human immunodeficiency virus (HIV) is considered as a sexually transmitted infection (STI). It can be transmitted by direct contact with the patient's blood or from mother to the infant during pregnancy, childbirth or breast-feeding (1).
It can damage the immune system as it kills CD4 cells, which are called T cells (type of the immune cell).
Untreated HIV kills more CD4 cells, and then the body is more likely to get various types of conditions and cancers and in developed stages it can be developed to AIDS.
AIDS is acquired immunodeficiency syndrome which is a chronic life-threatening condition results from HIV (1).
The normal ranges of the CD4 are of 500 to 1,600/ml3, but in HIV condition, CD4 count falls below 200/ml3 and then diagnosed as AIDS (2).
There’s currently no cure for AIDS, and without treatment, life expectancy after diagnosis is about 3 years and may be shorter if the person develops a severe opportunistic illness. On the other hand, treatment with antiretroviral drugs can prevent AIDS from developing.
HIV development has 3 stages:
stage 1: acute stage.
stage 2: clinical latency, or chronic stage
stage 3: AIDS (2).
Symptoms of HIV stages:
- It is known as primary infection or Acute HIV. Some people with HIV may show a flu-like symptoms within two to four weeks after the infection. It can be so mild that the patient might not notice them although the viral load is quite high at this stage, so it can spread more easily during first stage than the next one.
These symptoms can be:
Fever, headache, muscle aches and joint pain
Rash, sore throat and painful mouth sores.
- It is known as Clinical latent infection or Chronic HIV. In this stage the virus is still present in the body but in some cases no symptoms can be noticed it and can last for many years if no treatment is taken and some cases develop more severe disease much sooner.
The last stage (AIDS):
- In this stage the immune system has been severely damaged and more likely to develop opportunistic infections or opportunistic cancers (1).
There are many infections common to HIV and AIDS As:
1- Pneumocystis pneumonia (PCP) which is a fungal infection most common to cause of pneumonia in people infected with HIV.
2- Candidiasis which is a common HIV-related infection that leads to inflammation and a thick, white coating on the mouth, tongue, esophagus or vagina.
3- Tuberculosis (TB)
4- Cytomegalovirus which is a common herpes virus transmitted by the body fluids as blood, urine, saliva and breast milk. In healthy people the immune system can inactivate the virus, and it remains dormant in your body but when it weakens, the virus resurfaces damaging eyes, digestive tract, lungs or other organs.
5- Cryptococcal meningitis which is an inflammation of the membranes and fluid surrounding your brain and spinal cord (meninges).
6- Toxoplasmosis which results from Toxoplasma gondii, a parasite spread by cats (1).
There is no approved vaccines till now but researches are going on and that is because HIV is a complicated virus that mutates rapidly and often fends off immune system responses (2).
Researchers are still working on finding vaccine for HIV inspit of these obstacles as:
Peptide vaccines that depend on using small proteins from HIV to deliver an immune response.
Recombinant subunit protein vaccines by using larger protein pecies from HIV.
Live vector vaccines that use non-HIV viruses that can carry HIV genes into the body to trigger an immune response.
Virus-like particle vaccines by using a noninfectious HIV-like virus that has some, but not all, HIV proteins.
DNA-based vaccines by using HIV DNA to trigger an immune response (3).