Attention and neurodevelopment in young children who are HIV-exposed uninfected

ABSTRACTChildren HIV-exposed, uninfected (CHEU) are at risk for compromised developmental outcomes. Attention is important for behavioural, cognitive and academic skills, yet has not been thoroughly investigated compared to children HIV-unexposed uninfected (CHUU). Fifty-five CHEU and 51 CHUU children were recruited at 5.5 years of age. Measures of inattention (IA), hyperactivity/impulsivity (HI) and total scores were collected using the parent-reported ADHD-Rating-Scale-IV. Measures of intelligence, visuomotor skills, academics and adaptive functioning were obtained. Analyses of between-group differences were performed as were correlational and multiple regression models, accounting for maternal education, employment and delivery type. Few children met clinical cut-offs for probable ADHD (3.6% CHEU, 2.0% CHUU), and no group differences in measures of IA, HI and combined scores were found. CHEU scored significantly lower than CHUU on intelligence, visuomotor function, academic skills and aspects of adaptive behaviour, though within age expectations. Lower Full-Scale IQ and Processing Speed were associated with higher IA in CHEU and lower adaptive functioning with higher IA in CHUU. Across both groups, children of unemployed mothers had more HI symptoms. CHEU were not at increased risk for attention difficulties at 5.5 years of age. Maternal employment status highlights the contribution of sociodemographic factors in shaping behaviour and neurodevelopment.

Neurodevelopment of HIV-exposed uninfected children compared with HIV-unexposed uninfected children during early childhood

HIV-exposed uninfected (HEU) children during the preschool and early school ages may be at-risk for neurodevelopmental challenges due to in utero and perinatal exposure to HIV and/or antiretroviral (ARV) medications. HEU children and HIV-unexposed uninfected (HUU) children from the community were recruited and tested at 3 to 4 and 5 to 6 years of age. Demographic information, HIV/ARV exposure and measures of intelligence, visuomotor skills, and adaptive functioning were obtained. Nonparametric tests assessed group differences and multiple regression analyses adjusted for demographic variables. Additional multiple regression analyses were performed within the HEU group to investigate associations between neurodevelopmental measures and variables of HIV/ARV exposure. At 3 to 4 years, 211 HEU children and 31 HUU children were assessed, and 144 HEU children and 58 HUU children were assessed at 5 to 6 years of age. At 3 to 4 years of age, HEU children scored significantly lower on measures of Full-Scale IQ, Performance IQ, visual motor integration, and adaptive functioning. At 5 to 6 years of age, HEU children scored significantly lower on all neurodevelopmental measures. At both ages, children who were female and those with mothers who were employed achieved higher scores on measures intellectual ability and/or adaptive functioning. Within the HEU group, no consistent associations were found between neurodevelopmental measures and HIV/ARV specific variables. HEU children demonstrated significantly lower scores on neurodevelopmental measures than HUU children during early childhood. Gaps in verbal intellectual abilities were identified with age, highlighting the importance of monitoring neurodevelopment in this population over time. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Early academic achievement of HIV-exposed uninfected children compared to HIV-unexposed uninfected children at 5 years of age

HIV-exposed uninfected (HEU) children may be at-risk for poorer academic achievement compared to HIV-unexposed uninfected (HUU) children due to in utero and perinatal exposure to HIV and/or anti-retroviral (ARV) medication. Understanding the risk factors for academic underachievement is important for implementing timely intervention and academic supports. HEU (N = 110, mean (SD) age 5.59 (0.22) years) and HUU (N = 43, mean (SD) age 5.73 (0.64) years) children completed assessments of general intelligence (WPPSI-III) and academic achievement (WRAT-4). Parent interviews and medical record reviews were used to obtain sociodemographic and maternal health data. HUU children scored significantly higher than HEU children on single word reading (p = 0.006), math calculation skills (p = 0.003), Verbal IQ, Performance IQ, Full Scale IQ, and Processing Speed (all WPPSI-III measures p < 0.001). Verbal IQ at 3-4 years predicted academic achievement at 5-6 years of age, yet sociodemographic and medical factors did not. These findings demonstrate that HEU children obtained significantly lower scores of intellectual, reading, and math abilities during early childhood. Addressing these early gaps before HEU children enter primary school will be critical for optimizing their learning and academic potential.

Clinical Correlates of Human Immunodeficiency Virus-1 (HIV-1) DNA and Inducible HIV-1 RNA Reservoirs in Peripheral Blood in Children With Perinatally Acquired HIV-1 Infection With Sustained Virologic Suppression for at Least 5 Years

BACKGROUND

The Early Pediatric Initiation Canada Child Cure Cohort (EPIC4) study is a prospective, multicenter, Canadian cohort study investigating human immunodeficiency virus-1 (HIV-1) reservoirs, chronic inflammation, and immune responses in children with perinatally acquired HIV-1 infection. The focus of this report is HIV-1 reservoirs and correlates in the peripheral blood of children who achieved sustained virologic suppression (SVS) for ≥5 years.

METHODS

HIV-1 reservoirs were determined by measuring HIV-1 DNA in peripheral blood mononuclear cells and inducible cell-free HIV-1 RNA in CD4+ T-cells by a prostratin analogue stimulation assay. HIV serology was quantified by signal-to-cutoff ratio (S/CO).

RESULTS

Of 228 enrolled participants, 69 achieved SVS for ≥5 years. HIV-1 DNA, inducible cell-free HIV-1 RNA, and S/COs correlated directly with the age of effective combination antiretroviral therapy (cART) initiation (P < .001, P = .036, and P < .001, respectively) and age when SVS was achieved (P = .002, P = .038, and P < .001, respectively) and inversely with the proportion of life spent on effective cART (P < .001, P = .01, and P < .001, respectively) and proportion of life spent with SVS (P < .001, P = .079, and P < .001, respectively). Inducible cell-free HIV-1 RNA correlated with HIV-1 DNA, most particularly in children with SVS, without virologic blips, that was achieved with the first cART regimen initiated prior to 6 months of age (rho = 0.74; P = .037) or later (rho = 0.87; P < .001). S/COs correlated with HIV-1 DNA (P = .003), but less so with inducible cell-free HIV-1 RNA (P = .09).

CONCLUSIONS

The prostratin analogue stimulation assay, with its lower blood volume requirement, could be a valuable method for evaluating inducible HIV-1 reservoirs in children. Standard commercial HIV serology may be a practical initial indirect measure of reservoir size in the peripheral blood of children with perinatally acquired HIV-1 infection.

"Getting to Zero New HIV Infections in the Caribbean": Knowledge and Attitudes Toward Male Circumcision Among Adolescent Males in The Bahamas

Male circumcision (MC) plays a significant role in reducing new HIV infections, particularly in high prevalence countries. This cross-sectional study assesses the prevalence of MC and attitudes toward MC among youth aged 15-18 years in The Bahamas, a medium HIV prevalence country. The survey included 797 young men who completed a questionnaire on MC. Data analyses included chi-squared tests. The self-reported prevalence of MC among youth was 16.7% (121/759). Most of the circumcised youth were circumcised as infants, 84% (107/121) were pleased with their circumcision, and 71% would recommend it to others. For uncircumcised youth, 35% (189/533) would consider voluntary male circumcision (VMC) and 26% would recommend MC to others. In all scenarios, circumcised youth were more likely to be positive about MC. Among uncircumcised young men, being older (17-18 years compared to 15-16 years) was the only variable statistically associated with considering MC or recommending MC. After being presented with information on the benefits of MC for HIV prevention, the number of men who were positive about MC increased. Most of the young men in this cohort would consider VMC for reducing HIV incidence. Also, many stated that, if they had a male child, they would have him circumcised. The attitudes of these youth emphasize the need to provide information on HIV in addition to general health benefits of MC if there were to be a sustainable MC program within this population.

Breastfeeding by Women Living With Human Immunodeficiency Virus in a Resource-Rich Setting: A Case Series of Maternal and Infant Management and Outcomes

The reduction in human immunodeficiency virus (HIV) transmission through breastmilk with maternal combination antiretroviral therapy (cART) has led many pregnant women living with HIV and healthcare providers to question exclusive formula feeding in resource-rich settings. Here, we describe cART prophylaxis in 3 breastfed infants whose mothers had sustained virologic suppression; all 3 of these infants remained uninfected.

The relationship between stigma and a rehabilitation framework [international classification of functioning, disability and health (ICF)]: three case studies of women living with HIV in Lusaka, Zambia

PURPOSE

To explore how the International Classification of Functioning, Disability and Health, a rehabilitation framework, can provide a holistic understanding of stigma experiences of three women living with human immunodeficiency virus in Lusaka, Zambia.

METHODS

A secondary analysis of three cases by drawing on interview transcripts collected as part of a larger longitudinal study with eighteen women living with the virus. The interview tool used the rehabilitation framework to ask questions about the impact of the virus on the body, daily activities, social participation and the future. Vignettes were produced for each of the eighteen women including information on stigma and the rehabilitation framework. Three case studies were developed from women who provided comprehensive accounts of stigma and the International Classification of Functioning, Disability and Health.

RESULTS

Stigma experiences aligned well with three dimensions of the International Classification of Functioning, Disability and Health: participation restrictions, environmental and personal factors. These domains were used to understand stigma in three forms (i.e. enacted, self and structural stigma) as experienced by these women.

CONCLUSIONS

More research is needed to ascertain how stigma and rehabilitation are related in other environments and populations and to explore how to mitigate stigma within the rehabilitation context.IMPLICATIONS FOR REHABILITATIONRehabilitation professionals deal with aspects of stigma and discrimination in their clinical work and this analysis offers a way to consider HIV-related stigma within rehabilitation in an organized and theoretically-informed way.The insights from this study are important for the field of HIV and for advancing understanding of the complexities of stigma in the context of rehabilitation more broadly.This analysis offers guidance to rehabilitation providers about the nuanced and multi-faceted ways that stigma can occur in the context of rehabilitation, including within their own clinical practice.

Knowledge and awareness of Human Papillomavirus (HPV) and HPV vaccines among Caribbean youth: the case of the Bahamas

There is a high burden of cervical cancer in the Caribbean region, particularly in the Bahamas, yet there are few studies of Human Papillomavirus (HPV) and HPV vaccine in the region. The objective of this study was to assess the knowledge and awareness of HPV and the HPV vaccine among school-aged youth (15–18 years) living in the Bahamas.

Cross-sectional data were obtained from the “Getting to Zero” HIV study in the Bahamas conducted in 2014/2015 (n = 1553). The questionnaire elicited information on knowledge of HPV and HPV vaccines, using previously validated scales. Data analysis included Chi-square tests and Mann Whitney U test.

In this sample of school-aged youth, only 10.7% (146/1364) had ever heard of HPV. With respect to those who were sexually active (n = 685), only 10.7% had ever heard of HPV. For those who had heard of HPV, knowledge of HPV and HPV vaccines was assessed on an HPV Knowledge and HPV Vaccine Knowledge scale, respectively. There was no statistically significant difference in mean HPV knowledge score between males and females, or HPV vaccine knowledge scores, between males and females.

There was a general lack of awareness of HPV and HPV vaccines among school-aged youth in the Bahamas. This is an important gap in the HPV vaccine strategy and cancer prevention, as this is the age at which most people acquire HPV. It emphasizes the importance of developing a careful implementation plan, with an evaluation of knowledge and attitudes, in order to have an effective HPV vaccine uptake.

The conceptualization of stigma within a rehabilitation framework using HIV as an example

Stigma theory is concerned with inclusion and opportunities that influence well-being. Rehabilitation is also concerned with social inclusion and well-being. This is a central concern in one of the leading rehabilitation theories, the World Health Organization's International Classification of Functioning, Disability and Health. Despite these shared concerns, the relationship between the fields of stigma and rehabilitation has not been well theorized to date. Using human immunodeficiency virus (HIV) as an example, this article presents an analysis of three ways that stigma may be conceptualized within the context of the International Classification of Functioning, Disability and Health. Three broad spheres of stigma are described: enacted, self, and structural stigma. These three forms of stigma are then aligned in unique ways with three particular constructs of the International Classification of Functioning, Disability and Health: participation restrictions, environmental, and personal contextual factors. This conceptualization illustrates how rehabilitation professionals and other practitioners, policy makers and researchers can better understand the dynamic and nuanced forms of stigma and how they relate to rehabilitation. Implications for rehabilitation This article enables rehabilitation professionals to better understand stigma as it relates to rehabilitation and human immunodeficiency virus. Rehabilitation professionals have the important job of allies and advocates for persons experiencing restrictions in these domains as a result of stigma.

Childhood exposures to discarded needles and other objects potentially contaminated with blood-borne pathogens in Toronto, Canada

BACKGROUND

Exposure to discarded needles or other objects put children at risk for infection with blood-borne pathogens (BBP), including human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C.

OBJECTIVE

The purpose of this study was to retrospectively analyze the epidemiology, management and outcome of children following such exposures in the greater Toronto community setting.

METHODS

A retrospective study of children <19 years of age who had community-based exposure to objects that could contain BBP between January 2001 and December 2014. Sexual and hospital inpatient exposures were excluded. Patients were identified by medical record review of all children who had HIV testing performed.

RESULTS

Sixty-six community-based exposures to objects potentially contaminated with BBP were identified (71.2% needlesticks). The median age was 6.3 years (interquartile range 3.8, 7.8). Exposures occurred outdoors in the community (45.5%), in schools (30.3%), homes (15.2%) and community/outpatient clinics (9.0%). Of 11 (16.7%) identified source subjects, 7 were known to be HIV infected. HIV post-exposure prophylaxis was prescribed to 22 (33.3%) children; 15 (71.4%) completed the course. Only 41.2% of previously unvaccinated children were documented to have completed a full HBV vaccine series post-exposure. No blood-borne infections were documented, but only 60.6% had documentation of adequate follow-up testing.

CONCLUSIONS

Enhanced public health interventions in schools and other community settings are needed to reduce childhood risk of exposure to needlesticks or other objects potentially contaminated with BBP.

Longitudinal development of cognitive, visuomotor and adaptive behavior skills in HIV uninfected children, aged 3-5 years of age, exposed pre- and perinatally to anti-retroviral medications

Little is known about the neurodevelopmental outcomes of children older than 3 years of age born to HIV infected mother but who are HIV-uninfected (HEU), and who have been exposed in utero and early in life to HIV and to antiretroviral medications (ARVs). We conducted a longitudinal study of cognitive, visuomotor and adaptive function of HEU children, who were assessed at two ages, 3.5 and 5.5 years. Sixty-four children (33 female) were assessed. In comparison with population norms for their age, at 3.5 years of age they had scores significantly below age expectations on aspects of adaptive behavior, but at age 5.5 years, their scores did not significantly diverge from the population norms on any of the measures. Verbal intelligence was lower at age 5.5 than at age 3.5 years, although there were also improvements in some features of adaptive behavior. Exposure to PI-based ARVs (compared to NNRTIs) was associated with higher Performance IQ, visuomotor and communication scores at age 5.5 years. Birth, early growth, and sociodemographic variables were predictive of outcomes. This study is important in tracking the trajectory of neurocognitive development across the pre-school and early school age years. The findings suggest that the full impact of early ARV exposure may not be evident until a considerable period of development has occurred. The results raise the possibility of negative effects of early ARV exposure on neurodevelopment that emerge over time, and reiterate the importance of sociodemographic and early health variables for optimal development.

Lentiviral expression system for the purification of secreted proteins from human cell cultures

BACKGROUND

Recombinant proteins of therapeutic use are ideally produced in human cells to ensure appropriate co- and post-translational modifications. However, purification of secreted proteins from the culture media is impeded by low expression from transfected cell lines and the presence of serum proteins. Here we describe a simple and cost-effective approach based on lentiviral vector-mediated gene delivery and expression of a secreted His-tagged protein from human embryonic kidney 293 T cells and direct affinity chromatography purification from the cell culture media.

RESULTS

Using a protein-based HIV entry inhibitor, soluble CD4 (sCD4), we demonstrated that 293 T cells transduced with a lentiviral vector mediated over 10-fold higher secretion of sCD4 in comparison to 293 T cells transfected with the corresponding plasmid. Secretion of sCD4 increased with the dose of the lentiviral vector up to a multiplicity of infection of 50. Exchanging the native signal peptide of sCD4 with the signal peptide of human alpha-1 antitrypsin increased expression by 50 %. There was no difference in expression from a monocistronic or bicistronic lentiviral vector. Reduction of the serum concentration in the culture media had no significant effect on the secretion of sCD4. Small-scale purification from 50 ml of culture media with reduced serum content yielded up to 1 mg of pure sCD4. Purified sCD4 bound to recombinant HIV envelope glycoprotein 120 (Env gp120) and inhibited HIV entry at concentrations comparable to published results.

CONCLUSION

The procedure outlined in this study can be performed without the need for specialized reagents or equipment and could easily be adapted by any laboratory. Furthermore, the method could be used to produce sCD4 fusion proteins or other His-tagged proteins.

Relating Tuberculosis (TB) Contact Characteristics to QuantiFERON-TB-Gold and Tuberculin Skin Test Results in the Toronto Pediatric TB Clinic

BACKGROUND

Few data relate interferon-γ-release-assay results in children to source case sputum status, the best predictor of infectiousness of tuberculosis (TB) patients. We evaluated the QuantiFERON-Gold-in-tube assay (QFT) and tuberculin skin test (TST) in children with different types of TB exposure.

METHODS

The TST and QFT were performed in referred TB-exposed children and adolescents who had not undergone prior TST screening (tested in parallel), and the QFT was performed in referred TST-positive individuals. Source case characteristics were obtained from referring public health units. We excluded children with known immunocompromising conditions and those known to have TB disease at the time of evaluation.

RESULTS

For 103 patients tested in parallel, overall test agreement was very good in the Bacillus Calmette-Guerein (BCG) unimmunized contacts (κ = 0.83) and contacts of household smear-positive (HS+) cases (κ = 0.67), but test agreement was poor in those with lower-risk contact (κ = 0.34). Only 3 of 59 HS+ patients were QFT-positive and TST-negative. On multivariate analysis, a positive QFT was strongly associated with HS+ exposure (odds ratio [OR], 6.6; 95% confidence interval [CI], 2.2-20]) but not BCG; and a positive TST was associated with BCG alone. For 92 referred TST-positive individuals, the QFT was negative in 21% of HS+ contacts, 65% of lower-risk contacts (OR, 6.8; 95% CI, 1.9-25), and 82% of the patients with unknown contact history (OR, 15.5; 95% CI, 5-54). Application of the Canadian 2010 guidelines would exclude from treatment 43 (72%) of the 73 TST+, QFT- patients.

CONCLUSIONS

For close contacts of HS+ individuals, the QFT added little sensitivity to the TST for detection of TB infection. The QFT correlated much better with exposure than the TST, especially in BCG-immunized children, and it has the greatest potential benefit for evaluation of those at lower risk of latent TB infection.

Early initiation of combination antiretroviral therapy in HIV-1-infected newborns can achieve sustained virologic suppression with low frequency of CD4+ T cells carrying HIV in peripheral blood

BACKGROUND

A human immunodeficiency virus type 1 (HIV-1)-infected infant started on combination antiretroviral therapy (cART) at 30 hours of life was recently reported to have no detectable plasma viremia after discontinuing cART. The current study investigated the impact of early cART initiation on measures of HIV-1 reservoir size in HIV-1-infected children with sustained virologic suppression.

METHODS

Children born to HIV-1-infected mothers and started on cART within 72 hours of birth at 3 Canadian centers were assessed. HIV serology, HIV-1-specific cell-mediated immune responses, plasma viremia, cell-associated HIV-1 DNA and RNA, presence of replication-competent HIV-1, and HLA genotype were determined for HIV-1-infected children with sustained virologic suppression.

RESULTS

Of 136 cART-treated children, 12 were vertically infected (8.8%). In the 4 who achieved sustained virologic suppression, HIV serology, HIV-1-specific cell-mediated immune responses (Gag, Nef), and ultrasensitive viral load were negative. HIV-1 DNA was not detected in enriched CD4(+) T cells of the 4 children (<2.6 copies/10(6) CD4(+) T cells), whereas HIV-1 RNA was detected (19.5-130 copies/1.5 µg RNA). No virion-associated HIV-1 RNA was detected following mitogenic stimulation of peripheral blood CD4(+) T cells (5.4-8.0 million CD4(+) T cells) in these 4 children, but replication competent virus was detected by quantitative co-culture involving a higher number of cells in 1 of 2 children tested (0.1 infectious units/10(6) CD4(+) T cells).

CONCLUSIONS

In perinatally HIV-1-infected newborns, initiation of cART within 72 hours of birth may significantly reduce the size of the HIV-1 reservoirs. Cessation of cART may be necessary to determine whether functional HIV cure can be achieved in such children.

Quantiferon Gold-in-tube assay for TB screening in HIV infected children: influence of quantitative values

BACKGROUND

HIV infected children are at increased risk of TB disease and require annual TB screening. Data on use of IGRA for TB screening in them are limited. We retrospectively evaluated the usefulness of Quantiferon Gold-in-tube test (QFT), an IGRA in screening for LTBI in relatively healthy, immunologically stable HIV infected children.

METHODS

HIV infected children with no prior history of TB were screened for latent TB as part of routine care. They underwent risk of TB assessment, TST and QFT. QFT was repeated twice or three times depending on the quantitative values. Independent test validation was also performed.

RESULTS

Eighty one children had 109 QFT tests. All had adequate mitogen responses. The initial QFT was positive in 15 (18.5%) children; quantitative IGRA responses were 0.35-1.0 IU/mL in 9 (60%), 1.0-10 IU/mL in5 (33.3%) and >10 IU/mL in 1 (6.7%). None that tested positive had documented TB exposure or TB disease. Baseline characteristics in the QFT positive and negative groups were similar. Repeat testing within 17 weeks demonstrated reversion to negative in 79% of cases. Repeat blinded independent testing of all QFT positive results and a random selection of initial negative tests demonstrated concordance in 96% of cases. Seven children (QFT > 1.0 IU/mL or positive TST) were offered INH preventive therapy. In no case has TB disease developed in 2 years of close follow-up.

CONCLUSIONS

QFT is a valid method for LTBI screening relatively healthy, immunologically stable HIV infected children. However, reversion to negative on repeat testing and lack of correlation with TST results and risk of TB exposure makes interpretation difficult.

The MaBwana Black men's study: community and belonging in the lives of African, Caribbean and other Black gay men in Toronto

In Canada, there is a paucity of research aimed at understanding Black gay men and the antecedents to risk factors for HIV. This study is an attempt to move beyond risk factor analysis and explore the role of sexual and ethnic communities in the lives of these men. The study utilized a community-based research and critical race theory approach. Semi-structured interviews were conducted with eight key informants to augment our understanding of Black gay men and to facilitate recruitment of participants. In-depth interviews were done with 24 Black gay men. Our data showed that the construction of community for Black gay men is challenged by their social and cultural environment. However, these men use their resilience to navigate gay social networks. Black gay men expressed a sense of abjuration from both gay and Black communities because of homophobia and racism. It is essential for health and social programmers to understand how Black gay men interact with Black and gay communities and the complexities of their interactions in creating outreach educational, preventive and support services.

Vitamin D supplementation and CD4 count in children infected with human immunodeficiency virus

OBJECTIVE

To evaluate, in a randomized fashion, the impact of vitamin D supplementation on CD4 count and measures of vitamin D homeostasis in children infected with human immunodeficiency virus (HIV).

STUDY DESIGN

Children infected with HIV (n = 54) were randomized to receive no supplementation (group 1), vitamin D 5600 IU/week (group 2), or vitamin D 11 200 IU/week (group 3) for 6 months. Viral load, CD4 percent, CD4 count, 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D, and other measures of vitamin D metabolism were measured at baseline and 6 months later.

RESULTS

A total of 53 participants completed the study. The mean age, CD4 percent, CD4 count, and log(10) viral load at baseline were 10.3 ± 3.9 years, 33% ± 10%, 927 ± 468 cells/μL, and 1.63 (95% CI, 0.76-2.50), respectively. The mean baseline 25(OH)D level was 53.1 ± 24.8 nmol/L; 85% of participants were vitamin D insufficient or deficient (<75 nmol/L). Serum levels of 25(OH)D increased significantly in participants who received supplementation with vitamin D (P = .0002 and P < .001 for participants receiving 800 IU/day and 1600 IU/day, respectively), but not in participants who did not receive supplementation (P = .27). Participants treated with 1600 IU/day of vitamin D achieved a higher mean increase in 25(OH)D than participants treated with 800 IU/day (P = .02). However, only 67% of the group supplemented with higher dose achieved vitamin D sufficiency. Vitamin D supplementation did not lead to an increase in CD4 percent or CD4 count.

CONCLUSION

In children infected with HIV with relatively preserved immune function, vitamin D supplementation in doses as high as 1600 IU/day does not impact CD4 count. Vitamin D insufficiency is common in this population, and achieving vitamin D serum levels of >75 nmol/L may require a daily intake ≥1600 IU.

"HIV isn't me…": HIV+ adolescents' experiences in a positive context of support and treatment

We describe the experiences of a sample of Canadian HIV+ youth whose intact adolescent identities contrast sharply with the expected identity challenges of persons living with a serious, chronic disease. We first showcase the positive HIV+ identities emerging from the successful management of HIV+ status through long-term HIV-related medical care and established pharmaceutical regimes. Second, we describe the medical, familial, and broader social context of support in which these adolescents' are negotiating HIV. Finally, we highlight the youth's expectations of future, specific identity and role challenges regarding intimacy and sexuality-related to disclosure of their private HIV+ identities and their embodied HIV+ status. Continued social and medical supports will be key to their emergence into adulthood as healthy HIV+ persons; with such supports, these youths' experiences highlight the capacity for living optimally with HIV.

Risk factors and outcomes among children admitted to hospital with pandemic H1N1 influenza

BACKGROUND

Limited data are available on disease characteristics and outcomes of children with 2009 pandemic influenza A(H1N1) virus infection (pandemic H1N1 influenza) who have required hospital admission.

METHODS

We reviewed the charts of 58 children with pandemic H1N1 influenza admitted to a large pediatric hospital in Ontario, Canada, between May 8 and July 22, 2009. We compared risk factors, severity indicators and outcomes of these children with those of 200 children admitted with seasonal influenza A during the previous 5 years (2004/05 to 2008/09).

RESULTS

Children with pandemic H1N1 influenza were significantly older than those with seasonal influenza (median age 6.4 years v. 3.3 years). Forty-six (79%) of the children with pandemic H1N1 influenza had underlying medical conditions; of the other 12 who were previously healthy, 42% were under 2 years of age. Children admitted with pandemic H1N1 influenza were significantly more likely to have asthma than those with seasonal influenza (22% v. 6%). Two children had poorly controlled asthma, and 6 used inhaled medications only intermittently. The median length of stay in hospital was 4 days in both groups of children. Similar proportions of children required admission to the intensive care unit (21% of those with pandemic H1N1 influenza and 14% of those with seasonal influenza) and mechanical ventilation (12% and 10% respectively). None of the children admitted with pandemic H1N1 influenza died, as compared with 1 (0.4%) of those admitted with seasonal influenza.

INTERPRETATION

Pandemic H1N1 influenza did not appear to cause more severe disease than seasonal influenza A. Asthma appears to be a significant risk factor for severe disease, with no clear relation to severity of asthma. This finding should influence strategies for vaccination and pre-emptive antiviral therapy.

Randomized controlled trial of short-term withdrawal of i.v. immunoglobulin therapy for selected children with human immunodeficiency virus infection

BACKGROUND

The aim of the present paper was to determine whether monthly i.v. immunoglobulin (IVIG) could be safely discontinued in antiretroviral-treated human immunodeficiency virus (HIV)-infected children.

METHODS

In a double-blind cross-over trial, children < or =18 years with HIV infection, well controlled on antiretroviral therapy, were randomized to alternating courses of 3 consecutive months of IVIG (400 mg/kg once a month) and 3 consecutive months of placebo for 1 year. The primary outcome was days of fever per month. Secondary outcomes were frequency of serious infections, changes in HIV viral load (VL), CD4+ counts and IgG levels.

RESULTS

Fifteen children were enrolled. Using the revised pediatric HIV clinical classification system of the Centers for Disease Control and Prevention, eight were severely symptomatic (C), four were moderately symptomatic (B) and three were mildly symptomatic (A). There were no statistically significant outcome measures. The mean number of days of fever per month with IVIG versus placebo was 0.55 days versus 1.48 days (P = 0.11). The difference was 0.9 days (95% confidence interval: +2.05 to -0.25). There were no serious infections in either period. For the IVIG versus placebo periods, mean CD4 counts were 970 cells/microL versus 906 cells/microL (P = 0.12), VL 2.90 log(10) copies/mL versus 2.82 log(10) copies/mL (P = 0.70) and IgG levels were 17.41 g/L versus 16.6 g/L (P = 0.13).

CONCLUSION

In antiretroviral-treated HIV-infected children short-term withdrawal of monthly IVIG was not associated with a significant increase in incidence of infections or a decline in immunologic function (CD4 count, viral load and IgG levels). These results suggest that monthly IVIG can be safely discontinued in HIV-infected children who are clinically stable and receiving combination antiretroviral therapy.

A study of provider-caregiver communication in paediatric ambulatory care

BACKGROUND

Provider-caregiver communication is a key ingredient in quality health care and patient safety, and effective communication has been shown to affect compliance and outcomes.

OBJECTIVES

To identify and compare communication issues among three paediatric outpatient clinics.

METHODS

In this prospective, qualitative study, a questionnaire was used to survey physicians, nurse practitioners and caregivers at three different infectious diseases clinics.

RESULTS

There was a statistically significant preponderance of families in the tuberculosis clinic for whom English was not the mother tongue and who were not fluent in English. Patients in the HIV clinic were less likely to be at their first appointment than were patients attending the other clinics. Patients in the general clinic were less likely to have been seen by the same physician on the previous visit. Parents from all three clinics were satisfied with the care they received, with communication and with rapport with their child. There was a trend toward parents in the tuberculosis clinic being happier with their clinic visit and less likely to complain about the wait time.

CONCLUSIONS

Language proficiency and lack of continuity of provider care were identified as potential risks for patient safety in the ambulatory setting. Further studies are necessary to identify language and cultural issues that may affect patient care in a tertiary paediatric hospital servicing a multiethnic population.

"Supposed to make you better but it doesn't really": HIV-positive youths' perceptions of HIV treatment

PURPOSE

Half of new HIV infections worldwide occur among young people. Youth, particularly young women aged 15-29 years, represent a growing population to experience HIV. This study investigated HIV-positive youths' perceptions of, and experiences with, antiretroviral treatment.

METHODS

A community-based, participatory approach was used to conduct a mixed methods research study. Thirty-four qualitative, in-depth, semi-structured interviews were conducted with HIV-positive youth (ages 12-24 years) in Ontario, Canada. Brief structured demographic surveys were also administered. A research team of HIV-positive youth, professionals, and researchers collaboratively analyzed the data for emerging themes.

RESULTS

Four major themes emerged: Treatment knowledge: confusion and skepticism. Many participants did not understand, or believe in, antiretroviral treatment. Some youth on treatment did not understand why they were taking medications. Treatment decision-making: lack of choice and feeling emotionally unprepared. Some youth did not feel that they had choices about treatment, and others did not feel ready to make treatment decisions. Difficulties taking medications. Youth had problems with social routine disruption, feeling "different" and side effects. Many viewed costs of medications as a barrier to treatment. Inconsistent treatment adherence and treatment interruptions, which were common amongst participants.

CONCLUSIONS

Youth may need support for managing difficulties with treatments, such as side effects, social impacts, and adherence. Developmentally appropriate, empowerment-based treatment education may be helpful for HIV-positive youth. The availability of social programs to provide treatment access does not guarantee that youth will be aware of them. This may indicate a need for youth-specific outreach.

Severe acute respiratory syndrome in pregnancy

BACKGROUND

There is limited worldwide experience with severe acute respiratory syndrome (SARS) in pregnancy. We present a case of SARS complicating pregnancy in the third trimester, with outcome data on both the mother and baby.

CASE

A 33-year-old gravida 2 para 1 fulfilling the World Health Organization case definition for probable SARS was admitted to our institution at 31 weeks of gestation with fever, a dry cough, and patchy infiltrates on chest X-ray. The patient was previously healthy and acquired SARS from close contact with an infected family member. Convalescent serology results were positive for antibodies to coronavirus. She stayed in hospital for 21 days and did not require intensive care admission or ventilatory support. Labor occurred spontaneously at term, and a healthy female baby was delivered with no evidence of infection.

CONCLUSION

Severe acute respiratory syndrome in pregnancy is a potentially life-threatening illness with complicated management issues. Hospitalization and care by a multidisciplinary team may optimize chances for a good outcome.

Toronto street youth and HIV/AIDS: prevalence, demographics, and risks

PURPOSE

The purposes of this study were: (a) to identify human immunodeficiency virus (HIV) prevalence in Toronto street youth through paired blood and saliva specimens; (b) to identify the HIV risk and prevention behaviors of street involved youth; and (c) to identify demographic or other factors that may contribute to the risk of street youth becoming infected with HIV/acquired immunodeficiency syndrome (AIDS) in the future.

METHODS

This was a cross-sectional convenience study of street-involved youth aged 14-25 years. The youth participated in interviews to identify HIV-related knowledge and personal risk and preventive behaviors. Following interviews, they were asked to provide a saliva sample, blood spot, or both. They could refuse one or both samples without jeopardizing their involvement or receiving an honorarium. Two males were the only participants who declined to provide a sample.

RESULTS

Fifteen of 695 (2.2%) youth tested positive for HIV infection. All were male, ranging in age from 18 to 25 years. Same and opposite sex, intravenous (IV) drug use, prostitution, and incarceration were risk factors associated with positive HIV test results. The rate of HIV infection was seven times greater for the group 20 years of age and older (20-25) compared to the younger group aged 14-9 years. The proportion testing positive for HIV from small cities, towns, and rural communities in Ontario was 40%; yet, they represented 21% of the study population. Most (57%) youth had been on their own for no more than 3 years and had moved frequently. Nearly two thirds (60%) had stayed in hostels or homeless shelters in the previous 6 months.

CONCLUSION

Street youth in Canada are at high risk of HIV infection with their risk increasing with age. Unprotected (same and opposite) sex, IV drug use, prostitution and incarceration were linked to their HIV infections. The high level of mobility identified by street youth challenges governments, communities, and public health officials to develop appropriate prevention strategies and to carefully monitor the spread of HIV infection in this vulnerable population.

Cytomegalovirus retinitis in immunosuppressed children

PURPOSE

To describe the ocular and systemic features of children with cytomegalovirus retinitis and their disease outcomes.

METHODS

Review of all cases of cytomegalovirus retinitis diagnosed or treated at a tertiary care pediatric hospital during a 10-year period.

RESULTS

Nine immunocompromised children younger than 16 years were diagnosed as having cytomegalovirus retinitis. The underlying causes of immunocompromise were severe combined immunodeficiency syndrome (n = 2), severe combined immunodeficiency syndrome after bone marrow transplantation (n = 1), acquired immunodeficiency syndrome (AIDS) (n = 2), AIDS and previous bone marrow transplantation for leukemia (n = 1), immunosuppressive therapy after renal transplantation (n = 1), chemotherapy for leukemia (n = 1), and congenital cytomegalovirus infection (n = 1). Five children (56%) had symptomatic extraocular cytomegalovirus infection. Only two children reported visual symptoms with cytomegalovirus retinitis at initial examination. Cytomegalovirus retinitis was bilateral in eight children (89%) and involved the posterior pole in at least one eye of all nine children. Four children (44%) died within 10 months of being diagnosed with cytomegalovirus retinitis. The remaining five children were alive, with follow-up ranging from 14 to 70 months. Successful bone marrow transplantation in one child and discontinuation of immunosuppressive medications in two children improved systemic immune function and permitted discontinuation of anticytomegaloviral therapy.

CONCLUSION

Pediatric cytomegalovirus retinitis is often asymptomatic and bilateral and involves the posterior pole at initial examination. Recovery of systemic immune function may occur in some children. Evaluation of children at risk and prompt treatment of cytomegalo. virus retinitis are important to prevent long-term visual morbidity.

Serum immunoreactive erythropoietin levels and associated factors amongst HIV-infected children

OBJECTIVES

To determine the spectrum of serum immunoreactive erythropoietin (SIE) levels amongst HIV-infected children aged < 13 years in relation to the levels among healthy children as well as those with renal failure; to examine the relationship between clinical and laboratory parameters and SIE levels.

DESIGN

A cross-sectional study with a descriptive non-interventional format. HIV-infected Canadian subjects were recruited through four tertiary Canadian and one Bahamian centre. Children with renal failure and healthy children were recruited from one of the Canadian centres.

METHODS

Study subjects had clinical and laboratory profiles determined at baseline and at each of five follow-up periods over 1 year. SIE levels were measured by radioimmunoassay with a normal range of 12-28 IU/I. Data handling and statistical functions were performed by the Canadian HIV Trials Network.

RESULTS

The study enrolled 133 HIV-infected subjects and 38 controls. Of these, 117 HIV-infected subjects, 24 healthy controls, and 11 controls with renal failure were eligible for analysis. The median age of infected subjects was 44 months, whereas that of healthy controls was 56 months, and 95 months for controls with renal failure. The median SIE levels were 14 and 11 IU/I for subjects with renal failure and healthy subjects, respectively. The median SIE level was 61 IU/I among zidovudine (ZDV)-treated subjects and 22 IU/I among ZDV-naive HIV-infected subjects. HIV-infected children almost invariably had SIE levels < 200 IU/I. The median SIE levels amongst HIV-infected subjects whose hemoglobin levels were < 100 g/l were 98 and 31 IU/I for ZDV-treated and ZDV-naive subjects, respectively (P = 0.002). This difference in median SIE levels between ZDV-treated subjects and ZDV-naive subjects was also observed among subjects whose hemoglobin levels were > 100 g/l (median, 58 and 15 IU/l, respectively; P < 0.001). Hemoglobin level was the most important predictor of log10 SIE (P < 0.01 for ZDV-treated and ZDV-naive subjects).

CONCLUSIONS

SIE levels amongst HIV-infected children were affected by HIV infection, use of ZDV, and presence or absence of anemia. SIE levels amongst HIV-infected children were generally lower than 200 IU/I. This characterization of SIE levels will facilitate clinical trials of exogenous recombinant human erythropoietin in HIV-infected children with anemia.

Quantification of human immunodeficiency virus type 1 RNA levels in plasma by using small-volume-format branched-DNA assays

We have developed small-volume (50 or 250 microl)-format branched-DNA assays for human immunodeficiency virus type 1 (HIV-1) RNA for use with specimens in which the volume is limited and/or a high viral load is anticipated. These formats exhibited good correlation with the standard 1-ml format; high specificity, reproducibility, and linearity; and no significant difference in the quantification of HIV-1 subtypes.

New drug interactions with zidovudine

Polypharmacy is commonly encountered in human immunodeficiency virus (HIV)-positive patients, and the risk and frequency of drug-drug interactions are significant in this patient population. Most HIV-positive patients receive the antiretroviral drug zidovudine (3'-azido-3'-deoxythymidine, ZDV), the first drug to be approved for the treatment of HIV. Many drug interactions with ZDV have already been reported. As HIV pharmacotherapy becomes more complex, the potential for drug-drug interactions is likely to increase significantly.

Evaluation of the role of routine serial cranial computed tomography in the management of children with human immunodeficiency virus infection

OBJECTIVE

To review the impact of routine follow-up cranial computed tomography (CT) scans on the management of children with human immunodeficiency virus (HIV) infection.

DESIGN

Longitudinal data collected from 58 HIV-infected children followed in one center for mean of 3.8 +/- 1.8 years.

SETTING

HIV/AIDS pediatric program following over 90% of the identified HIV-infected children in one region in Canada.

RESULTS

The baseline CT scans showed intracranial abnormalities in 35 of 58 children (60%). In five children with basal ganglia calcifications (BGC) without cerebral atrophy, there has not been progressive encephalopathy. For the 43 children who had serial CT scans for routine follow-up, 34 (79%) had changes in the scans that were concordant with the clinical assessment. In all but five children with progressive ventricular and sulcal dilatation on CT scan, there was simultaneous clinical evidence of encephalopathy. Those five children were already on antiretroviral therapy, and therapy was not changed in response to the CT scan findings.

CONCLUSION

Baseline CT scans provide useful diagnostic and prognostic information. Further research is needed to evaluate the role of cranial CT imaging in the management of pediatric HIV encephalopathy.

Screening for cytomegalovirus retinitis in children

OBJECTIVES

To identify immunosuppressed children who are at risk of cytomegalovirus (CMV) retinitis developing and to evaluate the use of laboratory results for identifying this risk.

DESIGN

Prospective cohort and retrospective case-control series.

SETTING

University hospital pediatric referral center.

PATIENTS

Fifty-six consecutive immunocompromised children (ie, the prospective group) with laboratory evidence consistent with acute or recently acquired CMV infection, which was defined as CMV cultured from the blood, urine, nasopharynx, or biopsy specimen, recent seroconversion, a 4-fold increase in the CMV antibody titer, or an antibody titer of 1:512 or greater. Ninety-three immunocompromised children (ie, the retrospective group) with acute CMV or previous CMV exposure, which was defined as a CMV titer of 1:4 or greater and less than 1:512.

MAIN OUTCOME MEASURE

Occurrence of CMV retinitis.

RESULTS

Cytomegalovirus retinitis developed in 3 children in the prospective group and in 4 children in the retrospective group. The causes of immunosuppression were severe combined immunodeficiency syndrome (n = 2), severe combined immunodeficiency syndrome status post bone marrow transplantation (n = 1), acquired immunodeficiency syndrome (n = 1), and acquired immunodeficiency syndrome status post bone marrow transplantation for leukemia (n = 1), renal transplantation (n = 1), and chemotherapy for leukemia (n = 1). Cytomegalovirus retinitis was associated with a positive CMV culture result from the urine (P = .03) or nasopharynx (P < .001) in the retrospective group. In the retrospective group, one child with congenital CMV infection and CMV retinitis was excluded from analysis because laboratory tests for CMV were not obtained prior to ganciclovir therapy.

CONCLUSIONS

Cytomegalovirus retinitis is uncommon in children compared with adults; it occurred in 5% of the children in our series. A screening ophthalmologic examination should be considered in immunocompromised children with positive CMV laboratory results, particularly positive results of urine or nasopharynx cultures.

HIV infection in vitro enhances the activity of src-family protein tyrosine kinases

OBJECTIVE

We examined the effect of HIV infection on src-family protein tyrosine kinase (PTK) activity to determine if alterations in src-family PTK activity could contribute to the HIV-related chronic immune system activation observed in patients infected with HIV.

METHODS

Jurkat, a CD4+ human T lymphocyte cell line was infected with HIV IIIB. Kinase activity was determined by in vitro immune complex kinase assays using antibodies specific for the src-family PTKs, p56lck, p59fyn and p60c-src expressed in T lymphocytes. PTK protein and total phosphotyrosine levels were assessed by Western blotting. The role of the gp120-CD4-Lck interaction in HIV-related PTK activation was determined using gp 120-treated Jurkat cells and HIV-infection of JCaM 1.6 cells, a Jurkat-derived cell line that lacks p56lck.

RESULTS

Cells infected with HIV for 24 h exhibited increased levels of total tyrosine phosphorylation and enhanced src-family PTK activity without altered levels of expression of src-family kinases. The activity of Lck and Fyn was enhanced within 30 min of infection. HIV-related src-family PTK activation was not a function of the gp120-CD4-Lck interaction and occurred in the presence of 10 mmol/l zidovudine indicating that reverse transcriptase and activation of the HIV genome is not required.

CONCLUSIONS

HIV-related activation of src-family PTK is a response of the cell to early stages of the virus life cycle, possibly either membrane fusion or viral uncoating. These results indicate that endogenous src-family PTKs may play a role in HIV-related immune activation and dysfunction. Moreover, activation of src-family PTK may be a mechanism used by the virus to facilitate some aspect of its own life cycle.

Characteristics of HIV-infected pregnant women in the Bahamas

The Commonwealth of the Bahamas has one of the highest rates of acquired immunodeficiency syndrome (AIDS) in the English-speaking Caribbean. A seroprevalence study of pregnant women attending antenatal clinics in New Providence in 1990-91 showed that of 3,914 pregnant women tested, 2.9% were human immunodeficiency virus (HIV) infected. Women born in the Bahamas constituted 79.2% of the women tested; 17.7% were born in Haiti. The rate of HIV infection was 2.5% in the Bahamian women as compared with 4.5% in those born in Haiti. The highest incidence was in women aged 25-34 years and in women who had multiple pregnancies. There was a significant association with a history of crack cocaine use by the Bahamian women. There was also a significant association between a lack of education and HIV infection in this group. There was a lower rate of condom use among women with less education and also among women in common-law relationships, but the association of lack of condom use and HIV infection did not reach statistical significance.

Quantitative measures of human immunodeficiency virus-specific antibodies predict progression to AIDS

Studies examining specific antibodies directed against antigenic components of human immunodeficiency virus (HIV), as potential markers of progression to AIDS, have reported inconsistent results. We used reflectance densitometry and survival analysis to determine whether single quantitative measures of HIV-specific antibodies predicted progression to AIDS in a prospective cohort of 159 HIV-infected homosexual men. Lowered baseline levels of p24 antibody and p24/gp41 antibody ratio were independent predictors of progression to AIDS and retained statistical significance after simultaneously controlling for CD4:CD8 ratio, age, use of zidovudine, and clinical symptoms. Quantitative measures of p24 antibody and p24/gp41 antibody ratio warrant further study with regards to their clinical application as markers of HIV disease progression.

Programmed cell death induced by HIV type 1 antigen stimulation is associated with a decrease in cytotoxic T lymphocyte activity in advanced HIV type 1 infection

The immune competence of peripheral blood mononuclear cells (PBMCs) from human immunodeficiency virus-seropositive (HIV+) patients was studied by assessing cytotoxic T lymphocyte (CTL) activity following recall HIV antigen stimulation. Target cells were HLA-A-matched EBV-transformed B cells expressing HIV-1 antigen. In the presence of recombinant IL-2 (rIL-2, 2 or 10 U/ml), about 50% of PBMCs from HIV+ asymptomatic patients responded to HIV-1 antigen stimulation in vitro with increased cytotoxic activity. In contrast, PBMCs from patients with overt AIDS, cultured in medium containing rIL-2 (2 U/ml) and HIV-1 antigen, showed no increase in cytotoxic activity; in the presence of rIL-2 (10 U/ml) and HIV-1 antigen, an inhibitory effect on CTL activity was observed. This inhibitory effect was associated with programmed cell death (apoptosis) of CD8+ lymphocytes and cells of both gamma/delta TcR-positive and -negative phenotypes. However, prior to the apoptosis, different TcR phenotypes of T lymphocyte reacted differently to HIV-1 antigen stimulation. The HIV-1 antigen initially appeared to cause gamma/delta TcR-positive T lymphocytes to proliferate and/or differentiate and later induced cell death. Whereas, prior to the apoptosis, no proliferation of gamma/delta TcR-negative T lymphocytes induced by HIV-1 antigen was observed.

Lack of correlation between phenotype activation markers of CD8 lymphocytes and cytotoxic T lymphocyte (CTL) function in HIV-1 infection: evidence for rescue with rIL-2

CTL activity against HIV-1 antigens expressed on HLA-A-matched EBV-transformed B target cells was detected in 33% (6/18) of freshly isolated PBMC (FPBMC) from patients in the early stages of HIV-1 infection (CDCII). No CTL activity was detected in FPMBC in patients with AIDS (CDCIV). However, the presence of CTL activity did not correlate with the expression of CTL activation markers. A dual-color flow cytometric examination revealed that the CD8+ lymphocytes bearing the memory (CD29) and activation (S6F1) surface molecules increased in number as the HIV-1 infection progressed. This functional and phenotypic discrepancy in memory CD8+ lymphocytes suggests that the memory CD8+ lymphocytes have lost cytotoxic function and become "paralyzed" as the HIV disease progresses. Incubation of PBMC of HIV(+) patients with rIL-2 reactivated predominantly HIV-specific CTL. However, rIL-2 stimulation also activated a "polyclonal or polyreactive" cytotoxic function. The reactivation of CTL function is rIL-2 dosage dependent and the amount of rIL-2 required for reactivation is associated with the severity of the disease. HIV antigen specific CTL in HIV(+) patients can be selectively expanded by HIV antigen stimulation in the presence of rIL-2. These results suggest that the in vivo IL-2 deficiency occurring in HIV-1 infection may be responsible in part for the "paralysis" of HIV specific CTL activity. Such activity can be rescued nonspecifically by exogenous rIL-2 stimulation and expanded specifically by HIV-1 antigen stimulation.

Pneumocystis prophylaxis for all, some, or no HIV-infected infants less than one year of age: A decision analysis approach

Pneumocystis carinii pneumonia (PCP) is associated with significant mortality and morbidity among infants infected with human immunodeficiency virus (HIV). The preferred prophylaxis strategy for such infants is a subject of debate. Medical decision analysis was used to determine the preferred strategy for primary PCP prophylaxis among asymptomatic HIV-infected infants less than one year of age, and to determine the thresholds at which different variables influence decision making. Utility measures (health state preference values) were used to determine whether prophylaxis should be given to all, some or no infants. In this regard, some infants would receive prophylaxis if baseline CD4 counts are fewer than 1500 cells/mm(3). The results suggest that the preferred option is to give prophylaxis to all asymptomatic HIV-infected infants despite CD4 counts, if the risk of PCP is equal to or greater than 25%. However, if the risk of PCP is less than 25%, prophylaxis is recommended for those infants with CD4 counts of fewer than 1500 cells/mm(3). The results complement current guidelines regarding PCP prophylaxis for HIV-infected infants.

Ongoing high-risk sexual behaviors in relation recreational drug use in sexual encounters. Analysis of 5 years of data from the Toronto Sexual Contact Study

The current study investigated the association between the use of recreational drugs at the time of sexual activity and high-risk sexual behavior in a Toronto cohort of 249 homosexual and bisexual men over a 5-year period commencing in 1984 to 1985 and concluding in 1989 to 1990. The main analysis was based on a total of 2536 visits. Univariate and multivariate Liang-Zeger regression models were used to relate the log of the sexual activity score (SARS) to the independent variables over the 20 follow-up visits while controlling for intercorrelations between variables from the same respondent. We found that there was a significant decline, over time, in the sexual activities that pose a higher risk of infection with human immunodeficiency virus. Recreational drugs still appear to be playing an important role in the continuation of higher-risk sexual activities. The use of poppers in conjunction with sex is a strong predictor of high-risk activity, as is use of alcohol and marijuana in conjunction with sex. Also, simultaneously strongly associated with higher-risk score is the Centers for Disease Control classification II. More emphasis needs to be placed on educating the population about the potential risks of combining reactional drugs with sexual activity.

Using serial observations to identify predictors of progression to AIDS in the Toronto Sexual Contact Study

The Toronto Sexual Contact Study comprises a cohort of 249 male sexual contacts of men with HIV disease which has been followed every 3 months for almost 5 years. On enrollment 143 were seropositive and 16 seroconverted during the follow-up period. By 31 December 1989, 41 of the 159 seropositive cohort members had developed AIDS. Using Cox relative risk regression models, we investigated the association of a number of laboratory and clinical variables and progression to AIDS. Fixed covariate models examined laboratory variables from the enrollment visit of cohort members, with time calculated from this date. In models assessing time dependent covariates, time was calculated from the estimated date of HIV infection. In the univariate models of either fixed or time dependent covariates, many variables were significantly associated with risk of progression to AIDS (T4 cell count, T4/T8 ratio, blastogenic responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen, serum IgA, appearance of p24 antigen, and the development of oral hairy leukoplakia, thrush, or herpes zoster). Appearance of persistent generalized lymphadenopathy was not associated with increased risk of progression. In the multivariate model which evaluated fixed laboratory covariates, T4/T8 ratio, IgA level, and PHA response at enrollment were significantly associated with elevated risk.(ABSTRACT TRUNCATED AT 250 WORDS)

The probability of progression to AIDS in a cohort of male sexual contacts of men with HIV disease

In a cohort of 249 male sexual contacts of men with AIDS or an AIDS-related condition (ARC), 143 cohort members were seropositive on enrollment and 16 seroconverted during follow-up. A logistic Weibull mixture model was used to estimate the probability of progression to AIDS after HIV infection when infection was assumed to occur during the period of sexual contact with the primary case. Forty cohort members developed AIDS while under study. It appears that at least 50% of men with HIV disease will progress to AIDS and that the best estimate of this probability lies anywhere in the interval 70% to 100%.

Inhibition of human immunodeficiency virus type 1 multiplication by antisense and sense RNA expression

Human immunodeficiency virus type 1 (HIV-1) primarily infects CD4+ lymphocytes and macrophages and causes AIDS in humans. Retroviral vectors allowing neomycin phosphotransferase (npt) gene expression were engineered to express 5' sequences of HIV-1 RNA in the antisense or sense orientation and used to transform the human CD4+ lymphocyte-derived MT4 cell line. Cells expressing antisense or sense RNA to the HIV-1 tat mRNA leader sequence, as part of the 3' untranslated region of the npt mRNA, remained sensitive to HIV-1 infection. In contrast, resistance to HIV-1 infection was observed in cells expressing antisense RNA to the HIV-1 primer-binding site or to the region 5' to the primer-binding site as part of the 3' region of the npt mRNA. Cells expressing the tat mRNA leader sequence in the sense orientation as a precise replacement of the 5' untranslated region of npt mRNA were also resistant to HIV-1. These results indicate that sense and antisense approaches can be used to interfere with HIV-1 multiplication.

Resistance to human immunodeficiency virus type 1 (HIV-1) infection in human CD4+ lymphocyte-derived cell lines conferred by using retroviral vectors expressing an HIV-1 RNA-specific ribozyme

Toward gene therapy for the treatment of human immunodeficiency virus type 1 (HIV-1) infections in AIDS, Moloney murine leukemia virus-derived retroviral vectors were engineered to allow constitutive and tat-inducible expression of an HIV-1 5' leader sequence-specific ribozyme (Rz1). These vectors were used to infect the human CD4+ lymphocyte-derived MT4 cell line. The stable MT4 transformants expressing an HIV-1 RNA-specific ribozyme, under the control of the herpes simplex virus thymidine kinase (tk) promoter, were found to be somewhat resistant to HIV-1 infection as virus production was delayed. In cells allowing ribozyme expression under control of the simian virus 40 or cytomegalovirus promoter, the rate of HIV-1 multiplication was slightly decreased, and virus production was delayed by about 14 days. The highest level of resistance to HIV-1 infection was observed in MT4 cells transformed with a vector containing a fusion tk-TAR (trans activation-responsive) promoter to allow ribozyme expression in a constitutive and tat-inducible manner; no HIV-1 production was observed 22 days after infection of these cells. These results indicate that retroviral vectors expressing HIV-1 RNA-specific ribozymes can be used to confer resistance to HIV-1 infection.

Percutaneous injuries among health care workers. The real value of human immunodeficiency virus testing of 'donor' blood

A decision analysis was conducted to examine whether health care workers should receive short-term (42 days) zidovudine treatment following percutaneous exposure to blood, as well as to determine the value of testing "donor" (patient's) blood. Three alternative options were analyzed: treat all, treat none, and test. In the treat all option, all health care workers receive short-term zidovudine therapy immediately after exposure; in the treat none option, no one receives zidovudine; and in the test option, donor blood is tested, and if it is human immunodeficiency virus (HIV) positive, zidovudine is given. Baseline variables were obtained from the literature. Each outcome was expressed as a utility; this is a method of quantifying the values that persons place on different health states. The results showed that the test option was preferred. Sensitivity analyses indicated that even if the risk of seroconversion were zero or the effectiveness of zidovudine were zero or the drug were withheld, this option was preferred, thus indicating some value of testing other than merely identifying health care workers who should receive zidovudine. In the baseline analysis, this was derived from the fact that approximately 95% of the health care workers would be reassured by a negative test; ie, only approximately 5% of donors are HIV positive. If the prevalence of HIV seropositivity exceeded 42%, the treat none option was preferred. This was found to be due to the fact that increased numbers of health care workers would be told that they were exposed to HIV-positive blood. The "worrying factor" associated with such an exposure was such that above 42% HIV seropositivity, the treat none option was preferred overall. Thus, the real value of testing donor blood is in identifying those persons (greater than 95%) who could be told that they were exposed to HIV-negative blood, that is, reducing their worrying factor to zero. Because acquired immunodeficiency syndrome is a fatal disease, and given that zidovudine is the only available therapeutic option at present, the drug has an important role to play if its effectiveness is greater than zero.

Regulation of tumor necrosis factor receptor expression by acid-labile interferon-alpha from AIDS sera

High levels of an unusual acid-labile interferon (IFN) alpha in sera of patients with human immunodeficiency virus (HIV) infection are associated with disease progression to acquired immunodeficiency syndrome (AIDS). Since IFNs have been shown to enhance the cytotoxic actions of tumor necrosis factor (TNF), a potent mediator of inflammation and cachexia, a study was undertaken to investigate whether the acid-labile IFN alpha produced in AIDS can regulate TNF receptor expression. The expression of TNF receptors was determined by studying the interaction of [125I]TNF with cellular receptors. The results show the acid-labile IFN alpha present in AIDS sera is capable of inducing the expression of cellular receptors for TNF. The extent of induction of TNF receptors depends on the concentration of the acid-labile IFN alpha in the AIDS sera. There is no significant induction of TNF receptors when the AIDS sera are preneutralized with polyclonal anti-IFN alpha antibodies. It is also shown that the synthesis of TNF by peripheral blood monocytes (PBM) from patients with HIV infection is enhanced during the progression of HIV infection in vivo. Thus, the TNF system is activated in patients with HIV infection. This activation may be a contributing factor to some of the physiological disturbances including the wasting syndrome observed in AIDS.

Sexual behaviour changes in a cohort of male sexual contacts of men with HIV disease: a three-year overview

We describe the sexual behaviour reported by 240 seronegative and seropositive homosexual men over a 3-year period. Sexual partners of men with HIV disease were recruited into a prospective study between July 1984 and July 1985 and were monitored every 3 months thereafter. Data on sexual activities were collected through interviewer-administered questionnaires. The cohort experienced a reduction in both the number of sexual partners and the volume of sexual activity. Reductions in the number of partners were early and dramatic. Changes in sexual activities were gradual and consistent in trend. The greatest reduction occurred in high risk activities (receptive and insertive anal intercourse). After 3 years of follow-up, only 10% of the men continue to be exposed to semen through unprotected receptive anal intercourse and 18% through unprotected receptive oral-genital sex. The proportion of men engaging in oral-genital contact and masturbation remained stable over the 3 years. Once informed of their serostatus, both seropositive and seronegative men reduced their high risk behaviour. The decline in rates of STDs and seroconversion confirmed that this cohort had indeed reduced their high risk behaviour.

Comparison of saliva and blood for human immunodeficiency virus prevalence testing

Testing saliva for the detection of human immunodeficiency virus (HIV) antibodies has many potential advantages for epidemiologic surveillance. A commercial ELISA kit and a standardized in-house immunoblot (IB) system were slightly modified to enhance antibody detection in saliva. Frozen saliva specimens from Toronto Sexual Contact Study participants (including sequential saliva specimens collected during seroconversion) were tested as were fresh saliva samples collected from a population of street-based intravenous drug users (IVDUs). HIV antibody results on saliva were compared with HIV serostatus determined by ELISA and IB on serum or dried blood spots. The overall sensitivity was 98.3% (117/119) for the kit and 99.2% (118/119) for IB; the specificity was 100% (429/429). In the IVDU population, compliance in the voluntary submission of specimens increased from 69% agreeing to provide blood samples to 89% agreeing to provide blood, saliva, or both. Saliva specimens can be easily collected under difficult field conditions with minimal training and provide a valuable alternative to testing blood for HIV-seroprevalence studies.

Erythema infectiosum and pregnancy-related complications

Erythema infectiosum, an acute, communicable viral disease with a highly distinctive exanthem, follows the usual course of a self-limiting benign disease. In pregnant women, however, it may be associated with fetal death and nonimmune hydrops fetalis. Because of the association of human parvovirus (HPV) B19 infection with fetal damage we reviewed the current knowledge of the clinical aspects of erythema infectiosum, focusing on pregnancy and fetal outcome, to determine the magnitude of fetal risk and offer recommendations for management. Among 180 infected pregnant women 44 fetal deaths (24%) occurred, 1 to 12 weeks after the infection was noted. Pregnant women should be advised that (a) because of the high prevalence (up to 65%) of anti-HPV B19 IgG antibody among adults most of them are not at risk and (b) if maternal infection does occur therapeutic abortion is not indicated since intrauterine infection causes fetal death more often than abnormal development. Infection should be suspected in pregnant women who exhibit the symptoms of erythema infectiosum with or without arthropathy. They should be monitored for an elevated serum alpha-fetoprotein level (indicating fetal aplastic crisis) and undergo serial ultrasonography for the detection of hydrops fetalis. Although the incidence of congenital malformation is no higher than the expected rate in the general population (3% to 5%), the precise incidence of fetal adverse outcomes remains unknown and requires investigation in larger, prospective studies.