Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about HIV.

And you can find written notes on this topic at zero to finals.com

or in the Infectious Diseases section of the second edition of the Zero to Finals Medicine book.

So let's get straight into it.

Being infected with the human immunodeficiency virus or HIV is referred to as being HIV positive.

Acquired immunodeficiency syndrome or AIDS occurs when HIV is not treated, the disease progresses and the person becomes immunocompromised.

Immunodeficiency leads to opportunistic infections and AIDS-defining illnesses, which we'll talk about in more detail shortly.

Let's start with some basics.

HIV is an RNA retrovirus.

HIV 1 is the most common type and HIV 2 is mainly found in West Africa. The virus enters and destroys the CD4

T helper cells of the immune system. An initial seroconversion flu-like illness occurs within a few weeks

of infection. The infection is then asymptomatic

until the disease progresses to immunodeficiency once the virus destroys enough CD4 T-helper

cells. Disease progression and immunodeficiency may occur years after the initial infection.

Let's talk about transmission.

HIV is not transmitted through day-to-day activities, including kissing.

It spread through unprotected anal, vaginal or oral sexual activity,

mother-to-child at any stage of pregnancy, birth or breastfeeding,

and this is called vertical transmission when it passes from the mother to the child,

and through mucus membrane, blood or open wound exposure to infected blood or bodily fluids. For example, sharing needles,

needle stick injuries or splashes of blood in the eye. Next let's talk about AIDS-defining illnesses.

...