HIV Transmission

This article gives the reader an understanding of the different ways in which HIV can be transferred from a person carrying the disease to a secondary person. It seeks to explain how the virus achieves this and some of the common behaviours that act as risk factors for HIV infection.

How likely are HIV infections to spread during risky behaviours?

When initially infected with HIV the levels of the virus present within your body rapidly increase. During this period you are highly infectious and risky behaviours are more likely to result in the passing on of the disease to others. The immune system eventually responds to the infection, reducing the amount of the virus present. This leads to a corresponding reduction in the likelihood of infecting others with the disease. After this reduction virus levels will gradually increase until the immune system is rendered incapable of fighting off disease. This leads to an increase in infectiousness over time as the disease progresses.

How does HIV infect others?

The HIV virus is present in sufficient levels within some of the bodily fluids of the carrier to cause infection. These are most commonly blood, semen, vaginal fluid and breast milk. Sharing of these fluids between two people can cause the disease to be passed on if any of these fluids enter the bloodstream of the uninfected party.

HIV can also be absorbed through mucus membranes leading to an infection. Mucus membranes can be found on the head and inner foreskin of the penis, clitoris and clitoral hood, vagina, rectum, mouth and stomach.

What are the main behaviours that can transmit HIV?

The different behaviours which can cause transmittal and infection of HIV fall into two main categories. These are contact of mucus membranes with infected bodily fluids or direct transfer of an infected fluid (usually blood) into the bloodstream of the HIV negative person.
Contact between infected fluid and mucus membranes can occur during unprotected vaginal, anal or oral sex. This occurs due to ejaculate and vaginal secretions coming into contact with mucus membranes or micro traumas is these areas. Sharing of sex toys can also pass the virus on.

Direct infection can occur due to injecting drug users sharing needles, unscreened blood transfusions and mother to child infection during and after pregnancy.

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