Necrotizing pneumonia in children: Report of 25 cases between 2008 and 2018 at a French tertiary care center

BACKGROUND

Necrotizing pneumonia (NP) is a serious and rare disease in children. Pediatric data on NP are limited and the impact of the 13-valent pneumococcal conjugate vaccine has been very poorly evaluated.

PATIENTS AND METHODS

We conducted a retrospective study at Toulouse University Hospital between 2008 and 2018. Children who presented with thin-walled cavities in the areas of parenchymal consolidation on imaging were included in the study.

RESULTS

The incidence of NP did not decrease during this period. Bacterial identification occurred in 56% of cases (14/25) and included six cases of Streptococcus pneumoniae, five of Staphylococcus aureus, two of Streptococcus pyogenes, and one of Streptococcus viridans. Streptococcus pneumoniae NP are more frequently associated with empyema/parapneumonic effusion compared to S. aureus NP (p = 0.02). Patients with S. pyogenes NP more often required volume expansion than did S. pneumoniae cases (p = 0.03). When comparing children born before and after implementation of the 13-valent pneumococcal conjugate vaccine, we identified a relative modification of the bacterial epidemiology, with an increase in the proportion of S. pyogenes NP and S. aureus NP and a decrease in the proportion of NP caused by S. pneumoniae.

CONCLUSION

Future studies are needed to assess the epidemiology of NP in children. Continued surveillance of identified pneumococcal serotypes is essential to document epidemiological changes in the coming years.

Influence of Nasopharyngeal Viral Load on the Spread of the Omicron BA.2 Variant

We used variant typing polymerase chain reaction to describe the evolution of severe acute respiratory syndrome coronavirus 2 Omicron sublineages between December 2021 and mid-March 2022. The selective advantage of the BA.2 variant over BA.1 is not due to greater nasopharyngeal viral loads.

Omicron Wave SARS-CoV-2 Diagnosis: Evaluation of Saliva, Anterior Nasal, and Nasopharyngeal Swab Samples

The Omicron variant differs from earlier strains of SARS-CoV-2 in the way it enters host cells and grows in vitro. We therefore reevaluated its diagnosis using saliva, nasopharyngeal swab (NPs), and anterior nasal swab (ANs) specimens from 202 individuals (64.9% symptomatic) tested at the Toulouse University Hospital SARS-CoV-2 drive-through testing center. All tests were done with the Thermo Fisher TaqPath COVID-19 reverse transcription-PCR (RT-PCR) kit. Overall, 92 subjects (45.5%) had one or more positive specimens. Global sensitivities of saliva, NPs, and ANs were 94.6%, 90.2%, and 82.6%, respectively. Saliva provided significantly greater sensitivity among symptomatic patients tested within 5 days of symptom onset (100%) than did ANs (83.1%) or NPs (89.8%). We obtained follow-up samples for 7/20 individuals with discordant results. Among them, 5 symptomatic patients were diagnosed positive on saliva sample only, soon after symptom onset; NPs and ANs became positive only later. Thus, saliva samples are effective tools for the detection of the Omicron variant. In addition to its many advantages, such as improved patient acceptance and reduced cost, saliva sampling could help limit viral spread through earlier viral detection. IMPORTANCE Diagnostic testing for SARS-CoV-2 is an essential component of the global strategy for the prevention and control of COVID-19. Since the beginning of the pandemic, numerous studies have evaluated the diagnostic sensitivity of different respiratory and oral specimens for SARS-CoV-2 detection. The pandemic has been since dominated by the emergence of new variants, the latest being the Omicron variant characterized by numerous mutations and changes in host tropism in vitro that might affect the diagnostic performance of tests depending on the sampling location. In this prospective study, we evaluated the clinical performance of NPs, ANs, and saliva for SARS-CoV-2 diagnosis during the Omicron wave. Our results highlight the effectiveness of saliva-based RT-PCR for the early detection of the Omicron variant. These findings may help to refine guidelines and support the use of a highly sensitive diagnostic method that allows earlier diagnosis, when transmission is the most critical.

A severe monkeypox infection in a patient with an advanced HIV infection treated with tecovirimat: clinical and virological outcome

A patient aged 28 years who is immunocompromised and living with HIV/AIDS became infected with the monkeypox virus (MPXV). His clinical condition deteriorated for 37 days, with fever, skin lesions, and diarrhea before going to the infectious diseases department, where his severe, protracted infection was treated with tecovirimat for 14 days. His condition rapidly improved, and the skin lesions decreased, as did the MPXV loads, with no adverse events. This case indicates that tecovirimat might be effective for treating patients who are immunocompromised and are infected with MPXV.

Human Cytomegalovirus Modifies Placental Small Extracellular Vesicle Composition to Enhance Infection of Fetal Neural Cells In Vitro

Although placental small extracellular vesicles (sEVs) are extensively studied in the context of pregnancy, little is known about their role during viral congenital infection, especially at the beginning of pregnancy. In this study, we examined the consequences of human cytomegalovirus (hCMV) infection on sEVs production, composition, and function using an immortalized human cytotrophoblast cell line derived from first trimester placenta. By combining complementary approaches of biochemistry, electron microscopy, and quantitative proteomic analysis, we showed that hCMV infection increases the yield of sEVs produced by cytotrophoblasts and modifies their protein content towards a potential proviral phenotype. We further demonstrate that sEVs secreted by hCMV-infected cytotrophoblasts potentiate infection in naive recipient cells of fetal origin, including human neural stem cells. Importantly, these functional consequences are also observed with sEVs prepared from an ex vivo model of infected histocultures from early placenta. Based on these findings, we propose that placental sEVs could be important actors favoring viral dissemination to the fetal brain during hCMV congenital infection.

Effects of Acute Dengue Infection on Sperm and Virus Clearance in Body Fluids of Men

We investigated the effects of dengue virus (DENV) on semen using samples collected 7, 15, 30, 60, and 90 days after symptom onset from 10 infected volunteers on Réunion Island. We assessed characteristics of semen and reproductive hormones and isolated motile spermatozoa from semen. We assayed semen for DENV using reverse transcription PCR and searched for DENV RNA by virus isolation in Vero E6 cell cultures. Four volunteers had >1 DENV RNA-positive semen samples; 2 volunteers had DENV RNA–positive semen at day 15 and 1 at day 30. No motile sperm were DENV positive. After exposure to positive semen, few Vero E6 cells stained positive for DENV antigens, indicating low levels of replicative virus. We found DENV had shorter duration in semen than in blood. These findings support the possibilities that DENV is sexually transmissible for a short period after acute dengue illness and that acute dengue induces reversible alterations in sperm.

Human Cytomegalovirus Infection Changes the Pattern of Surface Markers of Small Extracellular Vesicles Isolated From First Trimester Placental Long-Term Histocultures

Extracellular vesicles (EVs) have increasingly been recognized as key players in a wide variety of physiological and pathological contexts, including during pregnancy. Notably, EVs appear both as possible biomarkers and as mediators involved in the communication of the placenta with the maternal and fetal sides. A better understanding of the physiological and pathological roles of EVs strongly depends on the development of adequate and reliable study models, specifically at the beginning of pregnancy where many adverse pregnancy outcomes have their origin. In this study, we describe the isolation of small EVs from a histoculture model of first trimester placental explants in normal conditions as well as upon infection by human cytomegalovirus. Using bead-based multiplex cytometry and electron microscopy combined with biochemical approaches, we characterized these small EVs and defined their associated markers and ultrastructure. We observed that infection led to changes in the expression level of several surface markers, without affecting the secretion and integrity of small EVs. Our findings lay the foundation for studying the functional role of EVs during early pregnancy, along with the identification of new predictive biomarkers for the severity and outcome of this congenital infection, which are still sorely lacking.

Evaluation of two RT-PCR screening assays for identifying SARS-CoV-2 variants

Background

The recent emergence of new SARS CoV-2 variants (variants of concern, VOC) that spread rapidly and may lead to immune escape has emphasized the urgent need to monitor and control their spread.

Methods

We analyzed 2018 SARS-CoV-2 positive specimens collected between February 9 and March 22, 2021 using the Thermofisher® TaqPath™ COVID-19 CE-IVD RT-PCR kit (TaqPath) and the ID solutions® ID™ SARS-CoV-2/UK/SA Variant Triplex RT-PCR (ID triplex) assay to screen for VOCs.

Results

The ID triplex assay identified 62.8% of them as VOCs: 61.8% B.1.1.7 and 0.9% B.1.351/P.1. The agreement between the ID triplex results for B.1.1.7 and the TaqPath S gene target failure (SGTF)/ S gene target late detection (SGTL) profile for this variant agreed very well (k = 0.86). A low virus load was the main cause of discrepancies. Sequencing discordant results with both assays indicated that the TaqPath assay detected the B.1.1.7 lineage slightly better. Both assays suggested that the virus loads of B.1.1.7 variants were significantly higher than those of non-B.1.1.7 strains. Only 10/20 B1.351/P.1 strains detected with the ID triplex assay were confirmed by sequencing.

Conclusions

We conclude that the SGTF/SGTL profiles identified using the TaqPath assay and ID triplex results are suitable for detecting the B.1.1.7 lineage. The ID triplex assay, which rapidly determines all three current VOCs simultaneously, could be a valuable tool for limiting virus spread by supporting contact-tracing and isolation.

Testing individual and pooled saliva samples for sars-cov-2 nucleic acid: a prospective study

Control of the rapid spread of the SARS-CoV-2 virus requires efficient testing. We collected paired nasopharyngeal swab (NPs) and saliva samples from 303 subjects (52.8% symptomatic) at a drive-through testing center; 18% of whom tested positive. The NPs, salivas and five saliva pools were tested for SARS-CoV-2 RNA using the Aptima™ assay and a laboratory-developed test (LDT) on the Panther-Fusion™ Hologic® platform. The saliva sensitivity was 80% (LDT) and 87.5% (Aptima™) whereas that of NPs was 96.4% in both assays. The pooled saliva sensitivity of 72.7% (LDT) and 75% (Aptima™) was not significantly different of that of individual saliva testing. Saliva specimens appear to be suitable for sensitive non-invasive assays to detect SARS-CoV-2 nucleic acid; pooling them for a single test will improve laboratory throughput.

Influence of SARS-CoV-2 Variant B.1.1.7, Vaccination, and Public Health Measures on the Spread of SARS-CoV-2

The spread of SARS-CoV-2 and the resulting disease COVID-19 has killed over 2.6 million people as of 18 March 2021. We have used a modified susceptible, infected, recovered (SIR) epidemiological model to predict how the spread of the virus in regions of France will vary depending on the proportions of variants and on the public health strategies adopted, including anti-COVID-19 vaccination. The proportion of SARS-CoV-2 variant B.1.1.7, which was not detected in early January, increased to become 60% of the forms of SARS-CoV-2 circulating in the Toulouse urban area at the beginning of February 2021, but there was no increase in positive nucleic acid tests. Our prediction model indicates that maintaining public health measures and accelerating vaccination are efficient strategies for the sustained control of SARS-CoV-2.

Ribavirin for Hepatitis E Virus Infection After Organ Transplantation: A Large European Retrospective Multicenter Study

BACKGROUND

Ribavirin is currently recommended for treating chronic hepatitis E virus (HEV) infection. This retrospective European multicenter study aimed to assess the sustained virological response (SVR) in a large cohort of solid organ transplant (SOT) recipients with chronic HEV infection treated with ribavirin monotherapy (N = 255), to identify the predictive factors for SVR, and to evaluate the impact of HEV RNA mutations on virological response.

METHODS

Data from 255 SOT recipients with chronic HEV infection from 30 European centers were analyzed. Ribavirin was given at the median dose of 600 (range, 29-1200) mg/day (mean, 8.6 ± 3.6 mg/kg/day) for a median duration of 3 (range, 0.25-18) months.

RESULTS

After a first course of ribavirin, the SVR rate was 81.2%. It increased to 89.8% when some patients were offered a second course of ribavirin. An increased lymphocyte count at the initiation of therapy was a predictive factor for SVR, while poor hematological tolerance of ribavirin requiring its dose reduction (28%) and blood transfusion (15.7%) were associated with more relapse after ribavirin cessation. Pretreatment HEV polymerase mutations and de novo mutations under ribavirin did not have a negative impact on HEV clearance. Anemia was the main adverse event.

CONCLUSIONS

This large-scale retrospective study confirms that ribavirin is highly efficient for treating chronic HEV infection in SOT recipients and shows that the predominant HEV RNA polymerase mutations found in this study do not affect the rate of HEV clearance.This large-scale retrospective study that included 255 solid organ transplant recipients confirms that ribavirin is highly efficient for treating chronic hepatitis E virus (HEV) infection and shows that HEV RNA polymerase mutations do not play a role in HEV clearance.

Estimating the impact of public health strategies on the spread of SARS-CoV-2: Epidemiological modelling for Toulouse, France

The spread of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and the resulting disease COVID‐19 has killed over 2 million people as of 22 January 2021. We have used a modified susceptible, infected, recovered epidemiological model to predict how the spread of the virus in France will vary depending on the public health strategies adopted, including anti‐COVID‐19 vaccination. Our prediction model indicates that the French authorities' adoption of a gradual release from lockdown could lead in March 2021 to a virus prevalence similar to that before lockdown. However, a massive vaccination campaign initiated in January 2021 and the continuation of public health measures over several months could curb the spread of virus and thus relieve the load on hospitals.

Side effect of a 6 p.m curfew for preventing the spread of SARS-CoV-2: A modeling study from Toulouse, France

The spread of SARS-CoV-2 and the resulting disease Covid-19 has killed over 2 million people as of January 22, 2021. We have designed a model and used it to quantify the effect of a 6 p.m curfew on the SARS-CoV-2 epidemic in Toulouse, France. The data show that this measure can lead to the opposite effect from that intended due to larger groups of people on the authorized hours.

Hydroxychloroquine in Coronavirus Disease 2019 Patients: What Still Needs to Be Known About the Kinetics

Different dosage regimens of hydroxychloroquine are used to manage COVID-19 patients, without information on the pharmacokinetics in this population.Blood samples (n=101) were collected from 57 COVID-19 patients for 7 days and concentrations were compared with simulated kinetic profiles.Hydroxychloroquine exposure is low and cannot be predicted by other populations.

Quantifying the impact of public health protection measures on the spread of SARS-CoV-2

The new virus, SARS-CoV-2, has probably affected millions of people world-wide since December 2019 and killed thousand. We have designed a model and used it to quantify the effect of local protective measures on the SARS-CoV-2 epidemic, assess their effectiveness and adapt health service strategies in Toulouse, France.

Evaluation of the Aptima™ transcription-mediated amplification assay (Hologic®) for detecting SARS-CoV-2 in clinical specimens

BACKGROUND

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which appeared in late 2019, has been limited by isolating infected individuals. However, identifying such individuals requires accurate diagnostic tools.

OBJECTIVE

This study evaluates the capacity of the Aptima™ Transcription-Mediated Amplification (TMA) assay (Hologic® Panther System) to detect the virus in clinical samples.

STUDY DESIGN

We compared the Aptima™ assay to two in-house real-time RT-PCR techniques, one running on the Panther Fusion™ module and the other on the MagNA Pure 96 and Light-Cycler 480 instruments. We included a total of 200 respiratory specimens: 100 tested prospectively and 100 retrospectively (25 -ve/75 +ve).

RESULTS

The final Cohen's kappa coefficients were: κ = 0.978 between the Aptima™ and Panther Fusion™ assays, κ = 0.945 between the Aptima™ and MagNA/LC480 assays and κ = 0.956 between the MagNA/LC480 and Panther Fusion™ assays.

CONCLUSION

These findings indicate that the Aptima™ SARS-CoV-2 TMA assay data agree well with those obtained with our routine methods and that this assay can be used to diagnose coronavirus disease 2019 (COVID-19).

The SARS-CoV-2 seroprevalence is the key factor for deconfinement in France

A new virus, SARS-CoV-2, has spread world-wide since December 2019, probably affecting millions of people and killing thousands. Failure to anticipate the spread of the virus now seriously threatens many health systems. We have designed a model for predicting the evolution of the SARS-CoV-2 epidemic in France, which is based on seroprevalence and makes it possible to anticipate the deconfinement strategy.

Peripheral Plasma and Semen Cytokine Response to Zika Virus in Humans

We assessed Zika virus RNA and select cytokine levels in semen, blood, and plasma samples from an infected patient in South America. Viral RNA was detected in semen >2 months after viremia clearance; cytokine profiles differed in semen and plasma. After viremia, Zika virus appears to become compartmentalized in the male reproductive tract.

Multirecombinant Enterovirus A71 Subgenogroup C1 Isolates Associated with Neurologic Disease, France, 2016-2017

In 2016, an upsurge of neurologic disease associated with infection with multirecombinant enterovirus A71 subgenogroup C1 lineage viruses was reported in France. These viruses emerged in the 2000s; 1 recombinant is widespread. This virus lineage has the potential to be associated with a long-term risk for severe disease among children.

Detection of Zika, dengue and chikungunya viruses using single-reaction multiplex real-time RT-PCR

Zika (ZIKV), Dengue (DENV) and Chikungunya viruses (CHIKV) co-circulate in the same geographical areas during the same seasonal period through the same biting arthropods. Therefore a rapid sensitive and specific molecular assay for these viruses would be a considerable help in the disease management and the epidemiological survey. We developed a one-step multiplex real-time PCR for the simultaneous detection of these viruses. Intra and inter-reproducibilities varied from 0.41% to 3.29% and from 1.13% to 4.93% for each virus respectively. The specificity was 100%. Whole blood, plasma and urines were used for comparison with commercially available monoplex assays (RealStar® kits, Altona Diagnostics GmbH, Hamburg, Germany). The concordance was 96%, 92.9% and 95.7% for ZIKV, DENV and CHIKV respectively. No cross reaction and no PCR inhibition were observed for any of the clinical samples. This test can thus be used as a rapid molecular assay for ZIKV, DENV1-4 and CHIKV infections.

A fully automated system using transcription-mediated amplification for the molecular diagnosis of hepatitis E virus in human blood and faeces

BACKGROUND AND OBJECTIVES

We evaluated the performance of the Procleix HEV RNA assay implemented on the Panther automated platform for detecting HEV RNA.

STUDY DESIGN AND RESULTS

Analytical specificity was 100% and there was no cross contamination, as assessed by assaying 122 plasma samples from HEV RNA-negative blood donors. The limits of detection were determined by Probit analysis with the WHO HEV standard (HEV subtype 3a) and subtype 3f and 3c reference strains. The limit of detection was 24 [CI 95%: 19-33] IU/ml for subtype 3a, 34 [28-44] IU/ml for subtype 3c and 53 [41-76] IU/ml for subtype 3f. Inclusivity was assessed by testing 91 samples: HEV genotype 3 subtypes 3c (n = 29), 3e (n = 8), 3f (n = 50), genotype 4 (n = 3), and genotype 1 (n = 1). All the samples tested positive. Clinical performance was determined by testing prospectively 500 consecutive plasma samples and 19 faecal samples with the Procleix assay and a reference accredited quantitative RT-PCR assay. The assays were concordant for 492/500 plasma samples (98.4%) and 18/19 (94.7%) fecal samples. We also tested 92 IgM-positive/HEV RNA-negative samples with the reference assay. The IgM-positive samples included 43 (46%) that tested negative with the reference RT-PCR assay and positive with the Procleix HEV assay.

CONCLUSIONS

The Procleix HEV assay performed well and appears to be suitable for molecular diagnosis of HEV infection, monitoring HEV infections, and facilitating epidemiological investigations.

Effect of acute Zika virus infection on sperm and virus clearance in body fluids: a prospective observational study

BACKGROUND

Evidence of human sexual transmission during Zika virus emergence is a matter of concern, particularly in procreation, but to date, kinetics of seminal shedding and the effects of infection on human reproductive function have not been described. To investigate the effects of Zika virus infection on semen and clearance of Zika virus from semen and body fluids, we aimed to study a cohort of Zika virus-infected men.

METHODS

This prospective observational study recruited men presenting with acute Zika virus infection at Pointe-à-Pitre University Hospital in Guadeloupe, French Caribbean, where a Zika virus outbreak occurred between April and November, 2016. Blood, urine, and semen were collected at days 7, 11, 20, 30, 60, 90, and 120 after symptom onset, and semen characteristics, such as total sperm count, sperm motility, vitality, and morphology, and reproductive hormone concentrations, such as testosterone, inhibin, follicle-stimulating hormone, and luteinising hormone, were assessed. At days 7, 11, and 20, semen was processed to isolate motile spermatozoa. Zika virus RNA was detected by RT-PCR using whole blood, serum, urine, seminal plasma, semen cells, and motile spermatozoa fractions. Zika virus was isolated from different sperm fractions on Vero E6 cultures.

FINDINGS

15 male volunteers (mean age 35 years [SD 5; range 25-44) with acute Zika virus infection and positive Zika virus RNA detection in blood or urine were enrolled. Total sperm count was decreased from median 119 × 10⁶ spermatozoa (IQR 22-234) at day 7 to 45·2 × 10⁶ (16·5-89·6) at day 30 and 70 × 10⁶ (28·5-81·4) at day 60, respectively, after Zika virus infection. Inhibin values increased from 93·5 pg/mL (IQR 55-162) at day 7 to 150 pg/mL (78-209) at day 120 when total sperm count recovered. In motile spermatozoa obtained after density gradient separation, Zika virus RNA was found in three of 14 patients at day 7, four of 15 at day 11, and four of 15 at day 20, and replication-competent virus was found in the tested patient. Seminal shedding kinetics seemed heterogeneous among patients. Whole blood was the fluid most frequently positive for Zika virus RNA (62 of 92 samples) and three patients remained positive at day 120.

INTERPRETATION

Semen alterations early after acute Zika virus infection might affect fertility and could be explained by virus effects on the testis and epididymis. Frequency of shedding and high viral load in semen, together with the presence of replicative virus in a motile spermatozoa fraction, can lead to Zika virus transmission during sexual contact and assisted reproduction procedures. Whole blood seems to be the best specimen for Zika virus RNA detection, diagnosis, and follow-up.

FUNDING

Agence de la Biomédecine/Agence Régionale de Santé de la Guadeloupe/Inserm-REACTing.

ZIKA virus reveals broad tissue and cell tropism during the first trimester of pregnancy

The outbreak of the Zika Virus (ZIKV) and its association with fetal abnormalities have raised worldwide concern. However, the cellular tropism and the mechanisms of ZIKV transmission to the fetus during early pregnancy are still largely unknown. Therefore, we ex vivo modeled the ZIKV transmission at the maternal-fetal interface using organ culture from first trimester pregnancy samples. Here, we provide evidence that ZIKV strain circulating in Brazil infects and damages tissue architecture of the maternal decidua basalis, the fetal placenta and umbilical cord. We also show that ZIKV replicates differentially in a wide range of maternal and fetal cells, including decidual fibroblasts and macrophages, trophoblasts, Hofbauer cells as well as umbilical cord mesenchymal stem cells. The striking cellular tropism of ZIKV and its cytopathic-induced tissue injury during the first trimester of pregnancy could provide an explanation for the irreversible congenital damages.

Viral load kinetics of Zika virus in plasma, urine and saliva in a couple returning from Martinique, French West Indies

While the rapid spread of Zika virus (ZIKV) in South America has been declared a public health emergency few data are available on the kinetics of the virus load and the specific antibodies in individual patients. This report describes the kinetics of ZIKV decay in the body compartments and the kinetics of anti ZIKV IgG and IgM of two people returning from Martinique, French West Indies. ZIKV remained detectable in the plasma for roughly 2 weeks indicating that mosquito control measures should be prolonged accordingly. Remarkably, their urine samples consistently tested positive for even longer. The antibodies responses were different between the two patients but for both the rapid onset of IgM allowed a diagnosis from the end of the first week.

Keep children away from macaque monkeys!

To warn physicians and parents about the risk of macaque bites, we present two pediatric cases (a 4-year-old boy and a 10-year-old girl) of bites sustained while on holiday. The young boy developed febrile dermohypodermitis and was hospitalized for IV antibiotic treatment. He received an initial antirabies vaccine while still in the holiday destination. Except for local wound disinfection and antibiotic ointment, the girl did not receive any specific treatment while abroad. Both were negative for simian herpes PCR. When travelling in countries or cities with endemic simian herpes virus, parents should keep children away from monkeys. Travel agencies, pediatricians and family physicians should better inform families about the zoonotic risk.

Hepatitis E virus in patients with decompensated chronic liver disease: a prospective UK/French study

BACKGROUND

In developed countries, hepatitis E is a porcine zoonosis caused by hepatitis E virus (HEV) genotype 3. In developing countries, hepatitis E is mainly caused by genotype 1, and causes increased mortality in patients with pre-existing chronic liver disease (CLD).

AIM

To determine the role of HEV in patients with decompensated CLD.

METHODS

Prospective HEV testing of 343 patients with decompensated CLD at three UK centres and Toulouse France, with follow-up for 6 months or death. IgG seroprevalence was compared with 911 controls.

RESULTS

11/343 patients (3.2%) had acute hepatitis E infection, and three died. There were no differences in mortality (27% vs. 26%, OR 1.1, 95% CI 0.28-4.1), age (P = 0.9), bilirubin (P = 0.5), alanine aminotransferase (P = 0.06) albumin (P = 0.5) or international normalised ratio (P = 0.6) in patients with and without hepatitis E infection. Five cases were polymerase chain reaction (PCR) positive (genotype 3). Hepatitis E was more common in Toulouse (7.9%) compared to the UK cohort (1.2%, P = 0.003). HEV IgG seroprevalence was higher in Toulouse (OR 17, 95% CI 9.2-30) and Truro (OR 2.5, 95% CI 1.4-4.6) than in Glasgow, but lower in cases, compared to controls (OR 0.59, 95% CI 0.41-0.86).

CONCLUSIONS

Hepatitis E occurs in a minority of patients with decompensated chronic liver disease. The mortality is no different to the mortality in patients without hepatitis E infection. The diagnosis can only be established by a combination of serology and PCR, the yield and utility of which vary by geographical location.

Temporal evolution of the distribution of hepatitis E virus genotypes in Southwestern France

Southwest France is a highly endemic region for hepatitis E virus (HEV). This study examined the circulation of HEV strains between 2003 and 2014 in the Midi-Pyrénées, and compared these data with those from the rest of France. The polyproline region (PPR) of the ORF1 region of the HEV genome was also analyzed. HEV genotype was determined by sequencing a 348-nt fragment within the ORF2 gene for 333 strains in the Midi-Pyrénées and for 571 strains from the rest of France. PPR region was characterized for 56 strains. The frequency of subgenotype 3f decreased over time, whereas subgenotype 3c increased in the Midi-Pyrénées. Repartition of strains did not differ in the Midi-Pyrénées compared to the rest of France. HEV3i and HEV4 have been recently detected throughout France. PPR lengths showed that two major groups of HEV3f exist. Our study shows that HEV3 distribution in the Midi-Pyrénées was similar to the whole of France. Local dietary habits could explain the higher seroprevalence in the Midi-Pyrénées rather the circulation of a particular variant in this region.

Hepatitis E virus seroprevalence in three hyperendemic areas: Nepal, Bangladesh and southwest France

BACKGROUND

Hepatitis E causes a significant burden of disease in developing countries and has recently been increasingly recognized in developed countries. Comparing population anti-hepatitis E virus (HEV) seroprevalence across populations has been difficult.

OBJECTIVES

The aim of this study was to compare the anti-HEV IgG seroprevalence in both adults and children in three hyper-endemic areas (Nepal, Bangladesh and southwest France) using a sensitive, commercial anti-HEV IgG assay.

STUDY DESIGN

Serum or plasma from adults and children in Nepal (n=498), Bangladesh (n=1,009) and Southwest France (n=1031) were tested for anti-HEV IgG using the Wantai assay.

RESULTS

After age-standardization, anti-HEV IgG seroprevalence was 47.1%, 49.8% and 34.0% in Nepal, Bangladesh and southwest France, respectively. There was no difference in seroprevalence by gender in any of the countries. A paucity of infections in children 1-10 years-old was consistently observed (less than 15%) at all 3 locations.

CONCLUSIONS

Surprisingly similar high rates of anti-HEV antibodies were detected using a common, sensitive assay. Despite differences in the epidemiology and circulating genotype of HEV in Nepal, Bangladesh and southwest France, this study found more similarities in population seroprevalence than expected.

Seroprevalence in blood donors reveals widespread, multi-source exposure to hepatitis E virus, southern France, October 2011

The apparent seroprevalence of hepatitis E Virus (HEV)varies greatly among developed countries depending on the geographical area and the sensitivity of immunoassays. We used a validated assay to determine the prevalence of HEV IgG and IgM antibodies among 3,353 blood donors living in southern France,who gave blood during the two first weeks of October 2011 and participated in the study. Demographic and epidemiological information was collected using aspecific questionnaire. We also screened 591 samples for HEV RNA. Overall IgG seroprevalence was 39.1%and varied from 20% to 71.3% depending on the geographical area (p < 0.001) while IgM seroprevalence was 3.31%. Anti-HEV IgG was significantly correlated with increasing age (p < 0.001), eating uncooked pork liver sausages (p < 0.001), offal (p = 0.003), or mussels(p = 0.02). Anti-HEV IgM was associated with being male (p = 0.01) and eating uncooked pork liver sausages(p = 0.02). HEV RNA was detected in one of the 99 anti-HEV IgM-positive samples, but in none of the 492 anti-HEV IgM-negative samples. HEV is hyperendemic in southern France. Dietary and culinary habits alone cannot explain the epidemiology of HEV in this region, indicating that other modes of contamination should be investigated.

Seroprevalence in blood donors reveals widespread, multi-source exposure to hepatitis E virus, southern France, October 2011

The apparent seroprevalence of hepatitis E Virus (HEV) varies greatly among developed countries depending on the geographical area and the sensitivity of immunoassays. We used a validated assay to determine the prevalence of HEV IgG and IgM antibodies among 3,353 blood donors living in southern France, who gave blood during the two first weeks of October 2011 and participated in the study. Demographic and epidemiological information was collected using a specific questionnaire. We also screened 591 samples for HEV RNA. Overall IgG seroprevalence was 39.1% and varied from 20% to 71.3% depending on the geographical area (p?<?0.001) while IgM seroprevalence was 3.31%. Anti-HEV IgG was significantly correlated with increasing age (p?<?0.001), eating uncooked pork liver sausages (p?<?0.001), offal (p?=?0.003), or mussels (p?=?0.02). Anti-HEV IgM was associated with being male (p?=?0.01) and eating uncooked pork liver sausages (p?=?0.02). HEV RNA was detected in one of the 99 anti-HEV IgM-positive samples, but in none of the 492 anti-HEV IgM-negative samples. HEV is hyperendemic in southern France. Dietary and culinary habits alone cannot explain the epidemiology of HEV in this region, indicating that other modes of contamination should be investigated.

The use of a multiplex real-time PCR assay for diagnosing acute respiratory viral infections in children attending an emergency unit

•

Evaluate the use of multiplex real-time PCR for diagnosing respiratory infections.

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857/966 samples from 914 children were positive for one or multiple viruses.

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Respiratory syncytial virus and rhinovirus were the most prevalent.

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Co-infections were associated with severe respiratory symptoms.

•

The spread of respiratory viruses returned to the one it was before the flu outbreak.

Background

The use of a multiplex molecular technique to identify the etiological pathogen of respiratory viral infections might be a support as clinical signs are not characteristic.

Objectives

The aim of the study was to evaluate a multiplex molecular real-time assay for the routine diagnosis of respiratory viruses, to analyze the symptoms associated with the pathogens detected and to determine the spread of virus during the period.

Study design

Respiratory samples were collected from children presenting with respiratory symptoms and attending the emergency unit during the 2010–2011 winter seasons. Samples were tested with the multiplex RespiFinder^® 15 assay (PathoFinder™) which potentially detects 15 viruses.

Results

857 (88.7%) of the 966 samples collected from 914 children were positive for one (683 samples) or multiple viruses (174 samples). The most prevalent were the respiratory syncytial virus (39.5%) and the rhinovirus (24.4%). Influenza viruses were detected in 139 (14.4%) samples. Adenovirus was detected in 93 (9.6%) samples, coronaviruses in 88 (9.1%), metapneumovirus in 51 (5.3%) and parainfluenzae in 47 (4.9%). Rhinovirus (40%) was the most prevalent pathogen in upper respiratory tract infections while respiratory syncytial virus (49.9%) was the most prevalent in lower respiratory tract infections. Co-infections were associated with severe respiratory symptoms.

Conclusion

The multiplex assay detected clinically important viruses in a single genomic test and thus will be useful for detecting several viruses causing respiratory tract disorders.

Hepatitis E virus reinfections in solid-organ-transplant recipients can evolve into chronic infections

BACKGROUND

Hepatitis E virus (HEV) infections are a major cause of acute hepatitis in developing and industrialized countries. Little is known about anti-HEV immunity in solid-organ recipients.

METHODS

We screened 263 solid-organ recipients for anti-HEV immunoglobulin G (IgG) at transplantation. They were followed up for 1 year and tested for HEV RNA and anti-HEV antibodies 1 year after transplantation and if their liver enzyme activities increased.

RESULTS

A total of 38.4% had anti-HEV IgG at transplantation. The mean concentrations (±SD) of anti-HEV IgG at transplantation (8 ± 17.5 U/mL) and 1 year later (6.4 ± 12.0 U/mL, P = .4) were similar. There were 3 de novo HEV infections during the 1-year follow-up among patients who were HEV seronegative before transplantation, giving an annual incidence of 2.1%. We also identified 3 HEV reinfections among patients who were seropositive before transplantation through detection of HEV RNA, for an annual incidence of 3.3%. Their anti-HEV IgG concentrations were 0.3, 2.1, and 6.2 World Health Organization (WHO) units/mL before transplantation. Reinfection of the patient with the lowest IgG concentration at transplantation had evolved to a chronic infection.

CONCLUSIONS

Low anti-HEV antibodies (<7 WHO units/mL) seemed not to protect solid-organ recipients. HEV reinfection in immunocompromised patients can lead to chronic infection, as in primary infections.

Influence of polyproline region and macro domain genetic heterogeneity on HEV persistence in immunocompromised patients

Hepatitis E virus (HEV) can chronically infect immunocompromised patients. The polyproline region (PPR) and the macro domain of ORF1 protein may modulate virus production and/or the host immune response. We investigated the association between the genetic heterogeneity of HEV quasispecies in ORF1 and the outcome of infection in solid-organ transplant patients. Both sequence entropy and genetic distances during the hepatitis E acute phase were higher in patients whose infection became chronic than in those who cleared the virus. Hence, great quasispecies heterogeneity in the regions encoding the PPR and the macro domain may facilitate HEV persistence.

Simultaneous detection of gastrointestinal pathogens with a multiplex Luminex-based molecular assay in stool samples from diarrhoeic patients

We have evaluated the multiplex molecular method xTAG(®) Gastrointestinal Panel (GPP) for detecting pathogens in stool samples of diarrhoeic patients. We collected 440 samples from 329 patients (male:female ratio of 1.2:1), including 102 immunosuppressed adults, 50 immunosuppressed children, 56 children attending the neonatal unit and 121 children attending the emergency unit. Of these, 176 samples from 162 patients were xTAG(®) GPP positive (102 viruses, 61 bacteria and 13 parasites) and the assay was more sensitive than the conventional test for detecting rotavirus (p <0.01), noroviruses (p <0.0001), Salmonella spp. (p <0.001), Campylobacter spp. (p <0.001) and toxigenic Clostridium difficile (p 0.005). The predominant pathogens were viruses (23.2%), with rotavirus (15.9%) being the most common. Bacterial agents were detected in 13.9%; the most common was Salmonella spp. (4.8%). Parasites were detected in 2.9%; Cryptosporidium spp. (2%) was the most common. There were 31 co-infections (7% of samples), involving two pathogens in 23 (5.2%) and three pathogens in eight (1.8%) samples. There were 113 (92.6%) positive samples from the children attending the emergency unit, 25 (17%) positive samples from immunosuppressed adults, 22 (25.3%) positive samples from immunosuppressed children and 16 (19%) positive samples from children attending the neonatal unit. The low turnaround time and technical hands-on time make this multiplex technique convenient for routine use. Nevertheless, conventional bacterial culture and parasitological stool examination are still required to detect other pathogens in specific cases and to determine susceptibility to antibiotics.

Evaluation of a polymerase chain reaction-electrospray ionization time-of-flight mass spectrometry for the detection and subtyping of influenza viruses in respiratory specimens

Background

PCR coupled to electrospray ionization mass spectrometry technology (PCR/ESI-TOF-MS) (PLEX-ID system, Abbott Ibis Biosciences) was developed to characterize microbial pathogens.

Objectives

To evaluate the performance of the PLEX-ID flu detection™ kit for detecting Influenza viruses by comparison with the multiplex RespiFinder^® Kit (PathoFinder).

Study design

Acute-phase respiratory samples (n = 293) were analysed for this purpose. A subpopulation of influenza type A positive samples, identified with the RespiFinder^® kit (n = 64), were subtyped with the RealTime ready Inf A/H1N1 Detection Set^® (Roche Molecular Diagnostics) and results were compared to the PLEX-ID Flu Detection™ kit.

Results

274 samples gave concordant results (93.5%, p < 0.0001): 65 influenza A-positive, 18 influenza B-positive and 191 negative samples. Of these, 7 samples were PLEX-ID positive/RespiFinder^® negative (5 influenza A and 2 influenza B) and 12 were PLEX-ID positive/RespiFinder^® negative (10 influenza A and 2 influenza B). PLEX-ID showed one sample as an influenza A and B co-infection while the RespiFinder^® assay showed it to be influenza A-positive. The sensitivity, specificity, positive and negative predictive values of the PLEX-ID™ system were 87.4%, 96.5%, 92.2% and 94.1% respectively. Thirteen of 19 discordant samples available for retesting were investigated further with the Anyplex™II RV16 Detection kit (Seegene): seven were RespiFinder^® concordant, while six were PLEX-ID™ concordant. Subtyping of 61/64 influenza A samples was concordant (95.3%): 55 were H1N1pdm09 and six were non-H1N1pdm09. Three samples gave negative PLEX-ID™ results (one H1N1pdm09 and two non-H1N1pdm09).

Conclusions

PCR/ESI-TOF-MS technology showed good diagnostic performances to detect and subtype influenza viruses.