HIV

HIV has no signs, so one can only detect it by testing whether the virus has entered the body.

Since HIV is very small and hides inside white blood cells, finding the virus itself (direct method) is not easy, so the indirect method is used to detect HIV. When HIV enters white blood cells, the white blood cells secrete a substance known as the HIV antibody. It is as if white blood cells post a sign that reads they have a guest called HIV. In routine HIV testing, we look for this antibody. In other words, we are using this indirect method and we are looking for a trace of virus.

HIV can be divided into three stages from a diagnostic point of view:

• Window period: From when the virus enters the body, it takes some time for antibodies secreted by white blood cells to be measurable. So, even if a person is tested, the result will be negative. This is called a window period that can last up to three months.
• HIV infection stage: This stage, which is the longest stage of the disease can last up to a person's lifetime. It is when the person still has no signs but the antibody is secreted and can be detected by testing to know that the person is infected with HIV.
• AIDS Stage: Signs of infectious/non-infectious diseases will appear if the person is not treated and cared for. At this point signs of many diseases will be observed and at the same time the antibody can be detected in blood.