From: mpmNS@fcolcc.hampshire.edu (mpmNS) Newsgroups: sci.med.aids,sci.med,misc.health.aids,soc.motss,bionet.molbio.hiv,sci.answers,soc.answers,misc.answers,news.answers Subject: Sci.Med.AIDS FAQ part 3 of 10 Followup-To: sci.med.aids Date: 22 Nov 1994 07:54:24 -0600 Organization: Hampshire College Lines: 283 Sender: sma@wubios.wustl.edu Approved: Yes: Jeff Rizzo ,phil@wubios.wustl.edu (J. Philip Miller) Message-ID: <18769@sci.med.aids> Reply-To: aids-faq@family.hampshire.edu NNTP-Posting-Host: wubios.wustl.edu Archive-name: aids-faq/part3 Posting-Frequency: monthly Last-modified: 10/8/94 Section 3. General Information on AIDS Q3.1 Testing Information (please contribute) Q3.2 AIDS and Opportunistic Infections. --------------------------------------------------------------------- Question 3.1. Testing Information (please contribute) All blood products in the U.S. are screened by ELISA assays for several infectious agents, including: HIV 1/2, HTLV I/II, HBV, HCV, Syphillis, Hepatitis B core, and a liver enzyme ALT, indicative of hepatic infections. Some blood donations are also tested for CMV, a more common virus that has devestating effects in immunocompromised individuals, such as cancer patients and transplant recipients. In addition to these laboratories, all donors are screened through questionaires that meet or exceed FDA requirements. What if a blood-bank finds out you are HIV positive? The Red Cross and other blood banks routinely test blood donations for HIV antibodies. The Red Cross has specifically asked that people not use blood donation as a way of finding out if they are HIV+. If you think you might be infected, go get a blood test. Many cities offer free anonymous HIV testing. Contact your local public health service office for details. This is particularly important if you think you might have been infected within the last six months, since there's the risk that you are indeed infected, but do not yet have antibodies to HIV. Blood donation is a fine thing to do--but how will you feel if you donate, then a month later you find out through some other means that you're HIV+? We're supposed to be making a gift of life, not death. The following article discusses how blood banks use the information, if you have tested positive for HIV antibodies. In addition to your possible role in killing another person, donating blood to obtain a free HIV test also risks your anonymity. From: McCullough J. The nation's changing blood supply system. JAMA. 1993 May;269(17):2239-45. "The coded identity of potential or actual blood donors who are found to be unsuitable on the basis of medical history or laboratory testing is entered into a donor referral registry (DDR). Before each donated unit of blood is made available for use, the coded identity of the donor is checked against the DDR to ensure that the donor has not been found to be unsuitable during a previous donation. Although potentially infectious donors are so informed and asked not to give blood in the future, this DDR check is thought to improve the safety of the blood supply by serving as an additional way of identifying potentially infectious blood should these donors return. The American Red Cross operates a single DDR with information from all of its 47 reginal centers. However, other blood banks' DDRs act only locally since there is no requirement that different blood banks in the same or neighboring communities exchange this DDR information. The operation of these DDRs costs money, consumes experts' time, and has the potential for many abuses such as failure to obtain informed consent and breeches of confidentiality. The value of a DDR in improving the safety of the blood supply has not been established. An analysis of the value of thse DDRs should be conducted, and based on the results, DDRs should be either eliminated or refined into an appropriate system." See also: Grossman BJ. Springer KM. Blood donor deferral registries: highlights of a conference. Transfusion. 1992;32:868-72. ------------------------------------------------------------------------ Question 3.2. AIDS and Opportunistic Infections. AIDS and Opportunistic Infections NIAID BACKGROUNDER: Office of Communications, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892 - September 1993 Opportunistic infections (OIs) cause most of the illnesses and deaths among people infected with HIV, the virus that causes AIDS. The National Institute of Allergy and Infectious Diseases (NIAID) leads the way in U.S. research on these life-threatening infections. As part of the NIAID effort, investigators are defining the optimal therapies, alone and in combination, to prevent and treat OIs. They seek ways to identify infections earlier and recognize resistance to therapies more quickly. What are OIs? The immune systems of most people with HIV gradually deteriorate, leaving them vulnerable to numerous viruses, fungi, bacteria and protozoa that are held in check in people with healthy immune systems. These microbes can become active in HIV-infected individuals, causing frequent and severe disease. NIAID uses a two-pronged approach to the prevention and treatment of OIs: basic laboratory research to learn how these microbes cause disease and clinical research to develop and evaluate promising therapies. Prevention and treatment of one such disease, Pneumocystis carinii pneumonia or PCP, has been a major thrust of the NIAID program. Other NIAID investigations include cytomegalovirus (CMV) infection, Mycobacterium avium complex (MAC) and tuberculosis (TB). Institute research focuses on these infections because, although they occur repeatedly among HIV-infected people, they are rare in the general population and few drugs are available now to prevent and treat them. PCP: The Most Common OI PCP remains the most common, life-threatening opportunistic infection in people with HIV, occurring in up to 80 percent of individuals who do not take preventive therapy. The PCP organism, a microscopic parasite, appears to infect most people during childhood. In people with healthy immune systems, the parasite normally remains dormant, but it may cause disease in those with damaged immune systems. PCP infection is characterized by a dry cough and shortness of breath. Individuals may experience other, less specific symptoms such as fever, fatigue and weight loss for weeks or even months before respiratory problems appear. As PCP infection progresses, the functioning lung tissue becomes clogged, which decreases the transport of oxygen from the inhaled air into the blood. At this point, the oxygen in the blood may be lowered to dangerous or even fatal levels. Without treatment, close to 100 percent of HIV-infected patients with PCP die. During the 1980s, the development of effective therapies led to better management of PCP. Drugs for preventing and treating PCP include aerosolized pentamidine and oral trimethoprim-sulfamethoxazole (TMP/SMX), but both can result in serious side effects that prevent some patients from taking the drugs. TMP/SMX is recommended more often than aerosolized pentamidine for treating and preventing PCP because the combination is effective, tolerated by about half of the patients who take it and may work against other disease-causing organisms as well. In 1992, an NIAID-supported trial proved that TMP/SMX is better than aerosolized pentamidine at preventing a second episode of PCP in people with AIDS who can tolerate either therapy. Although definitive research data are lacking, other agents may be considered in situations in which neither TMP/SMX nor aerosolized pentamidine can be given. The drug atovaquone is approved for patients with mild to moderate PCP who cannot tolerate TMP/SMX. One NIAID study showed that primaquine, an antimalaria drug, with clindamycin is an effective oral therapy for PCP. TMP with dapsone is an alternative treatment. The search for new, more effective, less toxic drugs and combinations of drugs to fight PCP continues. NIAID studies play an important role in this effort. One trial compares three drug regimens--TMP/dapsone, primaquine/clindamycin and TMP/SMX--for oral treatment of mild to moderate PCP. Another protocol looks at an 8-aminoquinoline, an antimalaria drug, while a third trial considers two regimens of TMP/SMX to prevent PCP. CMV: A Herpesvirus Infection with CMV, a virus in the herpes family, may occur throughout life. By age 50, about half of the general population has been exposed to this virus, yet most people do not become ill. After the original infection, the virus may lie dormant and reactivate itself if the immune system becomes suppressed. For people with HIV infection, CMV is one of the most frequent and serious OIs they face. CMV retinitis, an inflammation of the light-sensitive inner layer of the eye, is the most common CMV infection and leads to blindness if left untreated. Infections also may occur in the gastrointestinal tract, lungs, brain, heart and other organs. Both intravenous ganciclovir and foscarnet are approved to treat CMV retinitis. Lifelong maintenance on either treatment is required because the drugs do not kill CMV, they merely slow down its ability to grow. Even with therapy, the rate of relapse is high. NIAID studies of CMV and other herpesviruses have shown that intravenous foscarnet and ganciclovir are equally effective for CMV retinitis, although foscarnet was associated with increased survival for patients in the study. An ongoing trial is testing an oral form of ganciclovir to prevent CMV disease. The oral form of the drug would be much easier and safer for patients to take. MAC: A Bacterial OI Infection with MAC is diagnosed in up to 40 percent of people with AIDS in the United States, making it the most common bacterial OI. Usually, it affects people in advanced stages of HIV disease when the immune system is severely suppressed. The MAC organism is found widely in the environment and is thought to be acquired most commonly through the mouth or gastrointestinal tract. It can spread to the lungs, liver, spleen, lymph nodes, bone marrow, intestines and blood. MAC causes chronic debilitating symptoms--fever, night sweats, weight loss, fatigue, chronic diarrhea, abdominal pain, liver dysfunction and severe anemia. Rifabutin is the first drug to be approved for preventing MAC disease in people with advanced HIV infection. The Food and Drug administration based this approval on clinical studies showing that patients who received rifabutin were one-third to one-half as likely to develop MAC as were patients who received placebo. To prevent MAC disease, a U.S. Public Health Service Task Force on Prophylaxis and Therapy for MAC suggests that patients with HIV infection and fewer than 100 CD4 + T cells receive oral rifabutin for the rest of their lives unless disease develops. In the latter case, multiple drug treatment is needed. CD4+ T cells are immune system cells targeted and killed by HIV. No other drug regimen is recommended currently to prevent MAC. Azithromycin and clarithromycin are promising agents for prophylaxis, but studies of these agents have not been completed. Increasing evidence suggests that treatment can benefit patients with disseminated MAC, especially multiple-drug regimens including either clarithromycin or azithromycin. Therefore, the PHS task force suggests that all regimens, outside of a clinical trial, should consist of at least two drugs, including clarithromycin or azithromycin plus one other agent such as clofazimine, rifabutin, rifampin, ciprofloxacin and, in certain situations, amikacin. They recommend continued therapy for the patient's lifetime, as long as clinical benefit and reduction of mycobacteria are observed. NIAID has several studies under way looking at the roles of clarithromycin and azithromycin, and other drugs such as sparfloxacin, alone and in combination, to prevent and treat this serious disease. TB: An Airborne Disease TB, a chronic bacterial infection, causes more deaths worldwide than any other infectious disease. About one-third of the world's population harbors the predominant TB organism, Mycobacterium tuberculosis, and is at risk for developing the disease. The World Health Organization (WHO) estimates that 4.4 million people worldwide are coinfected with TB and HIV. WHO predicts that by the year 2000, TB will take one million lives annually among the HIV-infected. Because of their weakened immune systems, people with HIV are vulnerable to reactivation of latent TB infections, as well as to new TB infections. Transmission of this disease occurs most commonly in crowded environments such as hospitals, prisons and shelters--where HIV-infected individuals make up a growing proportion of the population. Active TB may occur early in the course of HIV infection, often months or years before other OIs. TB most often affects the lungs, but it also can cause disease in other parts of the body, particularly in people with advanced HIV disease. Of particular concern for people with AIDS is multi-drug-resistant TB (MDR-TB). MDR-TB can occur when patients fail to take their TB medicine for the prolonged periods necessary to destroy all TB organisms, which then become resistant to the drugs. These resistant organisms can be spread to other people. Even with treatment, for individuals coinfected with HIV and MDR-TB, the death rate may be as high as 80 percent, as opposed to 40 to 60 percent for people with MDR-TB alone. The time from diagnosis to death may be only months for some patients with HIV and MDR-TB, as they are sometimes left without adequate treatment options. The initial site of TB infection is in the balloon-like sacs at the ends of the small air passages in the lungs. In these sacs, white blood cells called macrophages ingest the inhaled TB organism. Some of the organisms are killed immediately, while others remain and multiply within the macrophages. If the organism breaks out of the sacs, TB can become active disease. This spreading sometimes results in life-threatening meningitis and other problems. NIAID launched the first large U.S. study to assess TB treatment strategies for people coinfected with HIV and TB. The study is aimed at finding state-of-the-art treatment. NIAID is the lead institute for TB research at the National Institutes of Health, supporting more than 50 research projects related to TB. Other OIs NIAID-supported scientists also study other OIs including fungal infections, herpes simplex virus infections, toxoplasmosis and cryptosporidium infections.