Human Immunodeficiency Virus Type 1 Seroprevalence Research Articles

Assessment of Human Immunodeficiency Virus Type 1 and Risk Practices among Female Commercial Sex Workers in Isla Margarita, Venezuela

Sexual transmission represents the principal mode of transmission for human immunodeficiency virus type 1 (HIV-1) worldwide. We examined the HIV-1 seroprevalence and risk factors for infection among 613 female commercial sex workers (FCSW) in Isla Margarita, Venezuela. Recruitment was conducted in street venues and working locations. None of the FCSW tested positive for HIV; this correlated with the low self-reported rates of sexually transmitted infections (6%), drug use (<20%), and alcohol abuse (12%). Condom use and safe-sex practices were found to be practiced regularly (>80% of time) with clients; however, such practices were found to be very uncommon in nonclient relations (<20% of the time). Understanding the sexual risk behaviors, beliefs, and drug use patterns of FCSW is important for future development of effective public prevention policies and educational campaigns aimed at decreasing the risk of infection with HIV-1 and other sexually transmitted infections among FCSW.

Female‐to‐Male Infectivity of HIV‐1 among Circumcised and Uncircumcised Kenyan Men

A lack of male circumcision has been associated with increased risk of human immunodeficiency virus type 1 (HIV-1) acquisition in a number of studies, but questions remain as to whether confounding by behavioral practices explains these results. The objective of the present study was to model per-sex act probabilities of female-to-male HIV-1 transmission (i.e., infectivity) for circumcised and uncircumcised men, by use of detailed accounts of sexual behavior in a population with multiple partnerships. Data were collected as part of a prospective cohort study of HIV-1 acquisition among 745 Kenyan truck drivers. Sexual behavior with wives, casual partners, and prostitutes was recorded at quarterly follow-up visits. Published HIV-1 seroprevalence estimates among Kenyan women were used to model HIV-1 per-sex act transmission probabilities. The overall probability of HIV-1 acquisition per sex act was 0.0063 (95% confidence interval, 0.0035-0.0091). Female-to-male infectivity was significantly higher for uncircumcised men than for circumcised men (0.0128 vs. 0.0051; P=.04). The effect of circumcision was robust in subgroup analyses and across a wide range of HIV-1 prevalence estimates for sex partners. After accounting for sexual behavior, we found that uncircumcised men were at a >2-fold increased risk of acquiring HIV-1 per sex act, compared with circumcised men. Moreover, female-to-male infectivity of HIV-1 in the context of multiple partnerships may be considerably higher than that estimated from studies of HIV-1-serodiscordant couples. These results may explain the rapid spread of the HIV-1 epidemic in settings, found throughout much of Africa, in which multiple partnerships and a lack of male circumcision are common.

Molecular Epidemiology of HIV Type 1 Isolates from the Czech Republic: Identification of an env E Subtype Case

85 GENETIC DIVERSITY is a hallmark of human immunodeficiency virus type 1 (HIV-1) biology and is generally responsible for the failure of both drug and vaccine interventions. Phylogenetic relationships based on this sequence heterogeneity have ben employed to subdivide circulating strains of HIV1 into 2 genetic groups (M and O) and at least 19 subtypes (A to J).1 Although specific subtypes tend to predominate in geographic regions (i.e., subtype B in Europe and America), increases in travel due to social±economic development and migration will lead to the spread of different HIV-1 subtypes in most countries. UNAIDS/WHO now estimates that more than 30 million people are infected with HIV-1 worldwide.2 Only 0.5% of this total were reported in eastern Europe and central Asia even though this region has experienced the most rapid increase in HIV-1 seroprevalence in the last decade. Fewer than 30,000 cases of HIV-1 infection were reported in eastern European countries in the early 1990s but this total has risen dramatically to more than 150,000 in 1997.2 Although the first HIV-1 infection in the Czech Republic was diagnosed in 1985,3 only 2000 HIV-infected individuals and fewer than 200 cumulative deaths have been reported since the beginning of the epidemic. Homosexual and intravenous drug user (IDU) transmission are responsible for most infections in the Czech Republic, but the rate of heterosexual transmission appears to be increasing.4 In this report, we have performed the first molecular characterization of HIV-1 isolates from the Czech Republic, identifying at least two different group M subtypes (B and E) of HIV-1 circulating in this country. Peripheral blood was obtained in 1997 from 22 HIV-1seropositive individuals with diverse clinical status, transmission routes, age, and sex (Fig. 1A). All patients were participating in diagnostic and research program in the National Institute of Public Health (Prague, Czech Republic). Homosexual transmission was responsible for the majority of HIV-1 infections in this sample population (Fig. 1A). Patients CZ5 and CZ19 may have contracted HIV-1 from confirmed sexual partners in Germany whereas patients CZ9 and CZ10 may have seroconverted while living in the Ukraine and South America, respectively. A sequence analysis of the HIV-1 envelope gene in all 22 samples established a possible phylogenetic relationship between HIV-1 strains found in the Czech Republic. In addition, a potential course of HIV-1 evolution in this country has been tracked, using samples from patients with different seroconversion dates scattered over the past 10 years. Proviral DNA was extracted directly from uncultured peripheral blood mononuclear cells (PBMCs) as previously described. A fragment of approximately 1.2 kb, spanning the V1±V5-coding region of gp120 (env gene), was amplified by polymerase chain reaction (PCR), using two sets of primer pairs (ED3±ED14 and ED5±ED126) for nested PCR as previously described.6 Owing to failure to amplify HIV-1 DNA from five different samples (CZ2, CZ5, CZ6, CZ7, and CZ14), we resorted to amplify a smaller segment of HIV-1 env DNA (C2±C3 region), using primer pairs ED5±ED12 and ED31±ED336 for external and nested PCR, respectively. The subtype of the env PCR products of each sample was determined using the heteroduplex mobility assay (HMA)6 and env fragments of 14 subtype-specific HIV-1 strains (belonging to subtypes A to H of group M). Nucleotide sequences between positions 7074 and 7286 (positions determined on the HIV-1-HXB2 genome, GenBank accession number K03455), corresponding to 70 amino acids in gp120env (i.e., the entire V3 loop and portions of the C2 and C3 region), were sequenced in both directions using primers E110 (5 9 -CTGTTAAATGGCAGTCTAGCAGGA-3 9 ) and E125 (5 9 -CAATTTCTGGGTCCCCTCCTGAGG-3 9 ) using the fmol method (Promega, Madison, WI).5 Nucleotide sequences were edited and translated by EDITSEQ software (DNASTAR, Madison, WI), then aligned using the CLUSTAL X version 1.63b program.8 Pairwise DNA matrices and phylogenetic analyses were performed with the MEGA version 1.02 program. As suspected, HMA results showed that 21 of 22 (95%) HIV1 isolates from the Czech Republic were most closely related to group M subtype B (data not shown). However, a specific heteroduplex of the CZ4 env sample and the clade E reference env fragments suggested a subtype E HIV-1 infection of this

Seroprevalence of human immunodeficiency virus type 1 and sexual behaviors in bisexual African-American and Hispanic men visiting a sexually transmitted disease clinic in New York City.

A cross-sectional human immunodeficiency virus type 1 (HIV-1) serosurvey was conducted between January 1988 and January 1993 at a New York City sexually transmitted disease clinic serving predominantly African-American and Hispanic patients. Overall, 14% (415/3,069) of participating men reported having sex with men; among these, only 52 (13%) were classified as "homosexual" (having had sex with men exclusively since 1978). Most men (87%) who reported having sex with other men also reported having sex with women. These included 147 (35%) "bisexuals" (sex with more than one man and at least one woman since 1978) and 216 (52%) "heterosexuals" (sex with women since 1978 and sexual contact with men before 1978 or only once thereafter). Although HIV-1 seroprevalence was highest among "homosexual" men (70%, 95% confidence interval (CI) 55-81), it was also high among "bisexual" men (35%, 95% CI 27-43) and "heterosexual" men (17%, 95% CI 13-23), and was lowest in men who reported having no male sex partners in their lifetime (9%, 95% CI 7-10). It is possible that transmission of HIV-1 from bisexual men to female sexual partners plays a greater role in heterosexual transmission than was previously recognized.

Seroepidemiology of HTLV-I in relation to that of HIV-1 in the Gauteng region, South Africa, using dried blood spots on filter papers.

The seroprevalence of human T-lymphotropic virus type I (HTLV-I), in relation to that of human immunodeficiency virus type I (HIV-1), was determined in a comparative unlinked anonymous antenatal and neonatal (for indirect measurement of maternal antibodies) serosurvey in the Gauteng region of South Africa, using dried blood spots (DBS) and modified particle agglutination assays. Samples were confirmed to be antibody positive by western blot. A total of 2582 DBS collected during 1993 and 1994 from subjects of African, European and coloured origin were tested. Ten were confirmed as positive for HTLV-I and 128 for HIV-1. No antibodies to HTLV-I or HIV-1 were demonstrated in the 221 women of European and coloured origin who were screened. The HTLV-I seroprevalence rate in subjects of African origin appeared to increase from 0% in 1993 to 0.49% in 1994, while HIV-1 seroprevalence rates of 5.2% and 5.4% were recorded for 1993 and 1994 respectively. No significant differences in HTLV-I and HIV-1 seroprevalence rates were noted for the two areas investigated. These results indicate that HTLV-I should be included in infection control programs, and provide baseline data for monitoring the possible spread of HTLV-I in the heterosexual population in this region.

Seroprevalence of Human T Cell Lymphotropic Virus Type II Infection, with or without Human Immunodeficiency Virus Type 1 Coinfection, among US Intravenous Drug Users

Seroprevalence of human T lymphotropic virus (HTLV) and human immunodeficiency virus type 1 (HIV-1) was determined among 7841 intravenous drug users (IVDUs) from drug treatment centers in Baltimore, Chicago, Los Angeles, New Jersey (Asbury Park and Trenton), New York City (Brooklyn and Harlem), Philadelphia, and San Antonio, Texas; 20.9% had evidence of HTLV infection, as determined using a p21e EIA for screening and p21e blot for confirmation. With a type-specific EIA and blot used in combination, HTLV-II was identified in 97.6% of HTLV-positive IVDUs whose sera could be subtyped. HIV-1 seroprevalence was 13.2%. HTLV-II without HIV-1 was most common in Los Angeles and San Antonio. HIV-1 without HTLV-II was most common in New York, New Jersey, and Baltimore. Dual infection was most common in New York and New Jersey. Logistic regression analysis revealed that seroprevalence of HTLV-II was significantly greater with HIV-1 infection and increasing age and among women, blacks, and Mexican-Americans. In conclusion, it appears that among US IVDUs, nearly all HTLV infection is attributable to HTLV-II, and HTLV-II infection is associated with HIV-1 and sociodemographic background.

Maternal-Newborn Human Immunodeficiency Virus Infection in Harlem

To determine the prevalence of human immunodeficiency virus type 1 (HIV-1) infection and its association with illicit drug use for mothers being delivered of infants at an inner-city municipal hospital. We anonymously tested the umbilical cord blood for HIV-1 antibody of 98.1% (2971/3028) of singleton infants with birth weight greater than 500 g born during 1989 and linked the results to a maternal-infant database from which all identifying information had been removed. Overall, HIV-1 seroprevalence was 3.3% (99/2971). Among HIV-1-seropositive mothers, 79% (78/99) gave no history of ever using injected drugs. Seropositivity for HIV-1 was independently associated with history of maternal cocaine use during pregnancy (odds ratio, 3.55; 95% confidence interval, 2.18, 5.78), history of ever using injected drugs (odds ratio, 6.02; 95% confidence interval, 3.14, 11.6), positive serologic test result for syphilis during pregnancy (odds ratio, 3.37; 95% confidence interval, 1.94, 5.88), and increasing maternal age per year (odds ratio, 1.04; 95% confidence interval, 1.00, 1.09). Voluntary testing programs failed to identify 71% (70/99) of all HIV-1-infected women. Infants placed into foster care were eight times more likely to be HIV-1 seropositive than those discharged to their mothers. Most HIV-1-infected mothers seem to have acquired the infection via heterosexual transmission rather than via injected drug use. Associations of maternal HIV-1 infection with cocaine use, syphilis, and increasing age probably operate through behaviors that increase maternal risk of exposure to an HIV-1-infected sexual partner or, in the case of syphilis, also through biologic factors that may predispose to HIV-1 transmission. The failure of voluntary testing to identify most HIV-1-infected mothers provides a strong rationale for routine HIV-1 testing during pregnancy and in the newborn period.

Probability of female-to-male transmission of HIV-1 in Thailand

SummaryThe epidemic of human immunodeficiency virus type 1 (HIV-1) infection in Thailand has allowed an estimate to be made of the probability of female-to-male HIV-1 transmission per sexual contact. In a study of 1115 21-year-old male military conscripts, of whom 77 (6·9%) were HIV-1 seropositive, sex with female prostitutes was identified as the principal mode of HIV-1 transmission. With a mathematical model including data on conscript's age at first sexual contact, frequency of sex with female prostitutes, and province of origin; as well as province- specific HIV-1 seroprevalence of prostitutes, we estimated the probability of HIV-1 transmission per sexual contact to be 0·031 (95% confidence limits [CL] 0·025-0 040). Allowing for random error in the self-reported frequency of contacts, the estimate was 0·056 (95% CL 0 041-0·075). The transmission probability was significantly greater among men with a history of sexually-transmitted diseases. These estimates are substantially higher than analogous estimates made in North America. This high per-act probability of heterosexual transmission helps to explain the rapid spread of HIV-1 in the emerging epidemic in Thailand and perhaps in other countries where HIV-1 transmission is predominately heterosexual.

HIV-1 seroprevalence and risk behaviors in an urban African-American community cohort.

Previous attempts at obtaining population estimates of human immunodeficiency virus type 1 (HIV-1) seroprevalence have been beset by problems of cooperation bias. As part of the fourth round of study with an urban African-American community cohort, the following investigation was aimed at assessing HIV-1 prevalence and the relative importance of sex and drug injection as risk factors in infection. Personal interviews were conducted in the home with 364 respondents, followed by voluntary blood sample collection from 287 of these individuals. Blood assays showed a point prevalence of 8.4% HIV-1 seropositivity in this community cross section, with a higher female-to-male ratio than appears among acquired immunodeficiency syndrome (AIDS) case reports. Most infected persons were unaware and unsuspecting of their infection. First, findings underscore the need to focus on risk behaviors rather than on risk groups. Second, the smaller than 2:1 ratio of infected men to women suggests that current AIDS case reports seriously underestimate HIV-1 infection among certain cohorts of African-American women. Finally, widespread ignorance of own infected status and inaccurate risk assessment signal the substantial task for community health educators in reaching inner-city African-American men and women at risk.

Racial and ethnic differences in human immunodeficiency virus type 1 (HIV-1) seroprevalence among homosexual and bisexual men. The Multicenter AIDS Cohort Study.

To determine whether the excess prevalence of human immunodeficiency virus type 1 (HIV-1) infection in US black and Hispanic homosexual men relative to white men can be explained by differences in sociodemographic factors, history of sexually transmitted diseases, or sexual and drug-use behaviors, the authors conducted a cross-sectional analysis of baseline HIV-1 seroprevalence and HIV-1 risk factors among 4,475 non-Hispanic white, 234 Hispanic white, and 194 black homosexual men from four centers in the United States (Baltimore/Washington, DC, Pittsburgh, Chicago, and Los Angeles). HIV-1 seroprevalence was significantly higher in Hispanic men (50%; odds ratio (OR) = 1.83, 95% confidence interval (CI) 1.41-2.39) and black men (47%; OR = 1.62, 95% CI 1.21-2.16) compared with white men (35%). Both Hispanic and black men more frequently reported a history of sexually transmitted diseases. Overall, Hispanics had the highest risk profile and blacks the lowest risk profile with respect to certain high-risk sexual behaviors (e.g., receptive anal intercourse and use of anonymous sexual partners) and recreational drug use. After multivariate adjustment, black race remained a significant independent risk factor for HIV-1 seropositivity (OR = 1.60, 95% CI 1.13-2.26), but Hispanic ethnicity was no longer statistically significant (OR = 1.17, 95% CI 0.82-1.69). Most of the excess HIV-1 prevalent infection among Hispanics was explained by their predominant recruitment from Los Angeles--the study center with the highest HIV-1 seroprevalence--and their greater prevalence of a history of sexually transmitted diseases and certain high-risk sexual practices. By contrast, adjustment for these same risk behaviors failed to explain the observed black-white differences in HIV-1 seroprevalence, and further studies are needed to elucidate the reasons for these unexplained racial differences. HIV-1 educational programs for homosexual men should take into account the behavioral differences that exist between white and minority racial/ethnic groups.

Seroprevalence of human immunodeficiency virus type 1 infection in Zambian children with tuberculosis.

Descriptions in the medical literature of human immunodeficiency virus type 1 (HIV-1) in children with tuberculosis (TB) are scanty. This study determined the seroprevalence of HIV-1 in 237 hospitalized children between the ages of 1 month and 14 years with a clinical diagnosis of TB (125 males and 112 females) and in 242 control children (149 males and 93 females). The overall HIV-1 seroprevalence rate in patients with TB was 37% (88 of 237) compared with 10.7% (26 of 242) among the control group (P < 0.00001: odds ratio 5.37, 95% confidence interval = 3.21 < 5.37 < 9.47). HIV-1 seropositivity in children with TB ranged from 53% (31 of 58) in the 12- to 18-month age group to 14% (9 of 61) in the 10- to 14-year-olds. The risk of TB attributable to HIV infection was 29%. The predominant clinical presentation in both seronegative (84.6%) and seropositive (89.7%) groups was that of pulmonary TB and there were no significant differences in clinical presentation between the two groups of patients. Only 54.8% of the patients attended follow-up clinics regularly whereas 32% were lost to follow-up within 3 months. Bacillus Calmette-Guérin vaccination coverage was 87.3% among TB patients and 90.5% in the controls. No significant differences in B. Calmette-Guérin vaccination rates between the seronegative and seropositive children were seen. Coinfection with HIV and TB in children is now one of the major public health problems in Zambian children.

High Socioeconomic Status is a Risk Factor for Human Immunodeficiency Virus Type 1 (HIV-1) Infection but Not for Sexually Transmitted Diseases in Women in Malawi: Implications for HIV-1 Control

A total of 6600 pregnant urban women attending an antenatal clinic of a major hospital in Malawi were evaluated for risk factors for human immunodeficiency virus type 1 (HIV-1) infection. HIV-1 seroprevalence was 23% and significantly (P < .001) associated with markers of heterosexual activity (history of sexually transmitted diseases [STDs], more than one sexual partner, reports of husbands with other partners, and all prevalent STDs except chlamydial infection) and higher socioeconomic status (as measured by husband's education). History of injections, scarification, and transfusions were not associated with HIV-1 infection. In two logistic regression models, higher socioeconomic status was a risk factor for HIV-1 infection (odds ratio [OR] = 2.69, P < .001) but not for STDs (OR = 0.94, P = .30). The opposite associations between HIV-1 and socioeconomic status and STDs and socioeconomic status suggest that HIV prevention strategies, in addition to STD diagnosis and treatment, should include interventions to reduce high-risk sexual activity and promote condom use.

Improving estimates of HIV-1 seroprevalence among childbearing women: use of smaller blood spots.

Nationwide, human immunodeficiency virus type 1 (HIV-1) seroprevalence surveys using dried neonatal blood specimens are critical to estimating HIV-1 seroprevalence among childbearing women. However, the noninclusion of blood specimens deemed "quantity not sufficient" (QNS) for HIV-1 antibody testing potentially introduces bias. In Wisconsin beginning in 1990, we modified the survey protocol to reduce QNS rates and assess bias introduced by QNS specimens. The HIV-1 antibody assay was modified to use four 1/8-in blood spots when a single 1/4-in blood spot could not be obtained. Both methods obtain identical blood volumes for testing. During a 27-month period, 7396 (4.8%) of 154,683 specimens were deemed QNS using 1/4-in blood spots. Of these, 6590 (89%) were of sufficient quantity to be tested using four 1/8-in blood spots; 6 (0.09%) specimens tested with 1/8-in blood spots were HIV-1 Western blot assay positive compared with 44 (0.03%) of 147,287 1/4-in specimens (odds ratio = 3.0; 95% confidence interval = 1.2, 7.4). Because noninclusion of QNS specimens potentially introduces bias, incorporating the results of HIV-1 antibody testing of QNS specimens using four 1/8-in blood spots can improve the accuracy of HIV-1 seroprevalence estimates in these serologic surveys.

Prevalence and risk determinants of human immunodeficiency virus type 2 (HIV-2) and human immunodeficiency virus type 1 (HIV-1) in west African female prostitutes.

The authors studied the prevalence and risk determinants for human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) in female prostitutes from Dakar (1985-1990), Ziguinchor (1987-1990), and Kaolack (1987-1990), Senegal, West Africa. Each cohort showed a distinct distribution of HIVs: 10.0% HIV-2 and 4.1% HIV-1 in Dakar, 38.1% HIV-2 and 0.4% HIV-1 in Ziguinchor, and 27.4% HIV-2 and 1.3% HIV-1 in Kaolack. In 1,275 female prostitutes from Dakar, increase years of sexual activity and a history of scarification were associated with HIV-2 seropositivity. In contrast, HIV-1 seroprevalence was associated with a shorter duration of prostitution and a history of hospitalization. In 278 female prostitutes from Ziguinchor, HIV-2 seroprevalence was associated with women of Guinea-Bissau nationality and increased years of sexual activity. In 157 female prostitutes from Kaolack, HIV-2 seroprevalence was associated with increased years of sexual activity and a history of never using condoms. The authors also studied the risk determinants for HIV-2 in the 1,280 Senegalese prostitutes pooled from all three sites. Controlling for ethnic group, women from Ziguinchor and Kaolack were more likely to be HIV-2 seropositive as compared with women from the Dakar site. Increased years of sexual activity were associated with HIV-2 seropositivity, while a history of excision and BCG vaccinations decreased the risk of HIV-2 infection.

Prevalence of Antibody to HIV-1 Among Entrants to US Correctional Facilities

Prevalence of antibody to the human immunodeficiency virus type 1 (HIV-1) was assessed among 10,994 consecutive male and female entrants to 10 correctional systems in the United States. The HIV-1 seroprevalence for the 10 systems ranged from 2.1% to 7.6% for men and 2.5% to 14.7% for women; seroprevalence among women was higher than among men across nine of 10 systems. Using age 25 years to divide the population, HIV-1 prevalence among young women (5.2%) was significantly higher than among young men (2.3%), but similar to that in both older women (5.3%) and older men (5.6%). Overall, HIV-1 rates for nonwhites (4.8%) were higher than those for whites (2.5%). Although categories were identified across correctional systems, which may serve to focus prevention programs, variability in rates among correctional systems indicates that program planning must take local conditions into consideration.

Risk of human immunodeficiency virus (HIV) transmission by blood transfusions before the implementation of HIV‐1 antibody screening

Little information is available regarding the risk of human immunodeficiency virus type 1 (HIV-1) infection for patients transfused before routine anti-HIV-1 screening of blood donors was instituted in March 1985. A model was developed for estimating both the proportion and the number of transfusion recipients in the San Francisco Bay area who were infected by HIV-1 during each of the 7 years preceding routine donor screening for anti-HIV-1. The model is based on analysis of 1) donation histories of HIV-1-infected donors identified at the regional blood center; 2) HIV-1 seroprevalence estimates for homosexual and bisexual men in San Francisco; and 3) HIV-1 infection and survival rates for recipients traced by the Transfusion Safety Study and Irwin Memorial Blood Centers' Look Back Program. The incidence of transfusion-associated HIV-1 infection is estimated to have risen rapidly from the first occurrence in 1978 to a peak in late 1982 of approximately 1.1 percent per transfused unit. The decrease after 1982 coincided with the implementation of high-risk donor deferral measures. It is estimated that, overall, approximately 2135 transfusion recipients were infected with HIV-1 in the San Francisco region alone. This number suggests a higher prevalence of transfusion-associated HIV-1 infection than has been generally recognized and indicates the need for continued tracing of potentially exposed recipients. The data also strongly support the effectiveness of early donor education and self-exclusion measures and emphasize the importance of continued research and development in this area.

ASSOCIATION OF DRUG INJECTION PATTERNS WITH ANTIBODY TO HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 AMONG INTRAVENOUS DRUG USERS IN BALTIMORE, MARYLAND

During 1988 and 1989, intravenous drug users recruited through extensive community outreach efforts in Baltimore, Maryland, were interviewed about drug injection and sex practices in the prior 11 years, with screening for antibody to human immunodeficiency virus type 1 (HIV-1). Neither interviewers nor subjects were aware of HIV-1 serostatus until 2 weeks after the interview. Among 2,616 intravenous drug users who last injected drug within the same calendar year as screening, HIV-1 seroprevalence was 30.1% for those with any use of shooting galleries, 23.3% for those who shared needles but did not use shooting galleries, and 16.3% for drug users who denied both needle-sharing and gallery use between 1977 and 1987. Among 608 drug users who reported persistent use of shooting galleries since 1977 or subsequent initiation into drug use, there was a tendency for HIV-1 seroprevalence to increase with more recent onset of an injection career. Combined with a milder but similar tendency among 739 drug users who reported persistent sharing of needles, and a seroprevalence of 15.1% among participants who had just started injecting drugs in the 18 months prior to baseline, these data provide indirect evidence that a high risk for HIV-1 infection might occur early during a drug injection career.

Use of Paper-Absorbed Fingerstick Blood Samples for Studies of Antibody to Human Immunodeficiency Virus Type 1 in Intravenous Drug Users

The suitability of paper-absorbed (PA) fingerstick blood specimens for antibody testing of human immunodeficiency virus type 1 (HIV-1) was examined in two populations of intravenous drug users (IVDU): 393 persons from a drop-in counseling and testing clinic and 145 from a methadone treatment clinic. From the first group, the same 66 immunoblot-confirmed enzyme immunoassay (EIA)-positive specimens were identified in sera from venipuncture and parallel fingerstick PA specimens. The latter had slightly higher EIA mean background levels resulting in 10 immunoblot-negative EIA-positive samples versus 6 in the sera group. HIV-1 seroprevalence was 17% of 393 from the drop-in clinic. By category of IVDU, the rates were 34% and 14% for active and recovering IVDU, respectively (P less than .001), and 36% in black and Latino compared with 13% in white IVDU (P less than .002). Of the 145 participants in the methadone program, 39% had antibody to HIV-1: 49% for blacks and Latinos compared with 30% in whites (P less than .01). The data indicate that antibody testing for HIV-1 by PA is equivalent to the serum antibody assay of venipuncture specimens. The fingerstick method appears to have greater use for serosurveys and screening programs because of convenience, safety, and ease of storage, transport, and processing of samples.

Seroprevalence Rates of Human Immunodeficiency Virus Infection at Sentinel Hospitals in the United States

To evaluate the epidemiology of infection with human immunodeficiency virus type 1 (HIV-1) in selected urban communities in the United States, we instituted active surveillance at sentinel hospitals by anonymous testing of samples of blood specimens for HIV-1 antibody. To reflect better the rates of HIV-1 seroprevalence in the communities served by the sentinel hospitals, we excluded specimens from all patients with diagnoses that are often associated with HIV infection. From January 1988 to June 1989, 89,547 specimens were tested at 26 hospitals in 21 cities. The overall rate of HIV-1 seroprevalence was 1.3 percent, but it ranged from 0.1 to 7.8 percent according to hospital (median, 0.7 percent). The age distribution of persons seropositive for HIV-1 was similar across hospitals and closely paralleled that of persons with the acquired immunodeficiency syndrome (AIDS). In areas of low seroprevalence, HIV-1 infections were highly concentrated among men. However, the male-to-female ratio (median, 7.0) decreased steadily with an increasing overall rate of seroprevalence (P less than 0.001); at the five hospitals with the highest rates of seroprevalence, the median male-to-female ratio was only 2.9. The median black-to-white ratio of HIV-1 seroprevalence was 1.8, but at hospitals with low rates of seroprevalence the rates in blacks and whites were nearly equal. At two hospitals in the communities with the highest prevalence of AIDS, 1.1 to 3.8 percent of adolescents 15 to 19 years old and 18 to 22 percent of all men 25 to 44 years old were seropositive for HIV-1. In these sentinel, urban populations there is tremendous variation in the rate of HIV-1 infection (over 70-fold). The very high seroprevalence at some sentinel hospitals indicates the need for routine screening for HIV-1 infection among some groups of patients, regardless of clinical presentation.

RETROVIRAL INFECTIONS (HIV-1, HIV-2, AND HTLV-I) IN RURAL NORTHWESTERN TANZANIA CLINICAL FINDINGS, EPIDEMIOLOGY, AND ASSOCIATION WITH INFECTIONS COMMON EN AFRICA

During a three-week period in March/April 1987, the authors examined 253 consecutive patients referred to a rural hospital in northwestern Tanzania. Sera were tested for antibodies to human immunodeficiency virus type 1 (HIV-1), human immunodeficiency virus type 2 (HIV-2), and human T-lymphotropic virus type I (HTLV-I), as well as for various parasites, hepatitis B virus, and Treponema pallidum. Neopterin (urinary and serum) was chosen as the immunologic parameter. In eight of the 253 patients (3.2%), a clinical diagnosis of acquired immunodeficiency syndrome (AIDS) was established. Three of the AIDS patients had HIV-1 antibodies, two had HIV-1 antigen, one had both HIV-1 and HIV-2 antibodies, and in one patient, only HIV-2 antibodies were found. The total HIV-1 and HIV-2 seroprevalence (antibodies plus antigen) was 4.3%; HTLV-I seroprevalence was 9.9%. No correlation could be found between HIV (or HTLV-I) seropositivity and raised levels of antibody to the above pathogens. There was, however, a significantly positive correlation between HIV seropositivity and history of gonorrhea, whereas a history of operations, injections, vaccinations, blood transfusions, or scarification did not influence the level of HIV seropositivity. The most frequently noted epidemiologic association with HIV seropositivity was traveling to or coming from Uganda or Rwanda. Two thirds of the studied Tanzanians had elevated neopterin levels, and all seven HIV-seropositive patients with clinical signs of AIDS had extremely high serum and urinary neopterin levels compared with HIV-seropositive patients without signs of AIDS. Increased neopterin levels reflect a stimulation of the T-cell/macrophage system.