Challenges to the census: international trends and a need to consider public health benefits.

The Canadian government decision to cancel the mandatory long-form census in 2010 (subsequently restored in 2015), along with similar discussions in the United Kingdom (UK) and the United States of America (USA), have brought the purpose and use of census data into focus for epidemiologists and public health professionals. Policy decision-makers should be well-versed in the public health importance of accurate and reliable census data for emergency preparedness planning, controlling disease outbreaks, and for addressing health concerns among vulnerable populations including the elderly, low-income, racial/ethnic minorities, and special residential groups (e.g., nursing homes). Valid census information is critical to ensure that policy makers and public health practitioners have the evidence needed to: (1) establish incidence rates, mortality rates, and prevalence for the full characterization of emerging health issues; (2) address disparities in health care, prevention strategies and health outcomes among vulnerable populations; and (3) plan and effectively respond in times of disaster and emergency. At a time when budget and sample size cuts have been implemented in the UK, a voluntary census is being debated in the US. In Canada, elimination of the mandatory long-form census in 2011 resulted in unreliable population enumeration, as well as a substantial waste of money and resources for taxpayers, businesses and communities. The purpose of this article is to provide a brief overview of recent international trends and to review the foundational role of the census in public health management and planning using historical and current examples of environmental contamination, cancer clusters and emerging infections. Citing a general absence of public health applications of the census in cost-benefit analyses, we call on policy makers to consider its application to emergency preparedness, outbreak response, and chronic disease prevention efforts. At the same time, we call on public health professionals to improve published estimates of monetary benefit (via either cost-benefit or cost-effectiveness analysis) to a given public health intervention.

Three-year incidence of AIDS in five cohorts of HTLV-III-infected risk group members.

The incidence of the acquired immune deficiency syndrome (AIDS) among persons infected with human T-lymphotropic virus type III (HTLV-III) was evaluated prospectively among 725 persons who were at high risk of AIDS and had enrolled before October 1982 in cohort studies of homosexual men, parenteral drug users, and hemophiliacs. A total of 276 (38.1 percent) of the subjects were either HTLV-III seropositive at enrollment or developed HTLV-III antibodies subsequently. AIDS had developed in 28 (10.1 percent) of the seropositive subjects before August 1985. By actuarial survival calculations, the 3-year incidence of AIDS among all HTLV-III seropositive subjects was 34.2 percent in the cohort of homosexual men in Manhattan, New York, and 14.9 percent (range 8.0 to 17.2 percent) in the four other cohorts. Out of 117 subjects followed for a mean of 31 months after documented seroconversion, five (all hemophiliacs) developed AIDS 28 to 62 months after the estimated date of seroconversion, supporting the hypothesis that there is a long latency between acquisition of viral infection and the development of clinical AIDS. This long latency could account for the significantly higher AIDS incidence in the New York cohort compared with other cohorts if the virus entered the New York homosexual population before it entered the populations from which the other cohorts were drawn. However, risk of AIDS development in different populations may also depend on the presence of as yet unidentified cofactors.

Risk of human immunodeficiency virus (HIV-1) infection among laboratory workers.

In a prospective cohort study of 265 laboratory and affiliated workers, one individual with no recognized risk factors for human immunodeficiency virus type 1 (HIV-1) infection was HIV-1 seropositive at the time of entry into the study. Molecular analyses of two HIV-1 isolates derived in two independent laboratories from a blood sample from this worker showed that the isolates were indistinguishable from a genotypic form of HIV-1 present in the H9/HTLV-IIIB cell line. Exposure to this strain of virus most probably occurred during work with concentrated virus or culture fluids from virus-producing cell lines under standard Biosafety Level 3 containment. Although no specific incident leading to this infection has been identified, undetected skin contact with virus culture supernatant might have occurred. This worker was the only one found to be positive among the subgroup of 99 workers who shared a work environment involving exposure to concentrated virus. The incidence rate of 0.48 per 100 person-years exposure indicates that prolonged laboratory exposure to concentrated virus is associated with some risk of HIV-1 infection, which is comparable to the risk for health care workers experiencing a needle stick exposure. While none of the ten workers with parenteral exposure to HIV-1 in this cohort became infected, a worker in another laboratory did seroconvert following an injury with a potentially contaminated needle. Strict Biosafety Level 3 containment and practices should be followed when working with concentrated HIV-1 preparations, and further refinement of the procedures may be necessary.

HTLV-III exposure among drug users.

The Centers for Disease Control hierarchical classification of those at risk for acquired immunodeficiency syndrome (AIDS) underestimates the number of cases in which illicit drug use may play a role in the exposure to human T-cell leukemia virus type III. The immunosuppressive effects of nitrite inhalants are not sufficiently documented to elucidate their role as a cofactor in the development of AIDS. The currently available data on the immunosuppressive effects of self-administered parenteral drugs and their diluents indicate an associated elevation of immunoglobulin M, depressed helper/suppression T-cell ratios, and even damage to DNA. Illicit psychoactive drugs and their diluents may influence the virulence of the virus among parenteral drug users. An association between parenteral drug use and prostitution is not unexpected. Female prostitutes who use parenteral drugs may be at high risk for exposure to the virus and thus may transmit this infectious agent to their clients and their families.

Epidemiology of human lymphotrophic retroviruses: an overview.

The discovery of HTLV-I opened the way for the subsequent recognition of other human retroviruses. HTLV-I is linked to an aggressive T-cell cancer. The availability of a marker for the AIDS agent, HTLV-III, has substantially enhanced our ability to define the nature of the AIDS epidemic, its clinical and subclinical manifestations, and the spectrum of disease outcomes associated with this exposure. Of particular interest is the fact that there is substantial risk for AIDS and AIDS-related outcomes in virally infected individuals as detected by antibody positivity. The preliminary data from these well defined cohorts provide a basis for estimating the enormity of the AIDS epidemic as it is starting to emerge and provide an opportunity for the forward thinking health strategies necessary for dealing with a pandemic of such proportions.

AIDS in Haitian-Americans: a reassessment.

PIP: The occurrence of acquired immunodeficiency syndrome (AIDS) in Haitians and Haitian-Americans has remained an enigmatic aspect of the AIDS mystery. Although Haitians are currently classified as a high risk group, this designation has been disputed. The incidence of AIDS in recent Haitian immigrants to the US has been estimated at 84/100,000, which is lower than the 200-240/100,000 figure put forward for other risk groups. To better understand the spread of AIDS within the Haitian population, a serologic study of human T-lymphotropic virus type III (HTLV-III) seropostivity was performed on 88 healthy Haitians and 21 Haitians with AIDS in New York City. 95.2% of Haitian AIDS patients compared with only 1.1% of controls had a positive ELISA for HTLV-III infection. The low rate of seropositivity in health Haitians contrasts sharply with the prevalence of seropositivity noted in other high risk groups. For example, HTLV-III antibodies have been detected in 53% of healthy New York homosexuals and over 60% of drug users in New York and New Jersey. A likely explanation is that only a small segment of Haitian-Americans are really at risk of HTLV-III infection, and that this risk is conferred not by practices widespread in the Haitian community but by homosexuality, drug abuse, blood transfusions, or other as yet unidentified modes of transmission. Support for this thesis is provided by data from Haiti, where AIDS cases have been associated with bisexuality, an extremely high prevalence of veneral diseases, and contact with prostitutes. It is concluded that the designation of the entire Haitian community as a high risk group for AIDS may be inappropriate.^ieng

HIV-2-associated AIDS in the United States. The first case.

A 41-year-old woman from the Cape Verde Islands, Africa, who had been residing in the United States for 11 months was found to have human immunodeficiency virus type 2 (HIV-2)-associated acquired immunodeficiency syndrome (AIDS). Antibody to HIV-2 was found by enzyme immunoassay and was verified by radioimmunoprecipitation. The patient was being treated for pulmonary tuberculosis at the time of her admission to our institution. Further laboratory and clinical evaluation at our facility revealed depressed CD4 lymphocytes, oral candidiasis, and cryptococcal meningitis with indeterminate results on serologic testing for HIV type 1 (HIV-1). The biopsy specimen of a lesion in the right occipital lobe of the brain documented Toxoplasma gondii, indicating a clinical diagnosis of AIDS. To our knowledge, our study presents the first known patient with HIV-2-associated AIDS in the United States. Our patient provides further evidence that HIV-2 causes severe immunodeficiency and opportunistic infection. The condition should be suspected in the face of normal or repeatedly equivocal HIV-1 antibody test results in the presence of clinically documented AIDS.

Cross-sectional study of immunologic abnormalities in intravenous drug abusers on methadone maintenance in New York City.

One hundred and ninety-nine patients with a history of intravenous drug abuse, and enrolled on the St Luke's-Roosevelt Hospital Center Methadone Program, had baseline evaluations performed from September 1984 to April 1987. The study was designed to examine immunologic parameters associated with HIV seropositivity and those predictive of progression to AIDS-related complex (ARC) and AIDS. Sixty-four patients (32%) had antibodies to HIV by enzyme-linked immunosorbent assay (ELISA), with confirmation by Western blot and none of these patients had ARC or AIDS at the time of initial evaluation. The mean values for white blood-cell count, absolute lymphocyte count, proportion and absolute CD4, and CD4/CD8 ratio were decreased significantly in the HIV-seropositive group compared with the HIV-seronegative group. On the other hand, levels of circulating beta 2-microglobulin, SCD8, SIL-2R, and HIV p24 antigen were significantly elevated in the HIV-seropositive group compared with the HIV-seronegative group.

HTLV-I/II seroprevalence and HIV/HTLV coinfection among U.S. intravenous drug users.

Data from a continuing multiyear seroprevalence survey of human T-lymphotropic virus types I or II (HTLV-I/II) among intravenous drug users in seven U.S. locations were analyzed to detect demographic patterns of seropositivity and coinfection with human immunodeficiency virus type 1 (HIV-1). Seropositivity for HTLV-I/II and HIV-1 was detected by whole-virus enzyme immunoassay, with Western blot confirmation. Of 1,800 subjects recruited from methadone maintenance and detoxification clinics, 207 (11.5%) were infected with HTLV-I/II. Seropositivity for HTLV-I/II varied by racial group, age, sex, and geographic location. Blacks had a higher (age- and location-adjusted) infection rate (17.1%) than Hispanics (8.7%) or whites (5.6%), and seropositivity showed a strong gradient with increasing age. Females had a slightly higher rate (14.0%) than males (10.0%), after adjustment for age and location. Among the seven locations, the rate varied from approximately 1% (Miami and Baltimore) to 20% (Los Angeles), although the former rates were based on relatively few subjects (47 and 65, respectively). Overall, the occurrence of coinfection by HIV-1 and HTLV-I/II did not occur more frequently than expected by chance.

Trends in HIV infection among intravenous drug users in Innsbruck, Austria.

The first HIV test among intravenous drug users (IVDUs) at the AIDS clinic and/or the drug dependency clinic of the University of Innsbruck was the basis for the calculation of the proportions of those testing HIV seropositive annually over the period 1985-1990. The numbers testing HIV seropositive at the drug dependency clinic declined drastically, from 72.2% in 1985 to 12.5% in 1990 (chi 2 = 29.62, p less than 0.0001), whereas they rose at the AIDS clinic during this period, from 48.4% to 100% (chi 2 = 5.82, p = 0.016). Overall 132 of the 268 (49.2%) individuals examined tested HIV seropositive. There were 102 individuals of the original 146 seronegative IVDUs who were retested, for an overall incidence rate of HIV seroconversion of 5.8/100 persons-years. Risk of seroconversion was associated with a steady sexual partnership with an HIV seropositive IVDU and with an age of less than or equal to 25 years at study entry (13.1 versus 8.7/100 persons-years). No seroconversions occurred in the subgroup of patients treated by the methadone maintenance treatment program. The cumulative incidence (Kaplan-Meier) rate for HIV seropositivity after 64 months was 22%, lower than the proportions testing HIV seropositive found in 1985 at each of the two clinics, which suggests that the speed of the spread of the epidemic of HIV infection among IVDUs has slowed in our region. Counseling of IVDUs should emphasize the risks of sexual acquisition, particularly among persons with steady relationships who may not perceive their risk.

Counterimmunoelectrophoresis for detection of human serum antibody to HTLV-III.

We examined the usefulness of a counterimmunoelectrophoresis (CIE) technique for detecting antibodies to HTLV-III using sera that previously had been assessed for antibodies to HTLV-III by the standard enzyme-linked immunosorbent assay (ELISA). We selected a subset of 53 sera from patients with the acquired immune deficiency syndrome (AIDS) or the generalized lymphadenopathy syndrome (GLS) in which 81.1% were initially ELISA-positive, and 96.2% were positive by Western blot technique. In our standard HTLV-III CIE technique, 58.5% were positive and repeat testing increased the yield to 67.9%. Varying several parameters of the standard CIE assay did not improve sensitivity. We also studied 20 ELISA-negative and 10 ELISA-borderline sera from normal controls; all were negative by CIE. These results indicate that CIE may be used for detection of human serum antibodies to HTLV-III, but that the present assay was less sensitive than the HTLV-III ELISA.

Partial resistance to infection by R5X4 primary HIV type 1 isolates in an exposed-uninfected individual homozygous for CCR5 32-base pair deletion.

It is known that certain individuals remain persistently seronegative despite repeated exposure to HIV-1. Studies have shown that some exposed uninfected (EU) individuals who are homozygous for a 32-bp deletion in the CCR5 gene are resistant to infection with non-syncytium-inducing (R5) viruses. In the present investigation, we provide evidence that a highly exposed-uninfected individual with the CCR5 32-bp deletion (EUdelta32-1) also has partial resistance to syncytium-inducing (R5X4) HIV-1 viruses, when compared with unexposed-uninfected individuals with (UUdelta32-1 and UUdelta32-2) and without (UU-1 and UU-2) the 32-bp deletion. The partial resistance of EU cells was due neither to altered coreceptor expression, nor to specific mutation or deletion in the coding region of chemokine coreceptors CXCR4 and CCR3. While SDF-1, the ligand for CXCR4, blocked entry of R5X4 viruses to a similar extent in EUdelta32 and UUdelta32, there was a differential production of soluble factors by EUdelta32. Both CD4+ and CD8+ cells from EUdelta32-1 produced soluble factors that efficiently suppressed infection by HIV-1 R5X4 viruses when compared with supernatant from UUdelta32. These data provide evidence that additional soluble factors are involved in resistance to infection with R5X4 viruses.

Exposure factors for HIV-1 infection among heterosexual drug abusers in New Jersey treatment programs.

In a cross-sectional study of 926 subjects from 10 drug treatment programs conducted in 1984 in New Jersey, the seroprevalence of human immunodeficiency virus (HIV) was 35% overall; 30% in whites, 33% in hispanics, and 46% in blacks (p = 0.01 for comparison of blacks to non-blacks). Univariate analysis showed the seroprevalence of HIV was not associated with age or gender, but did correlate with frequency of cocaine or heroin injection (p trend less than 0.001); frequency of needle sharing (p trend = 0.007); and inversely with levels of education (p = 0.05). The prevalence of HIV was also inversely related to the distance of the treatment center from lower Manhattan; being highest for distances of less than 5 miles from lower Manhattan and lowest for distances of 80 miles, with intermediate rates for the intervening distances (p trend less than 0.001). In multivariate analyses, HIV seropositivity was consistently associated with the frequency of needle sharing (p = 0.02) and less than 12 years (high school level) of education (p = 0.02), but not with black race. However, blacks who shared needles less than once a month had a relative risk of 3.2 (95% CI 1.2, 7.7) while non-blacks who shared less than once a month had a relative risk of only 0.9 (95% CI 0.3, 2.4). The risk in non-blacks increased to more than twofold with more frequent needle sharing. When the analysis was stratified by gender and adjusted for needle sharing and geography, a significant twofold increased risk was observed for female (but not male) subjects who had two or more heterosexual partners compared with those who had one partner.(ABSTRACT TRUNCATED AT 250 WORDS)

Viral variability and serum antibody response in a laboratory worker infected with HIV type 1 (HTLV type IIIB).

Molecular clones of HIV-1 were obtained from isolates cultured from peripheral blood mononuclear cells (PBMCs) and directly from uncultured PBMCs from a laboratory worker accidentally infected with the HIV-1 laboratory strain, HIV-1(HTLV-IIIB). Envelope sequences corresponding to the first 752 amino acids of HIV-1(HTLV-IIIB) clone BH10 were obtained from clones of cultured virus and sequenced. Three env clones obtained shortly after infection differed among themselves at only seven nucleotide positions, resulting in one amino acid substitution and one frameshift mutation. These envelope sequences were as similar to the envelope sequences of various IIIB clones as the latter were to each other. env divergence increased over the course of infection. However, the overall diversity in env clones obtained two or more years after infection was still comparable to that among IIIB env clones from the original IIIB culture. Multiple clones of partial env gene sequences containing the V3 loop were also obtained directly from uncultured PBMCs by polymerase chain reaction amplification. The env sequences of these clones were generally similar to those of the cultured viruses. Within the V3 region, the earliest isolates retained the sequence of the HXB2 clone from IIIB. Clones obtained later showed a progressive divergence in V3. An A-to-T substitution within the GPGRAF sequence at the tip of the V3 loop was observed within 1 year after infection, and this mutation predominated in all subsequent isolates. Antibodies against the V3 loops of IIIB and divergent 1987 and 1990 LW isolates appeared simultaneously in laboratory worker serum and persisted with no significant differences in titer. Furthermore, neutralization studies with autologous sequential sera suggested selection for the A-to-T change in V3 was not due to V3-directed antibodies. These results demonstrate a surprising homogeneity among env sequences of HIV-1 from an infected laboratory worker, perhaps because the initial infection originated from a relatively homogeneous population of tissue culture-adapted virus.

A method for predicting individual HIV infection status in the absence of clinical information.

Latent structure analysis can be used to determine sensitivity and specificity rates of human immunodeficiency virus antibody assays in the absence of previous clinical or laboratory results. The technique was applied to the analysis of data obtained when a panel of serum samples, collected as part of a large-scale screening project, were subjected to four conventional bioassays (ag121, p24, gp120, and an enzyme-linked immunosorbent assay). To determine the accuracy of this statistical approach, the results of latent structure analysis were compared with the known clinical diagnoses of patients from whom the samples were taken, and nearly 100% agreement was obtained. Although a two-class latent structure model had some predictive value, a three-class model more adequately explained assay patterns. The use of the four standard assays in conjunction with the statistical methods described here would largely reduce the need for confirmatory Western blot assays in analyses of large panels of samples.

Mycoplasma genitalium infection and host antibody immune response in patients infected by HIV, patients attending STD clinics and in healthy blood donors.

Prevalence of Mycoplasma genitalium in humans is still not clear. We have developed a sensitive and specific serological assay for M. genitalium using lipid-associated membrane proteins (LAMPs) as antigens. Antibodies to LAMPs from M. genitalium showed little cross-reactivity to LAMPs from antigenically similar M. pneumoniae. For validity testing, urines from 104 patients were tested by PCR for M. genitalium. All 15 PCR+ patients had M. genitalium-LAMPs antibodies. Moreover, none of 64 antibody-negative patients were PCR+. Serological study of 1800 patients of various diseased groups and healthy blood donors showed M. genitalium was primarily a sexually transmitted microbe that infected patients with AIDS (44.0%), intravenous drugs users with or without HIV infection (42.5%), and also HIV- patients attending STD clinics (42.6%). Only 5.5% HIV- healthy blood donors and 1.3% HIV+ hemophiliacs tested positive. M. genitalium has been associated with acute non-gonococcal urethritis in male patients. However, many sexually active men and women appear to be chronically infected or colonized by the microbe without apparent clinical symptoms and may continue to transmit the organism through sexual contacts.

Risks and issues for the health care worker in the human immunodeficiency virus era.

The perception of degree of risk can vary markedly from actual risk. About 5% of the cases of AIDS and HIV infection in the United States have occurred in health care workers, a percentage that has remained stable over time. Nearly all of these infections are related to lifestyle factors, not occupational risk. The rise of occupational transmission is greatest with parenteral injuries. If there is an HIV risk to patients, it appears to be very much smaller than the risk to workers although it has received even more publicity. Apprehension exists concerning the future framework of the medical care delivery system and who will care for whom. The sensitive handling of legitimate fears and the balancing of conflicting risks will continue to be a challenging task in the decades ahead.

HIV infection and the healthcare worker.

The perception of degree of risk can vary markedly from actual risk. About 5% of the cases of AIDS and HIV infection in the United States have occurred in healthcare workers, a percentage that has remained stable over time. Nearly all of these infections are related to lifestyle factors, not occupational risk. The risk to patients appears to be very much smaller, but has received even more publicity. Apprehension exists concerning the future framework of our medical care delivery system and who will care for whom. The sensitive handling of legitimate fears and the minimization and balancing of conflicting risks will be a challenging task in the decades ahead.

Safe sex? Misconceptions, gender differences and barriers among injection drug users: a focus group approach.

Heterosexual transmission is one factor involved in the spread of the human immunodeficiency virus (HIV) within the injection drug use (IDU) population and between IDU and non-IDU individuals. Insufficient information is currently available to reduce this heterosexual transmission. As a basis for designing a questionnaire aimed at the IDU population, we conducted 5 focus groups to collect information on knowledge of and attitudes toward safe sex as held by male and female IDUs in methadone treatment. We identified misconceptions related to HIV infection, condoms, and sexual behavior. We also found gender-based differences in knowledge and learning style. Also, while individuals felt a responsibility to prevent HIV transmission, they lacked sufficient control to do so. The wide range of responses on questions concerning sexually transmitted diseases (STDs), condoms, reproductive decisions, and methods of promoting safe sex provides a basis for developing a questionnaire designed to identify and target specific subgroups for educational intervention.

PIP: Five focus groups were formed among 22 male and 16 female heterosexual intravenous drug users (IDUs) in February and March, 1991, at three methadone treatment centers in northern New Jersey. Discussion among seven to eight participants was stimulated by questions on attitudes toward and knowledge of sexual practices and sexually transmitted diseases, particularly HIV infection. The information served as part of preparations for the design of an HIV questionnaire for the IDU population. This paper reports on the focus group findings and identifies three areas of importance for questionnaire design and educational efforts: 1) misconceptions about HIV infection, condoms, and sexual terms; 2) gender differences in knowledge and learning style; and 3) the juxtaposition of awareness of responsibility with the lack of ability to use appropriate judgement. Participant characteristics were as follows: 59% Black males, 27% White males, and 14% Hispanic males, aged 20-43 years (mean of 35 years). Of the females aged 20-43 years (mean of 29 years), 44% were Black, 37% were White, and 19% were Hispanic. Most were HIV seronegative. Misconceptions existed about condoms and HIV transmission. Misconceptions traveled easily among peers. The answers to questions reflected a diversity of understanding. A variety of educational messages and approaches must be designed for specific subgroups within the drug using population. The recommendations are to use a variety of educational messages, to try to reach men, and to conduct research for finding out common characteristics of intravenous drug users who do not use condoms. Findings are reported by each of the ten questions asked. Questions pertain to why people do not use health care, what are sexual diseases, what is sexual protection, what is a condom, how to use or request use of condom, how to prevent having children, what protection is possible for couples when one member is HIV positive, what are some common sexual terms, and what can be done to prevent HIV infection.