Analytical and clinical evaluation of four commercial SARS-CoV-2 serological immunoassays in hospitalized patients and ambulatory individuals.

BACKGROUND: This study aimed to compare four anti-SARS-CoV-2 immunoassays in populations presenting different clinical severity levels. METHODS: Three populations were included: "severe-to-critical" ICU-hospitalized patients (n = 18), "mild-to-moderate" hospitalized patients (n = 16) and non-hospitalized symptomatic patients (n = 24). Four commercial immunoassays were analyzed and validated: anti-IgG ARCHITECT® (Abbott), anti-Total antibodies (Ab) VITROS® (Ortho Clinical Diagnostics), anti-IgG NovaLisa® (NovaTec Immundiagnostica) and Healgen® IgM and IgG (Zhejiang Orient Gene Biotech). Sensitivities were evaluated according to days post-symptoms onset (pso). Specificities were evaluated on SARS-CoV-2-negative control sera collected before January 2020. RESULTS: A majority of severe-to-critically ill patients showed detectable Ab already at day 14 and sensitivities reached 100 % after 22 days pso. For patients with "mild-to-moderate" illness, sensitivities increased by at least 5-fold from day 0 to day 14 pso. Non-hospitalized symptomatic individuals already seroconverted at day 14 days pso with 100 % sensitivities for Total Ab VITROS®. Specificities were evaluated at 97 % for ARCHITECT® and NovaLisa®, 98 % for VITROS® and at 94 % for Healgen® combined IgM and IgG. Five "severe-to-critically" ill patients presented high positive Ab levels for at least 16 weeks pso. CONCLUSION: The Ab levels and the evaluated sensitivities, representing the true positive rate, increased overtime and were related to the COVID-19 severity. Automated Total Ab immunoassay showed better sensitivities and specificity for immunological surveillance and vaccine evaluation.

Nosocomial outbreak of extended-spectrum ß-lactamase-producing Enterobacter cloacae among cardiothoracic surgical patients: causes and consequences.

BACKGROUND: Enterobacteriaceae are recognized as leading pathogens of healthcare-associated infections. AIM: To report the investigation of a nosocomial outbreak of extended-spectrum ß-lactamase-producing Enterobacter cloacae affecting cardiothoracic surgery patients in a Belgian academic hospital. METHODS: Cases were defined based on epidemiological and microbiological investigations, including molecular typing using repetitive element-based polymerase chain reaction and multi-locus sequence typing. Case-control studies followed by field evaluations allowed the identification of a possible reservoir, and the retrospective assessment of human and financial consequences. FINDINGS: Over a three-month period, 42 patients were infected or colonized by CTX-M-15-producing E. cloacae strains that belonged to the same clonal lineage. Acquisition mainly occurred in the intensive care unit (N = 23) and in the cardiothoracic surgery ward (N = 16). All but one patient had, prior to acquisition, undergone a cardiothoracic surgical procedure, monitored by the same transoesophageal echocardiography (TOE) probe in the operating room. Despite negative microbiological culture results, the exclusion of the suspected probe resulted in rapid termination of the outbreak. Overall, the outbreak was associated with a high mortality rate among infected patients (40%) as well as significant costs (€266,550). CONCLUSION: The outbreak was indirectly shown to be associated with the contamination of a manually disinfected TOE probe used per-operatively during cardiothoracic surgery procedures, because withdrawal of the putative device led to rapid termination of the outbreak.

Prospective evaluation of a high multiplexing real-time polymerase chain reaction array for the rapid identification and characterization of bacteria causative of nosocomial pneumonia from clinical specimens: a proof-of-concept study.

The purpose of this study was evaluation of the VAPChip assay based on the "Rapid-Array-PCR-technology" which targets 13 respiratory pathogens and 24 ß-lactam resistance genes directly on respiratory clinical specimens. The first step included analysis of 45 respiratory specimens in order to calibrate and determine the threshold for target genes. The second prospective step involved 85 respiratory samples from patients suspected of nosocomial pneumonia collected in two academic hospitals over an 8-month period. Results of the VAPChip assay were compared to routine methods. The first step showed a large proportion of positive signals for H. influenzae and/or S. pneumoniae. For identification, discrepancies were observed in seven samples. Thresholds were adapted and two probes were re-designed to create a new version of the cartridge. In the second phase, sensitivity and specificity of the VAPchip for bacterial identification were 72.9% and 99.1%, respectively. Seventy (82%) pathogens were correctly identified by both methods. Nine pathogens detected by the VAPChip were culture negative and 26 pathogens identified by culture were VAPChip negative. For resistance mechanisms, 11 probes were positive without identification of pathogens with an antimicrobial-susceptibility testing compatible by culture. However, the patient's recent microbiological history was able to explain most of these positive signals. The VAPChip assay simultaneously detects different pathogens and resistance mechanisms directly from clinical samples. This system seems very promising but the extraction process needs to be automated for routine implementation. This kind of rapid point-of-care automated platform permitting a syndromic approach will be the future challenge in the management of infectious diseases.

When polymerase chain reaction does not help: cytomegalovirus pneumonitis associated with very low or undetectable viral load in both blood and bronchoalveolar lavage samples after lung transplantation.

Cytomegalovirus (CMV) pneumonitis occurs frequently among solid organ transplant recipients and is classically associated with significant viral replication in both blood and bronchoalveolar lavage (BAL) samples. We present a case of a 64-year-old lung transplant recipient who presented with CMV pneumonitis that was diagnosed based on the association of viral inclusion in the BAL sample, rapid response to ganciclovir, and absence of other infectious etiology. Surprisingly, we observed very low or undetectable viral load both in blood and BAL samples. Diagnosis of CMV pneumonitis should rely on the association of clinical, pathological, radiological, and microbiological signs, while quantitative nucleic acid amplification testing should be interpreted with caution.

Central skull base osteomyelitis: a rare but life-threatening disease.

We present the case of a 70-year-old non-diabetic patient who presented to the emergency department with unrelenting otalgia. A severe otitis externa (OE) and mastoiditis were treated with broad spectrum antibiotics and surgical drainage. No bacteria was isolated from surgical samples. Because the otalgia persisted, a magnetic resonance (MR) was performed and showed an infiltrating process at the skull base. Biopsies failed to prove malignancy or granulomatosis. The patient's neurological state deteriorated. The suspicion of a skull base osteomyelitis (SBO) was raised and proven by CT-guided biopsies that grew Pseudomonas aeruginosa. Meropenem and ciprofloxacin, given for 8 weeks, lead to a fast clinical improvement and a full recovery. SBO is uncommon, often complicating severe OE. Pseudomonas aeruginosa is the main pathogen. Prompt diagnosis and adequate antibiotherapy are required to lower mortality and morbidity. The diagnosis may be delayed because of unawareness and large differential diagnosis including solid neoplasic tumours, malignant hemopathies and granulomatosis.

About three cases of ulceroglandular tularemia, is this the re-emergence of Francisella tularensis in Belgium?

Tularemia is a zoonosis caused by Francisella tularensis that can be transmitted by several ways to human being and cause different clinical manifestations. We report three clinical cases of tularemia with ulceroglandular presentation in young males acquired during outdoor activities in Southern Belgium. Confirmation of the diagnosis was established by serology. Only three cases of tularemia have been reported in Belgium between 1950 and 2012 by the National Reference Laboratory CODA-CERVA (Ref Lab CODA-CERVA) but re-emergence of tularemia is established in several European countries and F. tularensis is also well known to be present in animal reservoirs and vectors in Belgium. The diagnosis of tularemia has to be considered in case of suggestive clinical presentation associated with epidemiological risk factors.

Epidemiology and outcome of invasive pneumococcal disease among adults in Belgium, 2009-2011.

This epidemiological study examined morbidity and case fatality of invasive pneumococcal disease (IPD) in adults in Belgium as well as distribution and antibiotic susceptibility of Streptococcus pneumoniae serotypes.Adults hospitalised with microbiologically proven IPD were prospectively enrolled. The study started in 2009 with patients aged ≥50 years, whereas in 2010 and 2011, patients aged ≥18 years were included. The clinical presentation, patient profile, treatment, outcome, and mortality were recorded during hospitalisation.Outcome was also assessed one month afterdischarge. Of the 1,875 patients with IPD identified, 1,332 were included in the analysis. Bacteraemic pneumonia, affecting 1,049 of the patients, was the most frequent IPD type (79%), and chronic obstructive pulmonary disease and cancer were the main comorbidities.One-third of patients required admission to intensive care unit. A total of 208 (16%) patients died during hospitalisation and an additional 21 (2%) within one month after discharge. Case fatality rates of ≥20%were observed in patients with chronic heart failure, hepatic disease, and renal insufficiency. Serotypes 7F, 1, 19A, and 3 were the most prevalent and together accounted for 47% (569/1,214) of all IPD cases and 42% (80/189) of mortality. Of the patient isolates, 21% (255/1,204) were resistant to erythromycin and 22% (264/1,204) to tetracycline. Penicillin non-susceptibility was mostly found in serotype 19A isolates. These baseline data are essential when assessing the impact of pneumococcal conjugate vaccination in adults in the future.

Evaluation of the appropriateness of intravenous amoxicillin/clavulanate prescription in a teaching hospital.

BACKGROUND: Despite the implementation of strategies aiming at improving antimicrobial utilisation, inappropriate use remains an increasing problem with important consequences on both antibiotic resistance and hospital costs. OBJECTIVE: To evaluate the appropriateness of prescribing the intravenous amoxicillin/clavulanate combination (Augmentin). METHODS: Prospective observational five-week study in a Belgian teaching hospital. Patients receiving prophylactic or therapeutic intravenous amoxicillin/clavulanate were enrolled. Data were collected by a pharmacist and the appropriateness of antibiotic treatment was analysed in collaboration with an infectious disease specialist according to local recommendations. The primary outcome measure was the appropriateness of indication, dosage, intravenous to oral switch and duration of therapy. RESULTS: One hundred and six patients were evaluated. The most common indications for amoxicillin/clavulanate prescriptions were: respiratory tract infections (38%), surgical/interventional prophylaxis (28%) and intra-abdominal infections (11%). Overall, 43% of intravenous amoxicillin/clavulanate prescriptions were fully appropriate. Indication for use was appropriate in 87% and dosage in 74% of cases. In contrast, the timing of intravenous to oral switch and duration of therapy were inappropriate in 64% and 53% of cases, respectively. CONCLUSIONS: This study identified two main areas for improving amoxicillin/clavulanate prescribing: (1) the intravenous to oral switch, which is often too late or nonexistent and (2) the duration of therapy, which is too long particularly in respiratory tract infections. The results have been presented to clinicians and specific interventions for optimisation are being discussed and implemented.

Another case of "European hantavirus pulmonary syndrome" with severe lung, prior to kidney, involvement, and diagnosed by viral inclusions in lung macrophages.

Puumala virus (PUUV) is considered a classic Old World etiologic agent of nephropathia epidemica (NE), or hemorrhagic fever with renal syndrome (HFRS). HFRS is considered to be distinct from hantavirus (cardio-)pulmonary syndrome (HPS or HCPS), described in the New World. Here, we report a severe case, which fulfilled most, if not all, Centers for Disease Control and Prevention (CDC) criteria for HPS, needing non-invasive ventilation and subsequent acute hemodialysis. However, the etiological agent was PUUV, as proved by serological testing, real-time polymerase chain reaction (PCR), and sequencing. Viral antigen was detected by specific anti-PUUV immunostaining, showing, for the first time, greenish intracytoplasmic inclusions in bronchoalveolar lavage (BAL) macrophages. This case definitely confirms that HPS can be encountered during PUUV infections. Interestingly, special findings could render the diagnosis easier, such as greenish homogeneous cytoplasmic inclusions, surrounded by a fine clear halo in BAL macrophages. Therefore, although the diagnosis remains difficult before the onset of renal involvement, the occurrence of severe respiratory failure mimicking community-acquired pneumonia must alert the clinician for possible HPS, especially in endemic areas.

Clinical, virological and epidemiological assessment of 2009 influenza A (H1N1) pandemic in a Belgian university hospital.

BACKGROUND: Recommendations were applied before and during the Belgian pandemic (2009) H1N1 influenza wave at a university hospital (420 beds), for optimizing isolation processes and therapeutic management of possible and confirmed infected cases. METHODS: All patients presenting to the Emergency Department (ED) between August 1st and December 31st 2009 were screened for ILI symptoms, and were isolated for clinical assessment in case of positive screening. Patients categorized as possible influenza cases and who required hospitalization were isolated in dedicated wards. Specific diagnostic algorithms were implemented. Medical charts were retrospectively reviewed and matched with results of the microbiology laboratory. Patient's characteristics were analyzed, the contribution of laboratory diagnosis on therapy and lengh of stay (LOS) in isolation was also assessed. RESULTS: 310 patients out of 6068 had a positive screening for ILI, of these, 265 were retained as possible influenza cases and 139 required hospitalization. Twenty-eight children (8 requiring hospitalization) and 20 hospitalized adult patients had confirmed influenza infection. Five adult patients were admitted to the intensive care unit (ICU), 3 requiring extracorporeal membrane oxygenation (ECMO). There was no death related to the new influenza strain. The majority of confirmed patients were diagnosed during the Belgian epidemic wave, with a sensitivity of antigen detection of 50% in children and 35% in adults comparatively to real-time PCR (RT-PCR). CONCLUSIONS: The impact of (2009) H1N1 pandemic influenza remained limited, except for ICU patients requiring ECMO. Implementation of screening, isolation, and virological diagnosis processes led to significant improvement of patient management.

Vertebral osteomyelitis with spinal epidural abscess in two patients with Bacteroides fragilis bacteraemia.

We report 2 cases of vertebral osteomyelitis and contiguous epidural abscess due to Bacteroides fragilis with no concomitant or past intra-abdominal infection. Decompressive surgery with laminectomy was required for both patients due to the occurrence of neurologic deficits. Clinical recovery was achieved after 8 weeks of antibiotic therapy. It included 3 weeks of intravenous therapy with clindamycin followed by an oral regimen of clindamycin for 1 patient and oral metronidazole for the other. In both cases, magnetic resonance imaging (MRI) has proved to be essential for diagnostic. The primary source of infection remained unknown despite careful investigations.

Ecthyma gangrenosum in a non-neutropaenic, elderly patient: case report and review of the literature.

Ecthyma gangrenosum is a cutaneous infection most commonly associated with Pseudomonas aeruginosa bacteraemia, but it may also be encountered after breakdown of mechanical defence barriers and local infection. The characteristic lesions of ecthyma gangrenosum are haemorrhagic blisters with surrounding erythema that rapidly evolve to necrotic ulcers. A high mortality rate is reported, especially when diagnosis is delayed and in the absence of appropriate therapy. Ecthyma gangrenosum usually occurs in critically ill and immunocompromised patients. Haematological malignancies and neutropaenia are the major risk factors, but other comorbidities (e.g. diabetes mellitus and malnutrition) have also been involved. Here, we report a case of ecthyma gangrenosum in a non-neutropaenic elderly patient with multiple comorbidities and review the literature on ecthyma gangrenosum.

A 62-month retrospective epidemiological survey of anaerobic bacteraemia in a university hospital.

The incidence of anaerobic bacteraemia was studied retrospectively over 62 months at Mont-Godinne University Hospital, Yvoir, Belgium. The distribution of organisms, clinical presentations, choice of antimicrobial therapy and clinical outcome were analysed. The proportion of positive blood cultures yielding obligate anaerobes was 3.3%. The overall incidence of clinically significant anaerobic bacteraemia was 0.51 cases/1,000 patient admissions (0.61 cases/10,000 hospital-days), but was significantly higher in patients with active haematological malignancies than in other groups (5.97/10,000 vs. 0.33/10,000 hospital-days; p < 0.05). The Bacteroides fragilis group accounted for 61% of isolates, followed by Clostridium spp. (12.2%), Peptostreptococcus spp. and Leptotrichia spp. (7.3% each) and Fusobacterium spp. (4.8%). The most common risk-factors were gastrointestinal surgery (49%) and active haematological malignancies with chemotherapy and/or bone marrow graft (47%). One or more co-morbidities were present in 30 (77%) of 39 patients. The lower gastrointestinal tract (41%) and the oropharynx (23%) were the two most frequent presumed or proven sources for bacteraemia, with the origin remaining unknown in eight (20.5%) cases. The overall mortality rate (evaluated 7 days after the occurrence of bacteraemia) was 13%. Fatal outcome correlated with the severity of underlying diseases and the immunosuppressed status of the patients rather than with the causative pathogen or the effectiveness of antimicrobial therapy. Likewise, there was no difference in the mortality rate between patients with monomicrobial and polymicrobial bacteraemia. Overall, the data re-emphasise the importance of anaerobic bacteraemia, especially in patients with haematological malignancies.

Pyrexia due to pyogenic sacroiliitis with iliopsoas abscess after spinal cord injury.

STUDY DESIGN: Single case report. OBJECTIVES: To present an unusual cause of fever in a patient with spinal cord injury (SCI). SETTING: University Hospital, Belgium. METHODS: A 52-year-old man with a complete T9 paraplegia was admitted to hospital with a 7 day history of fever above 39 degrees C without pain and without gastrointestinal, urinary, or respiratory complaints. The patient had had a flap coverage for a sacral pressure ulcer 6 months prior to admission. RESULTS: Bone scintigraphy demonstrated markedly increased activity in the left sacroiliac joint. Computed tomography (CT) revealed an infection of the left sacroiliac joint with a large abscess involving the iliopsoas muscle. The responsible organism, Pseudomonas aeruginosa, was isolated from abscess liquid obtained by CT-guided aspiration. We postulated that P. aeruginosa had colonized the eschar and, due to the proximity, infected the sacroiliac joint and the adjacent iliopsoas muscle. Prompt intravenous antibiotic therapy ensured clinical improvement and radiological regression. CONCLUSION: Pyogenic sacroiliitis is a relatively rare condition that may be difficult to diagnose in patients with normal sensation, and even more so in SCI patients. As far as we know, psoas abscess associated with pyogenic sacroiliitis has never been described in SCI patients. This infectious pathology must be kept in mind in SCI patients with fever of unknown origin and with a history of sacral eschar.

Staphyloccocal scalded skin syndrome in an adult.

We report a case of staphyloccocal scalded skin syndrome due to an oxacillin-susceptible Staphylococcus aureus in an 81-year-old woman. The patient was admitted to the emergency room with arthritis of the left shoulder, ten days after an intra-articular injection of corticosteroids. The shoulder's puncture showed a purulent liquid and gram positive cocci in cluster suggesting the presence of Staphylococcus sp. on the Gram-stain. The culture confirmed the identification of an oxacillin-susceptible Staphylococcus aureus. Before administration of any dose of oxacillin, blisters appeared on the skin, that quickly ruptured, particulary in areas of friction. The exfoliated areas were extensive and resolution of all the lesions was reached after 3 weeks. The skin biopsy showed superficial epidermolysis confirming the diagnosis. Staphyloccocal scalded skin syndrome is usually described in neonates and young children, often in outbreaks. Few cases have been reported in adults, most often associated with severe underlying diseases. The mortality rate is low in children but can reach almost 60% in adults. The most important diagnosis to exclude is Lyell's syndrome which can be done by the skin biopsy.

Phase II double-blind, placebo-controlled study of the safety and efficacy of cidofovir topical gel for the treatment of patients with human papillomavirus infection.

Genital condylomata acuminata are nonmalignant human papillomavirus (HPV)-induced tumors in which HPV types 6 and 11 are most commonly found. Usual treatments for condylomata acuminata are nonspecific and are based on the destruction or removal of infected tissue. These procedures are often painful and are characterized by a high relapse rate. We report here what is to our knowledge the first double-blind, placebo-controlled study of the use of cidofovir, a nucleotide analogue, for the treatment of genital papillomavirus infections. Thirty patients were enrolled in the study; 19 received cidofovir, and 11 received placebo. The median number of warts and the median baseline wart area were comparable for both groups. Nine (47%) of 19 patients in the cidofovir group had a complete response (total healing), compared with 0 of the patients in the placebo group (P=.006). None of the patients in the cidofovir group experienced progression of the disease, compared with 5 (45%) of 11 patients in the placebo group. The side effects recorded for both groups were comparable.

Cytogenetic observations after meglumine antimoniate therapy for visceral leishmaniasis.

Few data are available concerning the genotoxic effects of antimonial salts therapy in humans. A patient suffering from visceral leishmaniasis was treated for 15 days with a cumulative dose meglumine antimoniate 42.5 g. Peripheral blood lymphocytes sampled before treatment, 7 days later, and at the end of therapy (day 15) were examined for the presence of structural chromosome aberrations, sister chromatid exchanges (SCEs), and micronuclei in binucleated cells. The treatment resulted in an increase of binucleated cells carrying micronuclei, with no changes in chromosome structural aberrations or in mean SCE frequency. On the basis of these observations and of experimental results reported in the literature, we conclude that therapy with meglumine antimoniate apparently does not represent a mutagenic or carcinogenic risk to humans.