sex is the most effective way to avoid HIV.
If you choose to have vaginal sex, use a latex condom to help protect both
you and your partner from HIV and other STDs. Studies have shown that latex
condoms are very effective, though not perfect, in preventing HIV
transmission when used correctly and consistently. If either partner is
allergic to latex, plastic (polyurethane) condoms for either the male or
female can be used.
Yes, it is possible for either partner to become infected with HIV through performing or receiving oral sex, though it is a less common mode of transmission than other sexual behaviors (anal and vaginal sex). There have been a few cases of
HIV transmission from performing oral sex on a person infected with HIV.
While no one knows exactly what the degree of risk is, evidence suggests
that the risk is less than that of unprotected anal or vaginal sex.
If the person performing oral sex has HIV, blood from their mouth may
enter the body of the person receiving oral sex through
the lining of the urethra (the opening at the tip of the penis);
the lining of the vagina or cervix;
the lining of the anus; or
directly into the body through small cuts or open sores.
If the person receiving oral sex has HIV, their blood, semen (cum),
pre-seminal fluid (pre-cum), or vaginal fluid may contain the virus.
Cells lining the mouth of the person performing oral sex may allow HIV
to enter their body.
The risk of HIV transmission increases
if the person performing oral sex has cuts or sores around or in
their mouth or throat;
if the person receiving oral sex ejaculates in the mouth of the
person performing oral sex; or
if the person receiving oral sex has another sexually
transmitted disease (STD).
Not having (abstaining from) sex is the most effective way to avoid
If you choose to perform oral sex, and your partner is male,
use a latex condom on the penis; or
if you or your partner is allergic to latex, plastic
(polyurethane) condoms can be used.
Studies have shown that latex condoms are very effective, though not
perfect, in preventing HIV transmission when used correctly and
consistently. If either partner is allergic to latex, plastic
(polyurethane) condoms for either the male or female can be used. For
more information about latex condoms, see "Male
Latex Condoms and Sexually Transmitted Diseases."
If you choose to have oral sex, and your partner is female,
use a latex barrier (such as a natural rubber latex sheet, a
dental dam, or a cut-open condom that makes a square) between your
mouth and the vagina. A latex barrier such as a dental dam reduces
the risk of blood or vaginal fluids entering your mouth. Plastic
food wrap also can be used as a barrier.
If you choose to perform oral sex with either a male or female
partner and this sex includes oral contact with your partners anus
(analingus or rimming),
use a latex barrier (such as a natural rubber latex sheet, a
dental dam, or a cut-open condom that makes a square) between your
mouth and the anus. Plastic food wrap also can be used as a barrier.
If you would like more information or have personal concerns, call
CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348
(TTY), in English, en Español.
Yes. At the start of every intravenous injection, blood is introduced into the needle
and syringe. HIV can be found in the blood of a person infected with the virus.
The reuse of a blood-contaminated needle or syringe by another drug injector
(sometimes called "direct syringe sharing") carries a high risk of HIV
transmission because infected blood can be injected directly into the
Sharing drug equipment (or "works") can be a risk for spreading
HIV. Infected blood can be introduced into drug solutions by
using blood-contaminated syringes to prepare drugs;
reusing bottle caps, spoons, or other containers ("spoons" and
"cookers") used to dissolve drugs in water and to heat drug solutions; or
reusing small pieces of cotton or cigarette filters ("cottons") used to
filter out particles that could block the needle.
"Street sellers" of syringes may repackage used syringes and sell them as
sterile syringes. For this reason, people who continue to inject drugs
should obtain syringes from reliable sources of sterile syringes, such as
It is important to know that sharing a needle or syringe for any use,
including skin popping and injecting steroids, can put one at risk for HIV and
other blood-borne infections.
Yes. Having a sexually transmitted disease (STD) can increase a person's risk
of becoming infected with HIV, whether the STD causes open sores or breaks
in the skin (e.g., syphilis, herpes, chancroid) or does not cause breaks in
the skin (e.g., chlamydia, gonorrhea).
If the STD infection causes irritation
of the skin, breaks or sores may make it easier for HIV to enter the body
during sexual contact. Even when the STD
causes no breaks or open sores, the infection can stimulate an immune response
in the genital area that can make HIV transmission more likely.
if an HIV-infected person is also infected with another STD, that person
is three to five times more likely than other HIV-infected persons to
transmit HIV through sexual contact.
Not having (abstaining from) sexual
intercourse is the most effective way to avoid all STDs, including HIV. For
those who choose to be sexually active,
the following HIV prevention activities are highly effective:
Engaging in behaviors that do not involve vaginal or anal intercourse
or oral sex
The risk of health
care workers being exposed to HIV on the job is very low, especially if they
carefully follow universal precautions
(i.e., using protective practices and personal protective equipment to prevent
HIV and other blood-borne infections). It is important to remember that casual,
everyday contact with an HIV-infected person does not expose health care workers
or anyone else to HIV. For health care workers on the job, the main risk of
HIV transmission is through accidental injuries from needles and other sharp
instruments that may be contaminated with the virus; however, even this risk
is small. Scientists estimate that the risk of infection from a needle-stick
is less than 1 percent, a figure based on the findings of several studies
health care workers who received punctures from HIV-contaminated needles or
were otherwise exposed to HIV-contaminated blood.
Although HIV transmission is possible in health care settings, it is extremely
rare. Medical experts emphasize that the careful practice of infection control
procedures, including universal precautions (i.e., using protective practices
and personal protective equipment to prevent HIV and other blood-borne infections),
protects patients as well as health care providers from possible HIV transmission
in medical and dental offices and hospitals.
1990, the CDC reported on an HIV-infected dentist in Florida who apparently
infected some of his patients while doing dental work. Studies of viral DNA
sequences linked the dentist to six of his patients who were also HIV-infected.
has not yet been able to establish how the transmission took place. No additional
studies have found any evidence of transmission from provider to patient
in health care settings.
CDC has documented rare cases of patients contracting
HIV in health care settings from infected donor tissue. Most of these cases
occurred due to
following universal precautions and infection control guidelines. Most
also occurred early
in the HIV epidemic, before established screening procedures were in place.
No. While it is possible to get infected with HIV if you are stuck with a needle that is contaminated with HIV, there are no documented cases of transmission outside of a health-care setting.
CDC has received inquiries about used needles left by HIV-infected injection drug users in coin return slots of pay phones, the underside of gas pump handles, and on movie theater seats. Some reports have falsely indicated that CDC "confirmed" the presence of HIV in the needles. CDC has not tested such needles nor has CDC confirmed the presence or absence of HIV in any sample related to these rumors. The majority of these reports and warnings appear to be rumors/myths.
CDC was informed of one incident in Virginia of a needle stick from a small-gauge needle (believed to be an insulin needle) in a coin return slot of a pay phone and a needle found in a vending machine that did not cause a needle-stick injury. There was an investigation by the local police and health department and there was no report of anyone contracting an infectious disease from these needles.
Discarded needles are sometimes found in the community. These needles are believed to have been discarded by persons who use insulin or inject illicit drugs. Occasionally the public and certain workers (e.g. sanitation workers or housekeeping staff) may sustain needle-stick injuries involving inappropriately discarded needles. Needle-stick injuries can transfer blood and blood-borne pathogens (e.g., hepatitis B, hepatitis C, and HIV), but the risk of transmission is extremely low and there are no documented cases of transmission outside of a health care setting.
CDC does not recommend routinely testing discarded needles to assess the presence or absence of infectious agents in the needles. Management of exposed persons should be done on a case-by-case basis to determine (1) the risk of a blood-borne pathogen infection in the source and (2) the nature of the injury. Anyone who is injured from a needle-stick in a community setting should contact their health-care provider or go to an emergency room as soon as possible. Antiretroviral medications given shortly after being stuck by a needle infected with HIV can reduce the risk of HIV infection. The health-care provider should then report the injury to the local or state health department. Guidance on non-occupational exposure can be found at
Antiretroviral Postexposure Prophylaxis After Sexual, Injection-Drug Use, or Other Nonoccupational Exposure to HIV in the United States.
transmission of HIV appears to be a rare occurrence. However, there are case
reports of female-to-female transmission
of HIV. The well-documented risk of female-to-male transmission of HIV shows
that vaginal secretions and menstrual blood may contain the virus and that
mucous membrane (e.g., oral, vaginal) exposure to these secretions has the
potential to lead to HIV infection.
In order to reduce the risk of HIV transmission, women who have sex with women
should do the following:
of a mucous membrane, such as the mouth (especially non-intact tissue),
to vaginal secretions
and menstrual blood.
Use condoms consistently
and correctly each and every time for sexual contact with men or when using
sex toys. Sex toys should
not be shared. No
barrier methods for use during oral sex have been evaluated as effective by
the Food and Drug Administration (FDA).
However, natural rubber latex sheets, dental dams, cut open condoms,
or plastic wrap may offer some protection from contact with body fluids during
and possibly reduce the risk of HIV transmission.
Know your own and
your partner’s HIV status. This knowledge can
help uninfected women begin and maintain behavioral changes that reduce the risk
of becoming infected. For women who are found to be infected, it can
in getting early treatment and avoiding infecting others.
A risk of HIV transmission does exist if instruments contaminated with blood
are either not sterilized or disinfected or are used inappropriately between
clients. CDC recommends that single-use
instruments intended to penetrate the skin be used once, then disposed
of. Reusable instruments or devices that penetrate the skin and/or
contact a client's blood should be thoroughly cleaned and sterilized
View the CDC fact sheet on the sterilization of patient-care equipment
and HIV (from the CDC Division of Healthcare Quality Promotion Web
Personal service workers who do tattooing or body piercing should
be educated about how HIV is transmitted and take precautions to prevent
HIV and other blood-borne infections in their settings.
If you are considering
getting a tattoo or having your body pierced, ask staff at the establishment
what procedures they use to prevent the spread of HIV
and other blood-borne infections, such as the hepatitis B virus. You also
the local health department to find out what sterilization procedures are
in place in the local area for these types of establishments.
It depends on the type of kissing. There is no risk from closed-mouth kissing.
There are extremely rare cases of HIV being transmitted via deep “French” kissing but in each case, infected blood was exchanged due to bleeding gums or sores in the mouth. Because of this remote risk, it is recommended that individuals who are HIV-infected avoid deep, open-mouth “French” kissing with a non-infected partner, as there is a potential risk of transferring infected blood.
There is no risk of transmission closed-mouth kissing.
There is a remote risk from deep, open-mouth kissing if there are sores or bleeding gums and blood is exchanged. Therefore, persons living with HIV should avoid this behavior with a non-infected partner.
It is very rare, but in specific circumstances HIV can be transmitted by a human bite. In 1997, CDC published findings from a state health department investigation of an incident that suggested blood-to-blood transmission of HIV by a human bite. There have been other rare reports in the medical literature in which HIV appeared to have been transmitted by a human bite. Biting is not a common way of transmitting HIV, in fact, there are numerous reports of bites that did not result in HIV infection. Severe trauma with extensive tissue damage and the presence of blood were reported in each of the instances where transmission was documented or suspected. Bites that do not involve broken skin have no risk for HIV transmission, as intact skin acts as a barrier to HIV transmission.
There is no risk from a bite where the skin is not broken.
There is a remote risk of transmission by human bite. All documented cases where transmission did occur included severe trauma with extensive tissue damage and the presence of blood.
No. In some persons living with HIV, the virus has been detected in saliva, but in extremely low quantities. Contact with saliva alone has never been shown to result in transmission of HIV, and there is no documented case of transmission from an HIV-infected person spitting on another person.
No. HIV is not transmitted by day-to-day contact in the workplace, schools, or
social settings. HIV is not transmitted through shaking hands, hugging, or
a casual kiss. You cannot become infected from a toilet seat, a drinking fountain,
a door knob, dishes, drinking glasses, food, or pets.
HIV is not an airborne
or food-borne virus, and it does not live long outside the body.
Although contact with blood
and other body substances can occur in households, transmission of HIV is
in this setting.
A small number of transmission
cases have been reported in which a person became infected with HIV as
a result of
contact with blood or other body secretions from an HIV-infected person
in the household. For information on these cases refer to the May 20,
and Mortality Weekly Report, “Human Immunodeficiency Virus Transmission
in Household Settings — United States.”
Persons living with HIV and persons providing home care for those
living with HIV should be fully educated and trained regarding appropriate
No. From the start of the HIV epidemic there has been concern about HIV transmission
from biting and bloodsucking insects, such as mosquitoes. However, studies
conducted by the CDC and elsewhere have shown no evidence of HIV transmission
from mosquitoes or any other insects–even in areas where there are many cases
of AIDS and large populations of mosquitoes. Lack of such outbreaks, despite
intense efforts to detect them, supports the conclusion that HIV is not transmitted
The results of experiments and observations of insect biting behavior
indicate that when an insect bites a person, it does not inject its own or
bitten person's or animal's blood into the next person bitten. Rather, it injects
saliva, which acts as a lubricant so the insect can feed efficiently. Diseases
such as yellow fever and malaria are transmitted through the saliva of specific
species of mosquitoes. However, HIV lives for only a short time inside an insect
and, unlike organisms that are transmitted via insect bites, HIV does not reproduce
(and does not survive) in insects. Thus, even if the virus enters a mosquito
or another insect, the insect does not become infected and cannot transmit
HIV to the next human it bites.
There also is no reason to fear that a mosquito
or other insect could transmit HIV from one person to another through HIV-infected
blood left on its mouth
parts. Several reasons help explain why this is so. First, infected people
do not have
constantly high levels of HIV in their blood streams. Second, insect mouth
parts retain only very small amounts of blood on their surfaces. Finally,
scientists who study insects have determined that biting insects normally do
from one person to the next immediately after ingesting blood. Rather, they
to a resting place to digest the blood meal.
There are no documented cases of HIV being transmitted during participation in
sports. The very low risk of transmission during sports participation would
involve sports with direct body contact in which bleeding might be expected
If someone is bleeding, their participation in the sport should be
interrupted until the wound stops bleeding and is both antiseptically cleaned
bandaged. There is no risk of HIV transmission through sports activities where
bleeding does not occur.
No incident of food being contaminated with HIV-infected blood or semen has been reported to CDC. Furthermore, CDC has received no reports of HIV infection resulting from eating food, including condiments.
HIV does not live long outside the body. Even if small amounts of HIV-infected blood or semen was consumed, exposure to the air, heat from cooking, and stomach acid would destroy the virus. Therefore, there is no risk of contracting HIV from eating food.
No, this story is not true. Many scientific studies have been conducted to examine all the possible ways that HIV is transmitted. These studies have not shown HIV to be transmitted through air, water, insects, or casual contact.