Presence of human immunodeficiency virus (HIV) type 1, group M, non-B subtypes, Bronx, New York: a sentinel site for monitoring HIV genetic diversity in the United States.

In the United States, human immunodeficiency virus (HIV) type 1, group M, subtype B is the predominant subtype. A cross-sectional study of HIV-infected patients at the Bronx-Lebanon Hospital Center, Bronx, NY, between September 1997 and February 1998 identified 3 (1. 2%) of 252 persons infected with non-B subtypes: subtypes A and F, 1 each, and 1 potential recombinant subtype B(env)/F(prt). All 3 persons were born in the United States and tested positive for HIV antibodies between 1988 and 1997 while living in the Bronx. None reported travel to other countries, receipt of blood products, or drug injection. This study is among the first to indicate probable transmission of non-B HIV-1 subtypes in the United States. The occurrence of non-B HIV-1 subtypes in long-term US residents without a history of foreign travel may have implications for the evaluation and development of antiretroviral drugs, vaccines, and tests intended for use in the United States to diagnose HIV infection and screen blood.

Adherence to antiretroviral medications in an inner-city population.

Adherence to antiretroviral medications is essential for optimal treatment of HIV infection. We investigated nonadherence to antiretroviral medications in an inner-city population by using a confidential interview and a self-administered anonymous questionnaire. We estimated adherence on the day before and the month before the interview and asked reasons for nonadherence. Of 173 people who were taking antiretroviral medications, all participated in the confidential interview and 101 also completed the anonymous questionnaire. Results of the confidential interview and the anonymous questionnaire revealed rates of 6% and 28%, respectively, for nonadherence to any drug on the preceding day and of 11% and 39%, respectively, in the preceding month. The most common reasons for nonadherence in both methods were forgetfulness, inaccessibility of medications, and perceived or actual toxicity. On 12% of the anonymous questionnaires one reason for nonadherence was perceived or actual lack of drug efficacy: this reason was not given in any of the confidential interviews. Responses about the extent of nonadherence and the reasons for it may differ depending on the method of ascertainment. Interventions to improve adherence should focus on making medication dosages easier to remember, ensuring a continued supply of medications, and circumventing toxicities.

Presence of human immunodeficiency virus (HIV) type 1 subtype A infection in a New York community with high HIV prevalence: a sentinel site for monitoring HIV genetic diversity in North America. Centers for Disease Control and Prevention-Bronx Lebanon HIV Serosurvey Team.

To determine whether US residents are infected with subtypes of human immunodeficiency virus (HIV) type 1 other than subtype B (Western), the predominant North American subtype with a unique GPGR genetic sequence in the V3 loop, viruses from 22 HIV-infected adults were serotyped and subtyped. Twenty patients had subtype B (Western), of whom 15 had serotype B (Western), 3 had serotype A/C, 1 had serotype B (Thai), and 1 had a nontypeable serotype. Two had subtype A, both serotype A/C. Both subtype A-infected patients, only 1 of whom had been outside the United States, reported sex with persons traveling abroad, suggesting possible acquisition in the United States. Because US residents are infected with non-subtype B (Western) strains, US surveillance for HIV-1 diversity is needed to elucidate subtype-specific transmission patterns and pathogenesis and to guide evaluation and development of HIV diagnostic tests and vaccines.

Performance characteristics of a rapid HIV antibody assay in a hospital with a high prevalence of HIV infection. CDC-Bronx-Lebanon HIV Serosurvey Team.

BACKGROUND: The delay between collection of blood samples and availability of test results may be as long as 3 weeks and is one barrier to the acceptance of voluntary testing for human immunodeficiency virus (HIV) infection. Serologic tests that provide results rapidly could overcome this barrier, but the accuracy and reliability of rapid tests have not been well characterized in the United States. OBJECTIVE: To evaluate, in a "real world" setting, the performance characteristics of a rapid HIV assay that reduces the need for patients to return for counseling after the test. DESIGN: Testing of HIV antibodies by rapid and nonrapid assays and survey about risk behaviors for HIV. SETTING: A hospital in Bronx, New York, with a high prevalence of HIV-seropositive patients. PATIENTS: 837 patients who were not known to be infected with HIV, had not been admitted for conditions related to the acquired immunodeficiency syndrome, and agreed to participate in HIV testing and an interview. MEASUREMENTS: Sensitivity and specificity of a rapid HIV antibody assay based on comparisons with nonrapid assay and Western blot assay. RESULTS: According to nonrapid assays, 5.4% of patients were infected with HIV. The rapid assay was highly accurate in this sample overall: its sensitivity was 1.00, its specificity was 0.991, its positive predictive value was 0.865, and its negative predictive value was 1.00. The assay was also highly accurate in various subgroups. CONCLUSIONS: Accurate, rapid tests for HIV infection may enhance testing programs by preventing the need for delayed counseling of seronegative patients and by providing preliminary results to seropositive patients. These preliminary results may encourage patients to return for confirmatory test results and to adopt risk-reducing behaviors sooner.

Absence of human immunodeficiency virus type 2 infection among patients in a hospital serving a New York community at high risk for infection. Centers for Disease Control and Prevention/Bronx-Lebanon Hospital Center HIV Serosurvey Team.

BACKGROUND: Although human immunodeficiency virus type 2 (HIV-2) infection among United States residents is considered rare, there are US populations at high risk. Few studies have surveyed these populations with a high likelihood of infection, that is, those with high percentages of persons from HIV-2-endemic areas and high prevalences of behaviors that would allow for transmission. STUDY DESIGN AND METHODS: Patients (n = 832) enrolled in a confidential HIV serosurvey at a hospital that serves a community with a relatively high percentage of West African immigrants, drug injectors, and persons who practice high-risk sexual activity were evaluated. Sera were tested for HIV type 1 (HIV-1) and HIV-2 by rapid enzyme immunoassays, standard enzyme immunoassays and Western blots. RESULTS: Eight of 832 patients were weakly reactive to HIV-2 on rapid assay, but none was confirmed to be infected when tested by standard immunoassay and Western blot. Five of these eight were reactive to HIV-1. CONCLUSION: Weak reactivity to HIV-2 antibody on the rapid assay is best explained by cross-reactivity with HIV-1 antibody; thus, even in this population at high risk for infection, false-positive reactions are more likely than true infections. The finding that HIV-2 is absent in this population at potentially high risk for infection corroborates the findings of other studies that HIV-2 infection is rare among US residents. These results support previous recommendations that, in settings other than blood collection facilities, HIV-2 testing should be selectively offered to persons with epidemiologic risk factors.

HIV infection among patients in U.S. acute care hospitals. Strategies for the counseling and testing of the hospital patients. The Hospital HIV Surveillance Group.

BACKGROUND: Routine, voluntary testing of hospital patients for the human immunodeficiency virus (HIV) has been proposed in order to identify those with early HIV infection in a setting where there is ready access to counseling, appropriate clinical referral, evaluation, and therapy. We studied the pattern of HIV infection among patients in 20 U.S. hospitals, in order to evaluate possible national strategies for the routine, voluntary HIV counseling and testing of hospital patients. METHODS: Blood specimens remaining after clinical use from a systematically selected sample of patients at 20 hospitals in 15 U.S. cities were tested anonymously for antibody to HIV type 1 (HIV-1). Multivariate regression was used to determine which variables best predicted HIV seroprevalence in individual hospitals. Using these data, we estimated the number of HIV-positive patients in all U.S. hospitals and considered the efficiency of routine counseling and testing in different subgroups of patients and hospitals. RESULTS: From September 1989 through October 1991, 9286 of 195,829 specimens (4.7 percent) were positive for HIV-1 in the 20 hospitals. The seroprevalence of HIV at these institutions ranged from 0.2 percent to 14.2 percent. Among HIV-positive patients, 32 percent had symptomatic HIV infection or the acquired immunodeficiency syndrome (AIDS) at the time of admission or evaluation. In the 20 hospitals, HIV seroprevalence was 10.4 times (95 percent confidence interval, 8.8 to 12.0) the AIDS-diagnosis rate (the annual number of patients with new diagnoses of AIDS per 1000 discharges in 1990). In a multivariate model that included 13 hospital-specific variables, only the AIDS-diagnosis rate was associated with the hospital-specific HIV-seroprevalence rate (P less than 0.001). Using these data and the AIDS-diagnosis rates for all U.S. acute care hospitals, we estimated that 225,000 HIV-positive persons were hospitalized (95 percent confidence interval, 190,000 to 260,000) in all 5558 such hospitals in 1990, including 163,000 persons presenting with conditions other than HIV or AIDS (95 percent confidence interval, 130,000 to 196,000). In 1990, in 593 U.S. hospitals with AIDS-diagnosis rates of 1.0 or more per 1000 discharges, HIV testing of patients 15 to 54 years old (3 million patients, or 12.0 percent of all patients in U.S. acute care hospitals) would have identified an estimated 68 percent of all HIV-positive patients (110,000 patients) who were admitted with conditions other than symptomatic HIV infection or AIDS. CONCLUSIONS: We estimate that about 225,000 HIV-positive persons were hospitalized in 1990, of whom only one third were admitted for symptomatic HIV infection or AIDS. Routine, voluntary HIV testing of patients 15 to 54 years old in hospitals with 1 or more patients with newly diagnosed AIDS per 1000 discharges per year could potentially have identified as many as 110,000 patients with HIV infection that was previously unrecognized.

Methods of surveillance for HIV infection at U.S. sentinel hospitals.

The U.S. sentinel hospital surveillance system for human immunodeficiency virus (HIV) infection includes approximately 40 short-stay hospitals located in 31 metropolitan areas in the United States and Puerto Rico. Several hospitals began testing in late 1986, and additional sentinel hospitals have since been recruited. At each sentinel hospital, anonymous, unlinked testing for antibody to HIV is conducted monthly on 300 blood specimens, selected systematically and stratified by age of the patient. Specimens are excluded from patients whose reason for hospital visit on that occasion was for a medical condition associated with HIV infection or with risk factors for HIV infection, in order to limit the expected overrepresentation of HIV-infected persons among hospital patients compared with the general catchment population of the hospital. The incidence of acquired immunodeficiency syndrome (AIDS) in metropolitan areas with sentinel hospitals has been approximately twice the incidence of AIDS in the entire United States. However, while absolute levels of HIV seroprevalence should therefore be interpreted with caution, trends in the age-, sex-, and race-specific HIV seroprevalence at sentinel hospitals likely reflect trends in the communities served by the hospitals. Although concentrated in areas disproportionately affected by AIDS, sentinel hospitals will contribute seroprevalence data over time that reflect the impact of HIV infection across all age and behavioral risk groups. Sentinel hospitals will also constitute a key surveillance system to help integrate the age group-specific and risk group-specific findings from other activities in the CDC family of seroprevalence surveys.

Antitrypanosomal activity of trivalent antimonials in vitro and its significance.

The SbIII preparations available for clinical use were compared in vitro for their concentration/time/effect curves on Trypanosoma venezuelense (T. evansi), measuring decrease of motility and of parasite numbers. With these two criteria leading to similar relative results, the drugs are classified into a rapidly acting group, led by sodium emetic (AST), followed by its dimethylcysteine chelate (NAP) and Anthiomaline, and a less and more slowly acting one: Triostam, Astiban and Stibophen. The relative activity of these drugs in vitro is parallel to that encountered against Schistosoma mansoni, attributed to a similar pattern of intracellular absorption. In vivo effectiveness may depend on bioavailability of Sb in the host and the direct action on the parasite, reflected by its in vitro activity. The interplay of these two factors leads to a different in vitro/in vivo activity relationship of the antimonials even in the same host (mouse) and to its variation in other host species.