If Dickens had been alive to write of AIDS and HIV infection, he might have seen it as a tale of two worlds. For those in developed nations with AIDS the availability of life-saving drugs makes it the best of times; for the undeveloped world with little access to these drugs, it remains the worst of times. Yet some new initiatives are trying to reverse the tide in the most ravaged parts of Africa with health campaigns and low-cost generic drugs in targeted areas.
The tide of AIDS and HIV infection turned for the better in the United States and other developed countries in 1996 with the advent of antiretroviral drugs that literally brought thousands of patients back from the brink of death. The annual number of AIDS deaths fell by 70 percent between 1995 and 2001. Currently the annual death toll is about 16,000, changing the status of the disease from a death sentence to one that, for many, can be managed.
An estimated 900,000 Americans are now living with AIDS or HIV. About one quarter of that number have not yet been diagnosed.
Perhaps because AIDS is considered treatable, many have let their guard down or are in denial. About 40,000 new cases are diagnosed annually, with minorities disproportionately represented. According to the Centers for Disease Control, more than 50 percent of new infections occur in African Americans , although they make up only 13 percent of the overall population. AIDS is now the leading cause of death among African-American women between the ages of 25 and 34.
Diagnosis and monitoring are essential so that those infected with HIV can make the most effective use of medications that are available.
At least 20 different antiretroviral drugs are available to treat HIV and AIDS. There are also more than 80 new medications currently being developed, including 15 vaccines. Unfortunately an effective AIDS vaccine remains elusive and experts believe we are still a number of years away from that goal.
Four classes of antiretroviral drugs are used in varying combinations. The treatment is known as HAART–highly active retroviral therapy.
· NRTI (nucleoside reverse transcriptase inhibitors). They prevent viral replication by interfering with the transcription of DNA from viral RNA.
· NNRTI (nonnucleoside reverse transcriptase inhibitors). They prevent viral replication by interfering with the reverse transcriptase enzyme.
· PI (protease inhibitors) prevent cleavage of the core viral proteins. PIs have many potentially serious drug interactions.
· Fusion inhibitors require twice-daily injections and are very expensive, costing up to $25,000 per year. They’re used in patients who have failed other drugs.
When To Start Therapy
HAART therapy can mean the difference between life and death for AIDS patients, but because all of the drugs used in the various regimens have undesirable side effects, experts recommend that patients use them only when indicated.
About a quarter of Americans infected with AIDS have not been diagnosed and are not getting the treatment they need.
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Revised guidelines have recently been published for treating patients with HIV infection. Prepared by the Panel on Clinical Practices for Treatment of HIV Infection, convened by the Department of Health and Human Services, the guidelines recommend that patients should begin treatment when they have symptoms or when indicated by either of two markers, a low CD4+ cell count or a high HIV RNA viral load.
The normal CD4+ lymphocyte cell count is approximately 500 to 1400 cells/ microliter. When it falls below 200, it is considered a marker for immunologic AIDS and a definite indication for HAART treatment. Some researchers now propose beginning HAART when the CD4+ lymphocyte count falls below 350 cells /microliter.
HIV infection is a concern for both men and women, all racial and ethnic groups and all sexual preferences.
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The viral load is another marker used to indicate when treatment should begin. The viral load measures the extent of viral reproduction in plasma and is reported as the number of viral copies. When the viral load is high, (higher than 55,000 copies per mL), some experts recommend beginning therapy. At that level about one third of patients who are not treated will progress to AIDS within three years.
If the viral load is below 55,000 copies, the risk of progressing to AIDS in three years is only 15 percent. Many physicians advise patients at that level to wait if they have no other symptoms.
When a patient begins HAART, the viral load should decrease 10-fold within two months and be virtually undetectable within four to five months. Side effects of treatment can be daunting, however, and may include nausea, diarrhea, headache, insomnia, rash and complications affecting the liver, kidneys and heart. It’s important for patients to take medication as prescribed and to be monitored for complications. If a specific drug proves too toxic, a physician is usually able to substitute another that may be better tolerated.
Scientists are working to develop new drugs designed to outwit the stealthy HIV, a virus that evades the immune system’s normal defense mechanisms to gain entry into cells and then quietly hijacks the cell’s reproductive system to reproduce itself. There are currently 83 new medications under development. One new class of drugs called integrase inhibitors blocks an enzyme the virus needs to make a copy of itself; others are designed to keep the virus from attaching to or entering the cell in the first place.
Even though 40,000 new HIV infections still occur annually in the United States, the crisis here is relatively contained with most of those diagnosed with the disease gaining access to treatment.
Globally, AIDS has reached crisis levels. An estimated 42 million people are living with HIV/AIDS, most with little access to the life-saving drugs available to citizens of developed countries. AIDS will kill an estimated three million people this year, the majority in sub-Saharan Africa. Another five million persons will become infected.
In May, 2004, the United States announced a policy change that will make it possible to quickly approve combination anti-retroviral drugs that can be bought at lower prices for the peoples of Africa and the Caribbean. The new policy will also make it possible to combine several drugs into one pill, simplifying the complicated dosing schedule for poorer nations with limited access to health care.
Complacency is a major stumbling block in the battle against HIV/AIDS. The availability of drugs that can turn the tide against this formerly deadly disease means many lives are saved, but others continue to die despite access to drugs. Successful drug therapy is expensive, requires commitment to a complex dosing schedule and monitoring, and often involves toxic side effects.
Prevention is the key strategy. HIV infection is a concern for men and women, for all ethnic and racial groups and for all sexual preferences.
Safe sex means using condoms, limiting the number of sexual partners, avoiding contact with the blood or bodily fluid of an infected person and, for those who inject drugs, using only sterile needles. We know how to protect ourselves against HIV/AIDS transmission. We just have to assume the personal responsibility to protect ourselves.
REFERENCES:
“AIDS Treatment Plan,” Family Practice News,” January 1, 2004.
“Antiretroviral Therapy Should Begin When T Cells Drop Below 350 Cells/MircrL,” Medical Letter on the CDC & FDA, November 23, 2003.
Geoffrey Cowley, “New Inroads Against AIDS,” Newsweek, December 8, 2003.
“Eighty-Three New Medicines In Development for HIV/AIDS,” Virus Weekly, December 23, 2003.
Gregory Folkers and Anthony Fauci, “AIDS Agenda Still Daunting,” Issues in Science and Technology, Summer 2003.
Helen Frankish, “Coalition Launched to Fight Against HIV/AIDS In Women,” The Lancet, February 7, 2004.
Peter Freiberg, “Trials and Tribulations: Disappointing Results from the First-Ever Human AIDS Vaccine Trial Leave Researchers Asking What’s Next?” The Advocate. April 15, 2003.
Rajesh Gupta et al, “Scaling-Up Treatment for HIV/AIDS,” The Lancet, January 2004.
Margaret Heagarty, “AIDS: The Battle Rages On,” Issues in Science and Technology, Summer 2003.
Esther Kaplan, “Dying for AIDS Drugs,” The Nation, November 3, 2003.
“New Drugs Cause Prevention Complacency,” USA Today Magazine, October 2003.
Joanne Orrick, “Guidelines for Management of HIV Infection,” Drug Topics, July 21, 2003
Mark Schmidt and Eve Mokotoff, “HIV/AIDS Surveillance and Prevention,” Public Health Reports, May-June, 2003.
“Study: Generic Drugs Helping AIDS Fight,” Medical Letter on the CDC & FDA,” October 19, 2003.
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