[Effects of the 1987 revision of the definition for an AIDS case in Switzerland]. / Effekte der Revision der Aids-Falldefinition von 1987 in der Schweiz.

AIDS cases diagnosed in Switzerland after the revision of 1987 and reported to the Swiss Federal Office of Public Health until 31.12.1992 were categorised according to whether they conformed to the diagnostic criteria valid before the revision (= "pre-87"-group) or only to the new criteria introduced with the revision (= "post-87"-group). Compared to the "pre-87"-group, the proportion of injecting drug users was higher, the proportion of homosexual men was lower, the patients were younger and Pneumocystis carinii pneumonia (PCP) and Kaposi-sarcoma were diagnosed less frequently in the "post-87"-group. The revision of the AIDS case-definition affected the proportion of Aids-diagnoses with PCP over time. It improved the surveillance of AIDS morbidity in Switzerland but its effects must be distinguished from true phenomena of the AIDS-epidemic.

[Epidemiology of HIV infections in Switzerland and the German Federal Republic--contribution of official surveillance systems, of anonymous testing and of blood donor screening]. / Epidemiologie der HIV-Infektion in der Schweiz und in der Bundesrepublik Deutschland--der Beitrag der amtlichen Erfassungssysteme, der anonymen Teststellen und des Blutspenderscreenings.

Official records on HIV infections are useful instruments to register and demonstrate the spread of the virus in the population observed. The data resulting from the registries allow the estimation of the means and the variabilities of age, sex and the probable path of infection in the observed population. In Switzerland as well as in the Federal Republic of Germany, the mean age of persons whose positive HIV status is detected increases in the course of time. In Switzerland, relatively more women are infected, and injecting drug users play a more important role. In the Federal Republic of Germany the homo-/bisexual men seem still to be the most important group. Nevertheless, data without any reference baseline do not enable an inference to be drawn in respect of trends and prevalence in the general population. Data on blood donations, collected in Switzerland as well as in Germany, and data on anonymous testing collected in Switzerland, are helpful in estimating trends and prevalence in the general population. Data suggest that the overall prevalence is higher in Switzerland than in the Federal Republic of Germany. Of course, comparisons between different countries must take in account the different structure of reporting systems and attitudes toward these systems.

[AIDS in Germany: clinical manifestations of AIDS]. / AIDS in der Bundesrepublik Deutschland: Die klinische Manifestation von AIDS.

Since 1982, voluntary anonymous reports that meet the criteria of the WHO/CDC-AIDS definition are being collected by the Federal Health Office. By December 31st, 1989 a total of 4,306 AIDS cases has been registered. More than 80% of the reported cases are homo- and bisexual men and injection drug-users. The remaining cases are divided between hemophiliacs, persons who get infected by heterosexual contacts, blood transfusion recipients, and children infected pre- or perinatally. In 16% of all cases AIDS was diagnosed only on the basis of a Kaposi's sarcoma (KS) and in another 6% on the basis of KS and an opportunistic infection (OI). KS occurred mostly in homo- and bisexual men. The relative proportion of KS has steadily decreased from 30% up to 1986 to less than 20% in 1989. The overall incidence of KS decreased mainly due to the decrease of KS in homosexual men with AIDS. OI were diagnosed in 70% of the cases. Pneumocystis-carinii-pneumonia is most frequent (47%), followed by candida-oesophagitis (19%) and toxoplasmosis of brain in 9.5%. A malignant lymphoma was diagnosed in 3% of the cases. Furthermore, HIV-encephalopathy was seen in 2.8% and HIV-wasting-syndrome in 1.6% of cases. There is a different spectrum of diseases at the first manifestation of AIDS diagnosed in injecting drug-users. The reasons for this may be due to different life-style in this group.

Trends of HIV infections using the anonymous mandatory reporting system and other data sources in Switzerland and in the Federal Republic of Germany.

In Switzerland and in the Federal Republic of Germany the reporting of HIV infections is based on an anonymous mandatory reporting system for laboratories. In Switzerland, physicians have to complete a questionnaire on the patient's clinical status and risk behaviour. To make a rough estimate of the prevalence of HIV infections in the general population at low risk, data on blood donations are used in both countries. In Switzerland, additional data with information on positive and negative test results have been obtained since 1985 from anonymous test sites. In both countries, the data do not show evidence of an increasing incidence of HIV infection. The number of positive test results reported by the laboratories and physicians remains stable, and the rates of HIV-positive blood donations are declining. In the Federal Republic of Germany, homo-/bisexual men play the most important role in the epidemic, whilst in Switzerland, injecting drug users contribute most to the burden of HIV infection, and the proportion of persons probably heterosexually infected is increasing steadily. Possible selection biases need to be further discussed.

[Time-related incidence of AIDS--epidemiological developments in various groups with increased risk of HIV infection]. / Die Inzidenz von AIDS im Zeitverlauf--epidemiologische Entwicklung in einzelnen Gruppen mit erhöhtem Risiko für eine HIV-Infektion.

It is no longer possible to depict the number of AIDS cases over time as an exponential curve. In the group of homosexual/bisexual men, who still account for nearly 70% of all cases, the increase in the logistic model has reached a maximum (turning point of the logistic function). Nevertheless, in this group increasing numbers of cases are still to be expected. In the case of injecting drug users no such turning point can yet be detected with sufficient statistical accuracy.