Enhanced Humoral Responses Induced by Targeting of Antigen to Murine Dendritic Cells

Dendritic cells (DCs) are superior in their ability to induce and control adaptive immune responses. These qualities have motivated the hypothesis that targeted delivery of antigen to DCs in vivo may be an effective way of enhancing immunization. Recent results show that antigen targeted to certain DC surface molecules may indeed induce robust immune responses. Targeting of antigen to DCs can be accomplished by the means of monoclonal antibodies. This study compared the humoral responses induced in mice by in vivo targeting of DCs using monoclonal antibodies specific for CD11c, CD36, CD205, Clec6A, Clec7A, Clec9A, Siglec-H and PDC-TREM. The results demonstrate that antigen delivery to different targets on DCs in vivo gives rise to humoral responses that differ in strength. Targeting of antigen to CD11c, CD36, CD205, Clec6A, Clec7A and PDC-TREM induced significantly stronger antibody responses compared to non-targeted isotype-matched controls. Targeting of Clec9A and Siglec-H did not lead to efficient antibody responses, which may be due to unfavourable properties of the targeting antibody, in which case, other antibodies with the same specificity might elicit a different outcome. Anti-CD11c was additionally used for elucidating the impact of the route of vaccination, and the results showed only minor differences between the antibody responses induced after immunization either s.c., i.v. or i.p. Altogether, these data show that targeting of different surface molecules on DCs result in very different antibody responses and that, even in the absence of adjuvants, strong humoral responses was induced.

Amendment of arsenic and chromium polluted soil from wood preservation by iron residues from water treatment

An iron-rich water treatment residue (WTR) consisting mainly of ferrihydrite was used for immobilization of arsenic and chromium in a soil contaminated by wood preservatives. A leaching batch experiment was conducted using two soils, a highly contaminated soil (1033 mg kg(-1) As and 371 mg kg(-1) Cr) and slightly contaminated soil (22 5mg kg(-1) As and 27 mg kg(-1) Cr). Compared to an untreated reference soil, amendment with 5% WTR reduced leaching in the highly contaminated soil by 91% for Cr and 98% for As. No aging effect was observed after 103 d. In a small field experiment, soil was mixed with 2.5% WTR in situ. Pore water was extracted during 3 years from the amended soil and a control site. Pore water arsenic concentrations in the amended soil were more than two orders of magnitude lower than in the control for the upper samplers. An increased release of arsenic was observed during winter in both fields, mostly in the deepest samplers. This is likely due to the formation of a pseudo-gley because of precipitation surplus. Stabilization of arsenic and chromium contaminated soil using WTR is a promising method but the transformation of ferrihydrite in soil proves a concern in case of waterlogged soils. Still the amendment minimized the leaching of arsenic, even in cases of seasonal releases.

Transfusion-transmitted arboviruses

There exists considerable risk for transfusion transmission of arboviruses due to short periods of asymptomatic viraemia in populations with variable and sometimes extremely high incidence of arboviral infections. Aside from West Nile virus, few arbovirus transfusion transmissions have been proven, mostly due to difficulties in ruling out vector-borne transmission in recipients with arbovirus disease. Nevertheless, arbovirus transfusion risk models and assessments of viraemia prevalence in blood donations indicate substantial transfusion transmission of dengue and Chikungunya viruses in epidemic areas. Many other arboviruses, several of which are importation risks in the Americas, Europe and Asia, also cause large outbreaks and threaten transfusion safety. Prevention largely depends on excluding donors from outbreak areas or implementation of highly sensitive nucleic acid amplification tests. Because of the increasing emergence of arboviral disease globally, it is prudent to prepare for both endemic and exotic arboviruses capable of producing large epidemics and subsequent transfusion transmission risk.

West Nile virus infection and serologic response among persons previously vaccinated against yellow fever and Japanese encephalitis viruses

It is hypothesized that previous heterologous flaviviral exposure may modulate clinical illness among persons infected with West Nile virus (WNV). Little is known about the serological response in such persons. In summer 2003, a WNV outbreak occurred in Colorado, the location of the Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases (DVBID). DVBID employees, most previously vaccinated with yellow fever virus (YFV) or Japanese encephalitis virus (JEV) vaccines, were studied to determine whether previous vaccination affected symptom development among those subsequently infected with WNV during the outbreak, as well as their serological response. Serum samples collected in December 2003 and previously banked samples were tested using the plaque reduction neutralization test (PRNT) against WNV, Saint Louis encephalitis virus, dengue- 4 virus, JEV, and YFV. Specimens shown to have WNV antibody by PRNT were tested by IgM and IgG enzymelinked immunosorbent assays (ELISAs). Ten (9%) of 113 serosurvey participants had WNV neutralizing antibody titers in December 2003. PRNT titers from previous specimens showed that one of the ten had seroconverted to WNV before 2003. Of the remaining nine participants, seven reported illness in the summer of 2003, two of which were unvaccinated and five previously vaccinated. In the December 2003 specimens, five persons previously unvaccinated or vaccinated only against YFV had a fourfold or greater neutralizing titer with WNV than with other flaviviruses, whereas no persons previously vaccinated against JEV or JEV and YFV showed a similar difference in neutralizing titers. Eight of nine persons infected in 2003 had negative or indeterminate WNV MAC-ELISA results in the December 2003 sample; the ninth person was vaccinated against YFV one month previously, and was also YFV positive by MAC-ELISA. We conclude that previous flaviviral vaccination does not markedly affect the development of WNV fever and that the IgM antibody response in patients without neuroinvasive WNV disease is transient.

The seasonal distribution of campylobacter infection in nine European countries and New Zealand

In all temperate countries campylobacter infection in humans follows a striking seasonal pattern, but little attention has been given to exploring the epidemiological explanations. In order to better characterize the seasonal patterns, data from nine European countries and New Zealand have been examined. Several European countries with weekly data available showed remarkably consistent seasonal patterns from year to year, with peaks in week 22 in Wales, week 26 in Scotland, week 32 in Denmark, week 30 in Finland and week 33 in Sweden. In Europe, the seasonal peak was most prominent in Finland and least prominent in Scotland and Austria. In New Zealand the seasonality was less consistent since the peak was more prolonged. Possible explanations for the seasonal peaks are discussed. Research into the causes of campylobacter seasonality should help considerably in elucidating the sources of human infection.

West Nile virus serosurvey and assessment of personal prevention efforts in an area with intense epizootic activity: Connecticut, 2000

West Nile virus (WNV) can cause large outbreaks of febrile illness and severe neurologic disease. This study estimates the seroprevalence of WNV infection and assesses risk perception and practices regarding potential exposures to mosquitoes of persons in an area with intense epizootics in 1999 and 2000. A serosurvey of persons aged > or = 12 years was conducted in southwestern Connecticut during October 10-15, 2000, using household-based stratified cluster sampling. Participants completed a questionnaire regarding concern for and personal measures taken with respect to WNV and provided a blood sample for WNV testing. Seven hundred thirty persons from 645 households participated. No person tested positive for WNV (95% CI: 0-0.5%). Overall, 44% of persons used mosquito repellent, 56% practiced > or = two personal precautions to avoid mosquitoes, and 61% of households did > or = two mosquito-source reduction activities. In multivariate analyses, using mosquito repellent was associated with age < 50 years, using English as the primary language in the home, being worried about WNV, being a little worried about pesticides, and finding mosquitoes frequently in the home (P<0.05). Females (OR = 2.0; CI = 1.2-2.9) and persons very worried about WNV (OR = 3.8; CI = 2.2-6.5) were more likely to practice > or = two personal precautions. Taking > or = two mosquito source reductions was associated with persons with English as the primary language (OR = 2.0; CI = 1.1-3.5) and finding a dead bird on the property (OR = 1.8; CI = 1.1-2.8). An intense epizootic can occur in an area without having a high risk for infection to humans. A better understanding of why certain people do not take personal protective measures, especially among those aged > or = 50 years and those whose primary language is not English, might be needed if educational campaigns are to prevent future WNV outbreaks.

An outbreak of primary pneumonic tularemia on Martha's Vineyard

BACKGROUND

In the summer of 2000, an outbreak of primary pneumonic tularemia occurred on Martha's Vineyard, Massachusetts. The only previously reported outbreak of pneumonic tularemia in the United States also occurred on the island in 1978.

METHODS

We conducted a case-control study of adults with pneumonic tularemia and investigated the environment to identify risk factors for primary pneumonic tularemia. Patients with confirmed cases were residents of or visitors to Martha's Vineyard who had symptoms suggestive of primary pneumonic tularemia, were ill between May 15 and October 31, 2000, and had a positive laboratory test for tularemia. Controls were adults who had spent at least 15 days on Martha's Vineyard between May 15 and September 28, 2000.

RESULTS

We identified 15 patients with tularemia; 11 of these cases were primary pneumonic tularemia. Francisella tularensis type A was isolated from blood and lung tissue of the one man who died. Patients were more likely than controls to have used a lawn mower or brush cutter in the two weeks before the illness or before an interview, for controls (odds ratio, 9.2; 95 percent confidence interval, 1.6 to 68.0) and during the summer (odds ratio, undefined; 95 percent confidence interval, 1.8 to infinity). Lawn mowing and brush cutting remained significant risk factors after adjustment for other potentially confounding variables. Only one patient reported being exposed to a rabbit while cutting brush. Of 40 trapped animals, 1 striped skunk (Mephitis mephitis) and 1 Norway rat (Rattus norvegicus) were seropositive for antibodies against F. tularensis.

CONCLUSIONS

Study of this outbreak of primary pneumonic tularemia implicates lawn mowing and brush cutting as risk factors for this infection.

The Field Epidemiology Training Program (FETP) in Germany

The German Field Epidemiology Training Programme (FETP), which started in January 1996, is part of a national effort to improve research capacity for the epidemiology of infectious diseases in Germany. The aim of the two year programme is to develop a cadre of epidemiologists capable of performing outbreak investigations, epidemiological research, and surveillance at an international standard measured in articles published in international peer-reviewed journals. These epidemiologists will also be instructed to train future epidemiologists and public health personnel. The programme is similar to the Epidemic Intelligence Service (EIS) at the Centers for Disease Control and Prevention (CDC) in the United States and the European Programme for Intervention Epidemiology Training (EPIET). The German Federal Ministry for Education and Research funded the costs of a senior epidemiologist who was seconded from the CDC to help initiate this programme.

Widespread West Nile virus activity, eastern United States, 2000

In 1999, the U.S. West Nile (WN) virus epidemic was preceded by widespread reports of avian deaths. In 2000, ArboNET, a cooperative WN virus surveillance system, was implemented to monitor the sentinel epizootic that precedes human infection. This report summarizes 2000 surveillance data, documents widespread virus activity in 2000, and demonstrates the utility of monitoring virus activity in animals to identify human risk for infection.

An outbreak of pyodermas among neonates caused by ultrasound gel contaminated with methicillin-susceptible Staphylococcus aureus

OBJECTIVE

To investigate an outbreak of methicillin-susceptible Staphylococcus aureus (MSSA) infections in a neonatal clinic.

DESIGN

Prospective chart review, environmental sampling, and genotyping by two independent methods: pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). A case-control study was performed with 31 controls from the same clinic.

SETTING

A German 1,350-bed tertiary-care teaching university hospital.

RESULTS

There was a significant increase in the incidence of pyodermas with MSSA; 10 neonates in good physical condition with no infection immediately after birth developed pyodermas. A shared spatula and ultrasound gel were the only identified infection sources. The gel contained MSSA and was used for hip joint sonographies in all neonates. PFGE and RAPD-PCR patterns from 6 neonates and from the gel were indistinguishable and thus genetically related clones. The case-control study revealed no significant risk factor with the exception of cesarean section (P=.006). The attack rate by days of hip-joint sonography between April 15 and April 27, 1994, was 11.8% to 40%.

CONCLUSIONS

Inappropriate hygienic measures in connection with lubricants during routine ultrasound scanning may lead to nosocomial S. aureus infections of the skin. To our knowledge this source of S. aureus infections has not previously been described.

Hepatitis B and C among Berlin dental personnel: incidence, risk factors, and effectiveness of barrier prevention measures

A study of 215 Berlin dentists and 108 dental assistants recruited at the 1997 Berlin Dental Society meeting assessed their occupational risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. HBV vaccine coverage, and barrier prevention methods used. Among dentists, 7% (95% CI 4-11) and 0.5% (95% CI 0-3) had serological evidence of previous HBV and HCV infection, respectively. Similar figures for dental assistants were 1% (95% CI 0-5) and 0% (95% CI 0-4). Only 74% of dentists and 63% of dental assistants reported HBV vaccination. Approximately half always used gloves, eye glasses, or face masks. HBV unvaccinated dentists whose patients had HBV risk factors had a greater risk of HBV infection; those who always wore face masks were at lower risk (OR 0.2, 95% CI 0.02-0.98). These data indicate that among Berlin dentists, the HCV risk was lower than that of HBV and that face masks may have lowered the risk of HBV. The use of eye glasses or gloves did not appear to lower the risk of HBV acquisition in this population.

Developing national epidemiologic capacity to meet the challenges of emerging infections in Germany

In January 1996, the Robert Koch Institute, Germany's national public health institute, began strengthening its epidemiologic capacity to respond to emerging and other infectious diseases. Six integrated strategies were initiated: developing employee training, outbreak investigation, and epidemiologic research programs; strengthening surveillance systems; improving communications to program partners and constituents; and building international collaborations. By December 1999, five employees had completed a 2-year applied epidemiology training program, 186 health department personnel had completed a 2-week training course, 27 outbreak investigations had been completed, eight short-term research projects had been initiated, major surveillance and epidemiologic research efforts for foodborne and nosocomial infections had begun, and 16 scientific manuscripts had been published or were in press. The German experience indicates that, with a concerted effort, considerable progress in building a national applied infectious disease program can be achieved in a short time frame.

An echovirus 30 outbreak with a high meningitis attack rate among children and household members at four day-care centers

Echovirus 30 (E 30) outbreaks in defined cohorts have rarely been reported. In June 1996, an outbreak of E 30 occurred in four day-care centers (DCCs) in neighboring villages in Germany. A retrospective cohort study of DCC children, employees and household members was done to determine the extent of the outbreak and risk factors for illness. Forty-two percent (39/92) of DCC children, 13% (30/228) of their household members, 5% (1/19) of employees and 2% (1/49) of household members of employees were ill. Onsets occurred over 31 days. Thirteen percent (12/92) of DCC children had meningitis. In only one of 16 households with multiple family members ill, illness in a family member preceeded that of the DCC child. Household members of ill DCC children were 15 times more likely to report illness than those of non-ill DCC children. We conclude that this outbreak was associated with a very high incidence of meningitis, the outbreak began in the DCCs and then spread to household members, and that household members of ill children compared to those of non-ill children were much more likely to report illness.

A large outbreak of hemolytic uremic syndrome caused by an unusual sorbitol-fermenting strain of Escherichia coli O157:H-

Escherichia coli O157:H7 does not ferment sorbitol, a factor used to differentiate it from other E. coli. From December 1995 to March 1996, 28 children with hemolytic uremic syndrome in Bavaria, Germany, were identified; many had a sorbitol-fermenting (sf) E. coli O157:H- cultured. A case-control study showed a dose-response relationship between sausage consumption and illness. A second case-control study showed a relationship between mortadella and teewurst consumption and illness, particularly during December (mortadella odds ratio [OR], 10.5, P=.004; teewurst OR, 6.2, P=.02). Twelve sf O157:H- were characterized to determine clonality and virulence traits. The strains possessed the Stx2, eae, and EHEC-hlyA genes but were nonhemolytic on blood agar plates. The O157:H- isolates belonged to phage type 88 and had identical pulsed-field gel electrophoresis patterns. This outbreak was caused by sf E. coli O157:H-, which is not detectable by culture on sorbitol MacConkey's agar. Consumption of two sausages, including a raw beef-containing sausage, was statistically related to illness.

Influenza A outbreak among adolescents in a ski hostel

An outbreak of influenza A H3N2 with a high attack rate (49%) and abrupt onset (69% became ill within 2 days) occurred among 81 ski school participants who stayed in a crowded hostel in Austria in early 1997. Two students were hospitalized with pneumonia; one of them died. Cultures of blood and/or respiratory secretions from the hospitalized students yielded toxin-producing Staphylococcus aureus. Influenza A H3N2 was confirmed serologically in four participants, including one surviving hospitalized student, and by polymerase chain reaction of lung tissue from the deceased student. This investigation demonstrates that influenza can cause an explosive outbreak among skiers in a crowded hostel, leading to severe complications among previously healthy adolescents.

Applied infectious disease epidemiology in Germany

Applied epidemiology emphasizes the study of the distribution and determinants of disease and health in populations and the application of this study to the control of health problems of immediate public health consequence. Outbreak investigation symbolizes the use and methodology of applied epidemiology for public health. The steps of an outbreak investigation are summarized. Development of a network for applied infectious disease epidemiology involving health departments and other institutions is being built in Germany through epidemiologic training, building communication systems, providing support for outbreak investigation, development of national reference laboratories, and building a comprehensive research program.

Value and cost-effectiveness of screening blood donors for antibody to hepatitis B core antigen as a way of detecting window-phase human immunodeficiency virus type 1 infections. The HIV Blood Donor Study Group

BACKGROUND

The value of screening donors for antibody to hepatitis B core antigen (anti-HBc) for the prevention of posttransfusion hepatitis has declined markedly. However, anti-HBc screening may still be useful as a surrogate marker for the window period (WP) of human immunodeficiency virus type 1 (HIV-1) infection.

STUDY DESIGN AND METHODS

First, the relationship between anti-HBc reactivity and HIV-1 WP infections was examined among 225 donors who had seroconverted to anti-HIV-1 positivity between 1987 and 1990. In addition, data from 1654 HIV-1 seropositive donors were analyzed to characterize the relationship among anti-HBc reactivity, donor demographics, and HIV-1-related risk factors. The yield and cost-effectiveness of anti-HBc for HIV-1 prevention were then projected on the basis of a published decision analysis model.

RESULTS

Forty (18%) of 225 HIV-1-seroconverting donors tested anti-HBc-reactive on the donation preceding anti-HIV-1 seroconversion; in contrast, 341 (34%) of 1014 HIV-1-seropositive donors interviewed tested anti-HBc-reactive (chi-square test; p < 0.001). Anti-HBc reactivity was more common among HIV-1-seropositive donors reporting male-to-male sexual contact (169/360, 47%) and injection drug use (44/83, 53%) than among those with heterosexual contacts known to be HIV-1-positive (31/190, 16%) or transfusion exposure (3/21, 14%) or among females with no identified risk factors (21/124, 17%). The estimates of 18 to 34 percent sensitivity for anti-HBc in detecting HIV-1 WP donations and a current rate of 1 in 676,000 HIV-1 WP donations (after p24 antigen screening) suggest that continued use of anti-HBc screening could result in the transfusion of 5 to 12 fewer HIV-1-infected units per year in the United States, which would add 19 to 48 quality-adjusted years of life for the 3.5 million annual transfusion recipients at a cost of $992,020 to $2,345,000 per quality-adjusted life-year saved.

CONCLUSION

The low yield and very poor cost-effectiveness of anti-HBc screening indicate that this test is not an effective screening test for HIV-1 WP donations.

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND

This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T-lymphotropic virus via the transfusion of seronegative, infectious window-period blood.

STUDY DESIGN AND METHODS

Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window-period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window-period donations is the number of post-screening HIV-infectious donations removed by STS.

RESULTS

Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window-period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million.

CONCLUSION

STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.

Future issues in HIV/AIDS surveillance

Public health surveillance for human immunodeficiency virus (HIV) seeks to define and quantity the spectrum of HIV risk, infection, and disease at the local, state, and national levels. Reporting of cases of acquired immunodeficiency syndrome (AIDS) or HIV and seroepidemiologic surveys are the primary methods. In selected areas, this infrastructure supports supplemental systems that address issues of risk or infection beyond the scope of routine surveillance. Future concerns include maintaining the basic HIV/AIDS surveillance infrastructure, maintaining flexibility to meet emerging needs, improving surveillance for incident infections and risk behaviors, and enhancing the capacity of community-based groups to use surveillance data in setting priorities for prevention and care.

Prevalence of HIV infection in the United States, 1984 to 1992

OBJECTIVE

To estimate the number of persons infected with the human immunodeficiency virus (HIV) living in the United States and the change in HIV infection prevalence since 1984.

DESIGN

We estimated HIV prevalence from 3 data sources. We estimated past HIV infection rates from a statistical procedure based on national acquired immunodeficiency syndrome (AIDS) case surveillance data and estimates of the time from HIV infection to AIDS diagnosis. We also analyzed HIV prevalence data from 2 national surveys, a survey of childbearing woman and a household survey of current health status. We used other data sources to adjust these survey estimates to include groups not covered in the surveys.

RESULTS

Approximately 0.3% of US residents (650,000-900,000 persons) were infected with HIV in 1992. Approximately 0.6% of men (including adolescent boys > or = 13 years of age) were infected, including approximately 2% of non-Hispanic black men and 1% of Hispanic men. Approximately 0.1% of women (including adolescent girls > or = 13 years of age) were infected, including approximately 0.6% of non-Hispanic black women. Approximately half of all infected persons were men who had sex with men, and one fourth were injecting drug users. The prevalence of HIV infection increased from 1984 to 1992, with a greater relative increase among women than men.

CONCLUSIONS

The 3 different data sources and methods are consistent in estimating that 650,000 to 900,000 persons were infected with HIV in the United States in 1992. Among adolescents and adults of both sexes, the proportion infected was substantially higher among non-Hispanic blacks and Hispanics than among non-Hispanic whites. HIV-related illness will be a major clinical and public health problem in the United States for years to come.

Trends in human immunodeficiency virus seroprevalence among injection drug users entering drug treatment centers, United States, 1988-1993

National unlinked sentinel surveillance data were used to describe trends in prevalent human immunodeficiency virus infection among injection drug users entering drug treatment programs in the United States from 1988 through 1993. During this 6-year period, unlinked testing was performed on 70,882 specimens from injection drug users at 60 sentinel sites. The annual change in seroprevalence was estimated for each site by odds ratios obtained from logistic regression models fit within site-specific age and race/ethnicity subgroups. Overall trends for age and race/ethnicity subgroups across sites were described by summary odds ratios calculated using the inverse variance method. A decrease was observed among younger (age less than 30 years) whites both in areas with high (10% or higher) and low (less than 10%) prevalence, although this decrease was significant only in high-prevalence areas (odds ratio = 0.90, 95% confidence interval 0.81-0.99). Seroprevalence also decreased among older whites in high-prevalence areas, although this decrease was not significant (odds ratio = 0.95, 95% confidence interval 0.89-1.00). Seroprevalence remained stable among all other age and race/ethnicity subgroups. Stable seroprevalence among the dynamic population of injection drug users entering treatment suggests continued transmission among these individuals in both high- and low-prevalence areas of the United States.

Gabapentin, valproic acid, and ethanol intoxication: elevated blood levels with mild clinical effects

CASE REPORT

A suicidal, epileptic patient ingested ethanol, valproic acid, and gabapentin, a new antiepileptic drug. He did well clinically despite elevated blood gabapentin, valproic acid, and ethanol.

CONCLUSIONS

Preliminary data from this case and one previous report indicate relatively mild clinical signs and symptoms with gabapentin poisoning.

Estimated risk of transmission of the human immunodeficiency virus by screened blood in the United States

BACKGROUND

In the United States, transmission of the human immunodeficiency virus (HIV) by blood transfusion occurs almost exclusively when a recently infected blood donor is infectious but before antibodies to HIV become detectable (during the "window period"). We estimated the risk of HIV transmission caused by transfusion on the basis of the window period associated with the use of current, sensitive enzyme immunosorbent assays and recent data on HIV incidence among blood donors.

METHODS

We analyzed demographic and laboratory data on more than 4.1 million blood donations obtained in 1992 and 1993 in 19 regions served by the American National Red Cross, as well as the results of HIV-antibody tests of 4.9 million donations obtained in an additional 23 regions.

RESULTS

We estimated that, in the 19 study regions, 1 donation in every 360,000 (95 percent confidence interval, 210,000 to 1,140,000) was made during the window period. In addition, it is estimated that 1 in 2,600,000 donations was HIV-seropositive but was not identified as such because of an error in the laboratory. We estimated that 15 to 42 percent of window-period donations were discarded because they were seropositive on laboratory tests other than the HIV-antibody test. When these results were extrapolated to include the additional 23 Red Cross service regions, there was a risk of one case of HIV transmission for every 450,000 to 660,000 donations of screened blood. If the Red Cross centers are assumed to be representative of all U.S. blood centers, among the 12 million donations collected nationally each year an estimated 18 to 27 infectious donations are available for transfusion.

CONCLUSIONS

The estimated risk of transmitting HIV by the transfusion of screened blood is very small and nearly half that estimated previously, primarily because the sensitivity of enzyme immunosorbent assays has been improved.

Trends in HIV seroprevalence among persons attending sexually transmitted disease clinics in the United States, 1988-1992

Trends in seroprevalence of the human immunodeficiency virus (HIV) were examined among patients attending sentinel clinics for sexually transmitted diseases (STDs) throughout the United States. Cross-sectional, unlinked (blinded) surveys of HIV seroprevalence were conducted annually within clinics in 40 metropolitan areas. From 1988 to 1992, 552,665 specimens were tested in 80 STD clinics. The overall HIV seroprevalence was 33% (range among metropolitan areas: 5-52%) among gay and bisexual men, 3% (range: 0.3-11%) among heterosexual men, 2% (range: 0.1-11%) among women, and 10% (range: 0.5-45%) among heterosexual injecting drug users (IDUs). Controlling for clinic, age, and race/ethnicity, HIV seroprevalence decreased among all gay and bisexual men, but especially among white gay and bisexual men from 32% in 1989 to 22% in 1992. Among heterosexual men and women, HIV seroprevalence decreased among whites and, to a lesser degree, Hispanics, but remained essentially stable among African-Americans over time. Among heterosexual IDUs, seroprevalence was also unchanged. These results reflect changes in the HIV epidemic, which is becoming increasingly characterized by infected heterosexuals and IDUs, especially within minority populations.

Time course of detection of viral and serologic markers preceding human immunodeficiency virus type 1 seroconversion: implications for screening of blood and tissue donors

BACKGROUND

Almost all human immunodeficiency virus (HIV) transmission via blood or tissues that has occurred since anti-HIV screening was implemented in 1985 is traceable to blood given after infection but before antibody seroconversion, a time that is referred to as the window period. In this study, the performance of newer assays designed to detect viral and serologic markers soon after infection is assessed, and the reduction in the window period achieved by these assays is estimated.

STUDY DESIGN AND METHODS

Three cohort studies of persons at high risk for acquiring HIV infection were identified. These studies included well-controlled HIV type 1 (HIV-1) polymerase chain reaction (PCR) analyses of serial preseroconversion specimens from HIV-1-seroconverting homosexual men or intravenous drug users. Of 81 enrollees with anti-HIV-1 seroconversion documented by a viral lysate anti-HIV-1 enzyme immunosorbent assay (EIA) available in 1989, 13 (16%) had PCR-positive preseroconversion specimens. In the present study, sera from these 13 PCR-positive samples were further tested for anti-HIV by 10 contemporary EIAs and 6 supplemental assays, as well as being tested for plasma p24 antigen and HIV-1 RNA. Preseroconversion sera from 38 HIV-1 DNA PCR-negative cohort participants were also tested by selected anti-HIV EIAs and tested for p24 antigen and HIV-1 RNA. On the basis of these laboratory data and the intervals between blood drawing in all 81 men, the reduction in the preseroconversion window period achieved by these new assays was estimated with a mathematical model developed to analyze seroconversion data.

RESULTS

Nine (69%) of the 13 preseroconversion PCR-positive samples had anti-HIV that was detectable by one or more contemporary anti-HIV-1 or anti-HIV type 2 EIA. Supplemental antibody assays were negative on all four EIA-nonreactive preseroconversion samples and negative or indeterminate on a high proportion of the nine EIA-reactive PCR-positive samples. Eight (61%) of the 13 samples were p24 antigen-positive, and 11 (85%) were HIV-1 RNA-positive. The estimated reductions in the window period (relative to the index viral lysate-based anti-HIV EIA) were as follows: contemporary anti-HIV-1/2 EIAs, 20.3 days (95% Cl, 8.0-32.5); p24 antigen and DNA PCR, 26.4 days (95% Cl, 12.6-38.7); and RNA PCR, 31.0 days (95% Cl, 16.7-45.3).

CONCLUSION

Recent improvement in the sensitivity of anti-HIV assays has resulted in significant shortening of the preseroconversion window period. Consequently, the incremental reduction in the window period that could be achieved by implementing direct virus-detection assays has diminished significantly.

The effectiveness of the confidential unit exclusion option

BACKGROUND

The confidential unit exclusion (CUE) option is intended to reduce human immunodeficiency virus (HIV) transmission by excluding donors newly infected with HIV who have not yet developed HIV antibody (window-period donors); however, its efficacy in excluding window-period donors has not been evaluated.

STUDY DESIGN AND METHODS

The use of the CUE option was studied among the donors of 3.7 million units at 18 American Red Cross blood services regions during 1991 and 1992 and among 322 previously HIV-1-seronegative donors who subsequently donated a seropositive unit between 1987 and 1990 at 40 United States blood centers. These seroconverting donors had previously been shown to be highly likely to donate during their window period.

RESULTS

On the basis of data from these two populations, it was estimated that only 3 to 5 percent of units donated by window-period donors were not transfused because of the CUE option, that 0.4 percent of all donations were from donors who confidentially excluded their blood from transfusion, and that donors who confidentially excluded their blood were 21 times more likely to be HIV antibody-positive than donors who did not use the CUE option. It is estimated that, if all US blood centers used the CUE option, a total of 2 to 17 otherwise acceptable units donated by window-period donors would not be transfused annually.

CONCLUSION

Although donors who confidentially exclude their blood from transfusion are 21 times more likely to have HIV antibody, the rarity of window-period donors and the infrequency of confidential exclusion by window-period donors cause the CUE option to have minimal impact on transfusion safety.

Direct oral questions to blood donors: the impact on screening for human immunodeficiency virus

BACKGROUND

In December 1990, the Food and Drug Administration recommended that all United States blood centers implement a policy of asking prospective donors direct oral questions (DOQs) about human immunodeficiency virus (HIV) risk behaviors to increase the safety of the blood supply.

STUDY DESIGN AND METHODS

To evaluate the impact of the DOQ policy, HIV-related deferral and HIV seroprevalence data were analyzed at four American Red Cross blood centers for the year before the policy change and the year after. An epidemiologic analysis with stratification was conducted, including the calculation of odds ratios (OR) and 95-percent CIs.

RESULTS

Two of the four blood centers showed an overall significant increase in HIV-related deferral after implementation of the DOQ policy: OR = 4.04, (95% CI = 3.41, 4.76); OR = 2.93, (95% CI = 2.67, 3.21). The increase in HIV-related deferral was higher for women. HIV seroprevalence decreased at all four centers, including the two that did not see an increase in HIV-related deferrals. Seroprevalence declined by 14 percent in the two centers with increases in HIV-related deferral, which was neither significant nor attributable to DOQs.

CONCLUSION

Given that HIV antibody screening cannot detect HIV-seronegative (but infectious) "window-period" donations, the deferral of at-risk donors may offer some additional protection to the blood supply. However, evidence was not found of an increase in safety of the blood supply as measured by HIV seroprevalence.

Human immunodeficiency virus infection among health care workers who donate blood

OBJECTIVE

To estimate the prevalence of human immunodeficiency virus (HIV) infection among health care workers who donate blood.

DESIGN

Point prevalence survey of blood donors.

SETTING

20 U.S. blood centers that participate in an ongoing interview study of HIV-seropositive blood donors.

MEASUREMENTS

Prevalence rates for HIV in persons who reported being health care workers were measured directly for 6 of the 20 blood centers. For the other 14 centers, we derived the numerator from the interview study in the same manner used for the 6 centers; we estimated the denominator using blood collection logs at those centers and extrapolations from the survey completed at the 6 blood centers.

RESULTS

Between March 1990 and August 1991, 8519 health care workers donated blood at 6 hospitals and other medical facilities. Three persons were HIV seropositive: Two reported being health care workers and having nonoccupational risk factors for HIV infection; the occupation and other possible risk factors of the third seropositive donor could not be determined. Therefore, the highest overall prevalence of HIV infection among health care worker donors at these 6 centers was 0.04% (3 of 8519; upper limit of 95% CI, 0.1%). We estimated that during the same period, approximately 36,329 health care workers were tested for HIV at all 20 centers. Twenty-seven persons infected with HIV who donated at hospitals were identified; 7 did not return for interviews, so their health care occupations could not be verified. Thus, the highest estimated overall prevalence of HIV infection among health care worker donors at the 20 centers was 0.07% (27 of 36,329; upper limit of CI, 0.1%). Of the 20 known health care worker donors, 11 reported nonoccupational risks for HIV infection; 3 of the remaining 9 health care workers described occupational blood exposures that could have resulted in transmission of HIV.

CONCLUSIONS

Blood donors can serve as a sentinel cohort when evaluating the risk for occupationally acquired HIV infection. These findings suggest that among the many health care worker donors in this study, HIV infection attributable to occupational exposure was uncommon.

Duration of time from onset of human immunodeficiency virus type 1 infectiousness to development of detectable antibody. The HIV Seroconversion Study Group

BACKGROUND

For persons newly infected with the human immunodeficiency virus type 1 (HIV-1), the time from the onset of infectivity to the development of detectable HIV-1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV-1 transmission from HIV-1 antibody-screened blood transfusions.

STUDY DESIGN AND METHODS

To estimate the window period from infectivity to HIV-1 antibody positivity, 701 HIV-1-seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV-1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors.

RESULTS

There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV-1 risk factors or had HIV-1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV-1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV-1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV-1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV-1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log-normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days.

CONCLUSION

The window period averages 45 days, with few, if any, donors remaining infectious and seronegative for longer than 6 months.

Prevalence of antibody to the human immunodeficiency virus among clinical laboratory specimens: findings from a survey of primary care physicians

To evaluate human immunodeficiency virus type 1 (HIV-1) infection among patients of primary care physicians, we performed anonymous, unlinked HIV-1 antibody testing on leftover blood specimens submitted to 10 large commercial clinical laboratories for complete blood cell count or hematocrit determination, the most commonly ordered diagnostic tests. From January through August 1990, 55,613 specimens submitted by general internists, pediatricians, and family practitioners were sampled; 1,104 (2.0%) had HIV-1 antibody. Seroprevalence among the laboratories varied 50-fold, from 0.3 to 12.4%. The HIV-1 prevalence at each laboratory was not always consistent with the AIDS incidence in the area served by the laboratory. Overall the seroprevalence was almost eight times higher in men (3.9%) than in women (0.5%). Specimens from seropositive persons, especially from men, were unevenly distributed among the physician practices; only three practices submitted approximately 50% of all specimens from seropositive men. These data indicate that a few physicians treat the majority of HIV-1-infected primary care patients. The HIV-1 prevalence among specimens at a clinical laboratory is thus determined by whether few physicians submit specimens to that laboratory. These results could be of use, for instance, in analyzing proposals to mandate physician reporting of HIV-1 infection. The high HIV-1 prevalence among laboratory specimens underscores the potential for exposure to HIV-1-infected blood by clinical laboratory personnel and emphasizes the need for universal precautions for all blood specimens.

Guidelines for designing rapid assessment surveys of HIV seroprevalence among hospitalized patients. Centers for Disease Control and Prevention

The Centers for Disease Control and Prevention has developed guidelines for determining HIV seroprevalence among patients seeking medical care at acute-care hospitals. The guidelines enable hospital staff members to perform a simple, rapid, and inexpensive survey to determine seroprevalence among the patient population, protecting the anonymity of those who are tested. The guidelines are based on national experience with large-scale anonymous, unlinked HIV serosurveys. The data from a rapid assessment survey are particularly useful for evaluating the need to provide routine, voluntary HIV counseling and testing and treatment for HIV infection. Beyond that, such data can be used in targeting education efforts, in reinforcing the use of appropriate universal precautions, in resource allocation, and in determining the need for further studies of HIV infection among the population in the hospital catchment area.

Heterosexually acquired human immunodeficiency virus infection and the United States blood supply: considerations for screening of potential blood donors. HIV Blood Donor Study Group

The impact of heterosexual transmission of the human immunodeficiency virus (HIV) on the United States blood supply was assessed, and deferral criteria that may exclude potential donors who are at high risk for heterosexually acquired HIV infection were evaluated. Interviews were conducted with 508 HIV-seropositive blood donors from May 1, 1988, to August 31, 1989 (Phase 1), and with 472 donors from January 1, 1990, to May 31, 1991 (Phase 2), at 20 blood centers. From Phase 1 to Phase 2, the overall HIV prevalence decreased from 0.021 to 0.018 percent (p < 0.001). HIV risk factors among HIV-1-seropositive donors were similar during both study phases. Eleven percent of the men and 56 percent of the women reported as their only risk that they had a heterosexual partner who was at increased risk for HIV or was known to have HIV. These percentages were similar during both study periods. During Phase 2, 13 percent of the men and 17 percent of the women with heterosexual transmission risk had a positive serologic test for syphilis, hepatitis B core antibody, or hepatitis C antibody. Among HIV-1-seropositive donors reporting heterosexual risk, the median numbers of previous-year and lifetime sex partners for men were 2 and 30, respectively; for women, those numbers were 1 and 7, respectively. Thirty-one percent of the men and 6 percent of the women reporting heterosexual transmission risk also reported having had syphilis or gonorrhea within 3 years of donation. It is concluded that the impact of heterosexual transmission of HIV infection on transfusion safety is not worsening at this time.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in HIV prevalence among disadvantaged youth. Survey results from a national job training program, 1988 through 1992

OBJECTIVE

To describe trends in the prevalence of human immunodeficiency virus (HIV) among socially and educationally disadvantaged US youth.

DESIGN

Analysis of demographic and geographic trends of HIV infection among Job Corps students from January 1988 through December 1992.

SETTING

The Job Corps is a national training program for disadvantaged and out-of-school youth. POPULATION SCREENED: Youths aged 16 to 21 years who entered the Job Corps residential training centers during the survey period.

MAIN OUTCOME MEASURE

Trends in prevalence of HIV infection among Job Corps students stratified by sex, age, race, and region of the country.

RESULTS

Of the 269,956 Job Corps students screened, 812 (0.3%) tested positive for the antibody to HIV type 1. Seroprevalence of HIV for young men decreased from 3.6 per 1000 in 1988 to 2.2 per 1000 in 1992 (chi 2 test for trend, P < .001). Seroprevalence for young women increased from 2.1 per 1000 in 1988 to 4.2 per 1000 in 1990 (P = .001), with seroprevalence remaining stable from 1990 through 1992. The decreasing trends in HIV prevalence among men and increasing trends among women were primarily due to changes in seroprevalence in African-American students.

CONCLUSIONS

The overall prevalence of HIV infection of three per 1000 is high, given the youth of Job Corps students. The significant rise in HIV rates among female Job Corps students provides evidence of the increasing risk of infection for socioeconomically disadvantaged young women. Reasons for the declining trend in HIV prevalence among male Job Corps students are not clear. Efforts to prevent the spread of HIV infection among adolescents must focus on the group that is hardest to reach--out-of-school and impoverished youth.

Human immunodeficiency virus seroprevalence in primary care practices in the United States

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HIV seroprevalence in hospital patients in rural Georgia

To determine human immunodeficiency virus (HIV) seroprevalence among hospital patients in three rural community-based hospitals in southern Georgia, we anonymously tested patients 15 to 54 years old for antibodies to HIV-1 from residual blood specimens collected for routine diagnostic purposes. Data collected included age, sex, race, hospital service, presenting condition, physician's knowledge of HIV infection status, and discharge diagnosis. Of 1319 patients tested, seven (0.5%, 95% confidence interval = 0.2% to 1.1%) had antibodies to HIV-1. Of those seven, five had HIV infection unsuspected by their physicians, and four had an infectious disease. HIV seroprevalence was 0.5% for both men and women, 1.0% for blacks, and 0.3% for whites. HIV-positive patients were found on all hospital services. These results suggest that in rural southern Georgia hospitals, HIV should be routinely considered in the differential diagnosis of conditions that may be related to HIV. In addition, these data demonstrate a need for medical services or referral networks for HIV-related illnesses and a need for continuing HIV counseling and testing offered by local health departments in rural southern Georgia.

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.

Population-based monitoring of an urban HIV/AIDS epidemic. Magnitude and trends in the District of Columbia

OBJECTIVE

To assess the extent of the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic in the District of Columbia and demonstrate an approach to monitoring HIV infection and projecting AIDS incidence at a community level.

DESIGN

Backcalculation methods to reconstruct HIV incidence from AIDS incidence in subgroups. Results were compared with directly measured HIV seroprevalence in selected sentinel populations: childbearing women, civilian applicants for military service, and hospital patients admitted for conditions unrelated to HIV infection.

RESULTS

Between the start of the epidemic in 1980 and January 1, 1991, one in 57 District of Columbia men aged 20 to 64 years was diagnosed with AIDS. Unlike the plateau projected for the nation, AIDS incidence for the District of Columbia was projected to increase by 34% between 1990 and 1994. Models of HIV infection incidence suggested two broad epidemic waves of approximately equal size. The first occurred in men who have sex with men and peaked during the period from 1982 through 1983. The second began in the mid-1980s in injecting drug users and heterosexuals. We estimated that among District of Columbia residents aged 20 to 64 years, 0.3% of white women, 2.9% of white men, 1.6% of black women, and 4.9% of black men were living with HIV infection as of January 1, 1991. These estimates are broadly consistent with survey data: among black childbearing women in their 20s, HIV prevalence doubled to 2% between the fall of 1989 and the spring of 1991; from military applicant data, we estimated that over 5% of black men born from 1951 through 1967 were HIV-positive; in the sentinel hospital, HIV prevalence rates among male patients aged 25 to 34 years were 11.3% in white men and 16.9% in black men.

CONCLUSION

Backcalculation and surveys yielded quantitatively consistent estimates of HIV prevalence. Many injecting drug users and heterosexuals in the District of Columbia were infected after January 1, 1986. Similar monitoring of the epidemic in other localities is needed to focus efforts to reduce the incidence of HIV transmission.

Platelet aggregation and fatty acid composition of platelets in type 1 diabetes mellitus

A raised content of arachidonic acid in platelets from diabetic patients with retinopathy was found without differences in platelet aggregation: platelet aggregability was not related to platelet fatty acid composition. In diabetes, platelet aggregation was inversely correlated to non-esterified fatty acids in plasma and may suggest an inhibiting effect. Mean platelet volume was raised in the diabetic patients, but without hyperaggregability. The findings do not exclude a relationship between platelet fatty acids and platelet aggregability, but suggest that variations in levels of non-esterified fatty acids in plasma might interfere with platelet aggregation.

Human immunodeficiency virus infection in disadvantaged adolescents. Findings from the US Job Corps

OBJECTIVE--To describe the human immunodeficiency virus (HIV) epidemic among socially and educationally disadvantaged young persons in the United States.

DESIGN

-We analyzed demographic and geographic findings from the screening of Job Corps students for antibody to HIV. SETTING--The Job Corps is a federal training program for disadvantaged, out-of-school youth. POPULATION SCREENED--Residential students aged 16 to 21 years who entered the Job Corps from October 1987 through February 1990. MAIN OUTCOME MEASURE--Rates of observed HIV infection in entering students, stratified by demographic and geographic features. RESULTS--Of 137,209 Job Corps students screened, 488 were HIV seropositive (3.6 per 1000), a seroprevalence rate higher than that among military applicants of the same age. Overall seroprevalence was slightly higher in male (3.7 per 1000) than in female (3.2 per 1000) Job Corps students, but among those students aged 16 and 17 years, seroprevalence was higher among females (2.3 per 1000) than among males (1.5 per 1000) (P less than .05). For students aged 16 to 21 years, seroprevalence increased with year of age: 1.8 per 1000 per year for males and 0.7 per 1000 per year for females. Among those aged 21 years, HIV prevalence was 8.9 per 1000. For black and Hispanic students from large Northeastern cities, seroprevalence increased by 4.3 per 1000 per year of age and reached 24.8 per 1000 (one of 40) in students aged 21 years. However, among students from rural areas and small towns, HIV seroprevalence was disproportionately high in the Southeast. Compared with recently described US patients with the acquired immunodeficiency syndrome, HIV-infected students who entered the Job Corps were much more likely to be female. CONCLUSIONS--These findings show that disadvantaged, out-of-school adolescents are at high risk for HIV infection. The screening results identified surprisingly high seroprevalence in the southeastern United States and demonstrated a marked shift in the HIV epidemic to young women. Controlling the HIV epidemic among teenagers must include interventions that will reach adolescents early and outside of the formal educational system.

Human immunodeficiency virus type 1-infected blood donors: behavioral characteristics and reasons for donation. The HIV Blood Donor Study Group

Between May 1988 and September 1989, 829 human immunodeficiency virus type 1 (HIV-1)-seropositive donors were identified from 3,919,000 units of blood donated at 20 United States (US) blood centers. Of the 829,512 (62%) were interviewed to assess behavioral characteristics of the largest subgroup, men reporting sex with men, use of the confidential unit exclusion (CUE) and reasons for donation among all donors. Among 216 men reporting sex with men, 97 percent had male and 72 percent had female sexual contact since 1978. The majority identified themselves as bisexual (29%) or heterosexual (26%). Although 61 percent of 512 donors were aware of their risk behavior at donation, including 57 percent of those infected through heterosexual transmission, only 5 percent used the CUE. Reasons for donation included failure to read carefully (46%) or comprehend (15%) the deferral materials, pressure to donate (27%), a desire to be tested for HIV-1 (15%), and a reliance on screening to identify infected blood (10%). Reasons given for a perception of being at low risk included no recent risk behaviors, infrequent risk behaviors, or modification of risk behaviors. To reach high-risk donors, centers should assess whether referral materials provide necessary medical information and are clearly written for persons with diverse cultural and language backgrounds. Staff should be encouraged to avoid the use of culturally stigmatized terms and behaviors that may be perceived as high pressure.

Human immunodeficiency virus type 1-infected blood donors: epidemiologic, laboratory, and donation characteristics. The HIV Blood Donor Study Group

Transmission of human immunodeficiency virus type 1 (HIV-1) by homologous blood transfusion in the United States (US) is minimized by the deferral of potential donors who are at risk for HIV-1 infection and by the screening of all donations for HIV-1 antibody. HIV-1-seropositive donors at 20 blood centers were studied for information to be used in evaluating the safety of the US blood supply and making recommendations to increase that safety. From June 1988 to August 1989, 829 (0.04%) of 2,192,000 donors were found to be seropositive; 512 were interviewed. Of 388 seropositive men, 56 percent had had sex with men, 10 percent had used drugs intravenously, 8 percent had had sex with intravenous drug users, and 27 percent had no identified risk. Of 124 seropositive women, 58 percent had had sex with men at risk for HIV (81% of whom used drugs intravenously), 5 percent had used drugs intravenously, and 41 percent had no identified risk. Racial and ethnic minorities made up 68 percent of seropositive donors (black, 38%; Hispanic, 30%) and approximately 14 percent of all donors. The 157 persons with no identified risk had demographic characteristics and serologic test results for syphilis and hepatitis B that were more similar to those of HIV-1-seropositive donors with recognized risk than to those of seronegative donors. Three health care worker-blood donors (from an estimated 93,100 health care worker-donors) had infection that was probably acquired occupationally.(ABSTRACT TRUNCATED AT 250 WORDS)

Premarital screening for antibodies to human immunodeficiency virus type 1 in the United States. The Premarital Screening Study Group

To evaluate premarital human immunodeficiency virus (HIV) screening as an approach to AIDS prevention in the United States, we determined the HIV antibody seroprevalence in marriage license applicants in eight areas by blinded testing of blood specimens routinely collected for syphilis serology. The seroprevalences were 0.0-0.4 percent in women and 0.0-1.1 percent in men. We also examined the impact of mandatory premarital HIV screening on marriage rates in Louisiana and Illinois. In 1988, after screening began, 9 percent and 16 percent fewer marriage licenses than in the previous two years were issued in Louisiana and Illinois, respectively. We estimated that mandatory premarital screening, if adopted nationally, would cost $167,230,000. We conclude that compared with other HIV prevention programs mandatory premarital screening would be expensive and would probably have a minor impact on the HIV epidemic.

Seroprevalence rates of human immunodeficiency virus infection at sentinel hospitals in the United States. The Sentinel Hospital Surveillance Group

BACKGROUND AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Providing HIV counseling and testing services in methadone maintenance programs

Counseling about AIDS and optional confidential testing for antibody to HIV-1 have been available in state-supported methadone maintenance programs in Connecticut since 1 January 1987. In the first 2 years of the program, 2118 people received pre-test counseling. Overall, 1521 people agreed to anti-HIV-1-antibody testing and 1010 received post-test counseling. Other than the pre- and post-test counseling sessions, a total of 1600 HIV counseling sessions were conducted. This is the first statewide program for providing HIV counseling and testing in methadone maintenance programs in the United States. Our experience suggests that the prevention of both drug use and HIV-1 transmission can be integrated in drug treatment centers.