Acyclovir and transmission of HIV-1 from persons infected with HIV-1 and HSV-2

BACKGROUND

Most persons who are infected with human immunodeficiency virus type 1 (HIV-1) are also infected with herpes simplex virus type 2 (HSV-2), which is frequently reactivated and is associated with increased plasma and genital levels of HIV-1. Therapy to suppress HSV-2 reduces the frequency of reactivation of HSV-2 as well as HIV-1 levels, suggesting that suppression of HSV-2 may reduce the risk of transmission of HIV-1.

METHODS

We conducted a randomized, placebo-controlled trial of suppressive therapy for HSV-2 (acyclovir at a dose of 400 mg orally twice daily) in couples in which only one of the partners was seropositive for HIV-1 (CD4 count, > or = 250 cells per cubic millimeter) and that partner was also infected with HSV-2 and was not taking antiretroviral therapy at the time of enrollment. The primary end point was transmission of HIV-1 to the partner who was not initially infected with HIV-1; linkage of transmissions was assessed by means of genetic sequencing of viruses.

RESULTS

A total of 3408 couples were enrolled at 14 sites in Africa. Of the partners who were infected with HIV-1, 68% were women, and the baseline median CD4 count was 462 cells per cubic millimeter. Of 132 HIV-1 seroconversions that occurred after randomization (an incidence of 2.7 per 100 person-years), 84 were linked within couples by viral sequencing: 41 in the acyclovir group and 43 in the placebo group (hazard ratio with acyclovir, 0.92, 95% confidence interval [CI], 0.60 to 1.41; P=0.69). Suppression with acyclovir reduced the mean plasma concentration of HIV-1 by 0.25 log(10) copies per milliliter (95% CI, 0.22 to 0.29; P<0.001) and the occurrence of HSV-2-positive genital ulcers by 73% (risk ratio, 0.27; 95% CI, 0.20 to 0.36; P<0.001). A total of 92% of the partners infected with HIV-1 and 84% of the partners not infected with HIV-1 remained in the study for 24 months. The level of adherence to the dispensed study drug was 96%. No serious adverse events related to acyclovir were observed.

CONCLUSIONS

Daily acyclovir therapy did not reduce the risk of transmission of HIV-1, despite a reduction in plasma HIV-1 RNA of 0.25 log(10) copies per milliliter and a 73% reduction in the occurrence of genital ulcers due to HSV-2. (ClinicalTrials.gov number, NCT00194519.)

Tree-Based Methods for Discovery of Association between Flow Cytometry Data and Clinical Endpoints

We demonstrate the application and comparative interpretations of three tree-based algorithms for the analysis of data arising from flow cytometry: classification and regression trees (CARTs), random forests (RFs), and logic regression (LR). Specifically, we consider the question of what best predicts CD4 T-cell recovery in HIV-1 infected persons starting antiretroviral therapy with CD4 count between 200 and 350 cell/muL. A comparison to a more standard contingency table analysis is provided. While contingency table analysis and RFs provide information on the importance of each potential predictor variable, CART and LR offer additional insight into the combinations of variables that together are predictive of the outcome. In all cases considered, baseline CD3-DR-CD56+CD16+ emerges as an important predictor variable, while the tree-based approaches identify additional variables as potentially informative. Application of tree-based methods to our data suggests that a combination of baseline immune activation states, with emphasis on CD8 T-cell activation, may be a better predictor than any single T-cell/innate cell subset analyzed. Taken together, we show that tree-based methods can be successfully applied to flow cytometry data to better inform and discover associations that may not emerge in the context of a univariate analysis.

Oesophageal tone and sensation in the transition zone between proximal striated and distal smooth muscle oesophagus

Previous studies have shown that the proximal striated muscle oesophagus is less compliant and more sensitive than the distal smooth muscle oesophagus. Conventional and high resolution manometry described a transition zone between striated and smooth muscle oesophagus. We aimed to evaluate oesophageal tone and sensitivity at the transition zone of oesophagus in healthy volunteers. In 18 subjects (seven men, mean age: 28 years) an oesophageal barostat study was performed. Tone and sensitivity were assessed using stepwise isobaric distensions with the balloon located at transition zone and at distal oesophagus in random order. To study the effect induced on transition zone by a previous distension at the distal oesophagus and vice versa, identical protocol was repeated after 7 days with inverted order. Initial distension of a region is referred to as 'naïf' distension and distension of a region following the distension of the other segment as 'primed' distension. Assessment of three oesophageal symptoms (chest pain, heartburn and 'other') was obtained at the end of every distension step. Compliance was significantly higher in the transition zone than in the distal oesophagus (1.47 +/- 0.14 vs 1.09 +/- 0.09 mL mmHg(-1), P = 0.03) after 'naif' distensions. This difference was not observed during 'primed' distensions. Higher sensitivity at transition zone level was found in 11/18 (61%) subjects compared to 6/18 (33%, P < 0.05) at smooth muscle oesophagus. Chest pain and 'other' symptom were more often induced by distention of the transition zone, whereas heartburn was equally triggered by distension of either region. The transition zone is more complaint and more sensitive than smooth muscle oesophagus.

Role of the laboratory in ensuring global access to ARV treatment for HIV-infected children: consensus statement on the performance of laboratory assays for early infant diagnosis

A two day meeting hosted by the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) was held in May 2006 in Entebbe, Uganda to review the laboratory performance of virologic molecular methods, particularly the Roche Amplicor DNA PCR version 1.5 assay, in the diagnosis of HIV-1 infection in infants. The meeting was attended by approximately 60 participants from 17 countries. Data on the performance and limitations of the HIV-1 DNA PCR assay from 9 African countries with high-burdens of HIV/AIDS were shared with respect to different settings and HIV- subtypes. A consensus statement on the use of the assay for early infant diagnosis was developed and areas of needed operational research were identified. In addition, consensus was reached on the usefulness of dried blood spot (DBS) specimens in childhood as a means for ensuring greater accessibility to serologic and virologic HIV testing for the paediatric population.

Evaluation of the performance of the automated NucliSENS easyMAG and EasyQ systems versus the Roche AmpliPrep-AMPLICOR combination for high-throughput monitoring of human immunodeficiency virus load

This study presents the data of an evaluation of the automated Nuclisens easyMAG and EasyQ systems versus the Roche AmpliPrep-AMPLICOR combination for testing of high-volume human immunodeficiency virus (HIV) load. This represents a follow-up of a previous study investigating the performance of the real-time Nuclisens assay using the semiautomated NucliSENS miniMAG extraction procedure. Three hundred eighteen patient samples were analyzed using both methods. The easyMAG-EasyQ HIV type 1 system has a higher sensitivity and broader dynamic range than the Cobas AmpliPrep-AMPLICOR system when the standard Roche assay is used alone, 25 to 3,000,000 IU/ml versus 400 to 750,000 HIV RNA copies/ml, respectively. There was significant correlation between the assays (0.93; P < 0.0001), with good accuracy (percent similarity mean mu = 96%), good precision (percent similarity standard deviation = 4.97%), and overall good agreement with a low percent similarity coefficient of variation of 5.17 to 6.11%. Bland-Altman analysis revealed that the AMPLICOR assay generated higher values than the EasyQ combination, with 95% of results within clinically acceptable limits. The throughput of samples was greatly improved using the easyMAG-EasyQ system, allowing 144 samples to be processed within 6 h. The potential for contamination has been dramatically reduced using the automated extraction system. Additional negative controls have been added to the kit to monitor for contamination based on the South African experience. This assay thus presents a real option for monitoring HIV load assays in high-volume testing environments.

Chronic idiopathic thrombocytopenic purpura: present strategy, guidelines and new insights

Idiopathic thrombocytopenic purpura (ITP) is an immune-mediated thrombocytopenia. The diagnosis is made after exclusion of other secondary causes of thrombocytopenic disorders. The primary treatment goal is to prevent severe bleeding rather than achieve normal platelet counts. In adults ITP usually has an insidious onset and chronic course. Although ITP is a relatively common haematological disorder, there are important unresolved issues in its management, especially for chronic refractory ITP patients. New therapeutic agents have changed strategies for ITP treatment. This article reviews the treatment indications and options of chronic ITP in adults in the literature and compares them with the treatment indications and treatment options used by the Dutch internist.

Revised guidelines for diagnosis of perinatal HIV-1 infection in South Africa

No abstract available.

Malaria prevention in The Gambia: patterns of expenditure and determinants of demand at the household level

OBJECTIVE

To provide a better understanding of (1) the amounts households in The Gambia spend on a wide variety of malaria prevention measures, (2) how expenditure fluctuates throughout the year and (3) the main determinants of expenditure.

METHODS

A random sample of 1700 households from the Farafenni region were interviewed about their expenditure on malaria prevention over the past 2 weeks. Interviews were staggered over 12 months. Expenditure was measured for bed nets, treating and repairing bed nets, aerosols, coils, indoor spraying, smoke and other prevention strategies such as drinking herbs and cleaning the outside environment. Results Expenditure on bed nets, including treatment and repair, constituted only 10% of total expenditure on malaria prevention. Every fortnight, households spent an average of 8.40 Dalasis (D) on coils, 4.20 D on indoor sprays, 3.09 D on smoke and 3.06 D on aerosols, together making up 81% of total fortnightly expenditure. Of the 442 households that did not own a bed net, 68% said it was because they could not afford one. Every 2 months, the same households spent an average of US 5 dollars, the equivalent to the cost of an insecticide treated bed net, on other forms of prevention. Total expenditure was 42% higher during the wet season than for the rest of the year. For every month of the year, coils were the dominant form of prevention expenditure. Wealth, age, occupation of household head, location of residence and month of the year were significant determinants of prevention expenditure.

CONCLUSIONS

Households in The Gambia spend considerable amounts on a range of malaria prevention products and activities throughout the year. Bed nets represent a relatively small proportion of this expenditure even though they are perceived to be the most efficient and effective method of malaria control. A more concerted effort is needed to develop appropriate targeting strategies to encourage bed net use especially for children <5 years of age. Equal emphasis should be given to addressing barriers to purchasing nets such as their relative high upfront cost.

HIV/AIDS prevalence testing--merits, methodology and outcomes of a survey conducted at a large mining organisation in South Africa

OBJECTIVES

To determine the HIV prevalence rate at Anglo Platinum, a large, multinational organisation operating in South Africa (Gauteng, Limpopo and North-West), and to assess the merits, methodology and outcomes of the survey.

METHODS

A sample of 11,339 individuals, representing 18.4% of the organisation's employees, were tested for HIV. HIV prevalence was determined using the Wellcozyme HIV 1+2 GACELISA test (oral fluid assay), and variables such as age, site, grade and gender were analysed.

RESULTS

The overall prevalence rate was 24.6% (95% confidence interval (CI): 20.4-28.8), translating into approximately 15,167 HIV-infected individuals. Interestingly, there was considerable variation in prevalence between sites within the same geographical regions, highlighting the limitations of using data obtained from antenatal HIV surveillance surveys. As an example, the prevalence at sites in Limpopo province ranged from 9.8% to 19%, with the same basic demographic data in terms of race, age and gender.

CONCLUSION

The survey data enabled the organisation to plan resource allocation appropriately for each business unit following their commitment to the treatment of infected employees with antiretroviral therapy. These baseline prevalence data also provide an opportunity for monitoring of proposed interventions using cross-sectional surveys at designated intervals in the future.

Risk factors for defaulting from tuberculosis treatment: a prospective cohort study of 301 cases in the Gambia

SETTING

An urban tuberculosis (TB) clinic, The Gambia.

OBJECTIVE

To identify patient characteristics associated with increased rates of defaulting from treatment, specifically knowledge and cost factors amenable to intervention.

DESIGN

Prospective cohort study of TB cases at least 15 years of age commencing treatment, interviewed by semi-structured questionnaire and followed for attendance at thrice-weekly directly observed treatment (DOT).

RESULTS

Of 301 patients, 76 (25.2%) defaulted from treatment and 25 did not return for treatment. The defaulting rate was higher among those who said they were uncertain that their treatment would work (HR 3.64; 95%CI 1.42-9.31, P = 0.007) and among those who incurred significant time or money costs travelling to receive treatment (HR 2.67; 95%CI 1.05-6.81; P = 0.04). These factors had differing effects with respect to time: uncertainty over treatment success was important in the first 90 days of treatment, while increased cost of travelling to the clinic was important after 90 days.

CONCLUSION

In The Gambia, risk groups for defaulting can be recognised at the start of treatment and are at highest risk at different times. Home-based self-administration of medications after 3 months of DOT should be considered as confidence in treatment success rises, and the costs of travelling to receive treatment start to take their toll.