Information on HIV and HIV Testing

Terence P. Ma, Ph.D.

Introduction

AIDS, or Acquired Immune Deficiency Syndrome, was officially recognized in 1982, and probably has been around less than a dozen years. This devastating disease is caused by infection with the Human Immunodeficiency Virus (HIV). There are now over 100,000 reported cases of AIDS in the United States. About half of all these people have died. The methods by which this disease is transmitted is quite simple. It requires direct "bodily fluid" contact between two people. It does not make any difference if the person is single or married. It does not make any difference if the person is old or young. It does not make any difference if the person is straight, gay, or bisexual. It does not make any difference if the person is engaged in sex with men or with women. In this article, I shall briefly review some of the pertinent information about what is now called "HIV Spectrum Diseases" and the HIV tests so that you decide as to whether or not you want to get tested, and understand what the test and test results mean.

What is HIV?

HIV stands for Human Immunodeficiency Virus. Just as the name implies, it is a human disease. It has something to do with a deficiency in the immune system. Lastly, it is a virus. Since it is a virus, if we know how it is passed on, we can prevent being infected by it.

Before we talk about HIV, we should briefly discuss the immune system, that which is most affected by HIV. This is the system in the body which is responsible for fighting infections. Actually, there are two immune systems. First, there is a "humoral" immune system, the system by which we make "antibodies." An antibody is made to substances, usually proteins, that get into the body and do not belong there. These substances are called "antigens." For example, when we get the cold, we make antibodies against the cold virus. When we get a smallpox vaccination, for example, what we get is a small dose of the killed smallpox virus. Our bodies, then, make antibodies to the different parts of the virus, or the antigens, and are able to fight off and protect us from the "real" thing later on in life. Antibodies remain in the blood and we can test to see if someone has those antibodies. Second, there is the "cellular" immune system. This system is composed of different types of specialized blood cells called T-cells. One type of these cells, commonly called the T4 or T-helper cell, is responsible for activating the immune systems to make antibodies.

In HIV infection, certain types of cells are particularly affected. Specifically, in the blood system, the T4 cells are destroyed by HIV when it becomes active. Unfortunately, we don't know what activates HIV to start destroying T-cells. Thus, the cells which are responsible for activating the immune system to fight off infections, are destroyed and the body can no longer effectively defend itself against problems like infection. It is probably safe to say that no one has ever died of HIV, but they have died from things which HIV has allowed to infect the body by destroying the mechanism by which the body protects itself.

HIV Spectrum Diseases

In the "old" days of just five years ago, we used to just worry about AIDS and ARC (AIDS-Related Complex). However, the CDC (Centers for Disease Control, the people who tell doctors how they are to diagnose illnesses) have recently changed the way that they (and therefore doctors) are supposed to think about this disease. This "new" way of thinking is supported by a lot of scientific evidence and organizations such as The President's Commission on the Human Immunodeficiency Virus Epidemic (the Watkins Commission) and The Institute of Medicine of the National Academy of Sciences. This new way of thinking is to call the disease process "HIV spectrum diseases." As we might expect from the name, we should think of the disease as something that is related to HIV, and that it is a series or progression of HIV- related illnesses. The key idea is that it is not just one end or the other end of the scale that is important, but every little step in between is just as important.

The CDC has separated HIV spectrum diseases into four "groups" or stages. The four stages are:

1. the "acute infection" stage
2. the "asymptomatic" stage
3. the "generalized lymphadenopathy" stage
4. the "clinical" stage.

This is a series of groupings that are used to express points along a continuous progression of HIV infection. In the following paragraphs, I will briefly describe each of these stages.

In the "acute infection" stage, the person is initially infected. While some persons, within the first three weeks of infection, may show some signs like fever, swollen lymph nodes, fatigue, and such, often these signs are also associated with other types of illnesses including the flu, mononucleosis (the "kissing" disease), and the common cold. It is often impossible to tell when infection occurred. The reason is that while it only takes one time to get infected, sometimes a person is lucky enough not to get infected when they take risks. It is like playing Russian roulette, but riskier.

There is a major difference between "coming into contact" with HIV and being "infected." You can come into contact with HIV in ways that may or may not put you at risk of infection. For example, giving a hug, social kiss, or cleaning a person with HIV infection means that you have come into contact with HIV, but it does not mean that there is a risk of infection. However, unprotected sexual intercourse or sharing your works (IV drug needles, in particular) with someone who is infected does mean that there is a risk of infection. To be "infected" means that you have come into contact with HIV in a way that put you at risk for infection, and you have actually caught it. There are very specific ways that this can happen, and they will be discussed later. The bottom line is that a person who is infected is someone who has caught the disease.

The second stage is the "asymptomatic stage" of the HIV spectrum. In this stage, the people have "seroconverted," which means that they have a positive HIV test. So, what does this mean? According to recent reports, people can be in this stage for as many as 14 years ... as long as there has been HIV. It is even predicted that some persons can probably live in this stage for as many as 40 years, or more. However, we just don't know at this time. So, what does being in this stage mean? It simply means that the person had come into contact with HIV in a way that put them at risk of infection. Furthermore, the person has become infected, meaning that they caught the virus. Lastly, the person is infectious, meaning that they can pass it on. It does not mean that they have AIDS. It does not mean that they are going to die tomorrow of AIDS. It does not mean that they shouldn't be treated as reasonable, feeling, and totally human persons.

The third stage, the "generalized adenopathy" stage, is when the person starts getting sick. It is usually characterized by swollen lymph nodes all over the body for extended periods of time. It should be noted that not everyone gets swollen lymph nodes.

The fourth stage is the "clinical" stage. This is when the person is actually sick. For example, this is when people have long-term fever, weight loss, or diarrhea for over a month; when they have "neurological" problems including what is often called "AIDS dementia"; when they have "secondary infections" like Pneumocystis carinii pneumonia (PCP), toxoplasmosis, or oral candidiasis (thrush), that the body cannot fight off. This is also the stage when the person can get the rare cancers like Kaposi's Sarcoma, a cancer of the blood vessels, and other rare diseases. People who are said to have ARC or AIDS fall into this category. Generally, though, the term ARC is no longer used.

The point to remember, though, is that HIV infection is preventable. Furthermore, just because a person is infected with HIV does not mean that they will die tomorrow. People can die at any one of these stages, just as anyone can die at any time. The differences between people who have HIV spectrum diseases and those who do not are two. First, people who have HIV spectrum disease are infected and infectious, meaning that they have caught HIV and can pass it on. Second, people who have HIV spectrum disease should be extra cautious about their health and may want to monitor it more carefully.

HIV Testing

There are a variety of ways whereby the presence of HIV can be determined. The most common are blood tests for the presence of HIV antibodies. The two most frequently used techniques are the ELISA test and the Western blot. Two other techniques which are used include examining the blood for the presence of HIV antigen and testing for the presence of HIV genetic material. In this discussion, I will only talk about the most commonly used tests, the ELISA antibody test and the Western blot.

The ELISA Antibody Test

This is an inexpensive and relatively effective way to examine for the presence of antibodies to HIV. The test is based on the ELISA technique, which stands for Enzyme-Linked Immuno- absorbent Assay. Basically, it is a color change reaction that is done in a specially prepared plastic plate. What has been done, essentially, is that the proteins of the HIV are spread on the bottom of the plate. A small amount of serum (the clear fluid part of the blood) is added and if there are antibodies to the HIV proteins, they would attach to the proteins which are stuck onto the plate. The excess serum is washed off and some chemicals are added. When these chemicals are added, there may be a color change. If the color is clear or nearly clear, then the test is negative (meaning that the serum did not have HIV antibodies). If the color is blue, then the test is positive (meaning that the serum did have HIV antibodies). If the color is somewhere in between, then the test is "indeterminate" (meaning that we don't know for sure).

The Western Blot

The Western Blot is a technique developed by scientists to examine for the presence of proteins. Basically, using a technique called PAGE (polyacrylimide gel electrophoresis), proteins are separated into bands by their weight. Next, they are transferred to a strip of special paper called nitrocellulose paper. At this stage, the paper is completely colorless even though the proteins are already present. At a testing center, the strip of paper is dipped into the serum and the antibodies that are present will attach to its antigens, or, in this case, specific HIV proteins. The extra serum is washed off, chemicals are added, and a brownish-black color is left showing the bands of protein for which antibodies were present. That is to say, the parts of HIV for which the person had antibodies will show up. A person is said to have a negative Western blot if none of the bands are positive (or have turned color). In most places across the country, three or more positive bands indicate a positive Western blot. An indeterminate Western blot is anything else. Due to the expense of the procedure, this technique is not usually done.

The Test Result

The test result can be either positive, negative, or indeterminate. An indeterminate test result simply means that we aren't sure and that the person should take the test again. However, due to what has been happening with the person, the positive and negative results can be true or false.

The True Negative Result

In the case of a true negative test result, the test result is negative and the person is not infected with HIV.

The False Negative Result

People who have false negative results are those whose test result in negative, meaning that the test indicates that they have not been infected, but actually they have. There are two reasons why this can occur. The people were tested during the "window" period or they belong to an extraordinarily small group of individuals who do not make antibodies to HIV.

As I mentioned before, when a person is infected by a virus, the body makes antibodies to that virus. However, it takes the body a period of time to start making the antibodies. This period of time, then, is called the window. For the vast majority of people in the world, this "window" period for HIV infection is 2-8 weeks. In other words, if you have done any "risky" behaviors within the past 8 weeks, the test may not be able to tell us whether or not you are infected. Thus, it is recommended that persons wait for at least 8 risk-free weeks before being tested. For essentially all people, if they are exposed to HIV, they will have started making antibodies within 6 months.

The False Positive Result

There are certain conditions which can lead to a "false positive" result. That is, the tests indicate that the person has been infected, but in actuality, the person has not. Some of the conditions which may cause false positive test results include autoimmune diseases, chronic liver disorders (not simply hepatitis), multiple pregnancies, multiple blood transfusions, dialysis and recent occurrences of certain diseases like malaria.

The True Positive Result

In almost all cases of positive results, the reason for that result is that the person being tested had been in contact with a someone who is infected with HIV and got infected. People who have a true positive test result have caught the virus and can transmit the virus.

Taking the Test

Before taking the HIV test, there are certain questions that we must answer. First, we must evaluate the possibility of our having been infected. Second, we must honestly answer the question of whether or not we are ready for the result. Third, we must evaluate where we want to take the test and what sort of "services" we want from the testing center.

Am I Infected?

There are very specific ways how a person can get infected by HIV. Basically, it has to be some sort of direct introduction of bodily fluids having high concentrations of HIV with the "inside" of the body. While practically all fluids of a person who is infected has some amount of HIV, only three major bodily fluids, blood, semen, and vaginal secretions have sufficiently high concentrations of HIV to infect another person.

There are four major methods of blood-related transmission of HIV. They are

1. sharing works between IV drug users
2. from infected mothers to their babies
3. sharing uncleaned sex toys, and
4. unprotected sex during a woman's period (menstruation).

By definition, an IV drug user is a person who injects drugs directly into their own blood streams. When a needle used for this purpose is withdrawn, a small amount of blood remains in the tip of the needle. Imagine someone who is infected and shares their uncleaned needle with someone else. That second person would be directly injecting HIV into their own blood streams! About 30 percent of all AIDS cases are in IV drug users. It is recommended that all drug users clean their works with bleach and then flushed carefully with water before reusing them.

An infected mother has HIV in her blood already. The fetus (or unborn baby) gets its food, air, and gets rid of its wastes by transferring them from and to the mother. Therefore, it is very easy for the fetus to become infected by the mother. In fact, just about half of all babies born to mothers who are infected with HIV are also infected.

Sex toys, items like vibrators and dildoes, are usually made of hard plastic. These items, when placed in a body, tend to cause small tears and cuts ... most of which we can't even see. Imagine, then, this direct transfer of HIV from one person to the other if these items were not cleaned. It is recommended that they be cleaned with bleach and rinsed with water. It is also suggested that persons consider putting condoms over these items before use and changing condoms before sharing them with a partner.

Menstrual blood of infected women contains large amounts of HIV. Unprotected exposure to this blood places the partner at great risk of infection. The only clearly documented case of female-to-female HIV transmission was between two women having unprotected sex during their periods.

It is clear that the majority of cases of HIV transmission is through unprotected insertive sexual intercourse (having sex where a penis is inserted into the partner and a condom is not used). While the reasons why people get infected are not totally known, it is clear that the receptive partner is at higher risk of infection, particularly those who are receptive partners in anal sex. It is also clear that infection can be passed from the insertive partner to the receptive partner or from the receptive partner to the insertive partner. In the United States, there appear to be more cases of homosexual transmission of HIV than heterosexual transmission of the virus. This is probably because more homosexuals participate in anal intercourse than heterosexuals (although both groups have individuals who do not have anal sex and both groups have individuals who do). Unprotected anal intercourse is the most likely means of infecting another person. In order to minimize the risks of infection, protective measures such as using condoms and nonoxynol-9-containing spermicides is recommended.

By knowing the types of behaviors that put us at risk of infection and whether or not we are in the "window" period will help us determine whether or not this is the right time to take the test.

Do I Want to Take the Test?

When we know what we think the risks of our being infected are, we must decide whether or not we should take the test. Considerations which should be made include our readiness for the test result, the impact of our taking the test on our everyday lives, and the potential benefits of taking the test.

When we are asking ourselves if we are ready to take the test, the first question we need to ask is if we are ready to hear the result. What are you going to do if you get a positive result? What are you going to do if you get a negative result? It is only by answering those questions to ourselves honestly that we will be able to determine if we are ready to take the test.

We must also consider what might be the impact of taking the test might be. For example, many insurance companies ask the question whether or not you have been tested for HIV and what the result was. Some states have requirements that names of people who have tested positive be reported. Some places require that you provide a list of people with whom you have had sex so that the authorities can get in touch with them and suggest that they get tested (this procedure is known as partner notification). We must ask of ourselves if we are ready for the actual consequences of taking the test and evaluate that answer carefully.

Lastly, we should consider the benefits of taking the test. There is one overriding benefit to either a negative or positive test result. It is that we know our status. An important reason to know if we are positive is so that our personal physicians can more closely monitor our bodies. It has been demonstrated, for example, that we can slow down the progression to later stages of HIV spectrum diseases if we start HIV-positive persons on low dosages of AZT. Thus, there is also a clear medical benefit to early knowledge of a HIV-positive status.

Where Should I Take the Test?

There are three factors that you might want to consider before choosing a place to take the test. First, how good is the facility doing the test? Second, what kind of support do the people doing the testing provide? Third, how is the test result handled?

Many physicians are able to do the ELISA antibody tests in their own in-house laboratories. However, many of these facilities are not very well run and the test may not be done frequently. It may therefore be important to evaluate whether or not your physician's laboratory is the best place for a test. There are many sites throughout the country, some funded by the state or federal governments, and some privately funded which provide good testing services. These facilities, such as the Whitman-Walker Clinic, Children's Hospital National Medical Center, Planned Parenthood of Metropolitan Washington, are places to consider.

Another important question to evaluate is what type of "support" you will get when you get your test result. For example, will your questions be answered? Will you get your result from a telephone call or will someone tell you in person and help you over the hump, regardless of what the result may be? Regardless of what the result may be, will the facility provide counseling and other services to help you focus on what you are doing and how to reduce your risks of infection or getting sick? Depending on your own personal situation, you may or may not be able to handle any of these particular situations. It is important, therefore, to consider them before being tested.

Lastly, you should consider how the test result will be handled. Some facilities, for example, provide testing on an anonymous confidential basis. This means that the test result is given to you and only you (confidential) and is done in such a way that there is no possible way by which they can find out who you are unless you decide to give them that information (anonymous). Many facilities provide confidential testing meaning that they know who you are, and you need to tell them before you are tested, but that information is not provided to anyone else without your permission (confidentiality) or being subpeonaed by the court.

Conclusions

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