Unveiling the HER2-low phenomenon: exploring immunohistochemistry and gene expression to characterise HR-positive HER2-negative early breast cancer

PURPOSE

HER2-low breast cancer (BC) is a novel entity with relevant therapeutic implications, especially in hormone receptor (HR) positive BC. This study examines whether HER2 mRNA through the 21-gene assay, Oncotype DX (ODX), can refine the diagnosis of HER2-low and HER2-zero, obtained by immunohistochemistry (IHC).

METHODS

Between Jan 2021 and Jan 2023, 229 consecutive HR-positive HER2-negative early BC (T1-3 N0-1) have been characterised by IHC and ODX. HER2 status by IHC was either zero (IHC-0) or low (IHC-1 + and IHC-2 + /ISH-negative) while HER2-zero was further divided into HER2-null (IHC-0) and HER2-ultralow (IHC-1-10%). HER2 gene expression by ODX was negative if lower 10.7.

RESULTS

The distribution of HER2 IHC was as follows: 53.3% HER2-0, 29.25% HER2-1 + , and 17.5% HER2-2 + . The clinicopathological characteristics were similar in the three groups, with higher PgR-negative rate in HER2-zero (13.9% vs 3% vs 5%). The distribution of RS was homogeneous in the three groups with the median HER2 gene expression of 9.20 [IQR: 8.70-9.60]. HER2 gene expression gradually increased as the IHC score, with substantial overlap. After adjusting for confounders, HER2-1 + and HER2 2 + had a significant positive correlation between HER2 gene expression and IHC [OR 1.42, 95% CI 1.21 to 1.68, p < 0.001; OR 1.96, 95% CI 1.61 to 2.37, p < 0.001] compared to the HER2-zero group. HER2 gene expression did not differ between HER2-null and HER2-ultralow subgroups.

CONCLUSION

Due to the substantial overlap, the HER2 gene expression is unable to properly distinguish HER2-low and HER2-zero IHC whose accurate identification is critical in the context of HER2-negative BC.

Towards a better detection of patients at-risk of linezolid toxicity in clinical practice: a prospective study in three Belgian hospital centers

Introduction: Linezolid is a last-resort antibiotic for infections caused by multidrug-resistant microorganisms. It is widely used for off-label indications and for longer than recommended treatment durations, exposing patients at higher risk of adverse drug reactions (ADRs), notably thrombocytopenia. This study aimed to investigate ADR incidence and risk factors, identify thrombocytopenia-related trough levels based on treatment duration, and evaluate the performance of predictive scores for ADR development. Methods: Adult in- and outpatients undergoing linezolid therapy were enrolled in three hospitals and ADRs and linezolid trough levels prospectively monitored over time. A population pharmacokinetic (pop-PK model) was used to estimate trough levels for blood samples collected at varying times. Results: A multivariate analysis based on 63 treatments identified treatment duration ≥10 days and trough levels >8 mg/L as independent risk factors of developing thrombocytopenia, with high trough values correlated with impaired renal function. Five patients treated for >28 days did not develop thrombocytopenia but maintained trough values in the target range (<8 mg/L). The Buzelé predictive score, which combines an age-adjusted Charlson comorbidity index with treatment duration, demonstrated 77% specificity and 67% sensitivity to predict the risk of ADR. Conclusion: Our work supports the necessity of establishing guidelines for dose adjustment in patients with renal insufficiency and the systematic use of TDM in patients at-risk in order to keep trough values ≤8 mg/L. The Buzelé predictive score (if ≥7) may help to detect these at-risk patients, and pop-PK models can estimate trough levels based on plasma samples collected at varying times, reducing the logistical burden of TDM in clinical practice.

Prognostic value of HER2-low status in breast cancer: a systematic review and meta-analysis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-low expression in breast cancer has been recently identified as a new therapeutic target. However, it is unclear if HER2-low status has an independent impact on prognosis.

MATERIALS AND METHODS

A systematic literature research was carried out to identify studies comparing survival outcomes of patients affected by HER2-low versus HER2-zero breast cancer. Using random-effects models, pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for progression-free survival (PFS) and overall survival (OS) in the metastatic setting as well as disease-free survival (DFS), OS and pathological complete response (pCR) in the early setting. Subgroup analyses by hormone receptor (HoR) status were carried out. The study protocol is registered on PROSPERO (n.CRD42023390777).

RESULTS

Among 1916 identified records, 42 studies including 1 797 175 patients were eligible. In the early setting, HER2-low status was associated with significant improved DFS (HR 0.86, 95% CI 0.79-0.92, P < 0.001) and OS (HR 0.90, 95% CI 0.85-0.95, P < 0.001) when compared to HER2-zero status. Improved OS was observed for both HoR-positive and HoR-negative HER2-low populations, while DFS improvement was observed only in the HoR-positive subgroup. HER2-low status was significantly associated with a lower rate of pCR as compared to HER2-zero status both in the overall population (OR 0.74, 95% CI 0.62-0.88, P = 0.001) and in the HoR-positive subgroup (OR 0.77, 95% CI 0.65-0.90, P = 0.001). In the metastatic setting, patients with HER2-low breast cancers showed better OS when compared with those with HER2-zero tumours in the overall population (HR 0.94, 95% CI 0.89-0.98, P = 0.008), regardless of HoR status. No significant PFS differences were found.

CONCLUSIONS

Compared with HER2-zero status, HER2-low status appears to be associated with a slightly increased OS both in the advanced and early settings, regardless of HoR expression. In the early setting, HER2-low tumours seem to be associated to lower pCR rates, especially if HoR-positive.

Efficacy and safety of baricitinib in hospitalized adults with severe or critical COVID-19 (Bari-SolidAct): a randomised, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Baricitinib has shown efficacy in hospitalized patients with COVID-19, but no placebo-controlled trials have focused specifically on severe/critical COVID, including vaccinated participants.

METHODS

Bari-SolidAct is a phase-3, multicentre, randomised, double-blind, placebo-controlled trial, enrolling participants from June 3, 2021 to March 7, 2022, stopped prematurely for external evidence. Patients with severe/critical COVID-19 were randomised to Baricitinib 4 mg once daily or placebo, added to standard of care. The primary endpoint was all-cause mortality within 60 days. Participants were remotely followed to day 90 for safety and patient related outcome measures.

RESULTS

Two hundred ninety-nine patients were screened, 284 randomised, and 275 received study drug or placebo and were included in the modified intent-to-treat analyses (139 receiving baricitinib and 136 placebo). Median age was 60 (IQR 49-69) years, 77% were male and 35% had received at least one dose of SARS-CoV2 vaccine. There were 21 deaths at day 60 in each group, 15.1% in the baricitinib group and 15.4% in the placebo group (adjusted absolute difference and 95% CI - 0.1% [- 8·3 to 8·0]). In sensitivity analysis censoring observations after drug discontinuation or rescue therapy (tocilizumab/increased steroid dose), proportions of death were 5.8% versus 8.8% (- 3.2% [- 9.0 to 2.7]), respectively. There were 148 serious adverse events in 46 participants (33.1%) receiving baricitinib and 155 in 51 participants (37.5%) receiving placebo. In subgroup analyses, there was a potential interaction between vaccination status and treatment allocation on 60-day mortality. In a subsequent post hoc analysis there was a significant interaction between vaccination status and treatment allocation on the occurrence of serious adverse events, with more respiratory complications and severe infections in vaccinated participants treated with baricitinib. Vaccinated participants were on average 11 years older, with more comorbidities.

CONCLUSION

This clinical trial was prematurely stopped for external evidence and therefore underpowered to conclude on a potential survival benefit of baricitinib in severe/critical COVID-19. We observed a possible safety signal in vaccinated participants, who were older with more comorbidities. Although based on a post-hoc analysis, these findings warrant further investigation in other trials and real-world studies. Trial registration Bari-SolidAct is registered at NCT04891133 (registered May 18, 2021) and EUClinicalTrials.eu ( 2022-500385-99-00 ).

A simple parasitological technique to increase detection of Strongyloides stercoralis in Bolivian primary health care system

BACKGROUND

Strongyloides stercoralis is widespread; however, there is limited information on its prevalence owing to laboratory underestimation and low clinical manifestations. The Baermann method and agar culture stand out among the parasitological techniques. Strongyloides stercoralis is present in Bolivia, but its prevalence in children remains unknown. The objective of this study was to estimate the applicability of simple parasitological techniques to increase the detection of this parasite in children living in the tropics.

METHODS

This cross-sectional study was conducted in a tropical village in Cochabamba, Bolivia. Participants were 304 children aged 5 - 12 years who provided stool samples for different parasitological analyses (direct examination, Ritchie, Baermann, and Dancescu techniques), and their parents provided informed consent.

RESULTS

Up to 64.8% of pathogenic parasites were detected using the modified Ritchie method. The Baermann technique identified 17.8% of Strongyloides stercoralis cases, and a high sensitivity with respect to the Baermann technique was only for the Dancescu technique (75.9%) that is also specific for Strongyloides stercoralis, followed by 66.7% for the modified Ritchie technique, which is used in second-line care.

DISCUSSION

The Baermann technique is the best parasitological option for improving Strongyloides stercoralis diagnosis in the first-line care of the Primary Health Care System. A particular cycle of reinfection, combined with the environment and some other risk factors are related with persistence. Control is difficult without a proper diagnosis, and the Baermann technique is an approach to the solution. We conclude that with a high suspicion of the presence of Strongyloides stercoralis, the use of the Baermann technique is strongly recommended as support for direct examination in primary health care systems especially in tropical areas.

First finding of Aedes koreicus (Diptera: Culicidae) in the Netherlands

Since 2010, the Centre for Monitoring of Vectors (CMV) of the Netherlands Food and Consumer Product Safety Authority (NVWA), has a surveillance programme in place to detect and control invasive mosquito species (IMS) at locations with increased risk of importation. At the premises of companies that import used tyres from risk areas, the CMV implements surveillance using adult mosquito traps. In case of an IMS finding at a used tyre company location, the monitoring is intensified here (weekly sampling, additional BG-Sentinel traps and larval sampling), as well as within a predefined area with a radius of 500 m from the limits of the used tyre company location. On September 6th, 2021, eight Aedes larvae were found in a sample taken from a water-containing bucket. These larvae were both morphologically and molecularly (Illumina sequencing) identified as Aedes koreicus. Additional sampling at this first finding site of Ae. koreicus in the Netherlands, which was followed by mosquito control using larvicides, did not lead to further findings of the species.

Clinical Course and Risk Factors for Infection in Severe Forms of Alcohol-Associated Liver Disease

BACKGROUND AND AIMS

Infection is a major driver of mortality in patients with advanced alcohol-associated liver disease (ALD). The epidemiology and clinical course of patients infected with life-threatening forms of ALD, including severe alcohol-associated hepatitis (sAH) and decompensated alcohol-associated cirrhosis (DAC), and specific risk factors for infection remain mostly unknown.

APPROACH AND RESULTS

In this observational study, we assessed all infectious episodes occurring within a 90-day period from diagnosis in all consecutive patients with biopsy-proven sAH (modified Maddrey's discriminant function ≥ 32, Model for End-Stage Liver Disease [MELD] ≥ 18) and DAC (MELD ≥ 18) without alcohol-associated hepatitis in our tertiary hospital between 2003 and 2016. A total of 207 patients were included: 139 with sAH and 68 with DAC. One hundred seventeen (84%) patients with sAH and 41 (60%) patients with DAC experienced at least one infection episode at 90 days (P < 0.001). In multivariable analysis, factors associated with the development of infection were the presence of sAH and baseline MELD score. Bacterial infections represented the most common infection in the two groups, and only the MELD score was independently associated with the occurrence of bacterial infection. In both groups, pneumonia was the most prevalent bacterial infection, and gram-negative bacilli were the main pathogens. Invasive fungal infections (IFI) occurred in 20 (14.5%) patients with sAH and 3 (4.5%) with patients with DAC (P < 0.05). Multivariable regression showed that younger age, higher MELD, and corticosteroid therapy were independently associated with IFI. The 90-day cumulative incidence of death in patients infected with sAH and patients infected with DAC was 46% and 41.5%, respectively (P = 0.43).

CONCLUSIONS

Patients with sAH are more susceptible to develop infection than those with DAC. In life-threatening forms of ALD, patients who were infected share a similar mortality rate. Corticosteroid treatment, not sAH, seems to be the main risk factor triggering IFI.

Early β-lactam concentrations and infectious complications after lung transplantation

Antibiotic underdosing in prophylactic antibiotic regimes after lung transplantation (LTx) can increase the risk of infection. We aimed to study whether β-lactam concentrations achieved desirable pharmacodynamic targets in the early phase after LTx and the association between drug concentrations and the development of early infections or the acquisition of multidrug-resistant (MDR) strains. We reviewed patients in whom broad-spectrum β-lactam levels were measured after LTx during antibiotic prophylaxis. β-Lactam concentrations were considered "insufficient" if drug levels remained below four times the clinical breakpoint of the minimal inhibitory concentration for Pseudomonas aeruginosa. The primary outcome was the occurrence of an infection and/or acquisition of MDR pathogens in the first 14 days after transplantation. A total of 70 patients were included. "Insufficient" drug concentrations were found in 40% of patients. In 27% of patients, an early MDR pathogen was identified and 49% patients were diagnosed with an early posttransplant infection. Patients with "insufficient" drug concentrations acquired more frequently MDR bacteria and/or developed an infection than others (22/28, 79% vs. 20/42, 48% - p = .01). β-Lactam levels were often found to be below the desired drug targets in the early phase after transplantation and may be associated with the occurrence of early infectious complications.

Geographic differences in the distribution of parasitic infections in children of Bolivia

Background

A high percentage of the population in Latin America lives with intestinal parasitic infections, a neglected tropical disease frequently not treated. Intestinal parasitism is associated with other disorders, but information about the epidemiological situation in countries like Bolivia is scarce. Environmental conditions play a role in the prevalence of certain parasites. The main objective was to know the current situation of parasitic infections among children under 12 years old from different geographical areas of Cochabamba – Bolivia.

Methods

We analysed the laboratory reports of four second-line hospitals in different areas and the Tertiary Care Hospital. Results of stool examinations performed between 2011 and 2015 in children under 12 years of age were collected.

Results

We gathered the results of 23,221 examinations. The 89% of children were less than five years old. Pathogenic parasites were found in 31%. Entamoeba histolytica and Giardia lamblia were the two most prevalent parasites in all areas. Helminths were 19% of positive samples and Ascaris lumbricoides was the most prevalent. Parasitic infections are more frequent in tropical areas where helminths are highly concentrated. Pre-school age children (OR: 5.296; 95% CI: 4.81–5.83) and semi-tropical area (OR: 3.26; 95% CI: 2.90–3.66) were strongly associated to the presence of pathogenic parasites.

Conclusions

Parasitic infections in children are still very prevalent in Bolivia. Protozoan infections are a major problem, while the prevalence of helminths seems to be decreasing. The most vulnerable population is still concentrated in semi-tropical and tropical areas, where the risk of parasitic infection is probably increased due to poor environmental conditions. Our results could allow reconsideration of more effective parasitic disease control policies, taking into account regional characteristics.

Predictive Factors of In-Hospital Mortality in Older Adults with Community-Acquired Bloodstream Infection

OBJECTIVES

To assess the prevalence of intra-hospital mortality and associated risk factors in older people aged 75+, admitted with blood stream infections (BSI).

DESIGN

Single center retrospective study performed in an 850-bed of the academic hospital of the Université Libre de Bruxelles.

SETTING AND PARTICIPANTS

From January 2015 to December 2017, all inpatients over 75 years old admitted with BSI were included.

MEASURES

Demographical, clinical and microbiological data were collected.

RESULTS

212 patients were included: median age was 82 [79-85] years and 60 % were female. The in-hospital mortality rate was 19%. The majority of microorganisms were Gram-negative strains, of which Escherichia coli was the most common, and urinary tract infection was the most common origin of BSI. Compared to patients who survived, the non-survivor group had a higher SOFA score (6 versus 3, p<0.0001), a higher comorbidity score (5 versus 4, p<0.0001), more respiratory tract infections (28 vs 6 %, p < 0.0001) and fungal infections (5 vs 1 %, p = 0.033), bedridden status (60 vs 25 %, p < 0.0001), and healthcare related infections (60 vs 40 %, p = 0.019). Using Cox multivariable regression analysis, only SOFA score was independently associated with mortality (HR 1.75 [95%IC 1.52-2.03], p<0.0001).

CONCLUSIONS AND IMPLICATIONS

BSI in older people are severe infections associated with a significant in-hospital mortality. Severity of clinical presentation at onset remains the most important predictor of mortality for BSI in older people. BSI originating from respiratory source and bedridden patients are at greater risk of intra-hospital mortality. Further prospective studies are needed to confirm these results.

What is the optimal loading dose of broad-spectrum β-lactam antibiotics in septic patients? Results from pharmacokinetic simulation modelling

Optimal loading doses of β-lactams to rapidly achieve adequate drug concentrations in critically ill patients are unknown. This was a post-hoc analysis of a prospective study that evaluated broad-spectrum β-lactams [piperacillin (PIP), ceftazidime (CAZ), cefepime (FEP) and meropenem (MEM)] pharmacokinetics (PKs) in patients with sepsis or septic shock (n = 88). Monte Carlo simulation was performed for 1000 virtual patients using specific sets of covariates for various dosing regimens and different durations of administration. Pharmacodynamic (PD) targets were considered as drug concentrations exceeding at least 50% of time above four times the minimum inhibitory concentration (T_>4 × MIC) of Pseudomonas aeruginosa, according to EUCAST criteria, for PIP, 70%T_>4 × MIC for CAZ and FEP and 40%T_>4 × MIC for MEM. The probability of target attainment (PTA) was derived by calculating the percentage of patients who attained the PK/PD target at each MIC. The optimal loading dose was defined as the one associated with a ≥90% probability to achieve the PD targets. Our simulation model identified an optimal loading dose for PIP of 8 g given as a 3-h infusion (PTA of 96.2%), for CAZ and FEP of 4 g given as a 3-h infusion (PTA of 96.5% and 98.4%, respectively), and for MEM of 2 g given as a 30-min infusion (PTA of 93.4%), with the following antibiotic dose administered 6 h thereafter regardless of the drug. A higher first dose of broad-spectrum β-lactams should be given to adequately treat less-susceptible pathogens in septic patients. These findings need to be validated in a prospective study.

Host and microbial factors in kidney transplant recipients with Escherichia coli acute pyelonephritis or asymptomatic bacteriuria: a prospective study using whole-genome sequencing

BACKGROUND

Urinary tract infection is the most common infection among kidney transplant recipients (KTRs). Many transplant physicians fear that host compromise will allow low-virulence strains to cause pyelonephritis in KTRs, so they often treat asymptomatic bacteriuria with antibiotics. Identification of the host/microbe factors that determine the clinical presentation (i.e. pyelonephritis versus asymptomatic bacteriuria) once an Escherichia coli strain enters a KTRs bladder could inform management decisions.

METHODS

We prospectively collected all E. coli isolates causing either pyelonephritis or asymptomatic bacteriuria in KTRs at our institution (December 2012-June 2015). Whole-genome sequencing was used to assess bacterial characteristics (carriage of 48 virulence genes and phylogenetic and clonal background). Host parameters were also collected.

RESULTS

We analysed 72 bacteriuria episodes in 54 KTRs (53 pyelonephritis, 19 asymptomatic bacteriuria). The pyelonephritis and asymptomatic bacteriuria isolates exhibited a similar total virulence gene count per isolate [median 18 (range 5-33) and 18 (5-30), respectively; P = 0.57] and for individual virulence genes differed significantly only for the prevalence of the pap operon (pyelonephritis 39%,versus asymptomatic bacteriuria 0%; P = 0.002). No other significant between-group differences were apparent for 86 other bacterial and host variables.

CONCLUSIONS

Our findings suggest that bacterial adherence plays a role in the pathogenesis of pyelonephritis in KTRs despite significantly altered host urinary tract anatomy and weakened immunity. Whether KTRs might benefit from targeted therapies (e.g. vaccination or inhibitors of fimbrial adhesion) has yet to be studied.

Blood CD9+ B cell, a biomarker of bronchiolitis obliterans syndrome after lung transplantation

Bronchiolitis obliterans syndrome is the main limitation for long-term survival after lung transplantation. Some specific B cell populations are associated with long-term graft acceptance. We aimed to monitor the B cell profile during early development of bronchiolitis obliterans syndrome after lung transplantation. The B cell longitudinal profile was analyzed in peripheral blood mononuclear cells from patients with bronchiolitis obliterans syndrome and patients who remained stable over 3 years of follow-up. CD24^hi CD38^hi transitional B cells were increased in stable patients only, and reached a peak 24 months after transplantation, whereas they remained unchanged in patients who developed a bronchiolitis obliterans syndrome. These CD24^hi CD38^hi transitional B cells specifically secrete IL-10 and express CD9. Thus, patients with a total CD9⁺ B cell frequency below 6.6% displayed significantly higher incidence of bronchiolitis obliterans syndrome (AUC = 0.836, PPV = 0.75, NPV = 1). These data are the first to associate IL-10-secreting CD24^hi CD38^hi transitional B cells expressing CD9 with better allograft outcome in lung transplant recipients. CD9-expressing B cells appear as a contributor to a favorable environment essential for the maintenance of long-term stable graft function and as a new predictive biomarker of bronchiolitis obliterans syndrome-free survival.

Caspofungin dosage adjustments are not required for patients with Child-Pugh B or C cirrhosis

Background

Controversies remain over caspofungin dosage adjustments in cirrhosis, particularly Child-Pugh (CP) B or C. The product information for of caspofungin recommends a maintenance dose reduction from 50 to 35 mg for patients with CP-B cirrhosis.

Objectives

To quantify the impact of cirrhosis and the severity of hepatic impairment on the pharmacokinetics (PK) of caspofungin.

Patients and methods

We performed PK studies of a single 70 mg dose of caspofungin in patients with decompensated CP-B (n = 10) or CP-C (n = 10) cirrhosis and of multiple doses in 21 non-cirrhotic ICU patients with hypoalbuminaemia. A Monte Carlo simulation was performed to investigate the impact of a maintenance dose reduction from 50 to 35 mg on the steady-state area under the 24 h concentration-time curve.

Results

We observed a marginal reduction of caspofungin clearance in a PK study in patients with decompensated CP-B or CP-C cirrhosis. Dose reduction to 35 mg in cirrhotic patients resulted in lower drug exposure than with the approved dose in non-cirrhotic patients.

Conclusions

In contrast to the product information, we recommend giving the full dose of caspofungin regardless of the presence and severity of cirrhosis to avoid a subtherapeutic exposure.

The Effectiveness of Asian Bush Mosquito (Aedes japonicus japonicus) Control Actions in Colonised Peri-urban Areas in the Netherlands

The Asian bush mosquito (Aedes japonicus japonicus (Theobald)) is an invasive mosquito species in Europe. In 2012, it was for the first time detected in the Netherlands, in the municipality of Lelystad. After further research, thousands of specimens were found in the surrounding peri-urban areas of the city. A targeted mosquito control campaign began in 2015 with the objective of reducing populations in locations with the highest concentrations of Ae. japonicus breeding sites: allotment garden complexes. Mosquito control consisted of source reduction combined with application of the larvicide Vectomax in breeding sites. At eight complexes, mosquito control effectiveness has been systematically measured by sampling larvae from breeding sites. Six measurements were performed between 2015 and 2016. Results show that the effectiveness of mosquito control actions was similar in all treated allotment gardens and resulted in a significant reduction in Ae. japonicus larval abundance. Rain barrels at the allotments represent the most frequent breeding site in Lelystad, but every water filled artificial container is a potential breeding site for the species. Ae. japonicus was not found in the samples taken in other allotment gardens in the province of Flevoland; however, the collection methodology used proven to be effective in detecting this species when it has newly colonized surrounding areas. Targeted mosquito control actions at the breeding sites are crucial for successful reduction of populations of an invasive mosquito species, and systematic measurements of the effectiveness, is in this case, the base to understand the dynamics of Ae. japonicus populations after mosquito control.

The first detected airline introductions of yellow fever mosquitoes (Aedes aegypti) to Europe, at Schiphol International airport, the Netherlands

Background

Air-borne introduction of exotic mosquitoes to Schiphol airport in the Netherlands has been considered plausible based upon findings of mosquitoes in aircraft cabins during 2008, 2010 and 2011. Beginning in 2013, surveillance efforts at Schiphol had focused on promptly detecting accidental introductions at the airport facilities in order to quickly react and avoid temporary proliferation or establishment of mosquito populations, identify the origin of the introductions, and avoid potential transmission of vector-borne diseases.

Methods

BG-Mosquitaire mosquito traps were set at the most likely locations for arrival of the invasive Aedes mosquitoes as part of the mosquito monitoring program at Schiphol airport. Samples were collected bi-weekly. Upon detection of exotic specimens, information about the origin of the flights arriving to the particular location at the airport where specimens were captured was requested from airport authorities. The GIS tool Intersect was then used to identify airports of origin common to positive trapping locations during the specific trapping period. Captured Aedes aegypti mosquitoes were subsequently genotyped at 12 highly polymorphic microsatellite markers and compared to a reference database of 79 populations around the world to further narrow down their location of origin.

Results

In 2016, six adult yellow fever mosquitoes were captured indoors and outdoors at the airport of Schiphol in the Netherlands confirming, for the first time, air-borne transport of this mosquito vector species into Europe. Mosquitoes were captured during three time periods: June, September and October. Containers carried by aircrafts are considered the most likely pathway for this introduction. GIS analysis and genetic assignment tests on these mosquitoes point to North America or the Middle East as possible origins, but the small sample size prevents us from reliably identifying the geographic origin of this introduction.

Conclusions

The arrival of Ae. aegypti mosquitoes to Schiphol airport from flights arriving from overseas, demonstrates the potential risk of international flights to public health as carriers of arthropod vectors of disease. The results strongly suggest that disinsection of containers and their storage compartments inside the aircrafts could contribute to preventing future introductions of mosquito vectors. Invasive mosquito species introduced by aircrafts from overseas could become seasonally established during the warmer months in Europe, or permanently in certain climatically suitable areas for the species, with major consequences for human health.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2555-0) contains supplementary material, which is available to authorized users.

Optimizing β-lactams treatment in critically-ill patients using pharmacokinetics/pharmacodynamics targets: are first conventional doses effective?

INTRODUCTION

The pharmacokinetic/pharmacodynamic index determining β-lactam activity is the percentage of the dosing interval (%T) during which their free serum concentration remains above a critical threshold over the minimum inhibitory concentration (MIC). Regrettably, neither the value of %T nor that of the threshold are clearly defined for critically-ill patients. Areas covered: We review and assess the targets proposed for β-lactams in critical illness by screening the literature since 1997. Depending on the study intention (clinical cure vs. suppression of resistance), targets proposed range from 20%T > 1xMIC to 100%T > 5xMIC. Assessment and comparative analysis of their respective clinical efficacy suggest that a value of 100%T > 4xMIC may be needed. Simulation studies, however, show that this target will not be reached at first dose for the majority of critically-ill patients if using the most commonly recommended doses. Expert commentary: Considering that critically-ill patients are highly vulnerable and likely to experience antibiotic underexposure, and because effective initial treatment is a key determinant of clinical outcome, we support the use of a target of 100%T > 4xMIC, which could not only maximize efficacy but also minimize emergence of resistance. Clinical and microbiological studies are needed to test for the feasibility and effectiveness of reaching such a demanding target.

Outcome and Treatment of Nocardiosis After Solid Organ Transplantation: New Insights From a European Study

BACKGROUND

Solid organ transplant (SOT) recipients are at risk of nocardiosis, a rare opportunistic bacterial infection, but prognosis and outcome of these patients are poorly defined. Our objectives were to identify factors associated with 1-year mortality after nocardiosis and describe the outcome of patients receiving short-course antibiotics (≤120 days).

METHODS

We analyzed data from a multicenter European case-control study that included 117 SOT recipients with nocardiosis diagnosed between 2000 and 2014. Factors associated with 1-year all-cause mortality were identified using multivariable conditional logistic regression.

RESULTS

One-year mortality was 10-fold higher in patients with nocardiosis (16.2%, 19/117) than in control transplant recipients (1.3%, 3/233, P < .001). A history of tumor (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8), invasive fungal infection (OR, 1.3; 95% CI, 1.1-1.5), and donor age (OR, 1.0046; 95% CI, 1.0007-1.0083) were independently associated with 1-year mortality. Acute rejection in the year before nocardiosis was associated with improved survival (OR, 0.85; 95% CI, 0.73-0.98). Seventeen patients received short-course antibiotics (median duration 56 [24-120] days) with a 1-year success rate (cured and surviving) of 88% and a 5.9% risk of relapse (median follow-up 49 [6-136] months).

CONCLUSIONS

One-year mortality was 10-fold higher in SOT patients with nocardiosis than in those without. Four factors, largely reflecting general medical condition rather than severity and/or management of nocardiosis, were independently associated with 1-year mortality. Patients who received short-course antibiotic treatment had good outcomes, suggesting that this may be a strategy for further study.

Performance evaluation of direct fluorescent antibody, Focus Diagnostics Simplexa™ Flu A/B & RSV and multi-parameter customized respiratory Taqman® array card in immunocompromised patients

•

Limited sensitivity of direct fluorescent antibody testing in comparison to molecular methods.

•

Simplexa™ direct assay is sensitive and specific for the detection of Flu A, B and RSV.

•

Performing the TAC would increase the diagnostic yield and detection of co-infections significantly.

•

Immunocompromised patient population with overall positivity rate of 62%.

•

Co-infection rate of 15.3% found by TAC.

Background

Molecular assays for diagnosis of Flu A, Flu B, and RSV with short turn-around-time (TAT) are of considerable clinical importance. In addition, rapid and accurate diagnosis of a large panel of viral and atypical pathogens can be crucial in immunocompromised patients.

Objectives

First, to evaluate the performance of the Simplexa™ Direct assay system in comparison with direct fluorescent antibody (DFA) and customized Taqman® Array Card (TAC) testing for RSV, Flu A, and Flu B in immunocompromised patients. Second, to evaluate different algorithms for the detection of respiratory pathogens in terms of cost, turn-around-time (TAT) and diagnostic yield.

Study design

We collected 125 nasopharyngeal swabs (NTS) and 25 BAL samples from symptomatic immunocompromised patients. Samples for which Simplexa™ and TAC results were discordant underwent verification testing. The TAC assay is based on singleplex RT-PCR, targeting 24 viruses, 8 bacteria and 2 fungi simultaneously.

Results

The overall sensitivity was significantly lower for DFA testing than for the two molecular methods (p < 0.05). Performance characteristics of Simplexa™ testing were not significantly different compared to TAC testing (p > 0.1). For BAL samples only, the sensitivity and specificity of the Simplexa™ assay was 100%.

In total, 6.7, 16 and 18% of samples were positive for Flu A, Flu B or RSV by DFA, Simplexa™ and TAC testing, respectively. When considering not only these pathogens but also all results for TAC, the method identified 93 samples with one or more respiratory pathogens (62%). A co-infection rate of 15.3% was found by TAC.

The estimated costs and TAT were 8.2€ and 2 h for DFA, 31.8€ and 1.5 h for Simplexa™ and 55€ and 3 h for TAC testing.

Conclusions

Performing the Simplexa™ test 24 h a day/7 days a week instead of DFA would considerably improve the overall sensitivity and time-to-result, albeit at a higher cost generated in the laboratory. Performing the TAC would increase the diagnostic yield and detection of co-infections significantly.

Intravenous zanamivir or oral oseltamivir for hospitalised patients with influenza: an international, randomised, double-blind, double-dummy, phase 3 trial

BACKGROUND

Neuraminidase inhibitors are effective for the treatment of acute uncomplicated influenza. However, there is an unmet need for intravenous treatment for patients admitted to hospital with severe influenza. We studied whether intravenous zanamivir was a suitable treatment in this setting.

METHODS

In this international, randomised, double-blind, double-dummy, phase 3 trial, we recruited patients aged 16 years or older with severe influenza admitted to 97 hospitals from 26 countries. We randomly assigned patients (1:1:1 stratified by symptom onset ≤4 days or 5-6 days) to receive 300 mg or 600 mg intravenous zanamivir, or standard-of-care (75 mg oral oseltamivir) twice a day for 5-10 days; patients were followed up for 28 days. The randomisation schedule, including stratification, was generated using GlaxoSmithKline's RandAll software. Patients, site study staff, and sponsor were masked to study treatment. The primary endpoint was time to clinical response-a composite of vital sign stabilisation and hospital discharge-in the influenza-positive population. The trial was powered to show an improvement of 1·5 days or greater with 600 mg intravenous zanamivir. Pharmacokinetic, safety, and virology endpoints were also assessed. This trial is registered with ClinicalTrials.gov, number NCT01231620.

FINDINGS

Between Jan 15, 2011, and Feb 12, 2015, 626 patients were randomly assigned to receive 300 mg intravenous zanamivir (n=201), 600 mg intravenous zanamivir (n=209), or 75 mg oral oseltamivir (n=205) twice a day; 11 patients discontinued the study before receiving any study treatment. 488 (78%) of 626 patients had laboratory-confirmed influenza. Compared with a median time to clinical response of 5·14 days in the 600 mg intravenous zanamivir group, the median time to clinical response was 5·87 days (difference of -0·73 days, 95% CI -1·79 to 0·75; p=0·25) in the 300 mg intravenous zanamivir group and 5·63 days (difference of -0·48 days, 95% CI -2·11 to 0·97; p=0·39) in the oseltamivir group. Four patients with influenza A/H1N1pdm09 in the oseltamivir group developed H275Y resistance mutations. Adverse events were reported in 373 (61%) of treated patients and were similar across treatment groups; the most common adverse events (300 mg intravenous zanamivir, 600 mg intravenous zanamivir, oseltamivir) were diarrhoea (10 [5%], 15 [7%], 14 [7%]), respiratory failure (11 [5%], 14 [7%], 11 [5%]), and constipation (7 [3%], 13 [6%], 10 [5%]). 41 (7%) treated patients died during the study (15 [7%], 15 [7%], 11 [5%]); the most common causes of death were respiratory failure and septic shock.

INTERPRETATION

Time to clinical response to intravenous zanamivir dosed at 600 mg was not superior to oseltamivir or 300 mg intravenous zanamivir. All treatments had a similar safety profile in hospitalised patients with severe influenza.

FUNDING

GlaxoSmithKline.

[Lower respiratory tract infections in immunocompetent adult]

Lower respiratory tract infections represent one of the main causes of mortality in the world. They essentially consist of bronchitis, acute exacerbations of chronic obstructive bronchopulmonary diseases (COPD) and acute pneumonia. If acute bronchitis is mainly of viral origin, acute exacerbations of COPD and pneumonia are mainly due to a trio of bacteria (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis). Other pathogens as many viruses and atypical bacteria such as Mycoplasma pneumoniae, Legionella, some Enterobacteriaceae and very rarely Pseudomonas aeruginosa are also implicated. S. pneumoniae is the pathogen associated with the greatest morbidity and mortality and empirical antibiotic treatment should always be active on this germ. According to the type of infection and factors of comorbidity, empirical antibiotic treatment should cover a number of other pathogens. Beta-lactams, associated or not with macrolides/azalides are the first line treatment. Fluoroquinolones, although highly active against all pathogens, must be used only in restricted situations in order to avoid emergence of resistance to these antibiotics.

Evaluation of total body weight and body mass index cut-offs for increased cefazolin dose for surgical prophylaxis

French and American guidelines recommend increased dosage regimens of cefazolin (CFZ) for surgical prophylaxis in patients with a body mass index (BMI) ≥ 35 kg/m² or with a total body weight (TBW) ≥ 120 kg. The objective of this study was to evaluate the accuracy of these cut-offs in identifying patients who require CFZ dose adjustment. A pharmacokinetic study was conducted in patients of varying TBW and BMI who received 2 g of CFZ intravenously for prophylaxis prior to digestive surgery. Adequacy of therapy, defined as a serum concentration of unbound CFZ (fCFZ) ≥ 4 mg/L, was evaluated 180 min (T₁₈₀) and 240 min (T₂₄₀) after the start of CFZ infusion. Possible factors associated with insufficient fCFZ levels were also assessed. A P-value of <0.05 was considered statistically significant. A total of 63 patients were included in the study, categorised according to BMI (<35 kg/m², 20 patients; and ≥35 kg/m², 43 patients) and TBW (<120 kg, 41 patients; and ≥120 kg, 22 patients). All patients had adequate drug levels at T₁₈₀ but only 40/63 patients (63%) had adequate levels at T₂₄₀. At T₂₄₀, therapy was adequate in 15/20 patients (75%) and 25/43 patients (58%) with BMI <35 kg/m² and ≥35 kg/m², respectively (P = 0.20), and in 28/41 patients (68%) and 12/22 patients (55%) with TBW <120 kg and ≥120 kg, respectively (P = 0.28). No factor associated with insufficient fCFZ was identified. In conclusion, current BMI and TBW cut-offs are poor indicators of which patients could benefit from increased CFZ dosage regimens.

Initial empirical antibacterial therapy of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is the most frequently occurring nosocomial infection, accounting for considerable morbidity and mortality. Diagnosis can be difficult, creating important therapeutic challenges for intensivists. Early therapy is important in maximizing outcomes, but inappropriate antibacterial treatment has its own risks. A balance needs to be struck between the necessary therapeutic benefits and the negative effects (selection of resistant pathogens, costs, and adverse effects) of antibacterials. Several studies have indicated, in various groups of critically ill patients including those with VAP, that starting treatment with an ineffective antibacterial can increase hospital and intensive care unit length of stay and mortality. When the responsible microorganisms cannot be defined, it may be better to start treatment with a broad-spectrum antibacterial regimen, taking into account individual patient factors and local bacteriology patterns, including antibacterial resistance. As soon as the nature of the pathogen has been defined, the antibacterial agent(s) should be modified accordingly, with the primary aim to reduce the antibacterial spectrum. The optimal duration of therapy is controversial and probably best tailored to the individual patient depending on clinical response and resolution of the factors used to diagnose VAP in that patient. Consultation with an infectious disease specialist may facilitate these therapeutic decisions. With the high morbidity and mortality associated with VAP, prevention is an important issue. General measures include adequate hand hygiene. Physicians must be aware of the risk factors for VAP and of accepted and effective strategies of prevention.

Clinical evaluation of a multi-parameter customized respiratory TaqMan(®) array card compared to conventional methods in immunocompromised patients

BACKGROUND

Respiratory viral infections can cause significant morbidity and mortality in immunocompromised patients. Conventional tests routinely available at most institutions are limited by the number of detectable pathogens, by a poor sensitivity and/or a long turnaround time.

OBJECTIVES

To compare the performance of routine conventional testing with direct fluorescent antibody assays and viral culture to a customized TaqMan® array card (TAC) real-time PCR method, targeting 24 viruses, 8 bacteria and 2 fungi simultaneously.

STUDY DESIGN

We collected 143 respiratory samples from 120 symptomatic immunocompromised patients. Samples for which conventional and TAC results were discordant underwent further verification testing.

RESULTS

The TAC assay identified viral pathogens in more samples than did conventional testing (77/143 versus 27/143; McNemar P<0.0001), even when TAC results for viruses that could not be detected by conventional testing were excluded from analysis (59/143 versus 26/143; P<0.0001). In addition, the TAC assay identified 18 samples with non-viral pathogens. Verification testing confirmed positive TAC results for 50 out of 55 samples for which conventional testing was negative. Two out of three samples with a positive conventional test but negative TAC result were confirmed positive. A viral and a total pathogen co-infection rate of 5.6% and 11.8% were found, respectively.

CONCLUSIONS

The customized TAC assay resulted in a significantly increased identification of respiratory viruses. This study provides a practical real-life assessment of the performance of the TAC assay in a population for whom rapid and accurate diagnosis of viral and atypical pathogens is crucial for appropriate clinical management.

Population pharmacokinetics and dosing simulations of cefepime in septic shock patients receiving continuous renal replacement therapy

The aim of this study was to describe the population pharmacokinetics of cefepime in septic shock patients requiring continuous renal replacement therapy and to determine whether current or alternative dosing regimens can achieve PK/PD targets. In this observational PK study, 62 samples from 13 patients were analysed using non-linear mixed-effects modelling. Different dosing regimens were evaluated using Monte Carlo simulations with ultrafiltration flow rates (UFRs) of 1000, 1500 and 2000 mL/h. The probability of target attainment was calculated against a conservative (60% T(>MIC)) and a higher PK/PD target (100% T(>MIC)) against an MIC of 8 mg/L, the clinical susceptibility breakpoint for Pseudomonas aeruginosa. A one-compartment model with between-subject variability (BSV) on clearance and volume of distribution (V(d)) described the data adequately. UFR was supported as a covariate on both parameters. Typical values for clearance and V(d) were 4.4L/h (BSV 37%) and 40.9L (BSV 20%), respectively. Dosing simulations showed failure to achieve both a conservative and a higher PK/PD target using a dose of 1g q12h for patients treated with a high UFR (≥1500 mL/h). The dose of 2g q8h or 1g q6h leads to optimal target attainment for high UFR. One gram q8h is optimal for low UFR (≤1000 mL/h). We found important variability in PK parameters. Dosing simulations show that a dose of 2g q8h or 1g q6h is needed to ensure rapid achievement of adequate levels if the UFR is ≥1500 mL/h and 1g q8h for low UFR (≤1000 mL/h).

Elevated β-lactam concentrations associated with neurological deterioration in ICU septic patients

BACKGROUND

Although β-lactams are considered to have a safe therapeutic profile, neurotoxicity has been reported. The aim of this study was to assess the association between β-lactam concentrations and neurological alterations in septic ICU patients.

METHODS

Retrospective study on all ICU patients who were treated with meropenem (MEM), piperacillin-tazobactam (TZP) or ceftazidime/cefepime (CEF) and in whom at least one β-lactam trough concentration (C min) was determined. Drug levels were measured using high-performance liquid chromatography; C min was normalized to the clinical breakpoint of Pseudomonas aeruginosa (as determined by EUCAST) for each drug (C min/MIC). Changes in neurological status were evaluated using changes in the neurological sequential organ failure assessment score (ΔnSOFA) using the formula: ΔnSOFA = nSOFA(day of TDM) - nSOFA(ICU admission). Worsening neurological status (NWS) was defined as a ΔnSOFA ≥ 1 for an nSOFA on admission of 0-2.

RESULTS

We collected 262 C min in 199 patients (130 MEM, 85 TZP, 47 CEF). Median APACHE II score and GCS on admission were 17 and 15, respectively. Overall ICU mortality was 27 %. There were no differences in the occurrence of NWS between antibiotics (39% for MEM, 32% for TZP and 35% for CEF). The occurrence of NWS increased with increasing C min/MIC ranges (P = 0.008); this correlation was found for TZP (P = 0.05) and MEM (P = 0.01), but not for CEF. C min/MIC was an independent predictive factor for NWS (OR 1.12 [1.04-1.20]).

CONCLUSION

We found a correlation between high β-lactam trough concentrations and increased occurrence of neurological deterioration in septic ICU patients. Although our data cannot determine causality, monitoring of β-lactam levels should be considered when deterioration of neurological status occurs during critical illness.

When you can't see the wood for the trees. Mucor circinelloides: A rare case of primary cutaneous zygomycosis

A patient with refractory diffuse lymphoma treated for pulmonary invasive aspergillosis developed a concomitant primary cutaneous mucormycosis. The mucormycete was identified by sequencing as Mucor circinelloides. This case confirms the importance of a rapid pathogen diagnosis in immunocompromised patients and the usefulness of molecular methods for identification of rare fungal species.

β-Lactam pharmacokinetics during extracorporeal membrane oxygenation therapy: A case-control study

Most adult patients receiving extracorporeal membrane oxygenation (ECMO) require antibiotic therapy, however the pharmacokinetics of β-lactams have not been well studied in these conditions. In this study, data from all patients receiving ECMO support and meropenem (MEM) or piperacillin/tazobactam (TZP) were reviewed. Drug concentrations were measured 2h after the start of a 30-min infusion and just before the subsequent dose. Therapeutic drug monitoring (TDM) results in ECMO patients were matched with those in non-ECMO patients for (i) drug regimen, (ii) renal function, (iii) total body weight, (iv) severity of organ dysfunction and (v) age. Drug concentrations were considered adequate if they remained 4-8× the clinical MIC breakpoint for Pseudomonas aeruginosa for 50% (TZP) or 40% (MEM) of the dosing interval. A total of 41 TDM results (27 MEM; 14 TZP) were obtained in 26 ECMO patients, with 41 matched controls. There were no significant differences in serum concentrations or pharmacokinetic parameters between ECMO and non-ECMO patients, including Vd [0.38 (0.27-0.68) vs. 0.46 (0.33-0.79)L/kg; P=0.37], half-life [2.6 (1.8-4.4) vs. 2.9 (1.7-3.7)h; P=0.96] and clearance [132 (66-200) vs. 141 (93-197)mL/min; P=0.52]. The proportion of insufficient (13/41 vs. 12/41), adequate (15/41 vs. 19/41) and excessive (13/41 vs. 10/41) drug concentrations was similar in ECMO and non-ECMO patients. Achievement of target concentrations of these β-lactams was poor in ECMO and non-ECMO patients. The influence of ECMO on MEM and TZP pharmacokinetics does not appear to be significant.

Vancomycin population pharmacokinetics during extracorporeal membrane oxygenation therapy: a matched cohort study

Introduction

The aim of this study was to describe the population pharmacokinetics of vancomycin in critically ill patients treated with and without extracorporeal membrane oxygenation (ECMO).

Methods

We retrospectively reviewed data from critically ill patients treated with ECMO and matched controls who received a continuous infusion of vancomycin (35 mg/kg loading dose over 4 hours followed by a daily infusion adapted to creatinine clearance, CrCl)). The pharmacokinetics of vancomycin were described using non-linear mixed effects modeling.

Results

We compared 11 patients treated with ECMO with 11 well-matched controls. Drug dosing was similar between groups. The median interquartile range (IQR) vancomycin concentrations in ECMO and non-ECMO patients were 51 (28 to 71) versus 45 (37 to 71) mg/L at 4 hours; 23 (16 to 38) versus 29 (21 to 35) mg/L at 12 hours; 20 (12 to 36) versus 23 (17–28) mg/L at 24 hours (ANOVA, P =0.53). Median (ranges) volume of distribution (Vd) was 99.3 (49.1 to 212.3) and 92.3 (22.4 to 149.4) L in ECMO and non-ECMO patients, respectively, and clearance 2.4 (1.7 to 4.9) versus 2.3 (1.8 to 3.6) L/h (not significant). Insufficient drug concentrations (that is drug levels <20 mg/dL) were more common in the ECMO group. The pharmacokinetic model (non-linear mixed effects modeling) was prospectively validated in five additional ECMO-treated patients over a 6-month period. Linear regression analysis comparing the observed concentrations and those predicted using the model showed good correlation (r² of 0.67; P <0.001).

Conclusions

Vancomycin concentrations were similar between ECMO and non-ECMO patients in the early phase of therapy. ECMO treatment was not associated with significant changes in Vd and drug clearance compared with the control patients.

Blood feeding on large grazers affects the transmission of Borrelia burgdorferi sensu lato by Ixodes ricinus

The presence of Ixodes ricinus and their associated Borrelia infections on large grazers was investigated. Carcases of freshly shot red deer, mouflon and wild boar were examined for the presence of any stage of I. ricinus. Questing ticks were collected from locations where red deer and wild boar are known to occur. Presence of Borrelia burgdorferi s.l. DNA was examined in a fraction of the collected ticks. Larvae, nymphs and adult ticks were found on the three large grazers. Red deer had the highest tick burden, with many of the nymphs and adult females attached for engorgement. Most larvae had not attached. The mean number of ticks on the animals varied from 13 to 67. Ticks were highly aggregated amongst the animals: some animals had no ticks, while others had high numbers. Larvae and nymphs were mostly found on the ears, while adult ticks were attached to the axillae. The Borrelia infection rate of questing nymphs was 8.5%. Unengorged wandering nymphs on deer had a Borrelia infection rate of 12.5%, while only 0.9% of feeding nymphs carried a Borrelia infection. The infection rate of unengorged adult male ticks was 4.5%, and that of feeding female ticks was 0.7%. The data suggest that ticks feeding on red deer and wild boar lose their Borrelia infections. The implications of the results are discussed with respect to Borrelia epidemiology and maintenance of a Borrelia reservoir as well as the role of reproductive hosts for Ixodes ricinus.

β-lactam antibiotic concentrations during continuous renal replacement therapy

Introduction

The use of standard doses of β-lactam antibiotics during continuous renal replacement therapy (CRRT) may result in inadequate serum concentrations. The aim of this study was to evaluate the adequacy of unadjusted drug regimens (i.e., similar to those used in patients with normal renal function) in patients treated with CRRT and the influence of CRRT intensity on drug clearance.

Methods

We reviewed data from 50 consecutive adult patients admitted to our Department of Intensive Care in whom routine therapeutic drug monitoring (TDM) of broad-spectrum β-lactam antibiotics (ceftazidime or cefepime, CEF; piperacillin/tazobactam; TZP; meropenem, MEM) was performed using unadjusted β-lactam antibiotics regimens (CEF = 2 g q8h; TZP = 4 g q6h; MEM = 1 g q8h). Serum drug concentrations were measured twice during the elimination phase by high-performance liquid chromatography (HPLC-UV). We considered therapy was adequate when serum drug concentrations were between 4 and 8 times the minimal inhibitory concentration (MIC) of Pseudomonas aeruginosa during optimal periods of time for each drug (≥70% for CEF; ≥ 50% for TZP; ≥ 40% for MEM). Therapy was considered as early (ET) or late (LT) phase if TDM was performed within 48 hours of antibiotic initiation or later on, respectively.

Results

We collected 73 serum samples from 50 patients (age 58 ± 13 years; Acute Physiology and Chronic Health Evaluation II (APACHE II) score on admission 21 (17–25)), 35 during ET and 38 during LT. Drug concentrations were above 4 times the MIC in 63 (90%), but above 8 times the MIC in 39 (53%) samples. The proportions of patients with adequate drug concentrations during ET and LT were quite similar. We found a weak but significant correlation between β-lactam antibiotics clearance and CRRT intensity.

Conclusions

In septic patients undergoing CRRT, doses of β-lactam antibiotics similar to those given to patients with normal renal function achieved drug levels above the target threshold in 90% of samples. Nevertheless, 53% of samples were associated with very high drug levels and daily drug regimens may need to be adapted accordingly.

Invasive aspergillosis in patients with severe alcoholic hepatitis

BACKGROUND & AIMS

Severe alcoholic hepatitis (AH) has a poor short-term prognosis. Although infections are frequent complications of AH, the incidence of invasive aspergillosis (IA) and its impact on outcome remain unknown.

METHODS

We prospectively followed 94 biopsy-proven severe AH episodes for 3 months. We retrospectively reviewed our diagnosis of IA based on EORTC/MSG and AspICU criteria, except for host factors.

RESULTS

Fifteen IA (6 proven, 8 probable, and 1 possible) were diagnosed after a median delay of 26 days following diagnosis of AH. The sites of infection were the lungs (n=11) and central nervous system (n=2), while IA was disseminated in 2 cases. Baseline MELD score ≥24 and ICU admission were independent risk factors for IA. Thirteen IA occurred in the context of corticosteroids, and 2 had received no specific treatment for AH. Non-response to corticosteroids at day 7 was not a risk factor for IA, but IA was associated with absence of liver improvement at day 28. Despite antifungal treatment, 3-month transplant-free survival of patients with IA was 0% compared to 53% in those without IA. IA, Lille score ≥0.45, and overt encephalopathy were independent predictors of transplant-free mortality.

CONCLUSIONS

IA is a frequent complication of severe AH and carries a very high risk of mortality. Systematic screening for IA should be recommended in these patients. Further studies are needed to identify high-risk populations requiring antifungal prophylactic treatment.

First observation of African tigerfish Hydrocynus vittatus predating on barn swallows Hirundo rustica in flight

A population of African tigerfish Hydrocynus vittatus from the Schroda Dam, actively prey on barn swallows Hirundo rustica in flight. This behaviour was discovered during a radio telemetry study and documented using a motion picture video camera. These results show that an avivorous diet is a part of the feeding biology of H. vittatus, and may occur in other populations.

IL-12Rβ1 deficiency and disseminated Mycobacterium tilburgii disease

Mycobacterium tilburgii rarely causes disseminated disease. We describe a case of M. tilburgii infection in an otherwise healthy 33-year-old woman, who was found to carry bi-allelic mutations of the gene encoding the β1 chain of the IL-12 receptor.