Staggered enforcement of infection control and prevention measures following four consecutive potential laboratory exposures to imported Brucella melitensis

From 2015 until 2020, Brucella melitensis was isolated four times in our microbiology laboratory. All patients had travelled in endemic-areas. Immediately after the first occurrence, all laboratory staff were risk-stratified and preventive and protective measures were applied according to CDC guidelines. Nineteen workers were exposed and needed chemoprophylaxis and follow-up. At each subsequent occurrence, risk analysis was performed, and additional measures were implemented accordingly, leading to a progressive reduction of exposed staff members to none the fourth time. We describe here the additional measures that permitted this important exposure reduction.

A case report of serious haemolysis in a glucose-6-phosphate dehydrogenase-deficient COVID-19 patient receiving hydroxychloroquine

While the COVID-19 epidemic occurred since December 2019, as of end April 2020, no treatment has been validated or invalidated by accurate clinical trials. Use of hydroxychloroquine has been popularised on mass media and put forward as a valid treatment option without strong evidence of efficacy. Hydroxychloroquine (HCQ) has its own side effects, some of which are very serious like acute haemolysis in glucose-6-phosphate dehydrogenase (G6PD) deficient patients. Side effects may be worse than the disease itself. Belgian national treatment guidelines recommend the use of HCQ in mild to severe COVID-19 disease. As opinions, politics, media and beliefs are governing COVID-19 therapy, performance of randomised controlled blinded clinical trials became difficult. Results of sound clinical trials are eagerly awaited. We report a case of acute haemolysis leading to admission in intensive care unit and renal failure in a patient with uncovered G6PD deficiency.

Disrupted trabecular bone micro-architecture in middle-aged male HIV-infected treated patients

OBJECTIVES

HIV-infected individuals are at increased risk of incident fractures. Evaluation of trabecular bone micro-architecture is an important tool to assess bone strength, but its use has not yet been reported in middle-aged HIV-infected male individuals. The aim of the study was to compare bone micro-architecture between HIV-infected and HIV-uninfected men.

METHODS

In this cross-sectional study, 53 HIV-infected male individuals with a mean (± standard deviation) age of 49 ± 9 years who had been receiving antiretroviral therapy including tenofovir disoproxil fumarate (DF) for at least 60 months were compared with 50 HIV-uninfected male controls, matched for age and ethnic origin. We studied the volumetric bone density and micro-architecture of the radius and tibia using high-resolution peripheral quantitative computed tomography (HR-p QCT).

RESULTS

Volumetric trabecular bone density was 17% lower in the tibia (P < 10(-4) ) and 16% lower in the radius (P < 10(-3) ) in HIV-infected patients compared with controls. By contrast, the cortical bone density was normal at both sites. The tibial trabecular micro-architecture differed markedly between patients and controls: bone volume/total volume (BV/TV) and trabecular number were each 13% lower (P < 10(-4) for both). Trabecular separation and inhomogeneity of the network were 18% and 24% higher in HIV-infected patients than in controls, respectively. The radial BV/TV and trabecular thickness were each 13% lower (P < 10(-3) and 10(-2) , respectively). Cortical thickness was not different between the two groups.

CONCLUSIONS

The findings of lower volumetric trabecular bone density and disrupted trabecular micro-architectural parameters in middle-aged male HIV-infected treated patients help to explain bone frailty in these patients.

Impact of Various Antiretroviral Drugs and Their Plasma Concentrations on Plasma Lipids in Heavily Pretreated HIV-Infected Patients

OBJECTIVE

To evaluate the frequency and the magnitude of lipid abnormalities (LA) in respect to the nature of the antiretroviral drug and its plasma concentrations.

PATIENTS/METHOD

Trough concentrations (C(trough)) of protease inhibitors (PIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) were assessed at Weeks 4, 8, 24, 28, and 32. Fasting triglycerides (TG) and total cholesterol (CH) were sampled at Weeks 0, 12, 20, and 32. We analyzed the probability of occurrence of grade 3-4 CH (> 7.8 mmol/L) and TG (> 8.4 mmol/L) during a 24-week period according to the drug taken using a Kaplan-Meier analysis and log rank test. Relation between Week 8 PI or NNRTI C(trough) and Week 12 lipid levels was assessed using the Kendall correlation measure.

RESULTS

The PharmAdapt study included 252 patients (mean age 41 years, 83% males); the patients received a PI (73%), an NNRTI (50%), and/or a ritonavir (RTV) booster-containing (46%) regimen. Compared to any other regimen, use of lopinavir (LPV)/RTV or efavirenz (EFV) was associated with a higher risk of grade 3-4 CH. Use of LPV/RTV and RTV booster was associated with a higher risk of grade 3-4 TG. Use of any PI-containing regimen was associated with a higher risk for grade 3-4 CH and TG compared to non PI-based regimens. Kendall correlation coefficients for PI or NNRTI C(trough) and blood lipid levels were close to zero for all drugs and CH or TG, showing the absence of relation between drug concentrations and lipid levels.

CONCLUSION

Severity of lipid abnormalities is related to the nature of the antiretroviral drug. There is no short-term relation between PI or NNRTI trough concentrations and blood lipid levels in heavily pretreated patients.

Database-Supported Teleconferencing: An Additional Clinical Mentoring Tool to Assist a Multinational Company HIV/AIDS Treatment Program in Africa

BACKGROUND

The lack of human resources for health is presently recognized as a major factor limiting scale-up of antiretroviral treatment (ART) programs in resourcelimited settings. The mobilization of public and private partners, the decentralization of care, and the training of non-HIV specialist nurses and general practitioners could help increase the number of HIV-infected patients receiving ART. In addition to other forms of training, scheduled teleconferences (TCs) have been organized to support a comprehensive HIV treatment program delivered by a private company's health team.

OBJECTIVE

To describe the role of the TC as an additional tool in mentoring a company's health care workers (HCWs).

METHOD

For this study, all TC reports were retrospectively reviewed and the questions classified by topic. Participating Heineken physicians evaluated the technical quality and scientific relevance of the TCs through an anonymous survey.

RESULTS

From October 2001 to December 2003, 10 HCWs working in 14 operating companies in 5 African countries raised 268 problems during 45 TCs. A total of 79 questions (29%) were asked about antiretroviral (ARV) therapy, 53 (20%) about the diagnosis and treatment of opportunistic infection, 43 (16%) about ARV toxicity, 40 (15%) about care organization and policy, 32 (12%) about laboratory or drug supply, and 21 (8%) about biological parameters. The mean TC attendance rate was 70%. The level of satisfaction among local company physicians was 65% for logistics, 89% for scientific relevance, 84% for applicability of advice, and 85% overall. The most common complaints concerned the poor quality of the telephone connection and language problems for francophone participants.

CONCLUSION

Database-supported teleconferencing could be an additional tool to mentor company HCWs in their routine care of HIV-infected workers and family members. The role and costeffectiveness of telemedicine in improving health outcomes should be further studied.

Isoniazid preventive therapy for people living with HIV: public health challenges and implementation issues

Isoniazid preventive therapy (IPT) is recognised as an important component of collaborative tuberculosis (TB) and human immunodeficiency virus (HIV) activities to reduce the burden of TB in people living with HIV (PLHIV). However, there has been little in the way of IPT implementation at country level. This failure has resulted in a recent call to arms under the banner title of the 'Three I's' (infection control to prevent nosocomial transmission of TB in health care settings, intensified TB case finding and IPT). In this paper, we review the background of IPT. We then discuss the important challenges of IPT in PLHIV, namely responsibility and accountability for the implementation, identification of latent TB infection, exclusion of active TB and prevention of isoniazid resistance, length of treatment and duration of protective efficacy. We also highlight several research questions that currently remain unanswered. We finally offer practical suggestions about how to scale up IPT in the field, including the need to integrate IPT into a package of care for PLHIV, the setting up of operational projects with the philosophy of 'learning while doing', the development of flow charts for eligibility for IPT, the development and implementation of care prior to antiretroviral treatment, and finally issues around procurement, distribution, monitoring and evaluation. We support the implementation of IPT, but only if it is done in a safe and structured way. There is a definite risk that 'sloppy' IPT will be inefficient and, worse, could lead to the development of multidrug-resistant TB, and this must be avoided at all costs.

Management of adults living with HIV/AIDS in low-income, high-burden settings, with special reference to persons with tuberculosis

Because of the increasing availability of antiretroviral (ARV) agents for HIV in low-income countries, many clinicians now need training on their use. This is especially true for clinicians caring for individuals with tuberculosis (TB), given its close relationship with HIV/AIDS. This article summarizes the key decisions facing clinicians who manage HIV-infected persons, with particular reference to issues regarding those dually infected with TB. Health care provider-initiated diagnostic testing using rapid HIV tests should be offered to all individuals with symptoms and signs suggesting HIV infection, including all persons with TB. Issues to be included in pre- and post-test counseling sessions are discussed. HIV-infected patients should be evaluated to determine clinical staging of HIV; certain laboratory examinations should ideally be performed to assess the degree of immunosuppression and to aid decisions about when best to start ARV therapy and preventive therapies. The recommended ARV regimens and guidance on proposed patient follow-up are presented. Good adherence to ARVs is required and factors that induce and reinforce compliance are suggested. The treatment of TB is a high priority, and follows the same principles whether the patient is HIV-infected or not. Suggestions are made about ARV use in patients with TB. A standardized and complementary information system should be developed to monitor management of HIV-TB patients and performance of joint TB and HIV care efforts. By diagnosing and managing additional HIV cases detected through the portal of the TB control programme, clinicians will contribute to diminishing the burden of HIV, and thus, TB.

Updated European recommendations for the clinical use of HIV drug resistance testing

In most European countries, HIV drug resistance testing has become a routine clinical tool. However, its practical implementation in a clinical context is demanding. The European HIV Drug Resistance Panel was established to make recommendations to clinicians and virologists on this topic and to propose quality control measures. The panel recommends resistance testing for the following indications: i) drug-naive patients with acute or recent infection; ii) therapy failure, including suboptimal treatment response, when treatment change is considered; iii) pregnant HIV-1-infected women and paediatric patients with detectable viral load when treatment initiation or change is considered; and iv) genotype source patient when post-exposure prophylaxis is considered. In addition, for drug-naive patients with chronic infection in whom treatment is to be started, the panel suggests that resistance testing should be strongly considered and recommends testing the earliest sample for drug resistance if suspicion of resistance is high or prevalence of resistance in this population exceeds 10%. The panel does not favour genotyping over phenotype, however it is anticipated that genotyping will be used more often because of its greater accessibility, lower cost and faster turnaround time. For the interpretation of resistance data, clinically validated systems should be used to the greatest extent possible. It is mandatory that laboratories performing HIV resistance tests take regular part in quality assurance programs. Similarly, it is necessary that HIV clinicians and virologists take part in continuous education and meet regularly to discuss problematic clinical cases. Indeed, resistance test results should be used in the context of all other clinically relevant information for predicting therapy response. The panel also encourages the timely collection of epidemiological information to estimate the impact of transmission of resistant HIV and the prevalence of HIV-1 non-B subtypes in the different European countries.

Updated European Recommendations for the Clinical Use of HIV Drug Resistance Testing

In most European countries, HIV drug resistance testing has become a routine clinical tool. However, its practical implementation in a clinical context is demanding. The European HIV Drug Resistance Panel was established to make recommendations to clinicians and virologists on this topic and to propose quality control measures. The panel recommends resistance testing for the following indications: i) drug-naive patients with acute or recent infection; ii) therapy failure, including suboptimal treatment response, when treatment change is considered; iii) pregnant HIV-1-infected women and paediatric patients with detectable viral load when treatment initiation or change is considered; and iv) genotype source patient when post-exposure prophylaxis is considered. In addition, for drug-naive patients with chronic infection in whom treatment is to be started, the panel suggests that resistance testing should be strongly considered and recommends testing the earliest sample for drug resistance if suspicion of resistance is high or prevalence of resistance in this population exceeds 10%. The panel does not favour genotyping over phenotype, however it is anticipated that genotyping will be used more often because of its greater accessibility, lower cost and faster turnaround time. For the interpretation of resistance data, clinically validated systems should be used to the greatest extent possible. It is mandatory that laboratories performing HIV resistance tests take regular part in quality assurance programs. Similarly, it is necessary that HIV clinicians and virologists take part in continuous education and meet regularly to discuss problematic clinical cases. Indeed, resistance test results should be used in the context of all other clinically relevant information for predicting therapy response. The panel also encourages the timely collection of epidemiological information to estimate the impact of transmission of resistant HIV and the prevalence of HIV-1 non-B subtypes in the different European countries.

Efficacy, safety and predictive factors of virological success of a boosted amprenavir-based salvage regimen in heavily antiretroviral-experienced HIV-1-infected patients

BACKGROUND

Amprenavir (APV) has been shown to be effective in naive or treatment-experienced HIV-1 infected patients. However, the safety and efficacy of the APV 600 mg/ritonavir (RTV) 100 mg twice a day (bid) combination, the usually recommended dosage for boosted APV, have been less well studied. We assessed the predictive factors associated with virological success of APV/RTV-based regimens.

METHODS

Patients in the PharmAdapt study receiving an APV/RTV-containing regimen were included in the study. The predictivity of covariates on virological response at 4 months was analysed according to the data analysis plan. We processed logistic regression using bootstrapping to allow several covariates in the models.

RESULTS

Forty patients received an APV/RTV-containing regimen, 38 of whom were male (95%). Risk factors were heterosexual contacts (four patients; 10%), homosexual contacts (31 patients; 78%), and intravenous drug use (four patients; 10%). Twenty-seven per cent of patients were Centers for Disease Control and Prevention Classification System (CDC) stage A, 38% were stage B and 35% were stage C. The median baseline CD4 count was 313 cells/microL [interquartile range (IQR) 211, 414], and the median baseline viral load was 4.4 log(10) HIV-1 RNA copies/mL (IQR 3.7, 4.9). Patients were exposed to a median number of 7.5 (IQR 6, 9) drugs for a median number of 3.8 (IQR 3.3, 4.3) years. The baseline number of resistance mutations was 4 [IQR 3, 5 for nucleoside reverse transcriptase inhibitors (NRTIs), 1 (IQR 0, 2)] for non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 6 [IQR 5, 8 for protease inhibitors (PIs)]. At month 4, median viral load decreased to 1.2 log(10) copies/mL (IQR 0.3, 1.6); 50% of patients had a viral load<200 copies/mL by intention-to-treat analysis. The number of APV resistance mutations was associated with viral load changes. Median APV concentration was 1750 ng/mL (IQR 1130, 2520). At month 4, using several cut-offs, neither APV concentration nor the genotypic inhibitory quotient was predictive of viral load changes. Baseline viral load and the number of protease mutations were associated with outcome.

CONCLUSIONS

Efficacious APV concentrations need to be determined for antiretroviral-experienced patients. Baseline viral load and the number of mutations on the protease coding region (PRO) were associated with the virological outcome of APV/RTV-based regimens.

Variable virological outcomes according to the center providing antiretroviral therapy within the PharmAdapt clinical trial

PURPOSE

Differences in virological response between HIV-infected patients at different study centers were analyzed as a substudy of PharmAdapt, a multicenter prospective randomized study to evaluate the utility of therapeutic drug monitoring after a genotypic-based treatment adaptation.

RESULTS

After 12 weeks, the percentage of patients participating in PharmAdapt with HIV RNA < 200 copies/mL ranged from 17% to 69% between centers providing antiretroviral care. In a multivariate analysis, independent factors predictive of viral load <200 HIV RNA copies/mL at Week 12 included: lower baseline viral load, lower nonnucleoside reverse transcriptase inhibitor resistance, lower protease inhibitor resistance, and the center providing antiretroviral therapy. To evaluate the final factor, study sites were divided into two groups based on Week 12 HIV RNA values above or below the median.

CONCLUSION

Using this definition, observed differences between centers included the use of stavudine, abacavir-, and/or efavirenz-based regimens and use of online expert advice.

Acute renal failure as initial presentation of visceral leishmaniasis in an HIV-1-infected patient

We report the case of an HIV-infected patient who presented with acute renal failure due to visceral leishmaniasis (VL). Although renal failure is the leading cause of death in dogs, the natural reservoir of Leishmania infantum, renal involvement is usually absent in human VL. However, L. infantum can be considered a cause of renal failure in HIV-infected patients.

Intracellular concentration of protease inhibitors in HIV-1-infected patients: correlation with MDR-1 gene expression and low dose of ritonavir

BACKGROUND

Protease inhibitors (PIs) are substrates for the P-glycoprotein (P-gp/170) encoded by the multi-drug resistance gene (MDR-1). HIV infection is associated with increased expression of P-gp. The role of MDR gene overexpression in clinical pharmacokinetics is not known.

METHOD

We determined by HPLC, at trough and peak levels, the current PI concentrations in plasma (P) and in peripheral blood mononuclear cells (PBMCs) (intracellular concentration [IC]) from 49 HIV-infected patients receiving different treatment combinations: nelfinavir ([NFV] n = 12); indinavir ([IDV] n = 10); amprenavir ([APV] n = 5); ritonavir (RTV) 100 bid/IDV 800 mg bid (n = 6); RTV 400 bid/IDV 400 mg bid (n = 3); RTV 100 bid/saquinavir (SQV) 600 mg tid (n = 9); APV 600 bid/RTV 100 mg bid (n = 4). We determined the mean ratio of intracellular/plasma PI concentration for each treatment group. The MDR-1 gene expression was determined by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). HIV viral load was simultaneously measured.

RESULTS

49 patients (mean age 41 +/- 8.7 years; mean CD4 cell count 418 [57-972]; mean HIV RNA 2.1 +/- 0.8 log(10)) were included in the study. Patients who overexpressed the MDR-1 gene had significantly lower trough intracellular PI levels (p =.02) or lower intracellular accumulation of PI (p =.042). Patients treated with low-dose RTV in combined regimens with detectable RTV intracellular concentration showed lack of MDR-1 gene expression (p =.01). Patients with HIV RNA < 40 copies/mL had significantly higher RTV intracellular accumulation (p =.029).

CONCLUSION

In HIV-infected patients, IC of PI is inversely correlated with MDR-1 gene overexpression. Undetectable viral load was associated with the use of low-dose RTV, probably linked to better intracellular accumulation of the drug. Nevertheless, further investigation is needed to confirm these results.

HIV resistance to antiretroviral drugs: mechanisms, genotypic and phenotypic resistance testing in clinical practice

HIV resistance to antiretroviral agents is a major contributory cause of treatment failure. The dynamics of HIV replication, together with patient-, physician-, and drug-related factors, lead to emergence of HIV resistant strains in most of the patients. Phenotypic assays look for an increase in the antiretroviral drug (ARV) concentration that inhibits 50% of the growth of the tested HIV strain (IC50), comparatively with a reference strain cultivated in parallel. Genotypic tests detect resistance mutations in the reverse transcriptase and protease genes by comparing the gene sequences of a resistant virus to those of a wild-type strain that has previously been described. The efficacy of each ARV class and each individual ARV is threatened by specific mutations and resistance mechanisms. In retrospective studies of genotypic or phenotypic resistance testing, baseline resistance tests results were correlated with virological outcomes. There is some evidence from prospective studies that resistance testing may have some benefits when used to choose salvage regimens. However, problems in the areas of test interpretation, patient compliance, availability of active drugs, and technical test performance limit the usefulness of resistance testing in clinical practice. This article reviews the mechanisms underlying HIV resistance, the principles of phenotypic and genotypic tests, and the use of these tests in clinical practice.

Iatrogenic Cushing's syndrome in an HIV-infected patient treated with inhaled corticosteroids (fluticasone propionate) and low dose ritonavir enhanced PI containing regimen

In HIV-infected patients, ritonavir, a potent cytochrome P450 inhibitor, is increasingly used to improve the pharmacokinetic profile of the associated protease inhibitor. HIV physicians are often faced with potential drug-drug interaction while treating associated diseases. We report the case of an HIV-infected patient with clinical features of Cushing's syndrome due to the interaction of low dose ritonavir with inhaled fluticasone propionate (FP). Safety of life-long CYP450 inhibition has still to be demonstrated.

Prevalence of nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance-associated mutations and polymorphisms in NNRTI-naïve HIV-infected patients

BACKGROUND

The efficacy of treatment containing nonnucleoside reverse transcriptase inhibitors (NNRTIs) could be compromised in NNRTI-naïve patients already harboring a virus resistant to NNRTIs. On the contrary, hypersusceptibility to NNRTIs in patients having failed nucleoside reverse transcriptase inhibitor (NRTI)-containing regimens has been described and has been associated with improved outcome.

METHOD

We assessed the prevalence of NNRTI resistance-associated mutations or polymorphisms in 146 antiretroviral-naïve patients and in 181 HIV-infected patients who were given an NNRTI-based regimen. We phenotypically evaluated the NNRTI susceptibility of 41 strains presenting with amino acid substitutions at positions involved in NNRTI resistance.

RESULTS

In the 268 genotypically analyzable samples, the overall prevalence of NNRTI resistance-associated mutations was 2% (6/268 patients). The prevalence of strains with amino acid substitutions at reverse transcriptase (RT) gene positions (A98, K101, K103, V106, V108, V179) involved in NNRTI resistance was 15%. Hypersusceptibility to NNRTI was rare (2%, 1/41) in those samples. RT substitutions at positions involved in NNRTI resistance were not associated with a significantly worse virologic outcome in NNRTI-treated patients. Our understanding of small shifts in IC50 values (higher or lower) toward NNRTI is very limited. The significance of many RT mutations on NNRTI susceptibility is not clear.

CONCLUSION

In contrast to resistance mutations, RT substitutions at positions involved in NNRTI resistance are frequent. They are not associated with a worse virologic outcome or with decreased phenotypic susceptibility to NNRTIs. It may be prudent not to rule out the use of NNRTIs in patients with small shifts in IC50 values or poorly understood mutations.

Ceftazidime- and imipenem-induced endotoxin release during treatment of gram-negative infections

To determine whether ceftazidime and imipenem, which target two different penicillin-binding proteins, result in different amounts of endotoxin and cytokine release in patients with gram-negative infection, plasma endotoxin, interleukin-6, and tumor necrosis factor alpha were measured during the first 24 h of antibiotic therapy in 27 patients with gram-negative infection who had been randomized to receive either ceftazidime 2 g t.i.d. (n=12) or imipenem/cilastatin 1 g t.i.d. (n=15). The source of infection was the digestive tract (n=13), the urinary tract (n=5), the respiratory tract (n=2), soft tissue (n=2), i.v. line (n=2), or other (n=3). After the first antibiotic injection, a significant increase in the median concentration of plasma interleukin-6 and plasma tumor necrosis factor alpha was noted, without significant differences related to the antibiotic administered. Antibiotic-induced endotoxemia was detectable in nine patients (including 7 with bacteremia). In conclusion, ceftazidime and imipenem had similar effects on endotoxin and cytokine release during the treatment of gram-negative infections.

Hepatitis B or hepatitis C virus infection is a risk factor for severe hepatic cytolysis after initiation of a protease inhibitor-containing antiretroviral regimen in human immunodeficiency virus-infected patients. The APROCO Study Group

In a cohort of 1,047 human immunodeficiency virus type 1-infected patients started on protease inhibitors (PIs), the incidence of severe hepatic cytolysis (alanine aminotransferase concentration five times or more above the upper limit of the normal level >/= 5N) was 5% patient-years after a mean follow-up of 5 months. Only positivity for hepatitis C virus antibodies (hazard ratio [HR], 7. 95; P < 10(-3)) or hepatitis B virus surface antigen (HR, 6.67; P < 10(-3)) was associated with severe cytolysis. Before starting patients on PIs, assessment of liver enzyme levels and viral coinfections is necessary.

Importance of protease inhibitor plasma levels in HIV-infected patients treated with genotypic-guided therapy: pharmacological data from the Viradapt Study

OBJECTIVE

In a prospective randomized study, the impact of plasma protease inhibitor (PI) trough levels on changes in HIV RNA were assessed in patients treated with genotypic-guided therapy.

METHODS

Patients failing combination therapy (HIV-1 RNA > 10,000 copies/ml, and at least 6 months of therapy with nucleoside analogues and 3 months with PI) were randomly assigned into two arms: control group (C) in which the treatment was modified according to the standard of care; genotypic group (G) in which the treatment was modified according to resistance mutation profiles. Serial PI plasma levels were performed in patients throughout the 12 month study. PI levels were determined by high performance liquid chromatography. 'Suboptimal' concentration (SOC) was defined as at least two PI plasma levels below 2 x IC95. Others were defined as 'optimal' concentration (OC). Patients were categorized into four groups: G1 (SOC/control); G2 (OC/control); G3 (SOC/genotype); G4 (OC/genotype). An intent-to-treat analysis was performed with viral load as the primary endpoint.

RESULTS

A total of 81 patients [mean age 39.7 +/- 8 years, 59 men, 52.7% Centers for Disease Control and Prevention (CDC) stage C] were included in the pharmacological substudy. The two groups according to randomization arms were comparable in terms of risk factor, age, sex, previous treatments, baseline CD4 cell count, HIV-1 RNA and mean PI plasma concentrations. Linear regression analysis showed a significant relationship between PI concentration and HIV RNA in the plasma. OC and SOC were found in 67.9% (55/81) and 32.1% (26/81) of patients, respectively. Mean changes in HIV RNA from baseline at month 6 were: -0.23 +/- 0.29 log10 copies/ml (G1); -0.97 +/- 0.28 (G2); -0.68 +/- 0.37 (G3); -1.38 +/- 0.20 (G4). Multivariate analysis showed PI plasma concentrations to be an independent predictor of HIV-RNA evolution (P = 0.017).

CONCLUSION

Multiple parameters determine the response to antiretroviral therapy and causes other than the development of drug resistance should be considered in the setting of therapeutic failure. Suboptimal concentrations of PI limit the response to antiretroviral therapy. Therapeutic drug monitoring of the PI plasma concentration may therefore prove useful in optimizing antiretroviral therapy.

Economic evaluation of drug resistance genotyping for the adaptation of treatment in HIV-infected patients in the VIRADAPT study

BACKGROUND

Costs of antiretroviral therapy for HIV-infected patients have increased at a time when most countries are attempting to contain health care costs. Part of this increase results from HIV drug resistance associated with virologic failure and a subsequent shift to more complex and costly therapies. Genotypic guided treatment is associated with better virologic outcome. However, it is not yet known whether it will be cost effective.

METHODS

We present here an economic evaluation based on the results from the VIRADAPT study, a prospective, open-label, randomized trial comparing patients assigned to standard of care (n = 43), versus genotypic guided treatment (n = 64) for 6 months. Total follow-up for the extended trial was 1 year. Costs were computed from the viewpoint of the health care system. Hospitalization data were retrieved from the VIRADAPT study case report forms, costs were estimated from the cost of the corresponding diagnosis-related groups derived from the French national cost data base: these were actual costs and not charges. Data on the volume of tests prescribed, drugs, and clinic visits were retrieved from the VIRADAPT study database. The unit costs of tests and clinic visits were determined using the French national Social Security reimbursement price; costing of drugs used were based upon purchase price by either retail pharmacies or hospitals. Genotyping using TruGene HIV-1 assay was estimated at $500 per test from manufacturer's data (all figures in this paper are expressed in U.S. dollars).

RESULTS

Total mean (standard deviation) yearly costs per patients were $20,412 (+/-$10, 129) in the standard of care group and $18,484 (+/-$9,652) in the genotyping group (p =.35). Drug costs represented 55% of total costs. There was a trend toward a decrease in drug costs in the genotyping arm (p =.07), the greatest reduction being in the decreased use of protease inhibitors in the genotyping arm. The additional expense of genotyping appeared to be offset by the savings obtained in drug costs.

CONCLUSION

In our study, the cost of drug resistance testing is offset by a reduced use of protease inhibitors and their attendant costs. Although not reaching statistical significance, this trend in the reduction of drug costs and drug use presents a great interest for future trials.

The relation between baseline HIV drug resistance and response to antiretroviral therapy: re-analysis of retrospective and prospective studies using a standardized data analysis plan

To assess the relation between resistance to antiretroviral drugs for treatment of HIV-1 infection and virological response to therapy, results from 12 different studies were re-analysed according to a standard data analysis plan. These studies included nine clinical trials and three observational cohorts. The primary end-point in our analyses was virological failure by week 24. Baseline factors that were investigated as predictors of virological failure were plasma HIV-1 RNA, the number and type of new antiretroviral drugs in the regimen, and viral susceptibility to the drugs in the regimen, determined by genotyping or phenotyping methods. These analyses confirmed the importance of both genotypic and phenotypic drug resistance as predictors of virological failure, whether these factors were analysed separately or adjusted for other baseline confounding factors. In most of the re-analysed studies, the odds of virological failure were reduced by about twofold for each additional drug in the regimen to which the patient's virus was sensitive by genotyping methods, and by about two- to threefold for each additional drug that was sensitive by phenotyping.

Persisting long-term benefit of genotype-guided treatment for HIV-infected patients failing HAART. The Viradapt Study: week 48 follow-up

OBJECTIVE

We report the 12 months follow-up of the patients who participated in the Viradapt study.

METHODS

A total of 108 HIV-infected patients failing antiretroviral (ARV) therapy (HIV RNA > 10,000 copies/ml, therapy > 6 months with nucleoside reverse transcriptase inhibitors, > 3 months with protease inhibitors (PIs) were randomized into two arms: standard of care in the control arm, and treatment according to the resistance mutations in the protease and reverse transcriptase genes in the study arm. After the first 6 months of the randomized study, open-label, genotype-guided treatment was offered in both arms. A multivariate analysis was performed to assess the predictive factors of treatment success (HIV RNA < 200 copies/ml).

RESULTS

The two arms were comparable in terms of risk factors, age, sex, previous treatments, CD4 cell count and log10 HIV-1 RNA at baseline. At week 24, an interim combined analysis showed a statistically significant difference in the drop in viral load at months 3 and 6 (P = 0.015, repeated measures analysis of variance) in favour of the genotype group. Patients in both arms were then offered open-label genotyping. Genotype analysis was performed every 3 months, and treatment changes could accordingly be made. As some of the patients in the control arm had already progressed to months 9 or 12, only 69% (30/43) of these patients received genotype-guided treatment changes. In the genotype arm, the mean drop in HIV RNA of 1.15 log10 copies/ml, obtained at month 6, persisted at months 9 and 12 (1.15 log10 copies/ml +/- 0.17). In the control arm, an additional drop in HIV RNA to 0.98 log10 +/- 0.22 copies/ml was observed by month 12. In control patients receiving open-label genotype, the percentage of patients with HIV-1 RNA levels below detection limit (200 copies/ml) rose from 14% at month 6 to 30.5% at month 12. This percentage in the study arm remained stable at 31.3% and 30% at months 9 and 12, respectively. Genotype-guided therapy, primary protease mutations and PI plasma concentrations were significantly correlated with virological success.

CONCLUSION

In this heavily pretreated patient population, genotype-guided therapy resulted in a sustained reduction in HIV RNA of greater than one log10 throughout a 1 year follow-up period. Performance of genotype-guided therapy may have contributed to the additional viral load reduction seen in patients in the control group who received open-label genotyping after the 6 months point. Multivariate analysis showed that the presence of primary protease mutations, performance of genotype-guided treatment changes and PI plasma concentrations independently affected virological response.

Persisting Long-Term Benefit of Genotype-Guided Treatment for HIV-Infected Patients Failing Haart. The Viradapt Study: Week 48 Follow-Up

Objective

We report the 12 months follow-up of the patients who participated in the Viradapt study.

Methods

A total of 108 HIV-infected patients failing antiretroviral (ARV) therapy (HIV RNA >10000 copies/ml, therapy >6 months with nucleoside reverse transcriptase inhibitors, >3 months with protease inhibitors (PIs) were randomized into two arms: standard of care in the control arm, and treatment according to the resistance mutations in the protease and reverse transcriptase genes in the study arm. After the first 6 months of the randomized study, open-label, genotype-guided treatment was offered in both arms. A multivariate analysis was performed to assess the predictive factors of treatment success (HIV RNA <200 copies/ml).

Results

The two arms were comparable in terms of risk factors, age, sex, previous treatments, CD4 cell count and log10 HIV-1 RNA at baseline. At week 24, an interim combined analysis showed a statistically significant difference in the drop in viral load at months 3 and 6 ( P=0.015, repeated measures analysis of variance) in favour of the genotype group. Patients in both arms were then offered open-label genotyping. Genotype analysis was performed every 3 months, and treatment changes could accordingly be made. As some of the patients in the control arm had already progressed to months 9 or 12, only 69% (30/43) of these patients received genotype-guided treatment changes. In the genotype arm, the mean drop in HIV RNA of 1.15 log10 copies/ml, obtained at month 6, persisted at months 9 and 12 (1.15 log10 copies/ml ±0.17). In the control arm, an additional drop in HIV RNA to 0.98 log10 ±0.22 copies/ml was observed by month 12. In control patients receiving open-label genotype, the percentage of patients with HIV-1 RNA levels below detection limit (200 copies/ml) rose from 14% at month 6 to 30.5% at month 12. This percentage in the study arm remained stable at 31.3% and 30% at months 9 and 12, respectively. Genotype-guided therapy, primary protease mutations and PI plasma concentrations were significantly correlated with virological success.

Conclusions

In this heavily pretreated patient population, genotype-guided therapy resulted in a sustained reduction in HIV RNA of greater than one log10 throughout a 1 year follow-up period. Performance of genotype-guided therapy may have contributed to the additional viral load reduction seen in patients in the control group who received open-label genotyping after the 6 month point. Multivariate analysis showed that the presence of primary protease mutations, performance of genotype-guided treatment changes and PI plasma concentrations independently affected virological response.

Impact of infectious diseases specialists and microbiological data on the appropriateness of antimicrobial therapy for bacteremia

Antimicrobial therapy for 428 episodes of bacteremia in an 850-bed university hospital was prospectively evaluated for 1 year to measure the impact of two factors--blood culture results and the therapy chosen by infectious diseases specialists (IDSs)--on quality of treatment and outcome. Initial shock, a simplified acute physiology score of >15, and inappropriateness of the empirical treatment were independently associated with increased mortality. Empirical treatment was appropriate in 63% of the episodes. This proportion reached 78% for the episodes treated by IDSs, compared with 54% for the others (P < .001). After availability of blood culture results, the proportion of appropriate treatments increased to 94%, with 97% for IDS-treated patients and 89% for other patients (P = .008). IDSs more frequently shifted to oral antibiotics and used fewer broad-spectrum drugs. This study underlines the impact of blood culture results and of IDSs on the prescription of appropriate treatment for bacteremia and on the better use of antimicrobial drugs.

Drug-resistance genotyping in HIV-1 therapy: the VIRADAPT randomised controlled trial

BACKGROUND

Growing evidence has linked HIV-1 resistance mutations and drug failure. The use of genotypic-resistance analysis to assist therapeutic decision-making in patients failing therapy has not been investigated. We assessed the virological and immunological impact of genotypic-resistance testing.

METHODS

We did a prospective, open, randomised, controlled study of HIV-1-infected patients in whom combination therapy was not successful. We randomly assigned patients standard care (control, n=43) or treatment according to the resistance mutations in protease and reverse-transcriptase genes (genotypic group, n=65). The major endpoint was the change in HIV-1 RNA viral load. Analysis was by intention to treat.

FINDINGS

108 patients were enrolled. All patients were similar for risk factors, age, sex, previous treatment, CD4-cell count (214/microL [SD14]) and log HIV-1 RNA viral load at baseline (4.7 copies/mL [0.1]). At month 3, the mean change in HIV-1 RNA was -1.04 log (0.14) in the study group compared with -0.46 log (0.17) in the control group (mean difference 0.58 log [95% CI 0.14-1.02], p=0.01). At month 6, changes were -1.15 (0.15) log copies/mL, and -0.67 (0.19) log copies/mL in the genotypic group and the control group, respectively (mean difference 0.48 log [0.01-0.97], p=0.05). Difference in the drop in viral load combined at 3 months and 6 months was significant (p=0.015). At month 3, HIV-1 RNA was lower than detection level (200 copies/mL) in 29% (19/65) of patients in the genotypic group versus 14% (6/43) in the control group (p=0.017). At month 6, the values were 32% (21/65) and 14% (6/43) (p=0.067) for the genotypic group and the control group, respectively. Therapy was generally well tolerated, with ten patients (six in the genotypic group, four in the control group) requiring toxic-effect-related drug modification.

INTERPRETATION

We found genotypic-resistance testing to have a significant benefit on the virological response when choosing a therapeutic alternative. Further study of the use of genotypic-resistance testing in assisting clinical decision-making is warranted.

Molecular epidemiology of an outbreak of multidrug-resistant Enterobacter aerogenes infections and in vivo emergence of imipenem resistance

Molecular typing was used to investigate an outbreak of infection caused by multidrug-resistant Enterobacter aerogenes (MREA) susceptible only to gentamicin and imipenem in an intensive care unit (ICU). Over a 9-month period, ciprofloxacin-resistant E. aerogenes isolates were isolated from 34 patients, or 4.1% of ICU admissions, compared with a baseline rate of 0.1% in the previous period (P < 0.001). Infection developed in 15 (44%) patients. In vivo emergence of imipenem resistance (MIC, 32 micrograms/ml) of organisms causing deep-seated infection was observed in two (13%) of these patients following prolonged therapy with imipenem and gentamicin. Arbitrarily primed PCR (AP-PCR) analysis with ERIC1R and ERIC2 primers and pulsed-field gel electrophoresis (PFGE) analysis of XbaI macrorestriction patterns concordantly showed that outbreak-associated MREA isolates were clonally related and distinct from epidemiologically unrelated strains. AP-PCR and PFGE showed discrimination indices of 0.88 and 0.98, respectively. Space-time clustering of cases within units suggests that the epidemic-related MREA isolates were transmitted on the hands of the health care personnel. A case-control study and repeated environmental culture surveys failed to identify a common source or procedure associated with transmission. In spite of the early implementation of isolation measures, the incidence of MREA colonization remained stable until all colonized patients were discharged. This study confirms the usefulness of AP-PCR and PFGE analyses for the epidemiological study of E. aerogenes and underscores the difficulty of controlling the spread of multiresistant clones of this organism in the ICU setting. The emergence of imipenem resistance represents a threat because virtually no therapeutic option is available for such strains.

Semi-automatic external defibrillation

Malignant arrhythmia, which is responsible for most of the out-of-hospital cardiac arrests, is ventricular fibrillation (VF). The best treatment of VF is a controlled electric shock on the chest administered in a short delay. The emergency medical technicians (EMTs) qualified to carry out this treatment in Belgium and in districts often succeed in arriving on the spot 8 minutes earlier than the people of the Service Mobile d'Urgence et de Réanimation (SMUR). The delegation of defibrillation to ambulance crew members however implies a specific teaching, training and a medical control. The Brussels experience shows that semi-automatic external defibrillation by EMT-Ds (SAED) is feasible when criteria for applying SAED in the pre-hospital phase are applicable.