AIDS: Acquired Immunodeficiency Syndrome

AIDS is not transmitted, it’s acquired. While this might not make much sense at the beginning, it is all about the terminology. AIDS (acquired immune deficiency syndrome) isn’t a disease in itself; rather, AIDS is a condition that develops when a person’s body has been weakened by HIV (the human immunodeficiency virus). 
While the human immunodeficiency virus (HIV) is transmitted from an HIV+ to an HIV- person, causing a positive HIV status, the infection spreads inside the infected individual damaging the immune system. When HIV infection and its effects on the human body progress, the immune system is weakened. The final stage of the disease is called AIDS: Acquired Immunodeficiency Syndrome. HIV infection is usually a multistage disease(Read about HIV stages), with a latency period of an average of ten years. If no proper medical treatment is administered, around half of people infected with HIV develop AIDS within ten years.
 

What is Immunodeficiency?

Immunodeficiency means a weakened or not existing immune system. HIV invades the important T-lymphocytes, mainly CD4+ cells, of the immune system and decreases their number by directly damaging and destroying the cells.
Acquired immunodeficiency syndrome (AIDS) is defined in terms of either a CD4⁺ T cell count below 200 cells per µL or the occurrence of specific diseases in association with an HIV infection.
AIDS as the late stage disease of HIV infection reveals itself through initial conditions and specific complications which are not observed in a healthy individual.
 

AIDS Initial Conditions:

The most common initial conditions that alert to the presence of AIDS are:

• Pneumocystis pneumonia (40%)
• Weakness, weight loss, and cachexia in the form of HIV wasting syndrome (20%)
• Esophageal candidiasis (yeast infection of the esophagus)
• Respiratory tract infections
• Prolonged fevers and chills
• Sweats (particularly at night)
• Swollen lymph nodes
• Diarrhea

The damage of the immune system then makes the individual prone to infections with usually not so harmful organisms and parasites. These so called opportunistic infections are caused by pathogens that wait for an “opportunity” for the immune system to be weak enough in order to allow them to invade and cause diseases. These infections may affect nearly every organ system.
Opportunistic infections may be caused by bacteria, viruses, fungi and parasites that are normally controlled by the immune system. The type of infection with these opportunists is then depending on their presence and number in the individual’s environment.
Besides the vulnerability of an AIDS patient towards opportunistic infections, the prevalence of certain cancer types, specifically those caused by viruses, is also increased in AIDS patients.
 
Viral induced cancers in AIDS patient include Kaposi’s sarcoma (the most common cancer occurring in 10 to 20% of people with HIV), Burkitt’s lymphoma, primary central nervous system lymphoma, and cervical cancer. Lymphomas are the second most common cancer and the cause of death of nearly 16% of people with AIDS. Kaposi’s sarcoma and lymphomas are both   associated with human herpes virus 8. Cervical cancer is association with human papillomavirus (HPV).