Faculty Bibliography

By means of prospective cohort data from the Sydney AIDS Project, we report on 55 homosexual or bisexual men who have become infected with human immunodeficiency virus (HIV), as measured by the development of serum HIV antibodies (seroconversion). We have compared the sexual practices, recreational drug abuse, history of sexually-transmissible diseases, and antecedent immunological findings of the men who seroconverted with those of 588 subjects who persistently remained seronegative in the same time-period. The cumulative incidence rate of HIV infection over the three years of observation was 8.5%. The cumulative incidence rate ranged from less than 1% for the six months before August 1, 1984, to a peak of 5% in the six months before August 1, 1985. Of those subjects for whom we had data for the period of seroconversion, all but two of the subjects who seroconverted admitted to a recognized high-risk sexual practice in the six months before the first visit at which they were found to be seropositive. Univariate analysis found that men who seroconverted were significantly more likely to have had a greater number of recent sexual partners (relative risk per partner, 1.02; P less than 0.001), to have engaged in receptive anal intercourse (incidence rate ratio, 3.1; 95% confidence interval [CI], 1.3-7.6; P = 0.01) and to have used nitrite inhalant (incidence rate ratio, 2.6; 95% CI, 1.2-5.9; P = 0.02) and amphetamine (incidence rate ratio, 4.8; 95% CI, 2.2-10.5; P less than 0.001) drugs. The men who seroconverted were significantly (incidence rate ratio, 2.7; 95% CI, 1.2-6.1; P = 0.014) more likely to have antecedent T-suppressor-cell counts of greater than 800 cells/microL. Factors that retained significance in multivariate analysis were the number of recent sexual partners, recent amphetamine abuse and a T-suppressor-cell count of greater than 800 cells/microL

Intravenous drug users are the second largest group to develop the acquired immunodeficiency syndrome, and they are the primary source for heterosexual and perinatal transmission in the United States and Europe. Understanding long-term trends in the spread of human immunodeficiency virus among intravenous drug users is critical to controlling the acquired immunodeficiency syndrome epidemic. Acquired immunodeficiency syndrome surveillance data and seroprevalence studies of drug treatment program entrants are used to trace seroprevalence trends among intravenous drug users in the borough of Manhattan. The virus entered this drug-using group during the mid-1970s and spread rapidly in 1979 through 1983. From 1984 through 1987, the seroprevalence rate stabilized between 55% and 60%--well below hepatitis B seroprevalence rates. This relatively constant rate is attributed to new infections, new seronegative persons beginning drug injection, seropositive persons leaving drug injection, and increasing conscious risk reduction

Increasing mortality in intravenous (IV) drug users not reported to surveillance as acquired immunodeficiency syndrome (AIDS) has occurred in New York City coincident with the AIDS epidemic. From 1981 to 1986, narcotics-related deaths increased on average 32% per year from 492 in 1981 to 1996 in 1986. This increase included deaths from AIDS increasing from 0 to 905 and deaths from other causes, many of which were infectious diseases, increasing from 492 to 1091. Investigations of these deaths suggest a causal association with human immunodeficiency virus (HIV) infection. These deaths may represent a spectrum of HIV-related disease that has not been identified through AIDS surveillance and has resulted in a large underestimation of the impact of AIDS on IV drug users and blacks and Hispanics

Epidemiologic studies have reported associations between gastrointestinal cancer mortality and exposure to cutting fluids and abrasives in metal machining and precision grinding operations. Two previous studies found excess stomach cancer among workers exposed to water-based cutting fluids in bearing plants. This study reports similar findings in a third and larger population. Cause of death and work histories were determined for 1,766 bearing plant workers who died between Jan 1, 1950 and June 30, 1982. Mortality odds ratios (SMOR) and proportional mortality ratios (PMR) revealed significant excesses of gastrointestinal malignancies. The proportional mortality excess for stomach cancer among white men was greatest among those with more than 10 years' exposure in the major grinding group (PMR = 13/3.8 = 3.39; P less than .001). The SMOR by logistic regression for stomach cancer among white men was 2.3 (P = .02) for 25 years' grinding experience. For cancer of the pancreas among white men, there were significant associations with both machining and grinding jobs in straight oil (SMOR = 9.9 and 3.2, respectively, for 25 years duration). These findings could not be explained by confounding due to the ethnic background of the decedents. This study confirms previous evidence that grinding operations using water-based cutting fluids increase the risk for stomach cancer and provides moderate evidence that exposures to straight oil-cutting fluids increase the risk for cancer of the pancreas. There were indications, meriting further investigation, that non-malignant liver disease is associated with cutting fluid exposures and that lung cancer is associated with oil smoke from operations such as forging or heat treating

A cohort of 334 intravenous (IV) drug users from New York City drug treatment programs were followed over a mean 9-month period. Among the 165 who were seropositive at enlistment, four developed clinical AIDS, for an annual rate of 3%. Elevated IgA was a significant predictor of developing AIDS. Among 72 subjects who were initially seronegative and who were re-interviewed, four were seropositive at follow-up, for a seroconversion rate of 7% per year among seronegatives. Among seropositive subjects who did not develop AIDS or fatal AIDS related complex (ARC), continued drug injection was associated with rate of T4 cell loss, and there was a non-significant trend for males to lose T4 cells more rapidly than females. While it was not possible to distinguish the mechanism underlying the relationship between continued drug injection and T4 cell loss, seropositive IV drug users should be warned that continued injection may lead to increased HIV-related immunosuppression as well as, if injection equipment is shared, risking viral transmission to others

Sera from 4,652 children whose blood was submitted to the New York City Department of Health for lead analysis were tested for antibodies to Toxocara canis using an enzyme-linked immunosorbent assay (ELISA). Standardized to the age distribution of the study population, T. canis seropositivity (inverse titers greater than or equal to 16) was 5.7 per cent in males and 5.1 per cent in females. T. canis antibody titers and lead exposures as measured by Centers for Disease Control lead classes were positively correlated. Children who were seropositive to T. canis (cases) were compared to seronegatives (controls) matched on age (+/- 6 months), sex, time-of-screening (+/- 3 months) and CDC lead class. Logistic regression analysis of 155 case-control pairs demonstrated elevated relative risks (RRs) for geophagia (RR = 3.14; 95% CI = 1.75, 5.64) and having had a litter of puppies in the home (RR = 5.22; 95% CI = 1.63, 16.71). Compared to controls, cases had increased eosinophil counts, serum immunoglobulin E concentrations, and anti-hemagglutinin-A titers. Small deficits in cases compared to controls were found in performance on several neuropsychological tests after adjustment for potential confounders including case-control differences in race, socioeconomic status, and current blood lead concentrations. The study thus confirmed that T. canis infection is common in urban children and suggested that infection may be associated with adverse neuropsychological effects.

We report here the results of a survey of 308 intravenous drug abusers recruited from hospital-based methadone maintenance or drug detoxification programmes located in Manhattan, New York City. Complete interviews and serological analyses for antibodies to human immunodeficiency virus (HIV) using both enzyme-linked immunosorbent and Western blot assays were obtained from 290 (94%) of the subjects. HIV antibodies were found by both assays in 147 (50.7%) of the tested subjects; conflicting results were found in three (1%) of the subjects; and negative results on both tests were found in 140 (48.3%) of the subjects. Logistic regression analysis identified significant relative risks for HIV infection associated with the frequency of drug injection and the proportion of injections in 'shooting galleries'. Additional risk among men was associated with a history of homosexual relations. Traditional efforts taken by subjects to clean syringes between uses, such as washing with water or alcohol, showed no evidence of being protective. Programmes aimed at prevention of HIV infection should focus on reducing use of shooting galleries and sharing of needles and syringes as well as reducing intravenous drug abuse generally