Effect of the revised AIDS case definition on AIDS reporting in San Francisco: evidence of increased reporting in intravenous drug users.

To examine the effect of the revision of the US national AIDS case definition in September 1987, we compared demographic and clinical information for AIDS patients diagnosed and reported to the San Francisco Department of Public Health between 1 September 1987 and 31 October 1989. Of the 3167 patients diagnosed and reported during the study period, 584 (18%) met the revised case definition only, increasing AIDS case reporting in San Francisco by 23%. One hundred and thirty-four of these 584 patients (23%) subsequently developed diagnoses meeting the old definition. After adjusting for this proportion, the revised case definition increased reporting by 17%. The mean time between initial diagnosis with a disease meeting the revised definition and subsequent development of a disease meeting the old definition was 18.5 months. Patients who met the revised case definition only were slightly older and more likely to be Black, female, and intravenous drug users (IVDUs) than those meeting the old case definition. The majority of patients who met the revised case definition only had initial diagnoses of HIV wasting syndrome (26%), HIV encephalopathy (21%), and presumptive Pneumocystis carinii pneumonia (19%). The revised AIDS case definition has significantly increased the reporting of severe morbidity associated with HIV infection, particularly among IVDUs.

Projections of AIDS morbidity and mortality in San Francisco.

To develop a model for predicting acquired immunodeficiency syndrome (AIDS) morbidity in San Francisco, Calif, through June 1993, we combined annual human immunodeficiency virus seroconversion rates for homosexual and bisexual men and for heterosexual intravenous drug users with estimates of the cumulative proportion of the population with AIDS by duration of human immunodeficiency virus infection and with estimates of the size of the at-risk populations. We projected AIDS mortality by applying Kaplan-Meier estimates of survival time following diagnosis to the projected number of cases. The median incubation period for AIDS among homosexual and bisexual men infected with the human immunodeficiency virus was estimated to be 11.0 years (mean, 11.8 years; 95% confidence interval, 10.6 to 13.0 years). The model projects 12,349 to 17,022 cumulative cases of AIDS in San Francisco through June 1993, with 9,966 to 12,767 cumulative deaths.

Survival following diagnosis of Kaposi's sarcoma for AIDS patients in San Francisco.

To evaluate survival for AIDS patients diagnosed with Kaposi's sarcoma (KS), we calculated survival for 1,015 patients reported in San Francisco between July 1981 and December 31, 1987, representing 22% of total patients reported. These patients had a definitive initial diagnosis of KS, and developed no other diseases within 3 months of diagnosis. Patients were followed prospectively through December 31, 1988. All patients evaluated in this study were men. Survival was evaluated for subgroups based on age, race and ethnicity, year of diagnosis, and transmission category. The median survival for patients diagnosed with KS alone was 17.0 months, with a 5-year survival rate of 8.7%. Poorer prognosis was found for patients with older age at diagnosis and with later year of diagnosis. Proportional hazards analysis indicated that age (p less than 0.001) and year of diagnosis (p less than 0.05) were significant independent predictors of survival, while race or ethnicity and risk group were not.

The epidemiology of AIDS-related Kaposi's sarcoma in San Francisco.

To clarify further the epidemiology of AIDS-related Kaposi's sarcoma (KS) in San Francisco, we reviewed AIDS cases reported to the San Francisco Department of Public Health through August 31, 1990. Of the 7,119 patients reported, 2,346 (33%) had been diagnosed as having KS: 1,716 (73%) as their presenting clinical manifestation of AIDS and 648 (27%) as a later manifestation. Of these 2,364 KS patients, 2,075 (88%) were homosexual or bisexual men without histories of intravenous drug use, and 273 (12%) were homosexual or bisexual intravenous drug users. From 1981 to August 1989, the proportion of AIDS patients presenting with KS declined from 55 to 19% (p less than 0.001). However, the number of patients being diagnosed with KS has increased along with the overall number of AIDS patients, but this increase was less than the increase in number of patients with other opportunistic infections and malignancies. KS patients were less likely than patients without KS to be reported through an active surveillance system and less likely to be found through retrospective reviews of medical records, death certificates, and obituaries. We conclude that the proportion of AIDS patients with KS is continuing to decline in San Francisco and that this decline is not an artifact of the AIDS surveillance system.

Kaposi's sarcoma reporting in San Francisco: a comparison of AIDS and cancer surveillance systems.

A preliminary comparison of the reported incidence of Kaposi's sarcoma among males under 60 years of age residing in San Francisco was conducted using merged San Francisco AIDS Registry and California Tumor Registry (CTR) data. For the years 1980-1986, the number of cases reported by both registries was similar. However, only 961 (72.3%) of the 1,330 cases appearing in either registry appeared in both. Of the 160 Kaposi's sarcoma cases in the AIDS registry only, 11 (6.9%) were included in the CTR with another cancer diagnosis. Of the 209 Kaposi's sarcoma cases occurring only in the CTR, 109 (52.2%) were included in the AIDS registry with another diagnosis. The number of cases included in either or both registries was about 20% more than in either alone. Data sharing between the staff of these registries is precluded by confidentiality constraints.

Survival trends for patients with AIDS.

To evaluate trends in the length of survival for patients with acquired immunodeficiency syndrome, we calculated survival following diagnosis of acquired immunodeficiency syndrome for 4323 cases reported in San Francisco, Calif, between July 1981 and December 31, 1987. Patients were followed up prospectively through December 31, 1988. The median survival for all patients was 12.5 months, with a 5-year survival rate of 3.4%. Significantly improved survival was observed for patients diagnosed with Pneumocystis carinii pneumonia in 1986 and 1987. Survival for patients diagnosed with Kaposi's sarcoma declined significantly between 1981 and 1987. Survival was unchanged among patients diagnosed with other opportunistic infections or malignancies. Proportional hazards analyses indicated that initial diagnosis, age, and year of diagnosis were significant predictors of survival. For a subset of patients (n = 644), therapy with zidovudine was an additional significant predictor of survival. This study suggests that survival following diagnosis of acquired immunodeficiency syndrome has improved in recent years, primarily among patients with carinii pneumonia. Therapy with zidovudine may be partially responsible for these recent improvements.

The epidemiology of AIDS in Asian and Pacific Islander populations in San Francisco.

To evaluate the epidemiology of HIV infection in Asian and Pacific Islander populations in San Francisco, we compared cases of AIDS reported in Asians and Pacific Islanders with those reported in other racial and ethnic groups. The incidence of AIDS in Asians and Pacific Islanders was significantly lower than in Whites, Blacks, Latinos and American Indians and Alaska natives. AIDS cases among Asians and Pacific Islanders have increased 177% since 1985 compared with 54% in other racial and ethnic groups, with the greatest increase in homosexual and bisexual men and transfusion recipients. Among Asian and Pacific Islander ethnic groups, the incidence of AIDS was 168 cases per 100,000 in Polynesians, 141 per 100,000 in Japanese, 92 per 100,000 in 100 Filipinos, 72 per 100,000 in southeast Asians, and 21 per 100,000 in Chinese. We conclude that AIDS cases are disproportionately increasing in Asians and Pacific Islanders in San Francisco.

PIP: In Asia and in people of Asian and Pacific Islander ancestry in the United States, AIDS is a rare disease. San Francisco, with the highest incidence of AIDS in the United States, also has the highest percentage (21%) of Asians and Pacific Islanders. To understand the potential for AIDS in this select population, trends over time and the demographics of reported AIDS cases among the select population in San Francisco were analyzed. Records were reviewed of AIDS cases reported to the San Francisco Department of Health, which had a substantiated 98% report rate. As of March 31,1988, 83 (1.8%) of the 4689 cases and 42 (1.5%) of the 2831 deaths reported were among the select population. The incidence of AIDS among the select population (58.5/100,000) was significantly lower than among whites (1108.8/100,000), blacks (368.9/100,000), and latinos (421.0/100,000). Among the select population, however, AIDS increased more rapidly since 1985 than among the whites, blacks, or latinos. Of the 83 cases reported, 69 were homosexual or bisexual men without intravenous drug use, 3 homosexual or bisexual men with histories of intravenous drug use, 6 were transfusion recipients, 3 were heterosexual intravenous drug users, 1 was a heterosexual contact of a person at risk for AIDS, and 1 was a hemophiliac. Comparison of transmission categories of the select population with those of the other racial and ethnic groups showed a significantly greater (P 0.001) number of transfusion recipients and a significantly lower (P 0.02) number of homosexual and bisexual intravenous drug users. The greatest increase in cases among the select population was in homosexual and bisexual men without histories of intravenous drug use, which was greater than the increase among nonAsian or Pacific Islander homosexual and bisexual men (P 0.10). These findings support the theory that HIV entered the select population communities later than it did nonAsian or Pacific Islander communities.