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The Natural History of HIV Infection
These stages as sometimes called the "natural history" of infection progression and are described below. The natural history of HIV infection has been altered dramatically in developed countries because of new medications. In countries where there is no access to these expensive medications, or in cases where people do not become aware of their HIV infection until very late, the infection progresses as described below.
A cofactor is a separate condition that can change or "speed up" the course of infection. There are several cofactors that can increase the rate of progression to AIDS. They include a person's age, certain genetic factors and possibly drug use, smoking, nutrition and HCV.
Currently, if the infection is untreated, the average time from HIV infection to death is 10-12 years. Early detection and medical treatment may mean that the person will live longer.
Viral Transmission
This is the initial infection with HIV. When a person is infected with HIV, they will probably have virus circulating in their bloodstream, and may become infectious to others within five days. The person may be infectious before the onset of any symptoms. They will remain infectious for the rest of their lives.
Primary HIV Infection
During the first few weeks of HIV infection, an infected person has a very high amount of virus in their bloodstream. The high viral load means the individual may more easily pass the virus to others. Unfortunately, during primary infection, many people are unaware that they are infected.
The most common symptoms noticed by persons newly infected with HIV are fever, swollen glands in the neck, armpits and/or groin, rash, fatigue and a sore throat (also common with many other types of infections). These initial symptoms go away in a few weeks, but the individual continues to be infectious to others. This is sometimes called "seroconversion syndrome" or "seroconversion sickness." It resembles mononucleosis infection, with similar symptoms and length of illness.
It is extremely important that healthcare providers consider special testing for HIV itself (not antibodies) if an individual has behaviors which put him or her at risk for HIV and is presenting with the above symptoms. If individuals experience these symptoms after having unprotected sex or sharing needles, they should seek medical care and tell their provider why they are concerned about HIV infection.
Some healthcare providers believe that a newly HIV-infected person should begin to take drug therapies immediately. Others believe that people should wait. However, people should also assume that they could be taking HIV-related medications the remainder of their lives.
Seroconversion
Seroconversion is the time period that it takes from infection to the production of antibodies, which would show positive on an HIV test. This may vary from person to person. As discussed previously in the Testing and Counseling section of this course, HIV antibodies are detectable sometime within the first three to six months of infection, and in most cases will be detectable for life.
Asymptomatic HIV Infection
During this time period, an HIV-infected person has no noticeable signs or symptoms. The person may look and feel healthy, but can still pass the virus to others. It is not unusual for an HIV-infected person to live 10 years or longer without any outward physical signs of progression to AIDS. Meanwhile, the person's blood and other systems are affected by HIV. This would be reflected in laboratory tests. Unless a person in this stage has been tested for HIV, they will probably not be aware they are infected.
Symptomatic HIV Infection
During the symptomatic stage of HIV infection, a person begins to have noticeable physical symptoms that are related to HIV infection.
Anyone who has symptoms like these and has engaged in behaviors that transmit HIV should seek medical advice. The only way to know for sure if you are infected with HIV is to take an HIV antibody test.
AIDS
An AIDS diagnosis can only be made by a licensed healthcare provider. The diagnosis is based on the result of HIV-specific blood tests, and the person's physical condition. A diagnosis of AIDS is made because the person has an illness, one of the "AIDS-defining illnesses, and has white blood cell counts and other conditions that are specifically linked to making an AIDS diagnosis. Once a person is diagnosed with AIDS, even if they later feel better, they do not "go backwards" in the classification system for HIV infection. This means that they are always considered to have AIDS.
People who have an AIDS diagnosis may often appear to a casual observer to be quite healthy, but continue to be infectious and can pass the virus to others.
Over time, people with AIDS frequently have a reduced white blood cell count and develop poorer health. They may also have a significant amount of virus present in their blood, which is measured as viral load.
The 1993 Revised AIDS Surveillance Case Definition
In 1987, the CDC defined AIDS using a positive HIV antibody test plus a list of conditions that indicated a deficient immune system. In 1993, the CDC revised the definition of AIDS to include more conditions and a variety of CD4-cell counts. The revised definition meant that more people were considered to have AIDS. That year there was a "jump" in the number of people with AIDS, which reflected the change in classification system.
An AIDS diagnosis is only made by a licensed healthcare provider, based on a confirmed HIV test result, the presence of certain defining physical conditions, and the person's CD4-cell count.
HIV has a wide spectrum of clinical presentations in children. The CDC developed a revised pediatric HIV classification system in 1994, to clarify HIV-infected pediatric patients into categories based on their immune system, CD4 cells, and clinical category. Pediatric classification of AIDS is different than the classification for adults.
The 1993 AIDS Surveillance Case Definition for Adolescents and Adults, which is the most current definition, is comprised of a 3 x 3 staging system. In this definition, any person who is HIV-infected and has either an AIDS indicator condition or a CD4+, the T-cell count, less than 200 cells/mm3, or less than 14%, is considered to have AIDS.
AIDS Indicator Conditions (Adults)
The Difference Between Clinical Manifestations and Opportunistic Infections
When a person's immune system is suppressed, they have weaker defenses against the wide variety of bacteria, viruses, fungi and other pathogens that are present almost everywhere. A clinical manifestation is the physical result of some type of illness or infection.
The opportunistic diseases and infections associated with HIV infection are any of the infections that are part of an AIDS-defining classification. For example: the opportunistic infection cytomegalovirus often causes the clinical manifestation of blindness in people with AIDS.
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Infection
