"Peas in a pod": Oral History Reflections on Autistic Identity in Family and Community by Late-Diagnosed Adults

In this paper, we report on a participatory oral history study documenting the lives of late-diagnosed autistic adults in Australia. We interviewed 26 autistic adults about their life history and the impact of late diagnosis. All were diagnosed after the age of 35, growing up in an era when autism was not well known. Using reflexive thematic analysis, we uncovered a rich body of reflections on shared Autistic identity and identified three major themes within that data set: 'conceptualising the Autistic family', 'creating Autistic community', and 'contesting Autistic identity'. Overall, the study provides insights into the active creation of shared Autistic identity and the importance of Autistic community to these late-diagnosed autistic adults.

A capabilities approach to understanding and supporting autistic adulthood

There is little comprehensive research into autistic adulthood, and even less into the services and supports that are most likely to foster flourishing adult autistic lives. This limited research is partly because autism is largely conceived as a condition of childhood, but this focus of research has also resulted from the orthodox scientific approach to autism, which conceptualizes autistic experience almost entirely as a series of biologically derived functional deficits. Approaching autism in this way severely limits what is known about this neurodevelopmental difference, how research is conducted and the services and supports available. In this Review, we adopt an alternative research strategy: we apply Martha Nussbaum’s capabilities approach, which focuses on ten core elements of a thriving human life, to research on autistic adulthood. In doing so, we identify areas where autistic adults thrive and where they often struggle, and highlight issues to which researchers, clinicians and policymakers should respond. The resulting picture is far more complex than conventional accounts of autism imply. It also reveals the importance of engaging autistic adults directly in the research process to make progress towards genuinely knowing autism and supporting flourishing autistic lives.

The focus on functional deficits in conventional autism research constrains understanding of autistic lives. In this Review, Pellicano et al. appraise research on autistic adulthood through a capabilities lens to identify areas where autistic adults thrive, and where more research and services are needed to enhance their quality of life.

From ivory tower to inclusion: Stakeholders’ experiences of community engagement in Australian autism research

Autistic people, and other community stakeholders, are gaining increasing recognition as valuable contributors to autism research, resulting in a growing corpus of participatory autism research. Yet, we know little about the ways in which stakeholders practice and experience community engagement in autism research. In this study, we interviewed 20 stakeholders (academics, autistic people, family members/careers, research students, and service providers) regarding their experiences of community engagement in Australian autism research. Through reflexive thematic analysis of interview data, we generated four themes. First, our participants perceived academia as an “ivory tower,” disconnected from community members’ lives and priorities. Second, our participants identified that different stakeholders tended to hold different roles within their research projects: academics typically retained power and control, while community members’ roles tended toward tokenism. Third, our participants spoke of the need to “bridge the gap” between academia and the community, highlighting communication, accessibility, and planning as key to conducting effective participatory research. Lastly, participants emphasized the changing nature of autism research, describing participatory research as “the way of the future.” Our findings reflect both the progress achieved to date, and the challenges that lie ahead, as the field advances toward genuine co-production of autism research.

"I Knew She'd Get It, and Get Me": Participants' Perspectives of a Participatory Autism Research Project

Introduction

Autistic advocates and their supporters have long argued that conventional research practices provide too few opportunities for genuine engagement with autistic people, contributing to social disenfranchisement among autistic people. We recently described one attempt to develop and implement a participatory study in which a team of autistic and nonautistic researchers worked together to gather life histories from late-diagnosed autistic people. In the current study, we sought to understand the impact of this participatory approach on the participants themselves.

Methods

We spoke to 25 Australian late-diagnosed autistic adults (aged 45-72 years), who had been interviewed by an autistic researcher using an oral history approach. We asked them about their experience of being involved in that project and the research process more broadly. We thematically analyzed participants' interviews.

Results

Participants responded overwhelmingly positively to the opportunity to tell their life history, considering it illuminating and empowering. While recounting their life history was often described as "exhausting" and "draining," participants also reported feeling "supported all the way" and agreed "it was made easier because I had an autistic researcher interviewing me." One participant went so far as to say that they "probably would have dropped out [of the project] if it was run by people who weren't autistic."

Conclusions

These findings demonstrate that the benefits of coproduction to researchers and community partners extend to study participants and to the quality of the research itself. Involving autistic partners in the research process, especially in its implementation, can play a crucial role in enhancing autism research.

'A way to be me': Autobiographical reflections of autistic adults diagnosed in mid-to-late adulthood

LAY ABSTRACT

Using oral history methods, we interviewed and recorded 26 autistic adults in Australia about their life history. We wanted to better understand interviewees' self-reflections about their lives. The interviewers were autistic researchers and the interviews were analysed by autistic and non-autistic researchers. All of the adults we interviewed were born before 1975 and formally identified as autistic after age 35 years. This group of people is sometimes referred to as 'late-diagnosed autistic adults'. In general, there is not much research done about autistic adults and even less is known about those diagnosed late in life. In this article, we explore what these adults said about their sense of self and how that changed over time. These autistic adults told us about many negative experiences, including trauma, which had shaped how they think about themselves. For most, autism diagnosis had a very positive impact on their sense of self, allowing them to understand more about their own past and to feel good about their autistic identity. Previously some researchers have said that autistic people have a limited or impaired sense of self. Instead, our results show some autistic people can actually reflect deeply on their lives and their changing sense of self-identity over time.

"Just Ask Me": The Importance of Respectful Relationships Within Schools

An inclusive approach to education requires schools and educators to address the support needs and individual predispositions of all students. Our research highlights the crucial importance of effective and respectful communication with autistic students to facilitate their successful participation in schools. This paper explores the experiences of 24 autistic individuals aged 16-67 years, through synchronous semi-structured interviews and written responses. The research team comprised both autistic and allistic (non-autistic) researchers, who worked together to design the overall project, collect interview data, and analyse the data. Relationships were frequently discussed by participants and the importance of positive relationships was positioned as key to successful participation within educational contexts. Particularly damaging were assumptions made by teachers concerning individual ability based on labels given. Participants recalled ongoing challenges with resisting stereotypes and managing stigma, while trying to craft a positive autistic identity and advocate for rightful supports for their education. At the core of these negotiations were positive relationships, and teachers who asked participants what their needs were, and then listened and proactively responded to their answers. Recommendations for more positive schooling engagements with autistic young people are provided.

'I'm not just a guinea pig': Academic and community perceptions of participatory autism research

LAY ABSTRACT

Participatory research means working together (engaging) with the community that is affected by research to make decisions about that research. Participatory research is common in some fields, but it is still rare in autism research. In this study, we wanted to find out how Australian autism researchers and community members feel about participatory research. We worked with an Autistic Advisory Group to design this study, understand the results and write this article. We asked 127 people, all working on research from the Cooperative Research Centre for Living with Autism, to complete an online survey about participatory research. The survey included some questions that were answered on rating scales, and some where participants wrote their own answers. Seventy-nine people (64 researchers and 15 community members) completed most or all of the survey. The rating scales showed that most participants (82%) supported moderate or extensive community engagement in research, and most participants (72%) thought there should be more community engagement in autism research. In general, the participants rated their experiences of participatory research positively. Using the participants' own written answers, we found four main ideas: (1) participatory research is important, but difficult; (2) many people do not fully understand what participatory research is; (3) academics and community members do not work together as = and (4) research systems are not designed for participatory research. Our results suggest that autism researchers and community members want to do more participatory research, but they might need training, support and funding to do participatory research well.

Beer spoilage and low pH tolerance is linked to manganese homeostasis in selected Lactobacillus brevis strains

AIMS

Beer is a harsh medium for bacteria to survive, however, lactic acid bacteria including Lactobacillus brevis have evolved the ability to grow in beer. Here, the influence of environmental factors such as low pH, ethanol or hop content was assessed.

METHODS AND RESULTS

A transcriptomic analysis of two Lact. brevis beer-spoiling strains was performed comparing growth in nutritive media with or without the imposition of a stressor related to the beer environment. This allowed the identification of a manganese transporter encoding gene that contributes to low pH tolerance.

CONCLUSIONS

We report on the importance of a manganese transporter associated with pH tolerance and beer spoilage in Lact. brevis. The importance of manganese for Lact. brevis growth in a low pH environment was highlighted.

SIGNIFICANCE AND IMPACT OF THE STUDY

Bacterial spoilage of beer may result in product withdrawal with concomitant economic losses for the brewing industry. A limited number of genes involved in beer spoilage have been identified but none of them are universal. It is clear that other molecular players are involved in beer spoilage. The study highlights the complexity of the genetic requirements to facilitate beer spoilage and the role of multiple key players in this process.

Documenting the untold histories of late-diagnosed autistic adults: a qualitative study protocol using oral history methodology

INTRODUCTION

Receiving a diagnosis of autism in adulthood is increasingly common for a subset of individuals who were either misdiagnosed in childhood or missed out on a diagnosis altogether. This qualitative study, coproduced with autistic people, invites late-diagnosed autistic adults to share their life histories to (1) understand better the consequences of living without a diagnosis, (2) elucidate what precipitates an autism diagnosis in mid-to-late adulthood and (3) identify the perceived impact of receiving that diagnosis.

METHODS AND ANALYSIS

Oral histories have been a successful way to uncover overlooked and marginalised voices. We therefore adopt qualitative, oral history methodology in this study to understand these adults' experiences, especially of living in an era when autism was not well known. We will recruit 24 participants who will (1) have been born before 1975, (2) have received a clinical, autism diagnosis after the age of 35, (3) be English-speaking and (4) have spent most of their childhood and adulthood living in Australia. Participants will take part in four sessions, including the main, qualitative, oral history interview, through a range of possible formats to facilitate inclusion. The interview data will be analysed using reflexive thematic analysis.

ETHICS AND DISSEMINATION

The protocol has received institutional research ethics approval from Macquarie University's Human Research Ethics Committee (Ref.: 52019556310562). This study will yield understanding of the life experiences of autistic adults, especially middle-aged and older Australians, should inform more effective diagnostic practices and provide insight into the key factors that might promote resilience and enhance quality of life in autistic people. The findings will be disseminated to academic and clinical audiences through journal articles and conference presentations and to the autistic and autism communities through accessible reports. The interviews will also be prepared for digital archiving, which will enable ongoing access for future generations and communities.

Development of a respiratory virus panel test for detection of twenty human respiratory viruses by use of multiplex PCR and a fluid microbead-based assay

Virology laboratories historically have used direct fluorescent-antibody assay (DFA) and culture to detect six or seven respiratory viruses. Following the discovery of five new human respiratory viruses since 2000, there is an increasing need for diagnostic tests to detect these emerging viruses. We have developed a new test that can detect 20 different respiratory virus types/subtypes in a single 5-h test. The assay employs multiplex PCR using 14 virus-specific primer pairs, followed by a multiplexed target-specific primer extension (TSPE) reaction using 21 primers for specific respiratory virus types and subtypes. TSPE products were sorted and identified by using a fluid microsphere-based array (Universal Array; TmBioscience Corporation, Toronto, Canada) and the Luminex x-MAP system. The assay detected influenza A and B viruses; influenza A virus subtypes H1, H3, and H5 (including subtype H5N1 of the Asian lineage); parainfluenza virus types 1, 2, 3, and 4; respiratory syncytial virus types A and B; adenovirus; metapneumovirus; rhinovirus; enterovirus; and coronaviruses OC43, 229E, severe acute respiratory syndrome coronavirus, NL63, and HKU1. In a prospective evaluation using 294 nasopharyngeal swab specimens, DFA/culture detected 119 positives and the respiratory virus panel (RVP) test detected 112 positives, for a sensitivity of 97%. The RVP test detected an additional 61 positive specimens that either were not detected by DFA/culture or were positive for viruses not tested for by DFA/culture. After resolution of discordant results by using a second unique PCR assay and by using a combined reference standard of positivity, the RVP test detected 180 of 183 true positives, for a sensitivity of 98.5%, whereas DFA and culture detected only 126 of 183 true positives, for a sensitivity of 68.8%. The RVP test should improve the capabilities of hospital and public health laboratories for diagnosing viral respiratory tract infections and should assist public health agencies in identifying etiologic agents in respiratory tract infection outbreaks.

Multicenter comparison of nucleic acid extraction methods for detection of severe acute respiratory syndrome coronavirus RNA in stool specimens

The emergence of a novel coronavirus (CoV) as the cause of severe acute respiratory syndrome (SARS) catalyzed the development of rapid diagnostic tests. Stool samples have been shown to be appropriate for diagnostic testing for SARS CoV, although it has been recognized to be a heterogeneous and difficult sample that contains amplification inhibitors. Limited information on the efficiency of extraction methods for the purification and concentration of SARS CoV RNA from stool samples is available. Our study objectives were to determine the optimal extraction method for SARS CoV RNA detection and to examine the effect of increased specimen volume for the detection of SARS CoV RNA in stool specimens. We conducted a multicenter evaluation of four automated and four manual extraction methods using dilutions of viral lysate in replicate mock stool samples, followed by quantitation of SARS CoV RNA using real-time reverse transcriptase PCR. The sensitivities of the manual methods ranged from 50% to 100%, with the Cortex Biochem Magazorb method, a magnetic bead isolation method, allowing detection of all 12 positive samples. The sensitivities of the automated methods ranged from 75% to 100%. The bioMérieux NucliSens automated extractor and miniMag extraction methods each had a sensitivity of 100%. Examination of the copy numbers detected and the generation of 10-fold dilutions of the extracted material indicated that a number of extraction methods retained inhibitory substances that prevented optimal amplification. Increasing the volume of sample input did improve detection. This information could be useful for the extraction of other RNA viruses from stool samples and demonstrates the need to evaluate extraction methods for different specimen types.

Detection of severe acute respiratory syndrome coronavirus in stool specimens by commercially available real-time reverse transcriptase PCR assays

Three commercially available real-time reverse transcriptase PCR assays (the Artus RealArt HPA coronavirus LightCycler, the Artus RealArt HPA coronavirus Rotor-Gene, and the EraGen severe acute respiratory syndrome coronavirus POL assay) and three RNA extraction methodologies were evaluated for the detection of severe acute respiratory syndrome coronavirus RNA from 91 stool specimens. The assays' sensitivities were highest (58% to 75%) for specimens obtained 8 to 21 days after symptom onset. The assays were less sensitive when specimens were obtained less than 8 days or more than 21 days after the onset of symptoms. All assays were 100% specific.

Immunogenicity and adverse reactions of influenza vaccination in elderly patients given acetaminophen or placebo

The objective was to examine the antibody responses to influenza immunization in an elderly population and the effect of prophylactic acetaminophen on adverse responses due to inactivated whole virus vaccine containing influenza A (H3N2 and H1N1) and B antigens. During the autumn of 1990, 100 patients 65 years or older were immunized and randomly allocated to receive placebo or 1,950 mg (2 x 975 mg) of acetaminophen. They recorded any local and systemic side effects over a 3-day period. Serology was performed on pre- and post (4-6 weeks) -vaccination sera. Age and gender distribution in the study were: 47% who were 75 years or older, and 61% of the patients were female. Most of the patients (97%) had pre-existing antibodies to Influenza A or B. Average peak preimmunization antibody titers were 40 to B Yamagata and A Taiwan (H1N1) and 80 for A Shanghai (H3N2). Half of each treatment group had a 4-fold or greater rise in antibody titer in response to the vaccine. Only 30% of patients immunized the previous year but 80% of those never vaccinated previously demonstrated a 4-fold or greater serological response to the vaccine. However, measurement of protection rates (HI >/= 40) before and after vaccination indicated 81.1-100% protection for the 3 viruses not influenced by treatment, gender or a history of previous vaccination. Both treatment groups had equally small numbers of patients who recorded systemic symptoms of drowsiness, myalgia, fever and chills and about 50% had arm soreness. Although about 80% of previously unimmunized adults mounted a 4-fold antibody rise to influenza vaccine antigens whereas booster effects were seen in only 30% of those immunized the previous year, protection rates were high (81-100%) after immunization and were not affected by acetaminophen treatment. Adverse effects (15% systemic and 50% local) were not ameliorated by 1950 mg of acetaminophen in these elderly patients.

Correlation between culture testing of swabs and ligase chain reaction of first void urine from patients recently treated for Chlamydia trachomatis

We assessed the correlation between ligase chain reaction (LCR) on first void urine (FVU) and cultures of urethral and cervical swabs to detect chlamydia during three post-treatment follow up visits for 10 men and 19 women with genital chlamydial infections who had been treated with azithromycin or doxcycline.

Impact of urine collection order on the ability of assays to identify Chlamydia trachomatis infections in men

BACKGROUND

Noninvasive urine samples have been used to diagnose Chlamydia trachomatis infections, with the assumption that the first-void urine (FVU), defined as the first 20 to 30 ml at any micturition, would be the optimal collection. We compared testing technologies on first, second, and third volumes for diagnosis.

GOAL

The goal was to test in nonculture assays three sequential volumes of urine from men also undergoing urethral swabbing for C trachomatis culture specimens.

STUDY DESIGN

A total of 237 men attending an STD clinic (C trachomatis prevalence, 11%) collected three containers of urine (each containing 20-30 mL) for testing in four nonculture assays. A urethral swab specimen was tested in cell culture.

RESULTS

The numbers of men positive by testing of FVU with nucleic acid amplification (LCx chlamydia), nucleic acid hybridization (PACE 2), enzyme immunoassay (Chlamydiazyme), and a leukocyte esterase dipstick were 26, 7, 14, and 11, respectively; urethral culture identified 6 of the infected men. Comparative testing of all voids from the 26 men positive by the FVU assays demonstrated a reduction of LCx-positives. Non-amplified-test positivity declined precipitously in subsequent voids, approaching zero in the third void. The presence of symptoms and time of last void up to 8 hours had little effect on the number of positives detected by LCx of FVU.

CONCLUSION

Amplified testing of FVU was most effective for diagnosing infection in these men.

Specimen processing and concentration of Chlamydia trachomatis added can influence false-negative rates in the LCx assay but not in the APTIMA Combo 2 assay when testing for inhibitors

Inhibitors in clinical specimens can be detected by adding the target of nucleic acid amplification to the sample. Introduction of a Chlamydia trachomatis L2 434 preparation containing 12 elementary bodies (EBs) into first-void urine (FVU) from 225 nonpregnant women and 190 pregnant women before specimen processing by the assays produced false-negative rates of 0.48% (2 of 415 specimens) and 13% (44 of 338 specimens) by the APTIMA Combo 2 and the Chlamydia LCx tests, respectively. Reducing the amount of C. trachomatis added to one EB, a concentration closer to the APTIMA Combo 2 test cutoff, for a subset of 244 FVU specimens increased the number of specimens with false-negative results by the APTIMA Combo 2 assay to 7 (2.9%), suggesting that the strength of the input C. trachomatis per specimen has an influence on the number of specimens with false-negative results. Repeat testing after overnight storage and dilution decreased the APTIMA Combo 2 test false-negative rates to 0% (0 of 415 specimens) with the stronger inoculum and 0.8% (2 of 244 specimens) with the weaker inoculum; the false-negative rate of the LCx assay was reduced to 5.4% (18 of 334 specimens). When an additional 70 FVU specimens from women to which 12 EBs were added before specimen processing were tested by the LCx assay, 34 specimens had false-negative results, whereas 21 specimens had false-negative results when the C. trachomatis EBs were introduced after processing. Nine of the 21 specimens to which EBs were added after processing and all of the 34 urine specimens to which the target was added before processing remained falsely negative on repeat testing at a 1:2 dilution, suggesting that input C. trachomatis DNA was lost during processing by the LCx assay. In contrast, the APTIMA Combo 2 assay appears to have a higher sensitivity and either lost little nucleic acid during processing or demonstrated few problems with inhibitors of transcription-mediated amplification.

Accuracy of results obtained by performing a second ligase chain reaction assay and PCR analysis on urine samples with positive or near-cutoff results in the LCx test for Chlamydia trachomatis

Nucleic acid amplification assays such as the ligase chain reaction and PCR have encountered reproducibility problems. The initial extract and a newly extracted aliquot of urine specimens (n = 120) which had signal-to-cutoff (S/CO) ratios above 0.80 by the LCx Chlamydia assay were retested. Nucleic acid was extracted from an additional urine sample for testing by the AMPLICOR PCR Chlamydia assay. Fifteen percent (18 of 120) of the urine specimens were negative by all repeat tests (initial mean S/CO ratio by the LCx Chlamydia assay, 0.93; S/CO ratio range, 0.80 to 3.30). Repeat testing of the 102 specimens with possible positive results by the LCx Chlamydia assay by use of the initially extracted aliquot confirmed the results for 95 (93.1%) of the specimens; repeat testing of a newly extracted aliquot confirmed the results for 87 (85.3%) of the specimens. Twenty specimens had discordant results by the two repeat LCx Chlamydia assays. A total of 78 of 102 (76.5%) of the specimens were positive by the AMPLICOR PCR, and the AMPLICOR PCR confirmed the results for 82.1% (78 of 95) and 89.6% (78 of 87) of the specimens positive by the two repeat LCx Chlamydia assays, respectively. Some of the discrepancies observed by multiple repeat tests may have been due to specimen mislabeling or contamination during performance of the procedure rather than to the LCx Chlamydia assay. Both assays suffered from a lack of reproducibility on repeat testing with a small proportion of specimens, probably due to the presence of low levels of DNA, the presence of variable amounts of amplification inhibitors, and the loss of DNA during extraction.

Cost-effectiveness of screening swab or urine specimens for Chlamydia trachomatis from young Canadian women in Ontario

BACKGROUND

Undetected and untreated Chlamydia trachomatis infections can result in a significant health burden. Diagnostic testing refers to tests performed on patients with symptoms, whereas screening refers to testing specimens in asymptomatic patients. The goal of diagnostic testing and screening programs are early identification of infections to prevent upper tract infection and transmission to other partners.

GOAL

To compare the costs and outcomes of alternative diagnostic testing and screening programs for women ages 15 to 24 years in the province of Ontario, Canada.

STUDY DESIGN

Using outcome probabilities from the literature and a consensus group, together with the costs from insurance billing, a decision analytic model was constructed to determine the baseline risk of C trachomatis and related sequelae. Seven diagnostic testing and screening programs were compared over a 10-year period. The programs compared included the use of nucleic acid amplification assays collected from urine or endocervical swab specimens.

RESULTS

Largely because of lower sensitivity the urine-based testing or screening programs were dominated by the swab-based programs. The move from swab-based testing to a swab-based screening program for high-risk women costs $1873 per case of C trachomatis averted. Expanding the program further to include all women in Ontario between 15 and 24 years of age is considerably more costly at $5990 per case averted.

CONCLUSIONS

It is more costly and more effective to screen and treat high-risk women ages 15 to 24 years for C trachomatis than to perform only swab-based diagnostic testing on symptomatic women. Expanding the screening program to include all women ages 15 to 24 years is considerably more expensive and only moderately more effective than screening only high-risk women.

Pooling cervical swabs and testing by ligase chain reaction are accurate and cost-saving strategies for diagnosis of Chlamydia trachomatis

Specimen pooling to achieve efficiency when testing urine specimens for Chlamydia trachomatis nucleic acids has been suggested. We pooled endocervical swabs from 1,288 women and also tested individual swabs by ligase chain reaction (LCR). Out of 53 positive specimens, pools of 4 or 8 specimens missed two positives, providing 96.2% accuracy compared to individual test results. Dilution and positive-control spiking experiments showed that negative specimens with inhibitors of LCR in the pool reduced the signal. Conversely, two extra positives, detected only through pooling, were negative by individual testing but became positive after storage, suggesting that fresh positive specimens with labile inhibitors may be positive in a pool because of dilution of inhibitors. For this population of women with a 4% prevalence of C. trachomatis infection, substantial savings in cost of reagents (55 to 63%) and technologist time (50 to 63%) made pooling strategies a desirable alternative to individual testing.

The impact on accuracy and cost of ligase chain reaction testing by pooling urine specimens for the diagnosis of Chlamydia trachomatis infections

BACKGROUND AND OBJECTIVES

Nucleic acid amplification testing is the most accurate approach to diagnosing Chlamydia trachomatis infections. Our objective was to compare the accuracy and cost savings of pooling urines as opposed to individual testing.

STUDY DESIGN

Strategies of pooling urine specimens into groups of four (4x pool) or eight (8x pool) followed by testing the positive pools individually were compared to individual specimen testing to determine if significant cost savingS could be realized without compromising the sensitivity and specificity of the LCx C. trachomatis Assay (Abbott Laboratories, Abbott Park, Chicago, IL) performed in a busy private medical laboratory.

RESULTS

A total of 1,220 patient urine samples, 1,187 male (97%) and 33 female (3%), were tested using the normal LCx specimen to cutoff ratio (S/CO) of 1.0 and a decreased S/CO value of 0.2. Individual testing identified 98.2% (109/111) of positive urines. The 4x pooling maneuver identified 92.8% (103/111) of positive patients with the regular cutoff and 96.4% (107/111) when the cutoff was decreased. These values were 95.9% (47/49) and 97.9% (48/49), respectively, when eight urines were pooled. Both pooling and individual testing strategies identified all the negative samples accurately. Cost savings of pooling were calculated to be 44.5% for pools of four and 37.5% for pools of eight, applying the lowered cutoff.

CONCLUSIONS

Pooling urine specimens for testing with the C. trachomatis LCx system is a simple, accurate, and cost-saving approach that can significantly reduce the cost of amplified nucleic acid testing with minimal sacrifice of testing accuracy.

Impact of reference standard sensitivity on accuracy of rapid antigen detection assays and a leukocyte esterase dipstick for diagnosis of Chlamydia trachomatis infection in first-void urine specimens from men

A total of 128 previously frozen first-void urine (FVU) specimens from selected asymptomatic men were centrifuged and tested by three Chlamydia trachomatis rapid antigen detection tests and with a leukocyte esterase (LE) dipstick. When the results were compared to those of a reference standard of positivity determined by the Chlamydiazyme enzyme immunoassay as confirmed by a blocking assay, the sensitivities of the Testpack Chlamydia (Abbott), Clearview Chlamydia (Unipath), and Surecell Chlamydia (Kodak) tests and the LE dipstick test were 76.4, 76.4, 67.3, and 88.6%, respectively. Use of the ligase chain reaction (LCR), whose results were confirmed by direct fluorescent-antibody staining of elementary bodies, as the reference standard reduced the sensitivities to 70.9, 67.7, 62.9, and 87.5%, respectively. The specificities by use of LCR as the reference standard were 95.5, 95.5, 100, and 92.4%, respectively. These rapid chlamydial antigen tests performed reasonably well with FVU specimens, but the simple LE dipstick test, which had the highest sensitivity, would have enabled treatment of the greatest number of infected male patients.

The clinical utility of CMV surveillance cultures and antigenemia following bone marrow transplantation

At our institution, the cytomegalovirus (CMV) prophylaxis protocol for allogeneic bone marrow transplant (BMT) recipients who are CMV-seropositive or receive marrow from a CMV-seropositive donor consists of a surveillance bronchoscopy approximately 35 days posttransplant. Patients with a positive surveillance bronchoscopy for CMV receive pre-emptive ganciclovir. In order to determine the utility of other screening methods for CMV, we prospectively performed weekly CMV antigenemia, and blood, urine and throat cultures from time of engraftment to day 120 post-BMT in 126 consecutive patients. Pre-emptive ganciclovir was given to 11/81 patients (13.6%) because of a positive surveillance bronchoscopy for CMV. Results of CMV blood, urine and throat cultures and the antigenemia assay done prior to or at the time of the surveillance bronchoscopy were analyzed for their ability to predict the bronchoscopy result. The antigenemia test had the highest positive and negative predictive values (72% and 96%, respectively). The ability of these tests to predict CMV disease was evaluated in the 70 patients with a negative surveillance bronchoscopy who did not receive pre-emptive ganciclovir. Of 19 cases of active CMV disease, CMV antigenemia was positive in 15 patients (79%) a mean of 34 days preceding symptoms. Blood cultures were positive in 14/19 patients (74%) a mean of 31 days before onset of disease. CMV antigenemia is useful for predicting the surveillance bronchoscopy result, and also predicts the development of CMV disease in the majority of patients missed by the surveillance bronchoscopy.

Urine specimens from pregnant and nonpregnant women inhibitory to amplification of Chlamydia trachomatis nucleic acid by PCR, ligase chain reaction, and transcription-mediated amplification: identification of urinary substances associated with inhibition and removal of inhibitory activity

The presence of endogenous amplification inhibitors in urine may produce false-negative results for the detection of Chlamydia trachomatis nucleic acids by tests such as PCR, ligase chain reaction (LCR), and transcription-mediated amplification (TMA). Consecutive urine specimens from 101 pregnant women and 287 nonpregnant women submitted for urinalysis were processed for C. trachomatis detection. Aliquots were spiked with the equivalent of one C. trachomatis elementary body and were tested by three commercial assays: AMPLICOR CT/NG, Chlamydia LCX, and Chlamydia TMA. The prevalence of inhibitors resulting in complete inhibition of amplification was 4.9% for PCR, 2.6% for LCR, and 7.5% for TMA. In addition, all three assays were partially inhibited by additional urine specimens. Only PCR was more often inhibited by urine from pregnant women than by urine from nonpregnant women (9.9 versus 3.1%; P = 0.011). A complete urinalysis including dipstick and a microscopic examination was performed. Logistic regression analysis revealed that the following substances were associated with amplification inhibition: beta-human chorionic gonadotropin (odds ratio [OR], 3.3) and crystals (OR, 3.3) for PCR, nitrites for LCR (OR, 14.4), and hemoglobin (OR, 3.3), nitrites (OR, 3.3), and crystals (OR, 3.3) for TMA. Aliquots of each inhibitory urine specimen were stored at 4 and -70 degreesC overnight or were extracted with phenol-chloroform and then retested at dilutions of 1:1, 1:4, and 1:10. Most inhibition was removed by storage overnight at 4 or -70 degreesC and a dilution of 1:10 (84% for PCR, 100% for LCR, and 92% for TMA). Five urine specimens (three for PCR and two for TMA) required phenol-chloroform extraction to remove inhibitors. The results indicate that the prevalence of nucleic acid amplification inhibitors in female urine is different for each technology, that this prevalence may be predicted by the presence of urinary factors, and that storage and dilution remove most of the inhibitors.

Asthma and natural colds. Inflammatory indices in induced sputum: a feasibility study

We examined the feasibility of using induced sputum to evaluate the airway inflammatory response to natural acute respiratory virus infections. We recruited eight asthmatics and nine healthy subjects on Day 4 of a cold. Viral infection was confirmed in six of the asthmatics (influenza A or B) and six of the healthy subjects (influenza A, rhinovirus, adenovirus, respiratory syncytial virus, and coronavirus). In the subjects with confirmed virus infection, five of the asthmatics had an objective exacerbation of asthma during the cold. Their sputum on Day 4 showed a high median total cell count of 19.7 x 10(6) cells/ml with a modest neutrophilia (58. 5%) and high levels of interleukin-8 (IL-8) (16,000 pg/ml), eosinophilic cationic protein (ECP) (1,880 microgram/L) and very high levels of fibrinogen (250 mg/L). In contrast, the proportion (1.3%) and absolute number of eosinophils was low. IL-2 levels were within the normal range, whereas IL-5 and interferon gamma were under the limit of detection of the assays. In the healthy subjects with a confirmed virus infection the sputum findings were qualitatively similar but significantly less prominent. Sputum IL-8 on Day 4 was strongly correlated with neutrophils (rs = 0.8, p < 0.001). This correlation was also significant when each group was analyzed separately. On Day 21 there was a fall in the absolute number of neutrophils and in ECP and fibrinogen levels in both groups. Similar results were found in the two asthmatic and three healthy subjects with a cold of comparable severity but in whom viral infection was not confirmed. We conclude that induced sputum examination can be used to study the effects of natural colds and influenza on the airways of the lungs. The results also suggest that natural colds, on Day 4, cause neutrophilic lower airway inflammation that is greater in asthmatics than in healthy subjects. The greater inflammatory response in asthmatics may be due to the changes associated with trivial eosinophilia or to the different viruses involved.

Chlamydial cervicitis: testing the practice guidelines for presumptive diagnosis

OBJECTIVE

To test the recommendation from the Canadian guidelines for sexually transmitted diseases (STDs) that mucopurulent endocervical discharge and 10 or more polymorphonuclear leukocytes (PMNs) per high-power field of a Gram-stained endocervical smear or, when Gram staining is not possible, the presence of endocervical discharge and one of edema, erythema or induced mucosal bleeding of the cervix can be considered diagnostic for chlamydial cervicitis.

METHODS

A total of 596 consecutive women attending 2 family planning clinics for routine care underwent vaginal speculum examination and were tested for Chlamydia trachomatis and Neisseria gonorrhoeae. PMN counts from Gram-stained endocervical smears and the presence or absence of putative indicators of chlamydial infection were recorded.

RESULTS

The prevalence of chlamydial cervicitis was 6.2% (37/596), and no women tested positive for N. gonorrhoeae. Presumptive diagnosis of chlamydial cervicitis based on the guidelines criteria of mucopurulent endocervical discharge and 10 or more PMN per high-power microscopic field had a sensitivity and specificity of 18.9% and 97.0% respectively, a positive predictive value of 29.2% and a positive likelihood ratio (LR) of 6.2 (p = 0.003). Presumptive diagnosis based on endocervical discharge with edema, erythema or induced mucosal bleeding of the cervix had a sensitivity and specificity of 43.2% and 80.0% respectively, a positive predictive value of 12.5% and a positive LR of 2.2 (p = 0.002). In the presence of bacterial vaginosis or vaginitis, the LR for the criteria of mucopurulent endocervical discharge and 10 or more PMN per high-power field was 5.4 (p = 0.04), whereas the LR was 4.3 (p = 0.10) if bacterial vaginosis and vaginitis were absent.

CONCLUSIONS

In this setting, the practice of making a presumptive diagnosis of chlamydial cervicitis on the basis of the criteria given in the Canadian STD guidelines was not supported.

Can serology diagnose upper genital tract Chlamydia trachomatis infections? Studies on women with pelvic pain, with or without chlamydial plasmid DNA in endometrial biopsy tissue

BACKGROUND

Upper genital tract chlamydial infections in women are on the increase, and serology might be a convenient tool for diagnosis. Evaluations of this approach are needed in women with or without microbiologic evidence of organisms in the upper genital tract.

GOALS

To compare the results of antibody assays with cervical culture and upper genital tract histopathology in women with pelvic pain and chlamydial plasmid DNA in endometrial biopsies.

STUDY DESIGN

Chlamydia trachomatis plasmid DNA was detected by polymerase chain reaction (PCR) on extracted deparaffinized endometrial biopsy tissue. Five antichlamydial antibody assays were performed measuring total antibodies or immunoglobulin G (IgG), IgM, and IgA classes on sera from 14 women with plasmid DNA as well as 31 without plasmid DNA.

RESULTS

Accepting the presence of plasmid DNA as the gold standard, no single test had total diagnostic accuracy. The best sensitivity and specificity occurred with the following assays: whole inclusion fluorescence (WIF) (100% and 80.6%); microimmunofluorescence IgM (MIF IgM) (78.6% and 93.6%); and heatshock protein-60 enzyme immunoassay (42.9% and 100%). Although recombinant anti-lipopolysaccharide enzyme-linked immunosorbent assays measured anti-chlamydial antibodies in a large proportion of these women, specificity was low. The sensitivity and specificity of cervical culture was 28.6% and 100% and of endometrial histopathology was 71.4% and 48.4%. Analysis of patient serological profiles suggested that and 6 women without plasmid DNA may have been cases that were missed by PCR.

CONCLUSIONS

Evaluations of assays to diagnosis Chlamydia trachomatis upper genital tract infections could use the presence of organisms or their markers in the upper genital tract as a standard of comparison. Some of these serological assays, such as WIF or MIF IgM, may be helpful in diagnosis, but more studies are needed.

Sputum in severe exacerbations of asthma: kinetics of inflammatory indices after prednisone treatment

We have investigated the time-course of symptoms, forced expiratory volume in one second (FEV1), and the airway inflammatory changes in sputum selected from saliva and blood of 10 patients with severe exacerbation of asthma betwen presentation and after 1, 2, 3, 7, and 21 days of treatment. The sputum was induced by a modified standard protocol, and we examined its safety. The severe exacerbation of asthma was defined by the presence of nocturnal symptoms disturbing sleep and/or the need for inhaled short acting beta2-agonist > or = 8 puffs/d and an FEV1 after bronchodilator < 60% of predicted. The treatment consisted of additional prednisone 30 mg daily for 5 d followed by reduction to zero by day 10. Abnormal findings [median (interquartile range)] in spontaneous and induced sputum included low viability of cells [52.0 (34.0)%]; eosinophilia [20.0 (16.4)%]; many free eosinophil granules; and increased levels of fluid-phase ECP [1960 (9204) microg/L], fibrinogen [6045 (10720) microg/L], and IL-5 [160 (212) pg/ml]. Peripheral blood eosinophils [10.4 (7.6)%] and ECP levels [34.0 (35.0) microg/L] were increased. After treatment, symptoms, FEV1, blood eosinophilia, and serum ECP improved in the first 24 h. Sputum eosinophils and ECP did not improve until 48 h and fibrinogen not until 7 d. The improvement in sputum eosinophils and ECP levels was correlated with improvement of FEV1 and in fluid-phase IL-5. Thirty sputum inductions were performed safely in the majority with inhaled isotonic or 3% saline (23.3% or 63.3%, respectively) over a short duration (mean 8.4 min). The patients who had a fall in FEV1 of > or = 10% (10 occasions) after induction differed from those with a fall of < 10% only in the amount of inhaled beta2-agonist used by the patients in the preceding 24 h [8.0 (5.0) versus 4.0 (3.0) puffs/d, p = 0.01]. The results suggest that spontaneous or induced sputum can be used safely to follow the kinetics of effects of antiinflammatory treatment in a severe exacerbation of asthma. The clinical and blood indices improve before those in sputum, raising the possibility that examination of sputum is a better guide in these patients to follow the effects of treatment.

Rabbit model for Chlamydia pneumoniae infection

A rabbit model was established for Chlamydia pneumoniae infection that may be helpful to understand the pathogenesis of disease in humans. Twelve, pathogen-free, 1-month-old New Zealand White rabbits were inoculated with 1.0 x 10(7) to 5.0 x 10(7) CFU of purified C. pneumoniae (ATCC strain VR 1310) via the nasopharynx (1 rabbit died immediately postinoculation, and 11 were available for study). Five controls were inoculated with the carrier buffer. Ten of the 11 study rabbits demonstrated serological evidence of acute infection (immunoglobulin G antibodies, 1:8 to > 1:16), with the weakest response at 7 days and the strongest response at 28 days, whereas none of the controls showed any seroconversion. Study animals were sacrificed in batches of three, on days 7, 14, 21, and 28, but controls were sacrificed on days 7 and 28. Two-thirds of the animals demonstrated evidence of bronchiolitis and pneumonia on days 7 and 14 and resolution by day 21. Two study rabbits demonstrated, on histology, early and intermediate lesions of atherosclerosis: one animal (day 7) showed the accumulation of foamy macrophages (fatty streak) in the arch of the aorta, and the other animal (day 14) showed spindle cell proliferation of smooth muscle cells (intermediate lesion). Focal periaortitis was seen in the same animal (day 7). C. pneumoniae elementary bodies were demonstrated by immunocytochemical stain in the lungs (n = 2), liver (n = 3), spleen (n = 5), and aorta (n = 2), one of which corresponded to the intermediate lesion. C. pneumoniae was cultured from the lungs (n = 2), liver (n = 2), spleen (n = 2), and aortic arch (n = 1). All histopathological, immunocytochemical, and cultural studies were negative in the controls. Hence, the rabbit provides a useful animal model for the study of C. pneumoniae infection and its complications, particularly atherosclerosis.

Performance characteristics of recombinant enzyme immunoassay to detect antibodies to human immunodeficiency virus type 1 (HIV-1) and HIV-2 and to measure early antibody responses in seroconverting patients

We investigated the performance of a double-antigen sandwich recombinant enzyme immunoassay (EIA; Abbott Laboratories, North Chicago, Ill.) and compared it with that of a synthetic-peptide-based EIA (Biochem Immunosystems, Montreal, Quebec, Canada) for the detection of human immunodeficiency type 1 (HIV-1) and HIV-2 antibodies in 2,321 clinical serum samples. The results of both EIA methods and Western blot (immunoblot) were in agreement for 1,046 HIV-1 and 10 HIV-2 specimens from a panel of known positives. From a prospective panel of 1,085 specimens, 38 proved to be positive by both EIAs and Western blot, 3 were positive by the recombinant EIA only, and 9 were positive by the peptide EIA only, for calculated specificities of 99.71 and 99.04%, respectively. Of 180 specimens from a seroconversion panel collected from 77 patients, the results for 170 were in agreement by all antibody testing methods and 10 were found to be repeat reactive for HIV antibodies by the recombinant EIA only. All 10 were initial specimens of seroconverting patients; 7 were also reactive for HIV p24 antigen. An examination of four of these sera by radioimmunoprecipitation assay showed gp120 and gp160 bands in each. Analysis of the anti-Env antibody class in three of these samples showed that one consisted of immunoglobulin M (IgM) only and two contained both IgG and IgM antibodies. Although both EIA procedures were sensitive and specific in the detection of antibodies to HIV-1 and HIV-2 and both were capable of detecting early antibodies, the recombinant assay was more sensitive for antibody detection during early seroconversion.

Detection of Chlamydia trachomatis in genitourinary tract specimens using an automated enzyme-linked fluorescent immunoassay

BACKGROUND AND GOAL

The VIDAS Enzyme Linked Fluorescent Assay is a fully automated assay for the detection of Chlamydia trachomatis in clinical specimens. Because there is an increasing demand for automated assays for large volume laboratories and there is little performance data available, the authors evaluated the performance of the VIDAS enzyme linked fluorescent assay by comparing it with Chlamydiazyme and polymerase chain reaction.

STUDY DESIGN

Endocervical swabs from 330 women attending a hospital based obstetrics/gynecology clinic and 100 first void urine specimens from males attending a sexually transmitted disease clinic were tested by enzyme linked fluorescent assay, Chlamydiazyme, and polymerase chain reaction.

RESULTS

Fourteen of 330 endocervical specimens and 14 of 100 first void urine specimens were positive by Chlamydiazyme. Enzyme linked fluorescent assay detected 12 of 14 endocervical and 11 of 14 first void urine specimens. Compared with Chlamydiazyme, enzyme linked fluorescent assay had a sensitivity of 85.7% (12 of 14) for endocervical swabs and 76.9% (11 of 14) for first void urine specimens. Polymerase chain reaction detected an additional five endocervical and two first void urine specimens that had negative results by both enzyme linked fluorescent assay and Chlamydiazyme. All 7 were confirmed positive by polymerase chain reaction using a second primer set. Using an expanded gold standard of blocked Chlamydiazyme and confirmed polymerase chain reaction, enzyme linked fluorescent assay had a sensitivity of 63.2% (12 of 19) for endocervical swabs and 68.8% (11 of 16) for first void urine specimens compared with 73.7% (14 of 19) and 87.5% (14 of 16) for Chlamydiazyme. Polymerase chain reaction had a sensitivity of 100% (19 of 19) and 93.8% (15 of 16) for endocervical swabs and first void urine specimens, respectively. The specificity of enzyme linked fluorescent assay and Chlamydiazyme was 100%.

CONCLUSIONS

The VIDAS enzyme linked fluorescent assay for the detection of Chlamydia trachomatis in genitourinary specimens is highly specific but is not sufficiently sensitive for use as a routine diagnostic test.

PCR and direct fluorescent-antibody staining confirm Chlamydia trachomatis antigens in swabs and urine below the detection threshold of Chlamydiazyme enzyme immunoassay

In order to test the hypothesis that specimens blocking with a neutralizing reagent below the cutoff of the Chlamydiazyme enzyme immunoassay represent infected patients, we used direct fluorescent-antibody staining for elementary bodies (EBs) and PCR to confirm results for cervical swabs collected from 55,963 women and urethral swabs or first-void urine (FVU) samples collected from 5,781 men attending physicians' offices in the Toronto, Canada, area. Within a grey zone arbitrarily selected to represent values up to 40% below the positive threshold of the test run, 134 cervical swabs, 44 urethral swabs, and 39 FVU specimens exhibited a blocking response ( > 50% reduction in signal). Three or more EBs were observed in each of 98 cervical swabs (73.1%), 38 urethral swabs (86.4%), and 21 FVU specimens (53.8%). Of the 36 cervical swabs with fewer than three EBs, 33 were PCR positive; the positive PCR results for male specimens were 6 of 6 urethral swabs and 17 of 18 FVU samples. Application of the blocking test to specimens negative in the Chlamydiazyme enzyme immunoassay but having optical densities within 40% of the cutoff added 14.2% (217 of 1,531 specimens) more positive results to the survey. A total of 213 of 217 samples (98.2%) were reconfirmed as having EBs or DNA.

Sleep apnea in end-stage renal disease patients on hemodialysis and continuous ambulatory peritoneal dialysis

Fifteen unselected end-stage renal disease patients (nine hemodialysis [HD] and six continuous ambulatory peritoneal dialysis [CAPD]) were randomly selected from four Sydney metropolitan dialysis centers for sleep assessment by full polysomnography. Four of six CAPD patients and eight of nine HD patients were found to have clinically significant obstructive sleep apnea. An additional 21 unselected patients (10 CAPD and 11 HD patients) were assessed using overnight home monitoring of nasal airflow and arterial oxygen saturation. Of these, 8 of the 11 HD and 7 of the 10 CAPD patients were found to have obstructive sleep apnea. These data confirm the high incidence of obstructive sleep apnea in the end-stage renal disease population at large. Screening for obstructive sleep apnea should become a routine part of the management of these patients.

Obtaining consent for organ donation in nine NSW metropolitan hospitals

Organ donation rates vary markedly around the world. In an attempt to analyse why some patients' families are not asked about organ donation, the case notes of 6080 patients who died over a twelve-month period from April 1991 to March 1992 in nine hospitals in Sydney, NSW, were studied. Irreversible coma occurred in 515 patients. Of these, 177 were considered to be potentially brain dead donors, 126 of whom had a formal diagnosis of brain death. The clinicians caring for the patients at the time of death were asked at follow-up about the reasons for not considering donation, or the reasons for family refusal. Consent to proceed to organ donation was requested in 112 cases (49 donated and 63 refused) and not requested in 65. Analysis of the proportions asked and consenting in each hospital revealed no correlation. Half of the families refusing gave no reason (24/50) while eleven gave religious or cultural reasons, and six expressed a desire to prevent mutilation of the body as their primary reason for not consenting. There was universal failure to gain consent from families when the patient was not in an Intensive Care Unit. Analysis of those patients of whom consent was not sought showed that they died more quickly after admission, were older and died from causes other than trauma or intracranial haemorrhage. The odds of the family being asked dropped by about half as the age increased from one group to the next.(ABSTRACT TRUNCATED AT 250 WORDS)

Multi-organ donor transmission of hepatitis C virus to five solid organ transplant recipients and lack of transmission to corneal transplant recipients

BACKGROUND

A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection.

OBJECTIVES

To demonstrate the discordance between serological and PCR-based HCV detection in solid organ transplant recipients and the lack of transmission of HCV to the two corneal transplant recipients.

STUDY DESIGN

All 5 solid organ recipients were retrospectively shown to be HCV PCR-negative and -seronegative pre-transplant and HCV PCR-positive post-transplant. Serial serum samples on 3 recipients were evaluated by 2nd generation EIA, a prototypic structural and non-structural dual bead assay (EIA-SA, Abbott), the Chiron Recombinant Immunoblot Assay, 2nd generation (RIBA-2), and the Chiron RIBA HCV Test System Strip Immunoblot Assay 3.0 (RIBA-3, Chiron).

RESULTS

The dual bead EIA-SA and RIBA-3 were able to detect HCV seroconversion approximately 6 months earlier than the 2nd generation EIA in 2 recipients, and in 1 recipient only PCR detected infection within the first 10 months. There was no evidence of HCV transmission to the corneal recipients.

CONCLUSIONS

Although third generation assays such as the RIBA-3 and EIA-SA narrowed the window of HCV seronegativity in transplant recipients compared with the 2nd generation EIA, PCR was the most sensitive method of detecting acute HCV infection. Despite transmission of HCV to all of the solid organ recipients HCV was not transmitted to the corneal transplant recipients.

Confirmatory testing demonstrates that false-positive rates in the chlamydiazyme assay are influenced by gender and genital specimen type

BACKGROUND AND OBJECTIVES

Chlamydia trachomatis antigen testing of clinical specimens is replacing culture as the test of choice. Because of a potential for false positive results in low prevalence populations, there is an apparent need for confirming specimens positive by enzyme immunoassay (EIA).

GOAL OF THIS STUDY

To examine specimens falsely positive in the Chlamydiazyme EIA assay according to gender and specimen type.

STUDY DESIGN

Testing of genitourinary specimens from men and women consecutively enrolled from five health care delivery sources in an urban Canadian population. All specimens were initially tested in the Chlamydiazyme test and all positives repeated in a confirmatory blocking assay provided by the manufacturer. Additional confirmatory testing was performed using immunofluorescence (IF) staining for C. trachomatis elementary bodies (EB's) and polymerase chain reaction (PCR).

RESULTS

From Jan. 1, 1990 to June 1, 1991, multiple specimens from 656 men and 5,628 women of varying population prevalences were screened. EIA-positive specimens from women had a repeat negative rate of 22% to 27% from cervical swabs and 29% from urethral swabs. Male urethral swabs had a high repeat negative rate of 22% when EIA was the only positive test, but 2.4% when the specimen was positive by EIA and culture. EIA-positive first void urine (FVU) specimens from men had a repeat negative rate of 8.7% as opposed to 17% to 32% from women. Only 1.7% (2/115) of male FVU did not block compared to rates of 47% (22/47) to 80% (4/5) in FVU from women. Analysis of EIA optical densities (OD's) and EB counts showed an association between the absorbance range 0.1 to 1.4 OD and 0-85 EB's. The greatest number of EB's and highest OD's were seen with cervical specimens, followed by urine and urethral specimens in women infected at all three specimens. All 55 specimens that did not confirm in the blocking test had no EB's and a convenience sample of seven were negative by PCR. All of a subset of 50 blocked specimens contained EB's or were positive by PCR.

CONCLUSIONS

Although a variable proportion of specimens may not repeat positive in the EIA, use of the blocking reagent to confirm the repeat positives is highly recommended and the rate of blocking may be heavily influenced by gender and specimen type.

Effect of time elapsed since previous voiding on the detection of Chlamydia trachomatis antigens in urine

To determine if the time elapsed since previous voiding affects the sensitivity of an enzyme immunoassay (EIA) to detect Chlamydia trachomatis in urine, 882 women and 428 men were tested for chlamydial infection in urethral specimens by isolation in cell culture (women and men) and EIA with blocking confirmation (women only). Of the 36 women (4.1%) and 38 men (8.9%) who were positive for Chlamydia trachomatis in the urethra, 55.5% (20/36) and 81.6% (31/38) respectively were positive in the first void urine (FVU) sediment by confirmed EIA. In women the sensitivity of the EIA performed on FVU was 67.8% (19/28) if the urine had been in the bladder < 3 hours and decreased to 12.5% (1/8) if longer times had elapsed (odds ratio 13.7; 95% confidence interval 1.4 to 700.0) with no obvious confounding. In men a weaker association was present (odds ratio 2.7; 95% confidence interval 0.4 to 22.3). These findings should enable investigators to optimize the analysis of urine to diagnose chlamydial infections.

Kinetics of rubella-specific IgM antibody response in postnatal rubella infection

The serological diagnosis of primary postnatal rubella infection is based on detection of rubella-virus-specific IgM antibody or a four-fold rise in rubella-specific IgG antibody. Although there are several different methods of enzyme immunoassays that are commercially available, the cost benefit evaluation makes them impractical for use in developing countries. For this reason, we have standardized the measurement of rubella IgM antibody by HAI following serum fractionation by ion-exchange chromatography. The sera samples obtained from pregnant women infected with rubella virus at different times during gestation were fractionated and tested by HAI. Seven out of nine sera collected within the first two days after onset of rash showed detectable levels of rubella IgM antibody. All 57 sera collected between 3 and 30 days after the onset of rash contained rubella IgM antibody. After 30 days, only 1 of 5, or 20%, of sera contained IgM antibody. The HAI testing method was rapid and specific and the cost was not prohibitive. HAI-IgM testing could be used to diagnose primary rubella infections in developing countries where expensive EIAs are unaffordable.

Rapid, on-site diagnosis of chlamydial urethritis in men by detection of antigens in urethral swabs and urine

First-void urine (FVU) sediments of 240 men were tested for Chlamydia trachomatis antigens by two enzyme immunoassays, TestPack Chlamydia (15 min) and Chlamydiazyme (3.5 h), and the results were compared with urethral swab culture results. The sensitivity and specificity on FVU sediment for TestPack Chlamydia were 76.2% (32 of 42 specimens) and 95.5% (189 of 198 specimens) versus 81.0% (34 of 42 specimens) and 96.5% (191 of 198 specimens) for Chlamydiazyme, respectively. Rapid, on-site detection of chlamydial antigen in male FVU would shorten the infectious period by hastening diagnosis and treatment.

Immunoreactive serum calcitonin and skeletal histology in chronic renal failure

Serum calcitonin and serum parathyroid hormone (PTH) were measured in 50 patients undergoing regular haemodialysis for end-stage chronic renal failure, and an analysis of osteoclast and osteoblast activities was made in bone biopsies obtained by iliac crest trephine. Osteoclast and osteoblast activities were studied in a multivariate analysis in relation to factors which might reasonably be thought to influence activity, namely serum calcitonin, serum PTH, serum calcium, serum inorganic phosphate, and bone aluminium. Only serum PTH correlated strongly with osteoclast activity (p = 0.0047). Serum PTH correlated also with osteoblast activity (p = 0.0024). Serum inorganic phosphate correlated negatively with osteoblast activity (p = 0.0082). Serum calcitonin did not correlate with osteoclast or osteoblast activities but did correlate strongly with bone aluminium in a multivariate analysis (p = 0.0078). Bone aluminium did not correlate independently with osteoclast or osteoblast activities. This study affirms the implied powerful role of PTH in influencing osteoclast and osteoblast activities in end-stage chronic renal failure.