HIV and AIDS are different. HIV is Human Immunodeficiency Virus while AIDS stands for Acquired Immunodeficiency Syndrome. When the immune system becomes weakened by HIV, the illness progresses to AIDS.
There are two types of HIV: HIV-1 and HIV-2. Both are transmitted through the same routes and associated with similar opportunistic infections. However, HIV-1 is more common worldwide while HIV-2 is more localized at West Africa, Mozambique and Angola. HIV-2 is less easily transmitted and less pathogenic compare to HIV-1.
Stages of HIV infection
There are three stages of HIV infection: Acute, Chronic and AIDS.
- Acute HIV
Symptoms are relatively non-specific. HIV antibody test often negative but becomes positive within 3-6 months, this process is known as seroconversion. Large amount of HIV is present in the peripheral blood. Primary HIV syndromes usually resolves itself and HIV infected person remain asymptomatic for a prolonged period, often years. - Chronic HIV
At CD4 cell counts over 500 cells/uL, many complications overlap with conditions found in uninfected populations (bacterial pneumonia, tuberculosis, minor skin conditions), but they may be more frequent. At CD4 cell counts between 200 and 500 cells/uL, other conditions and opportunistic infections may begin to appear (Kaposi’s sarcoma, oral candidiasis, herpes zoster and others). HIV continues to reproduce, CD4 count gradually declines from its normal value of 500-1200. Once CD4 count drops below 500, HIV infected person at risk for opportunistic infection. - AIDS
When CD4 counts drops below 200, a person is considered to have advanced HIV disease. The following disease are predictive of the progression to AIDS:
- Persistent herpes-zoster infection (shingles)
- Oral candidiasis (Thrush)
- Oral hairy leukoplakia
- Kaposi’s sarcoma
If preventative mediations not started, the HIV infected person is now at risk for: - Pneumocystis carinii pneumonia (PCP)
- Cryptocccal meningitis
- Toxoplasmosis
If CD4 cell count drop below 50: - Mycobacterium avium
- Cytomegalovirus infections
- Lymphoma
- Dementia
- Most deaths occur with CD4 counts below 50
Goals of therapy
- Maximally suppresses HIV
- Allow for the longest time of full suppression
- Fits into the patient daily routine
- Be affordable
- Have minimal short term side effects
- Have minimal long term side effects
However, there are some considerations before HIV patient start antiretroviral therapy. Willingness to start, adhere and follow-up is the main consideration. This is because resistance develops easily if patient started on antiretroviral but does not compliance to the medication. Patient need to understand about adverse drug reaction of the medication and choices of treatment available. Underlying disease of patient such as diabetes, high blood pressure and heart disease should be take into consideration as well. Other social factors such as working hours and social support may affect patient’s compliance as well.
Medication compliance should be assessed and monitored every time during follow-up. This is very important to ensure successful suppression of viral replication and improve clinical outcome. Hence, regimens that are easy to take, low pill burden, low frequency and no food restrictions is preferred.