Incidence of campylobacteriosis among patients with AIDS in Los Angeles County.

The incidence and characteristics of campylobacteriosis among patients with acquired immune deficiency syndrome (AIDS) in Los Angeles County were assessed by matching the Campylobacter and AIDS surveillance reporting registries for the years 1983-1987. Campylobacter infection was reported in 29 (0.7%) of 4,433 AIDS cases. The average annual incidence of Campylobacter among AIDS cases (519/100,000) exceeded the crude population rate by 39-fold and exceeded the rate among males aged 15-55 years by 35-fold. Campylobacter infection was more common in female AIDS patients than male patients (p = 0.065). A distinct seasonal variation was noted with peaks occurring in July and November. The median survival time for AIDS patients with Campylobacter (14 months) was lower than that for AIDS patients without Campylobacter (21 months); however, we were not able to assess potential confounders such as subsequent opportunistic infections or antiviral therapy and prophylactic regiment to validate this finding. Campylobacter cases with AIDS had higher rates of bacteremia and hospitalization than Campylobacter cases without AIDS. Attempts should be made to elucidate the sources of Campylobacter and other enteric infections among AIDS patients.

Racial misclassification of American Indians with AIDS in Los Angeles County.

American Indian/Alaska Natives (AI/ANs) appear to be underrepresented in AIDS surveillance statistics. We estimated the accuracy of racial classification and reporting completeness of AIDS among AI/ANs in Los Angeles County by surveying community-based organizations (CBOs) that provide services to persons with AIDS and then comparing the survey to AIDS surveillance data. The surveyed CBOs reviewed 6,500 records and found 60 Native American (the classification used by CBOs for AI/ANs) clients with AIDS compared with six AI/AN AIDS cases reported to the Los Angeles County AIDS surveillance registry. Racial classification was evaluated for 37 (62%) of the 60 Native American CBO clients. Only 11 (30%) of the 37 were verified as AI/ANs. The remaining 26 (70%) misunderstood the racial nomenclature and were reclassified by the CBOs as other races. Of 10 verified AI/AN clients for whom names were available, eight (80%) had been reported to the AIDS registry. However, seven (88%) of these eight were erroneously reported as other races. Racial misclassification accounts for much of the underrepresentation of AI/ANs in the Los Angeles County AIDS surveillance registry.

Unrecognized human immunodeficiency virus type 1 infection in a cohort of transfused neonates: a retrospective investigation.

OBJECTIVE: To retrospectively identify unrecognized human immunodeficiency virus type 1 (HIV-1) infection among a cohort of children transfused as neonates before donated blood was routinely screened for HIV-1 antibody. METHODS: Records at a large, private, metropolitan hospital were reviewed to identify children who were transfused as neonates between January 1980 and March 1985 and discharged alive from the hospital. Multiple data sources were used to locate these children. Parents or guardians were contacted, and their children were offered HIV-1 antibody testing and physical examination. RESULTS: Of the 775 children identified as having received transfusions during the project period, 644 (83%) were located, and 443 (69%) were evaluated for HIV-1 infection. Among those evaluated, 33 (7%) had antibody to HIV-1, including 14 whose infections had not been previously diagnosed. At the time of enrollment, 13 children infected with HIV-1 were asymptomatic an average of 63 months after transfusion. CONCLUSION: HIV-1 antibody testing should be considered for all children, regardless of clinical status, who were transfused before routine blood donor screening was implemented in March 1985, particularly in areas with a high incidence of acquired immunodeficiency syndrome during those years.

Epidemiology of cryptosporidiosis among persons with acquired immunodeficiency syndrome in Los Angeles County.

To determine the occurrence and factors associated with Cryptosporidium among persons with acquired immunodeficiency syndrome (AIDS) in Los Angeles County, data were analyzed from the AIDS surveillance registry for the 10-year period 1983-1992. Among 16,953 persons with AIDS, a total of 638 (3.8%) cryptosporidiosis cases were reported during the study period. The prevalence of cryptosporidiosis was higher in persons whose suspected human immunodeficiency virus (HIV) exposure category was through sexual contact (3.9%) than among persons in other HIV exposure categories (2.6%; P < 0.01) and in immigrants from Mexico (5.2%) than in American born patients (3.8%; P < 0.01). Blacks (2.7%) were less likely than whites (4.1%) and Latinos (4.2%) to be reported with cryptosporidiosis (P < 0.001). A temporal trend was observed from 1983 to 1986 when the prevalence decreased from 6.7% to 3.6% (P < 0.001, by chi-square test for trend). After controlling for confounding variables by stratified analysis, persons whose HIV exposure was sexual (adjusted odds ratio [OR] = 1.7, 95% confidence interval [CI] 1.3, 2.4, P < 0.01) and immigrants from Mexico (adjusted OR = 1.6, 95% CI 1.2, 2.1, P < 0.01) were more likely to have cryptosporidiosis. The negative association with black race remained significant (adjusted OR = 0.7, 95% CI 0.57, 0.96, P = 0.02). The prevalence of cryptosporidiosis decreased with age in gay and bisexual males (Mantel-Haenszel test for trend, P < 0.01) but not among female and heterosexual male cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology of isosporiasis among persons with acquired immunodeficiency syndrome in Los Angeles County.

To determine factors associated with isosporiasis in persons with acquired immunodeficiency syndrome (AIDS) in Los Angeles County, data from the AIDS surveillance registry were analyzed for the eight-year period 1985-1992. Isosporiasis was reported in 127 (1.0%) of 16,351 persons with AIDS during the study period. Prevalence of infection was highest among foreign-born patients (3.2%), especially those from El Salvador (7.4%) and Mexico (5.4%), and in all persons of Hispanic ethnicity (2.9%). Persons with a history of Pneumocystis carinii pneumonia (PCP) were less likely than PCP-negative patients to have isosporiasis (0.2% and 1.4%, respectively, P < 0.01). A decrease in the prevalence of isosporiasis in patients negative for PCP was observed beginning in 1989 (P = 0.02). Prevalence decreased with age (P < 0.01, by chi-square test for trend). After controlling for multiple factors by logistic regression, isosporiasis was more likely to occur in foreign-born patients than in those born in the United States (adjusted odds ratio [OR] = 5.8, 95% confidence interval [CI] 3.4, 9.9, P < 0.001) and in Hispanics than in whites (non-Hispanics) (adjusted OR = 3.5, 95% CI 1.7, 7.2, P < 0.001). A prior history of PCP continued to be negatively associated with isosporiasis (adjusted OR = 0.2, 95% CI 0.1, 0.3, P < 0.001). Age and time remained independently associated with infection. These data suggest that isosporiasis among persons with AIDS in Los Angeles County may be related to travel exposure and/or recent immigration and that the use of trimethoprim-sulfamethoxazole (TMP-SMX) for PCP may effectively prevent primary infection or expression of latent isosporiasis. Physicians should have an increased index of suspicion for Isospora in AIDS patients with diarrhea who have immigrated from or traveled to Latin America, among Hispanics born in the United States, in young adults, and in those not receiving PCP prophylaxis. Food and water precautions should be advised and TMP-SMX prophylaxis considered for the prevention of Isospora infection for patients with human immunodeficiency virus infection who travel to Latin America and other developing countries.

Influenza in the elderly: report of an outbreak and a review of vaccine effectiveness reports.

An outbreak of influenza A in nursing home residents is reported and other studies of influenza vaccine effectiveness in elderly populations are reviewed. The outbreak occurred in a Los Angeles nursing home between February and March 1983. Of the 87 residents, 46 (53%) were affected with influenza-like illness. Attack rates were similar between immunized and unimmunized residents (52% versus 58%), and yielded a vaccine effectiveness estimate of 10%. No additional protection could be demonstrated in residents who received vaccine for two consecutive years. Seven persons died (mortality rate of 8.1%); the mortality rate was greater in the unimmunized (15.8%) than in the immunized (6.2%). Because this study and other field studies of influenza vaccine are limited in precision and power, a statistical summary of the various studies was constructed. Summarizing the studies of institutionalized elderly (in hospitals and nursing and retirement homes) yielded an estimate of 74% for the average vaccine effectiveness in mortality reduction, and an estimate of 33% for the average effectiveness in preventing clinical illness. For the non-institutionalized elderly, the corresponding estimates were 47% for mortality, and 5% for clinical illness. Despite the obvious limitations of such summaries, it seems reasonable to conclude that influenza vaccines have on the average been of clear benefit in the institutionalized elderly, while the benefits in the non-institutionalized elderly have been less dramatic and may warrant further investigation.

Municipal drinking water and cryptosporidiosis among persons with AIDS in Los Angeles County.

To assess unfiltered drinking water as a source of cryptosporidium infection in patients with the acquired immunodeficiency syndrome (AIDS) the prevalence of cryptosporidiosis among persons with AIDS in Los Angeles County was assessed by water service area. One water distributor, serving approximately 60% of the county's residents (area B), has consistently employed filtration. The other company, which serves the remainder of the county (area A), did not institute filtration until mid-December 1986. This difference provided a 'natural experiment' in which to assess the effect of municipal water filtration on the level of cryptosporidiosis among persons with AIDS. The prevalence of cryptosporidiosis among AIDS patients was compared for the two water service areas for the time period (1983-6) preceding the implementation of filtration in area A. From 1983 to 1986 the age-standardized prevalence of cryptosporidiosis among AIDS patients was 32% lower in area A (4.2%), which received unfiltered water, than in area B (6.2%). Following addition of filtration in area A, the prevalence of cryptosporidiosis among AIDS patients decreased by 20%; however, a decline, of 47%, was also observed in area B. The similar baseline levels of cryptosporidiosis and the corresponding post-filtration decline in both areas suggest that filtration had no effect on levels of cryptosporidiosis among persons with AIDS. Thus it does not appear that municipal drinking water is an important risk factor for cryptosporidiosis in AIDS patients residing in Los Angeles County.

Clinical effectiveness of rubella vaccine in a college population.

An outbreak of rash-like illness compatible with rubella occurred among the student population of a large university in Los Angeles between November 1, 1981 and January 31, 1982. A case-control study was conducted in order to estimate the effectiveness of rubella vaccine in preventing clinical rubella in this university population. Immunization and disease histories were obtained from parents and physicians for 39 cases and 86 controls. For those students with a clear documentation of immunization history, only one of 16 cases (6%) had evidence of prior rubella immunization, compared with 40 of 56 controls (71%). This yielded an estimated vaccine effectiveness of 97% (95% confidence limits of 82% to 100%). The level of protection observed for students immunized with rubella vaccine in our study population was high and comparable to that reported in other recent studies. This supports the notion that the current large reservoir of young adult susceptibles is primarily attributable to past failures to vaccinate school-age children, rather than vaccine failures.

The natural history of transfusion-associated infection with human immunodeficiency virus. Factors influencing the rate of progression to disease.

Patients infected by the human immunodeficiency virus (HIV) as a result of blood transfusions are unique in that their dates of infection are well defined and their medical conditions before infection are known. To characterize the natural history of transfusion-associated HIV infection, we studied 694 recipients of blood from 112 donors in whom AIDS later developed and from 31 donors later found to be positive for HIV antibody. Of the recipients tested, 85 were seronegative, 116 were seropositive, and 19 had AIDS. Of 101 HIV-seropositive recipients followed for a median of 55 months after infection, 54 had Centers for Disease Control Class IV disease, including 43 with AIDS. Life-table analysis suggested that AIDS will develop in 49 percent of infected recipients (95 percent confidence limits, 36 to 62 percent) within seven years after infection. As compared with recipients without AIDS, the 43 recipients with AIDS had received more transfusions at the time of infection (median, 21 vs. 7; P = 0.01). HIV-infected blood donors in whom AIDS developed were grouped according to whether AIDS developed within 29 months (the median) after donation (Group 1) or 29 or more months after donation (Group 2). As compared with the 31 recipients of blood from Group 2 blood donors, the 31 recipients of blood from Group 1 donors were more likely to have AIDS four years after infection (49 percent vs. 4 percent; P = 0.005) and illnesses resembling acute retroviral syndrome (14 of 24 vs. 5 of 22; P = 0.03). We conclude that most recipients of HIV-infected blood become seropositive, that AIDS develops in about half these recipients within seven years, and that the risk may be higher when AIDS develops in the blood donor soon after donation.