AIDS

In June 1981, the Centers for Disease Control and Prevention (CDC) reported that five young homosexual men had come down with a rare form of pneumonia and two had died. Little did the infectious disease experts in Atlanta know that this was the beginning of the AIDS epidemic. Since then, AIDS has killed more than 100,000 people in the United States, another 200,000 have the disease, and close to 1 million Americans are believed to be infected with HIV, the virus that causes AIDS. By some estimates, another 14 million people around the world are also HIV infected.

Human immunodeficiency virus (HIV) is classified in a group called retrovirus. There are several retroviruses, and they are able to infect human cells, change the cell’s DNA or genetic material, and either convert the cell into a cancer cell, destroy the normal cell function, or kill the cell. But although HIV infects and kills cells in the immune system, it does not directly cause cancers.

HIV infects certain key members of the immune system—white blood cells called CD4 or T4 cells—and slowly destroys the body’s ability to fight off germs. With early HIV infection, the person is infected but not yet sick. HIV-infected people are infectious to others, however.

AIDS is the end stage of HIV infection. It is diagnosed once the virus has so damaged the immune system that the infected person cannot fight off other germs and becomes sick with a variety of illnesses. A person with AIDS eventually dies from overwhelming infections, often pneumonia or ТВ, or from cancer.

The name AIDS came about because the scientists did not know what caused this disease, but did know that it destroyed the infected person’s immune system. At first they called it GRID, for Gay-Related Immune Deficiency. Soon others who were not gay were found to be infected—intravenous drug users and people who had received blood, especially hemophiliacs. So the name was changed to AIDS, for Acquired ImmunoDeficiency Syndrome.

In 1983, French scientists had found a virus they said caused AIDS, which they called LAV. In 1984, an American researcher, Dr. Robert Gallo, announced the discovery of the AIDS virus. He called it HTLV 111. By 1986, it was clear both viruses were the same, and the name was changed to HIV, for Human Immunodeficiency Virus, often referred to as the AIDS virus.

So far, scientists have found two strains of HIV: 1 and 2. HIV-1 causes most infections in the Western Hemisphere, Europe, and Central, South, and East Africa. HIV-2 is mainly found in West Africa, but some cases have occurred in Portugal and France. Parts of West Africa have both HIV strains. HIV-2 causes a similar illness to HIV-1, although most experts think HIV-2 results in less illness and death than HIV-1.

How people catch AIDS has been the most emotional and controversial part of the epidemic. The first recognized victims were homosexual men and intravenous substance abusers. These two groups are considered outcasts by some members of our society, and therefore AIDS was looked upon as a disease that struck only people with aberrant behavior. Some even called it a punishment for this behavior.

Then people who had received HIV-infected blood began coming down with AIDS. This group included hemophiliacs. Many unfortunate and disgraceful incidents occurred before the public became educated about how AIDS is spread: Infected hemophiliac children had their houses burned, people with HIV infection were fired from jobs and turned away from renting or buying homes, and funeral parlors refused to bury anyone who had died of AIDS.

Rock Hudson died from AIDS in 1985. After his death, AIDS started to become less remote to the general public, and the hysteria began to fade. Surgeon General Koop helped by issuing an excellent report on AIDS in 1986. He explained how AIDS is and is not spread and urged prevention efforts including sex education in schools and condom use. In May 1988, Dr. Koop mailed his report to all households in the United States. I remember how pleased I was to see this accurate information in my mail.

In 1986, the first reports appeared about health care workers who were infected with HIV after being stuck with needles or instruments containing patients’ HIV-infected blood. These reports caused understandable concern among hospital staff. Since then, all hospitals have set up programs to teach staff how AIDS is spread and what hospital workers must do to protect themselves.

How Do You Get It?

We don’t yet know how to cure AIDS, but we do know how it’s spread. You get HIV infection through contact with HIV-infected blood, semen, or vaginal secretions.

You do not get AIDS from casual contact. If you could, many more of us would have the infection because most hospital workers, among others, have either knowingly or unknowingly been in close contact with HIV-infected people.

The secretions containing HIV must get into your blood to infect you. The first and easiest route for the virus is by direct access to blood. People who receive blood transfusions with HIV-infected blood and intravenous drug abusers who inject HIV-contaminated needles into their veins are at greatest risk of becoming infected because the virus is gaining direct entry into their bloodstream.

The second and most common route is through mucous membrane cells that carry HIV to the blood. Sexual transmission occurs by this second route. When you have sexual contact with an infected person, certain conditions make it easier for the virus to gain entry to your bloodstream. Anal intercourse often causes tears and slight bleeding in the mucous membranes lining the anus, creating an opening for HIV-infected semen to enter the bloodstream.

If you have genital sores or ulcers, you are much more likely to become infected with HIV if exposed to it during sexual intercourse. Herpes, syphilis, or chancroid infection causes breaks in the mucous membranes of the vagina or penis, creating an ideal entry point for the virus. Gonorrhea and chlamydia cause inflammation in the mucous membranes, which also eases entry of the virus. Your risk of infection is five times higher when you already have another sexually transmitted disease. Sex during menses also increases the risk of HIV.

The more you are exposed, the higher are your chances that you will eventually get HIV. Some people have become infected after one sexual encounter with an infected person. Others have repeated contacts over many years and stay free of HIV. Because you can’t know whether you will be infected or not, and because for now AIDS is always incurable and fatal, you must assume that any unprotected sexual encounter with an infected person can give you HIV.

It is also possible to get HIV infection even when you have no genital sores or ulcers. Special immune cells called dendritic cells lurk in the mucous membranes of the penis, vagina, and cervix. These cells are highly susceptible to HIV, which they pick up and transport to your lymph nodes. There, dendritic cells allow HIV to reproduce, infecting T4 cells and other key cell players in the immune system. T4 cells take HIV to your bloodstream.

HIV is passed from an infected pregnant mother to her fetus either before the baby is born or during passage through the birth canal at delivery. The exact risk is unknown. It ranges from 13 to 40 percent but varies from country to country. Researchers are still learning why some babies are born infected and others are not. Certain factors that increase the risk of HIV transmission to the fetus during pregnancy and delivery have recently been identified. These include a bloody delivery which increases the baby’s exposure to maternal blood and a mother who has high levels of HIV in her blood.

HIV-infected mothers have also spread the infection to their babies through breast-feeding because the virus is present in breast milk. But many breast-fed babies of HIV-infected mothers do not become infected. Why some do and most do not remains a mystery.

Hospital workers can be infected by sticking themselves with a needle that contains HIV-infected blood or by blood splashes to their eyes or mouth. It is also possible for HIV-infected blood to enter through breaks in the skin, especially if the hands have many cuts and broken areas’ Hospital staff use protective clothing and masks when performing invasive procedures to avoid being splashed by internal body fluids that also contain virus.

In a sad and well-publicized case, a young woman in Florida was thought to be infected by her dentist during a tooth extraction and died from AIDS a few years later. A thorough investigation found that this same dentist may have infected six more of his patients before he died.

This case of the Florida dentist remains unexplained. Some people have suggested that he intentionally infected his patients. Such bizarre behavior may have been the result of the AIDS infection on his brain. Other reports say he used unclean tools. Because the dentist had died and his office records were destroyed by the time the connection was made, public health officials were unable to thoroughly investigate and we do not know what actually happened, or even if he really did infect his patients.
Since then, thousands of patients of both HIV-infected1 dentists and surgeons have been tested. By the end of March 1993, of the almost 20,000 people tested, none had caught HIV from their doctors or dentists.

From this information it is clear that your risk of acquiring HIV during a dental or medical procedure is extremely small. If the practitioner follows correct infection control and sterile techniques your risk is close to zero.

Most people have heard more about AIDS than any other infectious disease. But knowing about AIDS has not necessarily led people to change their risky behavior. AIDS continues to spread throughout North America and even more rapidly in the developing countries around the world.

In North America, AIDS is still chiefly a disease afflicting homosexual men and intravenous drug users. However, transmission through heterosexual contact is on the rise among young men and women. According to the World Health Organization, heterosexual contact accounts for 80 percent of all HIV infections worldwide.

In the United States, AIDS is the leading cause of death in adults aged 25 to 44, surpassing unintentional injuries and cancer. Young women 20 to 29 years old are now being infected at a faster rate than men, and since 1992 more women are being infected through heterosexual contact than through intravenous drug use. Many of these women were infected as teenagers. Teenage girls are more at risk of infection with HIV and all other sexually transmitted diseases (STDs) than older women because the lining to the vagina is thinner, contains less mucus, and is therefore a less effective barrier to HIV and other germs. As the numbers of infected women increase, so do the numbers of babies born with HIV infection.

Although we don’t know exact numbers, studies show that because of anatomical differences, there is greater chance that an infected male will give HIV infection to his susceptible female partner than an infected female will give it to her male partner. However, it can go either way.

How Do You Know If You Have It?

HIV Early HIV infection has no symptoms. HIV-infected people look perfectly healthy. You cannot tell who has it by looking at them, and doctors cannot tell by examining them. Some people will have what is called a primary HIV illness about two to four weeks after they are first infected with the virus. This is a flu-like illness that lasts 3 to 14 days. You may have a fever and body and muscle aches. Sometimes it is more like mono than the flu—you may get a rash and swollen glands in your neck. This will go away, but 4 to 12 weeks later you will test positive for the HIV antibody.

HIV TESTS The blood test that looks for antibodies to HIV was licensed in 1985. If you ask for an AIDS test, you will get the HIV antibody test. This test is also used to screen all blood products before transfusion and organs before transplantation.

It takes your body about six weeks after you have been infected with HIV before you make enough antibodies to show up in the test. This is called the window period and can last as long as three months and—rarely—as long as six months.

I advise anyone who is being tested that the test is really telling you what your HIV status was three months earlier. If you are worried that you may have been exposed in the last three months and your test is negative, you must be retested in three months. If you are absolutely sure that you have not been exposed to HIV in the previous six months and you test negative, you can rest assured that you are not infected with HIV and do not need to be retested. However, it is up to you to remain uninfected by practicing safe behavior.

Hospital workers who are exposed to HIV-infected blood from a patient are tested for infection at six weeks, three months, and six months after exposure. The window period is difficult to understand, and the waiting period is even more difficult to experience.

Other tests detect the actual virus rather than just HIV antibodies in the blood. These tests—polymerase chain reaction (PCR), HIV culture, and P24 antigen assay detect HIV infection much earlier, but now are expensive and difficult to do. They have been used mainly in research areas, but are becoming available in large hospital and commercial labs and provincial labs in Canada.

AIDS Certain conditions must be met before a diagnosis of AIDS is made. The list of conditions grows as we learn and understand more about HIV disease and recognize the many different illnesses it can cause.

In January 1993, the CDC expanded the definition of AIDS. A similar definition was adopted by Canadian health officials in July 1993. Doctors now diagnose AIDS in an HIV-infected person who also has certain other illnesses. The list of ailments is long and includes:

■ Pulmonary tuberculosis
■ Recurrent yeast infections in the lungs or bronchi
■ Other rare fungal infections
■ CMV
■ Chronic cold sores lasting more than one month caused by herpes simplex
■ Recurrent bacterial pneumonia
■ Salmonella blood infections
■ Wasting syndrome weight loss and poor appetite
■ Invasive cervical cancer
■ Kaposi’s sarcoma
■ Other rare cancers and tumors

AIDS TESTS The American 1993 definition also includes a blood test result. Europe and Canada do not include this test result in their AIDS definition. The test counts certain white blood cells called CD4 cells which are key members of the immune system. HIV infects and destroys CD4 cells. A healthy person has 800 to 1200 CD4 cells per cubic millimeter of blood. An HIV-infected person gradually loses these cells, which measure the health of our immune system. Once the number drops to fewer than 200 cells per cubic millimeter of blood and the HIV antibody test is positive, the person is considered to have AIDS.

How Sick Will You Be?

HIV can affect every organ in your body. The range of illness it causes is extremely variable and complex, more so than for any other infectious disease. I cannot describe how sick any given person with AIDS will be, but I’ll review the most common and best-described AIDS and HIV-related illnesses.
HIV

ADULTS

Early Stage. Most people feel fine. Some have a brief flu- or monolike illness for a few days or weeks at the time the virus enters the body. Some people have chronically swollen lymph glands in their neck, armpits, and groin. The CD4 cell count is normal—around 1,000 cells per cubic millimeter of blood. This stage lasts about five years.

There is little virus in your blood after the initial primary infection. Until recently experts thought this was a latent phase in which the virus was doing no harm. In fact, the virus is hiding in the lymph glands, reproducing there and slowly eroding the immune system. The phase is anything but latent.

Middle Stage (HIV infection). Most people have no symptoms, but their CD4 cell count is dropping to about 500, or half the normal level. Usually antiviral drugs are recommended at this point.

Some people will have abnormal skin tests during this stage. Even if infected with ТВ, they do not respond to the ТВ skin test. They become anergic, which means another part of their immune system is disintegrating. The average length for this stage is also five years.

AIDS or Late Stage. Once the CD4 cell count drops to 200, or one-fifth of what it should be, or you develop one of the conditions listed below, you are considered to have AIDS. At this point, symptoms worsen and more opportunistic infections occur. This stage can last five or more years. People with low CD4 cell counts but no AIDS-defining illness have a better outlook.

Many people develop AIDS in fewer than 10 years, however, and many others are healthy for longer periods. New anti-AIDS treatments have lengthened this period for some people, but for now, doctors think that everyone who develops AIDS will eventually die from it.

Many of the infections an AIDS patient gets are called opportunistic infections because the germs are taking a rare opportunity to infect humans. These are germs that cannot cause disease in a person with a healthy immune system, but take advantage of people with weakened immune systems. Yeast is a good example. Most of us have small numbers of yeasts and other fungi living in many parts of our bodies, but in people with AIDS the yeasts become overgrown and are impossible to get rid of.

Opportunistic infections attack the internal organs and account for at least 90 percent of all AIDS deaths.

■ The mouth is often the first area to be infected. Thrush, a fungus in the mouth, and chronic cold sores are common. These sores are painful and make it difficult to eat, especially hot or spicy foods.
■ Yeast infections attack the airways leading into the lungs and parts of the digestive system.
■ Many people suffer weight loss, diarrhea, fevers, and tiredness early in this stage.
■ Cryptosporidia, a parasite, causes chronic diarrhea. More than 90 percent of people with AIDS suffer from diarrhea.
■ Skin problems are common—dry, irritated skin, rashes, and skin reactions to medicines.
■ HIV infects brain cells leading to memory loss, weakness, paralysis, and an inability to perform normal tasks.

Opportunistic infections attack the internal organs:

■ Toxoplasmosis, a parasite, may infect the brain.
■ Cryptococcosis, a fungus, may attack the liver, bones, skin, and nervous system.
■ Cytomegalovirus may infect the eyes, brain, and lungs.
■ Cancers such as Kaposi’s sarcoma cause skin lesions and other lymphomas, or tumors, in the lymph glands.
■ Tuberculosis disease goes rapidly from latent infection to illness.
■ Pneumonias, usually Pneumocystis carinii pneumonia (PCP), attack the lungs. A commonly found
protozoa causes PCP. Healthy people, in whom it cannot cause illness, often carry it in their nose and throat. PCP is an opportunistic infection that is a frequent cause of illness and death in AIDS victims.
Another of the most common opportunistic infections that infect and kill HIV/AIDS-infected people is Mycobacterium avium complex (MAC). It causes disease only in people with very weakened immune systems. MAC causes fever, sweats, weight loss, and anemia.

Women with AIDS may have different illnesses than men have. They may suffer from chronic or frequent vaginal yeast infections, PID, or cervical cancer.

INFANTS AND CHILDREN

The range of illness and time from HIV infection to AIDS is even wider in children than adults. Some infants become ill, usually with PCP, within the first few months of life and die before they reach one year. Others show no signs of illness until they are about ten years old. Children who survive past the first year will come down with complicating infections, but in between should have long periods of fairly normal health.

Three distinct patterns have emerged among children with HIV infection:

1. About a quarter of HIV-infected children will get serious infections before they are 18 months old. These children develop AIDS faster and do poorly, even with treatment.
2. The next group develops milder symptoms early in life. They have more bacterial pneumonia, meningitis, and blood infections than non-HIV-infected children. These illnesses come and go, and the children usually live until they reach four to five years of age.
3. The third group is now appearing. These children grow up with few symptoms. Many are not diagnosed with HIV infection until they are about ten years old.
Studies suggest that babies who are infected while still in the uterus develop AIDS sooner than those who are infected during delivery. The outlook for babies born infected has improved since the early days. The majority of children infected from birth now live to at least five years old. However, most will eventually become sick and die before reaching adulthood.

Almost all infected children grow poorly and are shorter and weigh less than they should for their age. They don’t grow well because, although they have poor appetites, their bodies need more calories than a healthy child’s to gain weight. What energy these young bodies have is spent fighting the chronic HIV infection. Often the child feels tired and suffers from low fevers. As the disease progresses, the child will be delayed in development or lose the ability to do things he had previously been able to do. These children may be behind in walking, talking, and motor skills.

Other early stage problems in HlV-infected children are swollen glands, enlarged liver and spleen, thrush, recurring ear infections, bacterial pneumonia, and meningitis. PCP is very common in babies and children with HIV, and is often the first sign of infection among infants. Many die a few months after getting PCP. MAC is also common.

CD4 cell counts are decreased in HIV-infected infants and children, but the normal values for children younger than six are higher than the normals in adults. A CD4 cell count of less than 200 in an adult indicates a severely weakened immune system. This number does not apply to children younger than six years old. Normal values for young children depend on age. The younger the child, the higher the normal value.

Infectiousness

As far as we know, once you are infected with HIV you are infectious to others for life. This period begins even before your antibody test is positive. Some people are more infectious than others. In hepatitis В certain markers in the blood identify more infectious people. In HIV infection we don’t know what makes some people more infectious. Infectivity may depend on how much virus is in the blood and genital secretions. People who are in the later stages of AIDS have more virus in their blood. Studies found that health-care workers caught HIV only from patients who were in the last stage of AIDS.

Blood from patients with early-stage HIV is much less infectious. But because most people get HIV from others who do not yet have AIDS, this information doesn’t explain very much. The explanation may be that some strains of HIV are more infectious and some people are more susceptible to infection.
You must consider yourself infectious if your HIV test is positive.

Remember that HIV is not spread through casual contact. You can infect others only through sexual contact, by sharing needles and injecting drugs, through pregnancy to your unborn child, and by breast feeding. You cannot donate blood or organs.

How Do You Treat It?

The sad fact is we can’t cure it. But five drugs that slow the progress of the disease are now licensed for use, and many more are being tested. We await a drug that can cure AIDS, but researchers hold out little hope that such a breakthrough will occur anytime soon.

Current Drug Treatments

ADULTS

1. Zidovudine (ZDV) (Retrovir), formerly azidothymidine, or AZT. This drug, still commonly called AZT, slows the rate at which HIV multiplies and has been used to combat AIDS since March 1987. It is now generally agreed that it has a limited benefit over a limited time. Opinions differ on when it should be started and what dose is best.

HIV-infected people who take AZT before being diagnosed with AIDS have fewer opportunistic infections, less weight loss, and fewer tumors, and they function better than those who do not take it. The drug extends the period of time in which infected people experience no symptoms or only mild symptoms. Often, their CD4 cell counts increase after beginning the drug. But this increase is temporary, and the counts fall to low levels after a few weeks or months. Once AIDS is diagnosed, AZT improves the quality of life, but does not prolong life. Studies show that, on average, people with AIDS survive only three to five years after the diagnosis, whether or not they are taking AZT.

Current recommendations for AZT use in the United States, as of January 1994, are to start the drug at 500-600 mg per day when the CD4 cell count in an HIV-infected person drops to less than 500 cells per cubic millimeter of blood. Doctors will adjust the dose if side effects occur or the patient’s condition worsens. This recommendation will change as results from long-term studies appear and new drugs are approved.

HIV is able to become resistant to AZT after 6 to 24 months, at which point the drug no longer helps. Anemia and a drop in white blood cells are common side effects of taking AZT.

In 1994, results of a large study among pregnant women determined that taking AZT during pregnancy significantly decreases the risk of HIV transmission to the unborn baby. It appears so far that AZT causes neither birth defects nor premature birth, if taken after the 14th week of pregnancy.

2. Didanosine (ddI) (Videx). This was the second anti-AIDS drug to be approved by the FDA. It works in a similar way to AZT by slowing the rate at which HIV multiplies and is used to help people for whom AZT is no longer working. The side effects of ddl are numbness, tingling, and pain in the fingers and toes, headaches, and diarrhea.

3. Dideoxycytidine or zalcitabine (ddC) (Hivid). ddC is approved for use only in combination with AZT. But the Public Health Service clinical practice guidelines suggest that based on experience doctors can prescribe ddC alone to patients who do not tolerate AZT, or whose condition worsens while taking AZT.
4- Stavudine (d4T) (Zerit). This drug was approved in 1994 for HIV- or AIDS-infected adults. It is used when the other drugs are no longer working or are causing too many side effects.

5. A fifth drug was licensed in 1995. This drug—SC 48338—is used only in combination with AZT.
Doctors who treat AIDS patients are tending to give drugs in combinations. Combining drugs works well in combating bacterial and fungal infections, therefore it’s hoped that it will help combat AIDS as well. Ongoing trials of drug combinations are showing some promising results. You need a smaller dose of each drug when you take a combination.

• HIV/AIDS is a chronic disease that slowly damages the body’s immune system. HIV also has the knack of changing and becoming resistant to antiviral drugs.* Both these factors mean it will be a long and rocky road before drugs appear that can successfully control the virus. Most experts agree that future treatments will include a combination of drugs that attack different phases of HIV’s life cycle. New data from the many ongoing drug studies are appearing rapidly. Therefore, recommendations regarding which and how many drugs to take must be individualized by the doctor for each HIV/AIDS-infected patient. If you want information or wish to take part in the ongoing controlled studies on new drugs, call the U.S. Public Health Service AIDS clinical trial information service at (800) TRIALS-A [(800) 874-2572].

INFANTS AND CHILDREN

Zidovudine (ZDV or AZT) and didanosine (ddl). As of January 1995 these are the only two anti-AIDS medicines approved by the FDA for use in children younger than 13. Studies with these drugs and with ddC are ongoing and as of February 1995 the available information is incomplete as to how these drugs affect HIV disease in children and which drugs are best to use. In February 1995 results of a study begun in 1991 demonstrated that AZT alone was not effective in delaying progression of HIV disease in children aged 3 months to 18 years. Drug trials continue using ddl alone and ddl in combination with AZT, as well as ddC alone and in combination with AZT. Once these studies are complete, doctors will have a better idea what drugs to use when treating children with HIV infection or AIDS. Now HIV-infected children are usually started on a combination of either AZT and ddl or AZT and ddC when they develop symptoms or when their CD-4 cell count drops below a certain level which varies for children under six. Fewer than 500 cells per cubic millimeter of blood is the starting point for children over six and adults. HIV-infected children on anti-AIDS drugs usually gain weight, have fewer infections, and function better than those who are not given drug treatments. The dose is determined by the age and weight of the child.

PREVENTIVE MEDICINES

Fortunately, medicines exist to help prevent PCP and MAC in adults and children. Two different drugs help prevent PCP. They should be taken for life after the CD4 cell counts drop to below 200 or after the first bout of PCP regardless of blood count levels.

1. Trimethoprim/sulfamethoxazole or TMP-SMX (Bactrim, Septra). This drug works best and is usually prescribed first. You take one double-strength tablet every day. The current recommendations are to start TMP-SMX when the CD4 cell count drops below 200 or when an HlV-infected person has unexplained fevers or thrush, both of which are risk factors for PCP. TMP-SMX at higher doses also treats PCP infections.

TMP-SMX is safe for children older than one month. It is recommended that all infants older than four weeks born to HIV-infected mothers should be given PCP prevention regardless of CD4 cell counts. If tests prove the infant is not HIV infected then the drug should be stopped. This is important because the risk of PCP is highest in infants three to six months of age. Many HIV-infected babies do not survive their first bout of PCP. Known HIV-infected children older than 12 months should receive PCP prevention after the first bout of PCP, if symptoms such as thrush or unexplained fevers persist, or when their CD4 cell counts drop to dangerously low levels that are determined by the child’s age.

2. Aerosolized pentamidine. This medicine is given by special equipment called a nebulizer that aerosolizes the drug so that the infected person can breathe it directly into the lungs, where PCP infection starts. It’s usually given once a month. It does not work as well in preventing PCP, but is given to people who have allergic reactions or side effects from TMP-SMX.

Aerosolized pentamidine is approved only for children older than five who cannot tolerate TMP-SMX.

3. Rifabutin. This drug helps prevent Mycobacterium avium complex (MAC). It is recommended for prevention in AIDS patients whose CD4 blood cell level drops to below 100. The dosage is 300 mg once a day by mouth. Anyone taking this drug must first have a negative skin test and chest X-ray to be sure he or she does not have tuberculosis. There are one or two other drugs that are used in addition to or instead of rifabutin to treat MAC infection.

Rifabutin can be given to HIV-infected children with low CD4 counts at risk for MAC.

4. Other Preventive Medicines. Some studies have shown that dapsone, a drug that has been used to treat children with leprosy, also prevents PCP in adults. Because it is safe for children, it can be given to children older than one month who cannot tolerate TMP-SMX.

Oral acyclovir (Zovirax) taken daily may help control recurrent cold sores in children.