ACWN

AIDS Committee of Western Newfoundland Inc.

Transmission

HIV can be transmitted in 3 main ways:

  • Sexual Transmission
  • Transmission through blood
  • Mother-to-child Transmission

Contrary to some popular misconceptions , HIV is a difficult disease to obtain. Three conditions must be met for transmission to occur:

1. HIV Must Be Present
Infection can only happen if one of the persons involved is infected with HIV. Some people assume that certain behaviors (such as anal sex) cause AIDS, even if HIV is not present. This is not true.

2. There Must Be A Sufficient Quantity of HIV
The concentration of HIV determines whether infection may happen. In blood, for example, the virus is very concentrated. A small amount of blood is enough to infect someone. A much larger amount of other fluids would be needed for HIV transmission.

3. HIV Must Get Into The Bloodstream
It is not enough to be in contact with an infected fluid to become infected. Healthy, unbroken skin does not allow HIV to get into the body; it is an excellent barrier to HIV infection. HIV can only enter through an open cut or sore, or through contact with the mucous membranes in the anus and rectum, the genitals, the mouth, and the eyes.

Infectious Body Fluids

Non-Infectious Body Fluids

Blood (including menstrual blood)

Saliva

Semen

Tears

Vaginal secretions

Sweat

Breast milk

Feces
Urine

Blood contains the highest concentration of the virus, followed by semen, followed by vaginal fluids. Breast milk can also contain a high concentration of the virus, but in this situation, transmission depends on WHO and HOW. An adult can ingest a small amount of breast milk at no probable risk. But an infant, with its very small body and newly forming immune system, consumes vast quantities of breast milk relative to its body weight. Therefore an infant is at risk from breast milk, whereas an adult may not be.
HIV might be transmitted from an infected person to another from pre-seminal fluid (pre-cum). Although it is difficult for researchers to analyze definitively, it is thought that HIV may be transmitted through pre-cum (this is a clear fluid that lubricates the urethra for semen). Pre-seminal fluid can contain semen or white blood cells, both of which have HIV in an infected person. So going back to conditions required for transmission, HIV can be present, but it is present in a relatively, small amount, compared to semen or blood. Therefore, pre-seminal fluid presents a much lower risk for HIV transmission than ejaculate, but there is some risk, depending on where this fluid is going (as in all transmission situations).

Sexual Routes Of Transmission

Sex
There are many different ways to have sex and not all of them are as risky as others. HIV can enter the body from unprotected anal, vaginal, or oral sex. About two thirds of people with HIV acquired HIV from sexual intercourse with an infected partner.
To ensure little or no risk of contracting HIV don’t exchange fluids. Should you decide to take part in more risky sexual behaviors(anal, vaginal, or oral intercourse) you must use a latex barrier for protection with every sexual act.

Vaginal and anal intercourse

HIV can enter the body in several ways during sex. HIV can enter through small, even microscopic sores, cuts or openings in the walls of the rectum or vagina during intercourse . It can also directly infect the immune cells that line the walls of the vaginal and anus or the cells of the urethra. Anal sex is especially risky because the lining of the rectum is extremely delicate and almost always tears during intercourse. Without the use of a condom it is considered a high risk for HIV infection. Most HIV-positive people have no symptoms and may be unknowingly passing it on. If you are positive, and your partner is also, condoms will still help protect you. An immune system weakened by HIV will have trouble fighting off other STIs and they could trigger HIV-related symptoms.

Oral sex

(Mouth-Penis, Mouth-Vagina) is low risk for HIV infection. However, this does not mean no risk. Generally, the mouth is an unreceptive environment for HIV. As a result, the risk of HIV transmission through the throat, gums, and oral membranes is lower than through vaginal or anal membranes. There are however, documented cases where HIV was transmitted orally, so we can’t say that getting HIV-infected semen, vaginal fluid or blood in the mouth is no risk.

Two factors that decrease the risk of contracting HIV from oral sex are:

  • The amount of HIV in saliva has been found to be very small.
  • Swallowed semen and vaginal fluids do not enter the blood stream.

Factors that make us aware that some risk does exist are:

  • The HIV virus is found in semen and vaginal fluids.
  • The lining of the mouth is a mucous membrane, like the lining of the vagina and anus, it is very delicate. Microscopic tears could occur during oral activities and provide a route into the blood stream.
  • Cold sores or even small cuts from the teeth that are very common in the mouth, may provide an open wound for the virus to enter.
  • It is important to remember that oral sex can transmit a variety of other STIs, like syphilis and gonorrhea. To protect yourself, use a dental dam or a non-lubricated condom. A condom can easily make a dental dam. Just cut off the tip and slice it up the side. This makes a flat piece of latex that can be held over the woman’s vaginal and surrounding genital area.

Non-Sexual Routes Of Transmission

Needle sharing: Sharing a needle can pass blood directly from one person’s bloodstream to another. It is a very easy way to transmit a blood-borne virus. HIV can survive for several days in the small amount of blood that remains in a needle after use, so used needles are very risky for HIV transmission; they provide a direct path into the bloodstream. Ideally, used needles should never be reused, but if they are, they should always be cleaned with bleach or alcohol before re-use.

Tattooing, Piercing, Acupuncture, Electrolysis,and Shaving: Any procedure in which a needle or razor is used on more than one person involves a theoretical risk of HIV transmission because of the possibility of infected blood on the instrument. However, the risk can be reduced or eliminated through routine sterilization procedures.

Blood Transfusions: Since March 1985, all blood in Canada has been screened with the HIV antibody test. This practice has almost eliminated the risk of getting HIV through a blood transfusion.

Hemophilia Treatments: Hemophilia is a genetic disease in which people, mainly men, lack the ability to clot blood, resulting in the need for blood transfusions. Prior to 1992 there were no means of screening blood products for HIV and other diseases, therefore placing hemophilia patients at high risk. Today there are currently scanes put in place to insure that HIV infected blood does not enter  the blood supply.

Other Blood Products: Besides whole blood, platelets (red blood cells), have transmitted the virus. There are currently screening processes put in place to prevent the spread of infectious diseases. No other blood products are suspected of transmitting HIV, Gamma globulin and hepatitis B vaccine being examples. Gamma globulin, however, can temporarily transmit HIV antibodies, although not the virus itself. These antibodies will disappear within a few months.

Mother to Child: It is possible for an HIV-infected mother to pass the virus directly before or during birth, or through breast milk. If HIV infected mothers are treated appropriately during pregnancy it decreases the risk of passing the disease to their infant to below 1%. However if a mother is unaware of her status the baby is at a much higher risk of being infected.

Breast Milk: Breast milk contains HIV, and while small amounts of breast milk do not pose significant threat of infection to adults, it is a viable means of transmission to infants. The United Nations presented a recommendation at the 12th World AIDS Conference suggesting ,that infected mothers not breastfeed their infants.

Semen Donor Insemination: Donor semen is checked for HIV antibodies when the semen is collected. The semen is then frozen. The donor is required to come back after six months for a second HIV test, to confirm the initial HIV screening. The semen is not used before the procedure is completed.

Occupational Transmission

Contrary to common belief, HIV/AIDS is difficult to contract, even when working in a medical field.

• Contact with tissue under the skin (e.g. needle stick or cut) = approx. 0.3% (1 in 300)

• Contact with mucous membranes (e.g. splash to the eyes, nose or mouth) = approx. 0.1 (1 in 1000)

• Contact with intact skin (e.g. splash on forearm) = less than 0.1% (less and 1 in 1000). A small amount of blood on intact skin probably poses no risk at all; there have been no documented cases of HIV transmission this way. Risk may be higher if skin is damaged (e.g. recent cut), if the contact involves a large area of skin, or if the contact is prolonged.  

You cannot get HIV from . . .

Casual contact
Public toilets
Kissing
Pets
Drinking from the same glass
Swimming pools
Mosquitoes

To transmit HIV…

The virus needs to be present.
It needs to have direct access into the blood stream.

Insect Bites: HIV is not transmitted by mosquitoes, flies, ticks, fleas, bees or wasps. If a bloodsucking insect bites someone with HIV, the virus dies almost instantly in the insect’s stomach (as it digests the blood). HIV can only live in human cells.

Mosquitoes Cannot Transmit HIV For Two Reasons:
1.The mosquito draws blood and injects saliva. The blood from one person is not injected into the mosquito’s next victim.
2.HIV dies in the mosquito’s body. People sometimes are confused because malaria actually reproduces inside the mosquito’s digestive track, using the insect as part of its life cycle. HIV does not.
These facts are confirmed by looking at infection patterns. In areas where mosquitoes are common and where HIV is prevalent, the distribution of AIDS cases in the population is not different from other areas. If mosquitoes transmitted HIV, we would be seeing a disproportionate number of children and elderly infected in those areas.

These facts are confirmed by looking at infection patterns. In areas where mosquitoes are common and where HIV is prevalent, the distribution of AIDS cases in the population is not different from other areas. If mosquitoes transmitted HIV, we would be seeing a disproportionate number of children and elderly infected in those areas.

Casual Contact/Sharing Dishes or Food: HIV is not transmitted through casual, everyday contact. Since HIV is not transmitted by saliva, it is impossible to get it through sharing a glass, a fork, a sandwich, or fruit.

Swimming Pools and Hot Tubs: The chemicals used in swimming pools and hot tubs would instantly kill any HIV, if the hot water hadn’t killed it already.

Pets: Humans are the only animals that can carry HIV. People sometimes think they can get HIV from pets, because some animals carry viruses that produce similar immune deficiencies in their own species, e.g. FIV, feline immunodeficiency virus, in cats, and SIV, simian immunodeficiency virus, in some types of monkeys. However, FIV cannot be transmitted to people, nor can HIV be transmitted from humans to pets such as cats and dogs. (An exception is chimpanzees used in research that have been infected with HIV. Their blood poses a risk to researchers working with them).

Contact with Saliva, Tears, Sweat, Feces or Urine: Transmission can only occur when a sufficient amount of HIV enters the bloodstream, through cuts or mucous membranes. These body fluids either contain no HIV or it exists in a quantity too small to result in transmission. HIV is not transmitted by saliva, there is a great deal of evidence to support this fact. Countless numbers of people  have had saliva contact with people with AIDS , whether it be through kissing, sharing food, sharing joints, and many other means. We can find no evidence that these activities have transmitted the virus even a single time.

HIV SURVIVAL OUTSIDE THE BODY

Generally, when people ask the question, “How long can HIV survive outside the body?”, they have come into contact with some body fluid that they think might contain HIV, and are worried about transmission. Almost always these questions are about casual contact, and we know the virus is not transmitted except during unprotected sex, sharing needles, or through significant and direct exposure to infected blood.
The length of time HIV can survive outside the body depends on the amount of HIV present in the body fluid what conditions the fluid is subjected to in the environment.
In a laboratory, HIV has been kept viable (able to infect) for up to 15 days, and even after the body fluid containing it had dried. However, these experiments involved an extremely high concentration of the virus which was kept at a stable temperature and humidity. These conditions are very unlikely to exist outside of a laboratory. HIV is very fragile, and many common substances, including hot water, soap, bleach and alcohol, will kill it.
Air does not “kill” HIV, but exposure to air dries the fluid that contained the virus, and that will destroy or break up much of the virus very quickly.