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AIDS. 1993 Apr; 7(4):597-8.Commentary is directed to the effectiveness in low HIV seroprevalence countries of the use of the 1985 Centers for Disease Control/World Health Organization (CDC/WHO) clinical case definitions for AIDS. A study of HIV-1 and HIV-2 seroprevalence was conducted at the Regional Hospital of Gbadolite, Northern Zaire, in order to examine the relationship between clinical symptoms and the presence of HIV infection. The results showed that in a sample of 667 healthy subjects, who were blood donors and surgical patients without HIV symptoms, 8.2% were HIV-1 seropositive. 30 men (5.8%) and 25 women (17.1%) out of the 521 had HIV-1 antibodies, and no one had HIV-2 antibodies. A sample of 465 patients, who had at least one minor or major clinical symptom of AIDS corresponding to the CDC/WHO clinical case definition, showed 54 of the 200 men (27%) and 129 of the 265 women (48.7%) as seropositive. The conclusion was that specificity was poor for diagnosis of AIDS based on clinical case definitions. In another sample of 143 patients, different from the CDC/WHO clinical case definitions were: pyogenic abscess, tubo-ovarian abscess, epididymitis/orchitis, condylomata acuminata, piles, vaginal ulcerations, recurrent abortions, and amenorrhea/infertility. Further investigations of clinical symptoms are still needed, particularly where expensive testing for HIV infections is curbed by shortages in funding. Technical barriers also prevent reliable and practical HIV testing. It is recognized that the CDC/WHO definition was valuable in detecting cases in Uganda. Other field studies among African populations with HIV seroprevalence of 34-42% showed that the CDC/WHO definition had a specificity of 85-90%, a sensitivity of 55-59%, and a positive predictive value of 73%.
BMJ. British Medical Journal. 1992 Aug 8; 305(6849):325-6.The press widely publicized investigative findings at the international AIDS conference in Amsterdam, the Netherlands about patients with signs or symptoms consistent with AIDS or AIDS-related complex but who did not have HIV-1 or HIV-2 antibodies or the viruses themselves. Yet the formal scientific sessions ignored this topic and the conference summaries only casually mentioned it. Tests used to try to detect HIV were antibody testing, virus isolation, or molecular detection techniques. The press suggested several emotive questions not based on clinical data such as the safety of national blood supplies. 4 of the 5 patients in New York City had HIV risk factors. The only clinical indications of immunodeficiency in 1 patient was Mycobacterium tuberculosis infection and 2 somewhat low CD4 counts which may have actually been due to tuberculosis. Laboratory personnel have not yet reconfirmed reverse transcriptase activity of lymphocytes from 2 patients. So far these cases do not exhibit epidemiological criteria for a new transmissible agent. There has been no case clustering or a pattern of sexual or vertical association of cases. These cases may only be more detections of cases of rare spontaneous primary or secondary immunodeficiency disease. If epidemiological support does suggest a transmissible agent, laboratory personnel may find it difficult to isolate and identify agent. The US Centers for Disease Control and WHO wants to coordinate reporting and classification of cases so epidemiologists can quickly verify or reject laboratory findings based on a larger series of cases. Only with full evaluation of ongoing research and development of sensitive and specific detection systems for new pathogens can the scientific community address questions concerning the safety of blood supplies. This reaction of the press indicates a need for the peer review system to continue to establish the soundness of research before its release to the press to avoid undue concern.
WORLD HEALTH. 1991 Sep-Oct; 12.A researcher with WHO's Tropical Disease Research Programme reviews techniques used to diagnose malaria. Present techniques have not improved much since a French physician 1st used a microscope in 1880 to examine blood from a sick soldier and then noticed the parasites of Plasmodium falciparum. Yet optical quality has improved and special stains can now be used to color the parasites making them more recognizable. In fact, at a magnification of 600-700 times, a scientist can identify all 4 plasmodia, the blood forms of the plasmodia, and count the plasmodia. Blood samples and a microscope allow physicians to monitor the ill person's progress after they began treatment. Yet a microscope and the needed laboratory skills and other resources are not always present in health center in a village in countries where malaria is endemic. It is here where simple and effective techniques are needed the most. 1 approach is to detect antibodies to the plasmodia, but this takes much time. In addition, antibodies are only present after an individual has been infected for a relatively long time. Thus this technique cannot detect malaria early enough to provide proper treatment. Another approach readily identifies antigens. Yet the techniques required are complicated and require a lot of time. Besides antigen techniques are not as reliable as microscopic diagnosis. Researchers are presently experimenting on simple visual methods which are quick, inexpensive, and reliable. Molecules in the plasmodia which are in a small amount of blood will either react or not react with reagents incorporated on a dipstick or card. Thus physicians can detect what plasmodia are present and estimate parasite load. Another test can inform the physicians what antimalarial to prescribe and how much and resistance of the plasmodia to the antimalarial.
BMJ. British Medical Journal. 1991 Nov 9; 303(6811):1189-90.The article proposes that the clinical case definition for Acquired Immunodeficiency Syndrome in Africa is an unworkable concept, with the wrong definition, incorrect validation, improper use, and consequently is a poor surveillance tool. The definition was proposed by the World Health Organization in 1986 to satisfy the use in countries with limited diagnostic resources, and resources for serological testing. Critical review until now of this procedure was lacking. Currently serological testing is available and of high quality. It does not seem justifiable to continue using a provisional surveillance definition. Abandoning this classification procedure may also lead to the focus on problems other than opportunistic infections and AIDs. Clinical surveillance is important, but as well morbidity and mortality need monitoring. It is argued that the definition is an unworkable concept because patients with underlying immunosuppression disorders such as AIDs can not be easily distinguished from chronic disease patients; i.e., pulmonary tuberculosis, renal failure, uncontrolled diabetes, or diarrhea with weight loss. Clinical accuracy is insufficient. It is the wrong definition because pulmonary tuberculosis with a persistent cough cannot be distinguished for those HIV positive and those not. There is inconsistency in the WHO clinical definition and the Centers for Disease Control definitions of AIDs. The incidence of tuberculosis in countries with unmodified clinical case definitions may contribute to an inflated number of AIDs cases. The wrong standards were used to validate the WHO definition in evaluative studies. The reference sensitivity ranges indicate that the definition is insensitive to identifying seropositive patients. Also, the HIV status of patients does not equate with AIDs. Although designed for surveillance, the clinical case definition is used by doctors for individual patient management. Labeling a patient as having AIDs, when he is HIV negative, leads to negative consequences. Researchers compare African AIDs data with North American data with imprecise and noncomparable definitions. As a surveillance tool in countries with a fragmentary or without a vital registration system, it is an inaccurate tool. Alternatives to obtaining data about the spread and impact of HIV are cluster sampling, hospital surveillance of selected populations, anonymous testing of pregnant women or patients in sexually transmitted disease clinics. In Nairobi, a necropsy survey found that 16% had AIDs but 38% were HIV positive.