Severe acute respiratory syndrome coronavirus-2-related and imputable deaths in children: results from the French pediatric national registry

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for an important mortality rate worldwide. We aimed to evaluate the actual imputability of SARS-CoV-2 on the mortality rate associated with SARS-CoV-2-related illnesses in the pediatric intensive care unit (PICU). Secondary objectives were to identify risk factors for death.

METHODS

This national multicenter comparative study comprised all patients under 18 years old with positive SARS-CoV-2 polymerase chain reactions (PCRs) [acute corona virus disease 2019 (COVID-19) or incidental SARS-CoV-2 infection] and/or pediatric inflammatory multisystem syndrome (PIMS) recorded in the French PICU registry (PICURe) between September 1, 2021, and August 31, 2022. Included patients were classified and compared according to their living status at the end of their PICU stay. Deceased patients were evaluated by four experts in the field of pediatric infectiology and/or pediatric intensive care. The imputability of SARS-CoV-2 as the cause of death was classified into four categories: certain, very probable, possible, or unlikely, and was defined by any of the first three categories.

RESULTS

There were 948 patients included of which 43 died (4.5%). From this, 26 deaths (67%) could be attributed to SARS-CoV-2 infection, with an overall mortality rate of 2.8%. The imputability of death to SARS-CoV-2 was considered certain in only one case (0.1%). Deceased patients suffered more often from comorbidities, especially heart disease, neurological disorders, hematological disease, cancer, and obesity. None of the deceased patients were admitted for pediatric inflammatory multisystem syndrome (PIMS). Mortality risk factors were male gender, cardiac comorbidities, cancer, and acute respiratory distress syndrome.

CONCLUSIONS

SARS-CoV-2 mortality in the French pediatric population was low. Even though the imputability of SARS-CoV-2 on mortality was considered in almost two-thirds of cases, this imputability was considered certain in only one case.

What is the relevancy of a surveillance of mumps without a systematic laboratory confirmation in highly immunized populations? Epidemiology of suspected and biologically confirmed mumps cases seen in general practice in France between 2014 and 2020

BACKGROUND

In France, mumps surveillance is conducted in primary care by the Sentinelles network, the National Reference Centre for Measles, Mumps and Rubella and Santé publique France.

AIM

The objective of this study was to estimate the incidence of suspected mumps in general practice, the proportion of laboratory confirmed cases and the factors associated with a virological confirmation.

METHODS

General practitioners (GPs) participating in the Sentinelles network should report all patients with suspected mumps according to a clinical definition in case of parotitis and a serological definition in case of clinical expression without parotitis. All suspected mumps cases reported between January 2014 and December 2020 were included. A sample of these cases were tested by real time reverse transcriptase polymerase chain reaction (RT-PCR) for mumps biological confirmation.

RESULTS

A total of 252 individuals with suspected mumps were included in the study. The average annual incidence rate of suspected mumps in general practice in France between 2014 and 2020 was estimated at 11 cases per 100,000 population [CI95%: 6-17]. A mumps confirmation RT-PCR test was performed on 146 cases amongst which 17 (11.5 %) were positive. Age (between 20 and 29 years old), the presence of a clinical complication and an exposure to a suspected mumps case within the 21 days prior the current episode were associated with a mumps biological confirmation.

CONCLUSION

If these results confirm the circulation of mumps virus in France, they highlight the limits of a surveillance without a systematic laboratory confirmation in highly immunized populations.

Characteristics of respiratory viruses' circulation through a six-year period (2016-2022) in a pediatric population in Normandy, France, and the impact of COVID-19 pandemic

IMPORTANCE

The report highlights an epidemiological change in the circulation of respiratory viruses in pediatric populations due to strategies adopted against COVID-19 pandemic. COVID-19 has resulted in a significant increase in requests for multiplex respiratory research to identify the virus responsible for the symptoms. The diagnostic needs have increased, and the number of samples analyzed in 2021-2022 is equal to the samples analyzed over the four epidemic periods preceding the pandemic. The report suggests the importance of active surveillance of respiratory viruses' circulation and new recommendations for respiratory virus detection in pediatric patients.

Measles in vulnerable populations: An outbreak in Roma settlements of Loire-Atlantique, France, 2019

In May 2019, a measles outbreak occurred in the French subregion of Loire-Atlantique, particularly affecting Roma settlements. Various obstacles hindered the implementation of postexposure measures among Roma population, resulting in the spread of the cases to other settlements. Suspected cases of measles were immediately investigated and concerned settlements were visited for measles-mumps-rubella (MMR) vaccination. From July 1 to September 3, 2019, a first and then a second Health Reserve team helped for vaccination on the affected and then also the measles-free settlements. Vaccination uptake was monitored with the use of the department's vaccination center immunization registry. Genotyping of selected samples was performed for comparison with viruses circulating at the same time in France and Romania. As of September 16 2019, 109 cases of measles were confirmed among Roma population, including 99 (91%) children under 15 years. Of the 85 people eligible for vaccination, 60 (71%) had not been vaccinated and 23 (27%) had an unknown vaccination status. Sequence comparison revealed that 28/29 sequenced D8 strains were 100% identical to the strain responsible for a large number of cases throughout France in 2019, and to two sequences reported in Romania among sporadic cases. The vaccination campaign resulted in 1136 people on 35 settlements receiving at least one dose of MMR vaccine and in the increase of one-dose MMR vaccine coverage at 24 months from 43% (23/53) to 91% (48/53). With measles transmission continuing in Europe, efforts must be made to meet immunization coverage targets, particularly in hard-to-reach communities where outbreaks may be difficult to control.

Measles

Measles is a highly contagious, potentially fatal, but vaccine-preventable disease caused by measles virus. Symptoms include fever, maculopapular rash, and at least one of cough, coryza, or conjunctivitis, although vaccinated individuals can have milder or even no symptoms. Laboratory diagnosis relies largely on the detection of specific IgM antibodies in serum, dried blood spots, or oral fluid, or the detection of viral RNA in throat or nasopharyngeal swabs, urine, or oral fluid. Complications can affect many organs and often include otitis media, laryngotracheobronchitis, pneumonia, stomatitis, and diarrhoea. Neurological complications are uncommon but serious, and can occur during or soon after the acute disease (eg, acute disseminated encephalomyelitis) or months or even years later (eg, measles inclusion body encephalitis and subacute sclerosing panencephalitis). Patient management mainly involves supportive therapy, such as vitamin A supplementation, monitoring for and treatment of secondary bacterial infections with antibiotics, and rehydration in the case of severe diarrhoea. There is no specific antiviral therapy for the treatment of measles, and disease control largely depends on prevention. However, despite the availability of a safe and effective vaccine, measles is still endemic in many countries and causes considerable morbidity and mortality, especially among children in resource-poor settings. The low case numbers reported in 2020, after a worldwide resurgence of measles between 2017 and 2019, have to be interpreted cautiously, owing to the effect of the COVID-19 pandemic on disease surveillance. Disrupted vaccination activities during the pandemic increase the potential for another resurgence of measles in the near future, and effective, timely catch-up vaccination campaigns, strong commitment and leadership, and sufficient resources will be required to mitigate this threat.

Epidemiological and clinical insights from SARS-CoV-2 RT-PCR crossing threshold values, France, January to November 2020

BackgroundThe COVID-19 pandemic has led to an unprecedented daily use of RT-PCR tests. These tests are interpreted qualitatively for diagnosis, and the relevance of the test result intensity, i.e. the number of quantification cycles (Cq), is debated because of strong potential biases.AimWe explored the possibility to use Cq values from SARS-CoV-2 screening tests to better understand the spread of an epidemic and to better understand the biology of the infection.MethodsWe used linear regression models to analyse a large database of 793,479 Cq values from tests performed on more than 2 million samples between 21 January and 30 November 2020, i.e. the first two pandemic waves. We performed time series analysis using autoregressive integrated moving average (ARIMA) models to estimate whether Cq data information improves short-term predictions of epidemiological dynamics.ResultsAlthough we found that the Cq values varied depending on the testing laboratory or the assay used, we detected strong significant trends associated with patient age, number of days after symptoms onset or the state of the epidemic (the temporal reproduction number) at the time of the test. Furthermore, knowing the quartiles of the Cq distribution greatly reduced the error in predicting the temporal reproduction number of the COVID-19 epidemic.ConclusionOur results suggest that Cq values of screening tests performed in the general population generate testable hypotheses and help improve short-term predictions for epidemic surveillance.

Effect of Tenofovir Disoproxil Fumarate and Emtricitabine on nasopharyngeal SARS-CoV-2 viral load burden amongst outpatients with COVID-19: A pilot, randomized, open-label phase 2 trial

BACKGROUND

Tenofovir and emtricitabine interfere with the SARS CoV-2 ribonucleic acid (RNA)-dependent RNA polymerase (RdRp). Several cohorts reported that people treated by tenofovir disoproxil fumarate and emtricitabine are less likely to develop SARS CoV-2 infection and related severe COVID-19.

METHODS

We conducted a pilot randomized, open-label, controlled, phase 2 trial at two hospitals in France. Eligible patients were consecutive outpatients (aged ≥18 years) with RT-PCR-confirmed SARS-CoV-2 infection and an interval from symptom onset to enrolment of 7 days or less. Patients were randomly assigned in a 1:1 ratio to receive oral tenofovir disoproxil fumarate and emtricitabine (2 pills on day 1 followed by 1 pill per day on days 2-7) or the standard of care. The primary and secondary endpoints were SARS-CoV-2 viral clearance from baseline assessed by cycle threshold (Ct) RT-PCR on nasopharyngeal swab collected at day 4 and day 7, respectively. A higher Ct corresponds to a lower SARS CoV-2 viral burden. Other endpoints were the time to recovery and the number of adverse events. This trial is registered with ClinicalTrials.gov, NCT04685512.

FINDINGS

From November, 20^th 2020 to March, 19^th 2021, 60 patients were enrolled and randomly assigned to a treatment group (30 to tenofovir disoproxil fumarate and emtricitabine and 30 to standard of care). The median number of days from symptom onset to inclusion was 4 days (IQR 3-5) in both groups. Amongst patients who received tenofovir disoproxil fumarate, the difference from standard of care in the increase in Ct RT-PCR from baseline was 2.3 (95% confidence interval [-0.6 to 5.2], p = 0.13) at day 4 and 2.9 (95% CI [0.1 to 5.2], p = 0.044) at day 7. At day 7, 6/30 in the tenofovir disoproxil fumarate and emtricitabine group and 3/30 in the standard of care group reported no COVID-related symptoms. Adverse events included 11 cases of gastrointestinal side effects (grade ≤ 2), three of which leaded to drug discontinuation. Three patients had COVID-19 related hospitalisation, no participant died.

INTERPRETATION

In this pilot study of outpatients adult with recent non-severe COVID-19, tenofovir disoproxil fumarate plus emtricitabine appeared to accelerate the natural clearance of nasopharyngeal SARS-CoV-2 viral burden. These findings support the conduct of larger trials of tenofovir-based therapies for the prevention and early treatment of COVID-19.

FUNDING

No external funding.

Factors associated with the emergence of integrase resistance mutations in patients failing dual or triple integrase inhibitor-based regimens in a French national survey

BACKGROUND

Successful 2-drug regimens (2DRs) for HIV were made possible by the availability of drugs combining potency and tolerability with a high genetic barrier to resistance. How these deal with resistance development/re-emergence, compared with 3DRs, is thus of paramount importance.

MATERIALS AND METHODS

A national survey including patients who were either naive or experienced with any 2DR or 3DR but failing integrase strand transfer inhibitor (INSTI)-containing regimens [two consecutive plasma viral load (VL) values >50 copies/mL] was conducted between 2014 and 2019. Genotypic resistance tests were interpreted with the v28 ANRS algorithm.

RESULTS

Overall, 1104 patients failing any INSTI-containing regimen (2DRs, n = 207; 3DRs, n = 897) were analysed. Five hundred and seventy-seven (52.3%) patients were infected with a B subtype and 527 (47.3%) with non-B subtypes. Overall, 644 (58%) patients showed no known integrase resistance mutations at failure. In multivariate analysis, factors associated with the emergence of at least one integrase mutation were: high VL at failure (OR = 1.24 per 1 log10 copies/mL increase); non-B versus B subtype (OR = 1.75); low genotypic sensitivity score (GSS) (OR = 0.10 for GSS = 2 versus GSS = 0-0.5); and dolutegravir versus raltegravir (OR = 0.46). Although 3DRs versus 2DRs reached statistical significance in univariate analysis (OR = 0.59, P = 0.007), the variable is not retained in the final model.

CONCLUSIONS

This study is one of the largest studies characterizing integrase resistance in patients failing any INSTI-containing 2DR or 3DR in routine clinical care and reveals factors associated with emergence of integrase resistance that should be taken into consideration in clinical management. No difference was evidenced between patients receiving a 2DR or a 3DR.

Prolonged Maternal Shedding and Maternal-fetal Transmission of Measles Virus

Prolonged measles virus detection in maternal saliva and blood was evidenced in 6 pregnant women. Maternal-fetal transmission was evidenced in 2 of 4 infants who were asymptomatic at birth, 21-24 weeks after maternal infection. Whereas peripartum congenital measles is severe, asymptomatic measles virus vertical transmission can occur earlier in pregnancy.

Case Report: Leishmania and HIV Co-Diagnosis: How to Understand Medical History?

We report a case of a severe visceral leishmaniasis revealing an HIV-1 infection presenting as an acute primary infection. A young French man living in Paris with history of unprotected sex with a recent male partner and recent travel in Greece was admitted in our Infectious Diseases Department, presenting with acute febrile psychotic disorder, and positive HIV-1 serology with high viral load, very low CD4⁺ T-cells count and a western blot pattern suggesting an acute infection. The psychotic disorder was finally related to hemophagocytic lymphohistiocytosis diagnosed on bone marrow aspiration, supposedly secondary to HIV acute primary infection. The progressive worsening of pancytopenia despite antiretroviral treatment and the persistence of fever, chills and sweat led to the diagnosis of visceral leishmaniasis through bone marrow biopsy and leishmanial serology. He was treated with intravenous liposomal amphotericin B with quick improvement. We discuss the way HIV infection and visceral leishmaniasis may have interact to lead to the clinical presentation of our patient.

Surveillance of HIV-1 primary infections in France from 2014 to 2016: toward stable resistance, but higher diversity, clustering and virulence?

OBJECTIVES

Patients with primary HIV-1 infection (PHI) are a particular population, giving important insight about ongoing evolution of transmitted drug resistance-associated mutation (TDRAM) prevalence, HIV diversity and clustering patterns. We describe these evolutions of PHI patients diagnosed in France from 2014 to 2016.

METHODS

A total of 1121 PHI patients were included. TDRAMs were characterized using the 2009 Stanford list and the French ANRS algorithm. Viral subtypes and recent transmission clusters (RTCs) were also determined.

RESULTS

Patients were mainly MSM (70%) living in the Paris area (42%). TDRAMs were identified among 10.8% of patients and rose to 18.6% when including etravirine and rilpivirine TDRAMs. Prevalences of PI-, NRTI-, first-generation NNRTI-, second-generation NNRTI- and integrase inhibitor-associated TDRAMs were 2.9%, 5.0%, 4.0%, 9.4% and 5.4%, respectively. In a multivariable analysis, age >40 years and non-R5 tropic viruses were associated with a >2-fold increased risk of TDRAMs. Regarding HIV diversity, subtype B and CRF02_AG (where CRF stands for circulating recombinant form) were the two main lineages (56% and 20%, respectively). CRF02_AG was associated with higher viral load than subtype B (5.83 versus 5.40 log10 copies/mL, P=0.004). We identified 138 RTCs ranging from 2 to 14 patients and including overall 41% from the global population. Patients in RTCs were younger, more frequently born in France and more frequently MSM.

CONCLUSIONS

Since 2007, the proportion of TDRAMs has been stable among French PHI patients. Non-B lineages are increasing and may be associated with more virulent CRF02_AG strains. The presence of large RTCs highlights the need for real-time cluster identification to trigger specific prevention action to achieve better control of the epidemic.

Resistance to integrase inhibitors: a national study in HIV-1-infected treatment-naive and -experienced patients

OBJECTIVES

To describe integrase strand transfer inhibitor (INSTI) resistance profiles and factors associated with resistance in antiretroviral-naive and -experienced patients failing an INSTI-based regimen in clinical practice.

METHODS

Data were collected from patients failing an INSTI-containing regimen in a multicentre French study between 2014 and 2017. Failure was defined as two consecutive plasma viral loads (VL) >50 copies/mL. Reverse transcriptase, protease and integrase coding regions were sequenced at baseline and failure. INSTI resistance-associated mutations (RAMs) included in the Agence Nationale de Recherches sur le SIDA genotypic algorithm were investigated.

RESULTS

Among the 674 patients, 359 were failing on raltegravir, 154 on elvitegravir and 161 on dolutegravir therapy. Overall, 90% were experienced patients and 389 (58%) patients showed no INSTI RAMs at failure. The strongest factors associated with emergence of at least one INSTI mutation were high VL at failure (OR = 1.2 per 1 log10 copies/mL increase) and low genotypic sensitivity score (GSS) (OR = 0.08 for GSS ≥3 versus GSS = 0-0.5). Patients failing dolutegravir also had significantly fewer INSTI RAMs at failure than patients failing raltegravir (OR = 0.57, P = 0.02) or elvitegravir (OR = 0.45, P = 0.005). Among the 68 patients failing a first-line regimen, 11/41 (27%) patients on raltegravir, 7/18 (39%) on elvitegravir and 0/9 on dolutegravir had viruses with emergent INSTI RAMs at failure.

CONCLUSIONS

These results confirmed the robustness of dolutegravir regarding resistance selection in integrase in the case of virological failure in routine clinical care.

When a viral eruption hides another one: intrafamilial outbreak of parvovirus B19 and measles virus co-infections: case report

Background

Despite high overall population vaccine coverage, identified clusters of persons refraining from vaccination interfere with pursued measles elimination. Clinical diagnosis of measles is often obvious due to its typical rash. Yet, febrile rashes may occur during many viral infections. Misdiagnosis of a specific primary viral infection may have severe consequences, particularly in immunocompromised subjects or pregnant women. To our knowledge, this case presentation is the first description of a measles and parvovirus B19 coinfection outbreak. Analysis of this outbreak underlines rash diagnosis difficulties and potential serology interpretation pitfalls. This case report is helpful for the clinicians in the context of measles re-emergence and proposes several methods to improve the diagnosis approach.

Case presentation

We investigated an outbreak of rash in 6 out of 8 Traveler family members presenting to Rennes University Hospital (West of France). Anti-B19V and measles IgM/IgG antibodies were measured and detection of Parvovirus B19 and measles virus genomes were done on blood and/or respiratory samples. Virological investigations finally documented 6 cases of parvovirus B19 infections, including 4 associated with measles. Interestingly, in the four coinfection cases, the rash was typical of B19V primary infection for the two children but typical of measles for the two adults. Clinical diagnosis of rash may be misleading and thorough virological investigations may be required to avoid misdiagnosis.

Conclusions

This investigation first reports an intra-familial outbreak of MeV/B19V coinfections highlighting the high transmissibility of both viruses and the diagnostic challenges of dual rash-associated infections. This report also underlines the potential deleterious consequences of failure to identify measles cases, especially in a community with low vaccination coverage.

Impact of Human Immunodeficiency Virus Type 1 Minority Variants on the Virus Response to a Rilpivirine-Based First-line Regimen

Background

Minority resistant variants of human immunodeficiency virus type 1 (HIV-1) could influence the virological response to treatment based on nonnucleoside reverse transcriptase inhibitors (NNRTIs). Data on minority rilpivirine-resistant variants are scarce. This study used next-generation sequencing (NGS) to identify patients harboring minority resistant variants to nucleos(t)ide reverse transcriptase inhibitors and NNRTIs and to assess their influence on the virological response (VR).

Methods

All the subjects, 541 HIV-1-infected patients started a first-line regimen containing rilpivirine. VR was defined as a HIV-1 RNA load <50 copies/mL at month 6 with continued suppression at month 12. NGS was performed at baseline (retrospectively) on the 454 GS-FLX platform (Roche).

Results

NGS revealed resistance-associated mutations accounting for 1% to <5% of variants in 17.2% of samples, for 5%-20% in 5.7% of samples, and for >20% in 29% of samples. We identified 43 (8.8%) and 36 (7.4%) patients who harbored rilpivirine-resistant variants with a 1% sensitivity threshold according to the French National Agency for Research on AIDS and Viral Hepatitis and Stanford algorithms, respectively. The VR was 96.9% at month 12. Detection of minority rilpivirine resistant variants was not associated with virological failure (VF). Multivariate analysis indicated that VF at month 12 was associated with a CD4 count <250 cells/µL at baseline, a slower decrease in viral load at month 3, and rilpivirine resistance at baseline using the Stanford algorithm with a 20% threshold.

Conclusions

Minority resistant variants had no impact on the VR of treatment-naive patients to a rilpivirine-based regimen.

Measles outbreak linked to insufficient vaccination coverage in Nouvelle-Aquitaine Region, France, October 2017 to July 2018

On 30 October 2017, an outbreak of measles started in the Nouvelle-Aquitaine (NA) region in France among Bordeaux University students before spreading to other regions. Until 1 July 2018, 1,101 cases were reported in NA, including 98 complications and two deaths. Cases were related to clusters (e.g. students, healthcare workers) in 16%; 81% of cases were not vaccinated against measles as recommended. Vaccination coverage above herd immunity threshold remains the main preventative outbreak measure.

Phenotypic analysis of HIV-1 E157Q integrase polymorphism and impact on virological outcome in patients initiating an integrase inhibitor-based regimen

Objectives

To assess the phenotypic susceptibility of the E157Q polymorphism in HIV-1 integrase (IN) and the virological outcome of patients infected with E157Q-mutated virus initiating an IN inhibitor (INI)-based regimen.

Methods

This was a multicentre study assessing IN sequences from INI-naive patients among 17 French HIV clinical centres. E157Q site-directed mutants in pNL4.3 and pCRF02_AG contexts were assessed in a recombinant phenotypic assay.

Results

Prevalence of the E157Q polymorphism was 2.7% among 8528 IN sequences from INI-naive patients and its distribution was 1.7%, 5.6% and 2.2% in B, CRF02_AG and various non-B subtypes, respectively. Thirty-nine INI-naive patients with E157Q-mutated virus initiated an INI-based regimen. Among them, 15 had a viral load (VL) <50 copies/mL at initiation and virological suppression was maintained during the first year of follow-up in all but two exhibiting a viral blip. Twenty-four patients had a VL > 50 copies/mL at the time of INI-based regimen initiation. Among them eight were receiving a first-line regimen and the only two patients who did not reach VL < 50 copies/mL at week 24 were receiving elvitegravir. The 16 remaining patients were ART experienced in virological failure with drug-resistant viruses displaying several virological outcomes independently of the genotypic susceptibility score. Phenotypic analyses showed a fold change in EC50 of 0.6, 0.9 and 1.9 for raltegravir, dolutegravir and elvitegravir, respectively, in a subtype B context, and 1.1, 1.9 and 2.4 for raltegravir, dolutegravir and elvitegravir, respectively, in a CRF02_AG context.

Conclusions

Assessment of virological response in 39 patients initiating an INI-based regimen with E157Q-mutated virus, in combination with phenotypic analysis, suggests that particular attention should be paid to antiretroviral-naive patients and dolutegravir should be preferentially used in these patients.

Low dose Rituximab for pre-emptive treatment of Epstein Barr virus reactivation after allogenic hematopoietic stem cell transplantation

INTRODUCTION

The most used preemptive therapy for Epstein Barr virus reactivation post allogeneic hematopoietic stem cell (HSCT) transplant is Rituximab, 375 mg/m2, once weekly until EBV viremia negativity. There is no data suggesting such a high dose.

OBJECTIVE

We hypothesized that a lower dose of Rituximab would be as efficient with less toxicity.

PATIENTS

In a retrospective, monocentric study, we analyzed 16 consecutive patients treated preemptively with low dose Rituximab for EBV reactivation post HSCT. Patients were treated with low Rituximab dose of 100 mg/m² weekly. Success was defined by a decrease of EBV viremia of 1 log¹⁰ and below 1000 UI/ml, and the absence of post-transplant lymphoproliferative disorder (PTLD).

RESULTS

Success rate was 93.4% (15/16). One (1/16, 6%) PTLD was diagnosed after preemptive therapy, despite a negative viremia.

CONCLUSION

A low dose of Rituximab of 100 mg/m² per injection for pre-emptive therapy of EBV reactivation post HSCT is safe and effective for preventing PTLD. Prospective, randomized, multicentric trials with larger number of patient are needed to determine the best rituximab dose.

[State of immunization against measles among health professionals in at-risk units of the Caen University Hospital]

BACKGROUND

France is facing a new resurgence of measles. Since November 2017, the number of cases has been increasing sharply. Immunization coverage in the general population, all ages combined, is below the threshold required for a rapid decline of the virus propagation. Regarding health professionals, the rate of immunization against this disease is insufficiently documented. In this context, the Occupational Health Service of the University Hospital of Caen has carried out an inventory of health personnel knowledge of immunization against measles in the units the most exposed to risk.

METHODS

Knowledge of immunization against measles was studied in pediatric, imaging, and pediatric and adult emergencies departments of the University Hospital of Caen, and the Hematology Institute of Lower Normandy (IHBN). The analysis included all health professionals present within these units during the study period: March and April 2018. Data collection was carried out by consulting the medical files of the occupational health unit and considering the set of responses to postal inquiries sent to staff.

RESULTS

Measured immunization status data refer to 1017 health professionals. Based on the criteria specific to the recommendations, 234 (50.6%) of the 462 professionals born before 1980 and 437 (78.7%) of the 555 professionals born in or after 1980 could be considered as immune. Of the total sample, 115 (11.3%) had positive measles serology. Among these 1017 professionals, information on the state of immunization against measles was lacking for 174 (17.1%).

CONCLUSION

The state of immunization of the nursing staff remains insufficient to prevent the occurrence of measles cases and the staff is also insufficiently informed. It is essential to have knowledge of the immunization status of this population, to organize the vaccination of non-immunized personnel within the occupational health unit, to prevent the emergence of new cases of measles and to reinforce the information regarding the importance of precautions related to airborne transmission in case of measles.

Comparative performance of the Biocentric Generic Viral Load, Roche CAP/CTM v1.5, Roche CAP/CTM v2.0 and m2000 Abbott assays for quantifying HIV-1 B and non-B strains: Underestimation of some CRF02 strains

BACKGROUND

HIV-1 viral load testing is now recommended by the World Health Organization for every patient receiving antiretroviral therapy (ART).

OBJECTIVES

The objective of this study is to evaluate the performance of commercial assays for their ability to quantify HIV-1 strains currently circulating in France.

STUDY DESIGN

The performances of the Generic HIV-RNA assay from Biocentric were compared to those of the Roche CAP/CTM v1.5, Roche CAP/CTM v2.0 and Abbott m2000 RealTime HIV-1 assays. A total of 1885 HIV-1 plasma samples were tested, including 684 samples from patients included in the ANRS-Primo Cohort.

RESULTS

We found a good concordance of quantification between the Roche v2.0 and the Biocentric assays, both of which were superior to the Roche v1.5 assay. We show moderate agreement between techniques; however, CRF02_AG strains and undetermined viruses were underestimated when quantified with the Roche CAP/CTM v2.0. In contrast, a comparison of the Biocentric and Abbott assay results showed strong agreement between assays, indicating that both are well suited for quantification of CRF02_AG strains. Moreover, a 2% underestimation of the B subtypes was observed with the Biocentric assay.

CONCLUSIONS

These results have implications for viral load monitoring in Western Africa, where CRF02_AG strains are highly prevalent. Closer epidemiological surveillance and evaluation of commercial assays are still necessary to better evaluate the impact of the genetic evolution of circulating viruses on HIV-RNA quantification in the regions most affected by the HIV-1 epidemic.

Genetic diversity of human respiratory syncytial virus isolated among children with acute respiratory infections in Southern Cameroon during three consecutive epidemic seasons, 2011-2013

Background

Human respiratory syncytial virus (HRSV) is the main viral cause of severe lower respiratory tract disease in infants and young children. The aim of this study was to describe for the first time the genetic variability of HRSV in Cameroonian patients living in Yaounde for three consecutive epidemic seasons.

Methods

HRSV-positive nasopharyngeal samples detected in children less than 15 years in Yaounde were collected from September 2011 to December 2013. Semi-nested RT-PCR, sequencing, and phylogenetic analyses of the second hypervariable region of the G gene were performed.

Results

A total of 57 HRSV-positive samples were collected during the study period. Among these, 46 (80.7%) could be amplified in the G gene. HRSV group A (HRSV-A) and group B (HRSV-B) co-circulated in this population at 17.4 and 82.6%, respectively. HRSV-A strains clustered in the NA-1 genotype while HRSV-B strains clustered in the BA-9 genotype. HRSV-A strains accounted for 33.3% (2/6), 4.3% (1/23), and 29.4% (5/17) of the viruses isolated in 2011, 2012, and 2013, respectively.

Conclusions

This study reports molecular epidemiology data of HRSV in Cameroon for the first time. Additional studies are required to clarify evolutionary patterns of HRSV throughout sub-Saharan Africa to support antiviral and vaccine development.

Performance of genotypic algorithms for predicting tropism for HIV-1 CRF01_AE recombinant

OBJECTIVES

There is no consensus about the performances of genotypic rules for predicting HIV-1 non-B subtype tropism. Three genotypic methods were compared for CRF01_AE HIV-1 tropism determination.

METHODS

The V3 env region of 207 HIV-1 CRF01_AE and 178 B subtypes from 17 centers in France and 1 center in Switzerland was sequenced. Tropism was determined by Geno2Pheno algorithm with false positive rate (FPR) 5% or 10%, the 11/25 rule or the combined criteria of the 11/25, net charge rule and NXT/S mutations.

RESULTS

Overall, 72.5%, 59.4%, 86.0%, 90.8% of the 207 HIV-1 CRF01_AE were R5-tropic viruses determined by Geno2pheno FPR5%, Geno2pheno FPR10%, the combined criteria and the 11/25 rule, respectively. A concordance of 82.6% was observed between Geno2pheno FPR5% and the combined criteria for CRF01_AE. The results were nearly similar for the comparison between Geno2pheno FPR5% and the 11/25 rule. More mismatches were observed when Geno2pheno was used with the FPR10%. Neither HIV viral load, nor current or nadir CD4 was associated with the discordance rate between the different algorithms.

CONCLUSION

Geno2pheno predicted more X4-tropic viruses for this set of CRF01_AE sequences than the combined criteria or the 11/25 rule alone. For a conservative approach, Geno2pheno FPR5% seems to be a good compromise to predict CRF01_AE tropism.

SOFIA®RSV: prospective laboratory evaluation and implementation of a rapid diagnostic test in a pediatric emergency ward

Background

Respiratory syncytial virus (RSV) is responsible for severe respiratory infections and higher costs in medical care. The two aims of this work were to assess the performances of SOFIA^®RSV tests in “real-life-laboratory” conditions (study 1) and implemented at point-of-care testing in a pediatric emergency department (ED, study 2), during two consecutive winter seasons.

Methods

In study 1, fresh nasopharyngeal swabs from patients of all ages were sampled in 1.5 ml of Universal virological Transport Medium (UTM) and prospectively tested using SOFIA^®RSV tests. In study 2, conducted in a pediatric ED, nasopharyngeal swabs were placed in 3 ml of UTM. All SOFIA^®RSV tests were confirmed by molecular testing, considered as reference method. The epidemiological and clinical features of tested patients, as well as the care of these patients after obtaining quick results were evaluated.

Results

The sensitivities of SOFIA^®RSV in infants (aged under 24 months) performed in the laboratory and in the pediatric ED were respectively 95% (95% CI: 86.8–98.1) and 74.8% (95% CI: 68.0–80.9) compared to PCR. In study 1, the sensitivity among children (from 2 to 15 years old) and adults (above 15 years old) dropped to 45% (95% CI: 23.1–68.5) and 59% (95% CI: 32.9–81.6), respectively. In study 2, there were some differences in bed-management of SOFIA^®RSV positive compared to SOFIA^®RSV negative infants.

Conclusions

SOFIA^®RSV tests performed in the laboratory and in the pediatric ED show high and satisfactory sensitivities among young children under 24 months, which supports its robustness and reliability. However, the impact of these tests on patient care at point-of-care cannot be clearly assessed when considering the limits of the study 2 design.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2557-8) contains supplementary material, which is available to authorized users.

Immune Reconstitution Inflammatory Syndrome Unmasking or Worsening AIDS-Related Progressive Multifocal Leukoencephalopathy: A Literature Review

Incidence of progressive multifocal leukoencephalopathy (PML) in HIV-infected patients has declined in the combined antiretroviral therapy (cART) era although a growing number of acquired immunodeficiency syndrome (AIDS)-related PML-immune reconstitution inflammatory syndromes (PML-IRIS) have been published during the same period. Therapeutic management of PML-IRIS is not consensual and mainly relies on corticosteroids. Our main aim was, in addition to provide a thoughtful analysis of published PML-IRIS cases, to assess the benefit of corticosteroids in the management of PML-IRIS, focusing on confirmed cases. We performed a literature review of the 46 confirmed cases of PML-IRIS cases occurring in HIV-infected patients from 1998 to September 2016 (21 unmasking and 25 paradoxical PML-IRIS). AIDS-related PML-IRIS patients were mostly men (sex ratio 4/1) with a median age of 40.5 years (range 12-66). Median CD4 T cell count before cART and at PML-IRIS onset was 45/μl (0-301) and 101/μl (20-610), respectively. After cART initiation, PML-IRIS occurred within a median timescale of 38 days (18-120). Clinical signs were motor deficits (69%), speech disorders (36%), cognitive disorders (33%), cerebellar ataxia (28%), and visual disturbances (23%). Brain MRI revealed hyperintense areas on T2-weighted sequences and FLAIR images (76%) and suggestive contrast enhancement (87%). PCR for John Cunningham virus (JCV) in cerebrospinal fluid (CSF) was positive in only 84% of cases; however, when performed, brain biopsy confirmed diagnosis of PML in 90% of cases and demonstrated histological signs of IRIS in 95% of cases. Clinical worsening related to PML-IRIS and leading to death was observed in 28% of cases. Corticosteroids were prescribed in 63% of cases and maraviroc in one case. Statistical analysis failed to demonstrate significant benefit from steroid treatment, despite spectacular improvement in certain cases. Diagnosis of PML-IRIS should be considered in HIV-infected patients with worsening neurological symptoms after initiation or resumption of effective cART, independently of CD4 cell count prior to cART. If PCR for JCV is negative in CSF, brain biopsy should be discussed. Only large multicentric randomized trials could potentially demonstrate the possible efficacy of corticosteroids and/or CCR5 antagonists in the management of PML-IRIS.

Performance Evaluation of the VIDAS(®) Measles IgG Assay and Its Diagnostic Value for Measuring IgG Antibody Avidity in Measles Virus Infection

The objective of this study is primarily to compare the performance of the VIDAS(®) Measles immunoglobulin (Ig)G assay to that of two other serological assays using an immunoassay technique, Enzygnost(®) Anti-measles Virus/IgG (Siemens) and Measles IgG CAPTURE EIA(®) (Microimmune). The sensitivity and the agreement of the VIDAS(®) Measles IgG assay compared to the Enzygnost(®) Anti-measles Virus/IgG assay and the Measles IgG CAPTURE EIA(®) assay are 100%, 97.2% and 99.0%, 98.4%, respectively. The very low number of negative sera for IgG antibodies does not allow calculation of specificity. As a secondary objective, we have evaluated the ability of the VIDAS(®) Measles IgG assay to measure anti-measles virus IgG antibody avidity with the help of the VIDAS(®) CMV IgG Avidity reagent, using 76 sera from subjects with measles and 238 other sera. Different groups of populations were analyzed. In the primary infection measles group, the mean IgG avidity index was 0.16 (range of 0.07 to 0.93) compared to 0.79 (range of 0.25 to 1) in the serum group positive for IgG antibodies and negative for IgM. These data allow to define a weak anti-measles virus IgG antibody avidity as an avidity index (AI) < 0.3 and a strong avidity as an AI > 0.6. The VIDAS(®) Measles IgG assay has a performance equivalent to that of other available products. Its use, individual and quick, is well adapted to testing for anti-measles immunity in exposed subjects.

Study and interest of cellular load in respiratory samples for the optimization of molecular virological diagnosis in clinical practice

BACKGROUND

Respiratory viral diagnosis of upper respiratory tract infections has largely developed through multiplex molecular techniques. Although the sensitivity of different types of upper respiratory tract samples seems to be correlated to the number of sampled cells, this link remains largely unexplored.

METHODS

Our study included 800 upper respiratory tract specimens of which 400 negative and 400 positive for viral detection in multiplex PCR. All samples were selected and matched for age in these 2 groups. For the positive group, samples were selected for the detected viral species.

RESULTS

Among the factors influencing the cellularity were the type of sample (p < 0.0001); patient age (p < 0.001); viral positive or negative nature of the sample (p = 0.002); and, for the positive samples, the number of viral targets detected (0.004 < p < 0.049) and viral species.

CONCLUSION

The cellular load of upper respiratory samples is multifactorial and occurs for many in the sensitivity of molecular detection. However it was not possible to determine a minimum cellularity threshold allowing molecular viral detection. The differences according to the type of virus remain to be studied on a larger scale.

First detection of equine coronavirus (ECoV) in Europe

Equine coronavirus (ECoV) is involved mainly in enteric infections. Following the recent description of ECoV in 2000, this study reports for the first time the presence of ECoV in France and, on a wider scale, in Europe. ECoV was molecularly detected from diarrheic and respiratory specimens. Sequencing and phylogenetic analyses demonstrated that European strains are most closely related to the reference North American strain (ECoV-NC99) than the Asian strain (ECoV-Tokachi09).

[Day-care centers: Sites of viral contact]

La répétition des épisodes infectieux chez les nourrissons placés précocement en collectivités est une évidence. Leur tropisme sur la sphère respiratoire et l’appareil digestif l’est également. Leur probable retentissement au long cours est difficile à évaluer par la rareté des études prospectives. Le risque infectieux est lié en partie au type de structure de garde, ce risque est important dans les premiers mois de fréquentation et conditionne les récidives ultérieures. Les liens de causalité entre infection virale et asthme sont complexes. Les infections virales augmentent le risque d’asthme mais le statut asthmatique augmente aussi le risque de réponses sévères à une infection virale. Alors que les infections acquises dans cet environnement sont majoritairement virales, leur répétition conduit à une utilisation excessive des antibiotiques d’où une pression de sélection microbienne et un retentissement sur le microbiome digestif voire respiratoire.

Comparative evaluation of six commercialized multiplex PCR kits for the diagnosis of respiratory infections

The molecular diagnosis of respiratory infection can be performed using different commercial multiplex-based PCR kits whose performances have been previously compared individually to those of conventional techniques. This study compared the practicability and the diagnostic performances of six CE-marked kits available in 2011 on the French market, including 2 detecting viruses and atypical bacteria (from Pathofinder and Seegene companies) and 4 detecting only viruses (from Abbott, Genomica, Qiagen and Seegene companies). The respective sensitivity, specificity, accuracy and agreement of each multiplex technique were calculated by comparison to commercial duplex PCR tests (Argene/bioMérieux) used as gold standard. Eighty-eight respiratory specimens with no pathogen (n = 11), single infections (n = 33) or co-infections (n = 44) were selected to cover 9 viruses or groups of viruses and 3 atypical bacteria. All samples were extracted using the NUCLISENS® easyMAG™ instrument (bioMérieux). The overall sensitivity ranged from 56.25% to 91.67% for viruses and was below 50% with both tests for bacteria. The overall specificity was excellent (>94% for all pathogens). For each tested kit, the overall agreement with the reference test was strong for viruses (kappa test >0.60) and moderate for bacteria. After the extraction step, the hands-on time varied from 50 min to 2h30 and the complete results were available in 2h30 to 9 h. The spectrum of tested agents and the technology used to reveal the PCR products as well as the laboratory organization are determinant for the selection of a kit.

Viral epidemiology and severity of respiratory infections in infants in 2009: a prospective study

BACKGROUND

Viral respiratory infections are common in infants and can be severe. The new pandemic influenza virus H1N1v2009 was feared to cause particularly severe outcomes.

OBJECTIVE

This study aimed at evaluating the impact of H1N1v2009 on the viral epidemiology, the clinical presentation and the severity of respiratory infections in infants.

PATIENTS AND METHODS

This prospective epidemiologic study included all infants <2 years of age, both inpatients and outpatients, presenting with respiratory symptoms, from November 2009 through April 2010, at the pediatric emergency department of the University Hospital of Caen, France. A nasal swab was taken for viral detection and analyzed by immunofluorescence and, if negative, polymerase chain reaction. Severe respiratory infection was defined by a score of respiratory severity.

RESULTS

One thousand twenty-one infectious episodes with a respiratory sample met inclusion criteria. Eight hundred thirty-four samples (81.7%) were positive. The viruses with the highest incidence were the respiratory syncytial virus (34.2%), the rhinoviruses (23.9%), the coronaviruses (9.3%) and H1N1v2009 (7.7%). Of all infections, 28.6% were severe and more frequent in infants with risk factors. H1N1v2009 infections had a low risk of severe respiratory disease (odds ratios = 0.15) and hospitalization (odds ratios = 0.40) compared with the other viruses. Respiratory syncytial virus infections had a high risk of respiratory severity (odds ratios = 7.85) and were responsible for 71.4% of admissions to the intensive care unit.

CONCLUSION

Despite the modest impact of H1N1v2009 observed in this study, further surveillance is needed to detect virological factors that may increase its severity.

Epidemiological and phylogenic study of human metapneumovirus infections during three consecutive outbreaks in Normandy, France

Human metapneumovirus (hMPV) is responsible for respiratory tract disease, particularly in the young and elderly population. An epidemiological and phylogenic study was performed on children admitted to hospital with an acute lower respiratory tract infection (LRI). Data were obtained and analyzed over three consecutive winters, from 2002–2003 to 2004–2005. Each year during the winter period, from November to March, 2,415 nasal swabs were tested by a direct immunofluorescence assay (DFA) for influenza viruses A and B, respiratory syncytial virus, parainfluenza viruses, and adenoviruses. Rhinoviruses, enteroviruses, and coronaviruses OC43 and 229E were detected by RT‐PCR. A RT‐PCR designed for the M gene was performed on negative samples for hMPV detection and phylogenic analyses. For the three consecutive winters, hMPV represented 10%, 22.6%, and 8.8% of virus‐negative samples, respectively. In most cases, clinical symptoms indicated a LRI with a final diagnosis of bronchiolitis. During the winter of 2003–2004, all viral clusters (A1, A2, B1, and B2) that circulated in France shifted progressively from the A group to the B group. This study determined the prevalence of hMPV in Normandy, its clinical impact and permitted the analysis of the molecular evolution during the successive outbreaks. J. Med. Virol. 83:517–524, 2011. © 2011 Wiley‐Liss, Inc.

[Molecular diagnosis of respiratory enterovirus infections: Use of PCR and molecular identification for a best approach of the main circulating strains during 2008]

The PCR assays are currently used in diagnosis of enterovirus (EV) meningitis. Nevertheless, the use of molecular diagnosis of EV should be investigated in respiratory tract infections (RTI).

OBJECTIVES

To perform enterovirus molecular diagnostic tools, PCR and genotyping, in nasal samples for diagnostic and epidemiologic purposes.

METHODS

During 2008, 3612 nasal specimen (NS) were studied by IFD and MRC5 culture. Next, we realised successively viral isolation on HuH7 culture (for NS negative by IFD assay) and a duplex PCR enterovirus-rhinovirus for the 816 HuH7 positive supernatants. Furthermore, 327 NS collected from neonates were systematically tested by a real-time RT-PCR. This assay was used in routine for EV diagnosis setting in cerebrospinal fluid. Enterovirus genotyping was then performed for the 68 positive supernatants.

RESULTS

Thirty-five NS (0.97%) were positive for EV by culture (MRC5). A combination of both PCR assays, PEVRV and PEV, allowed an additional identification of 41 EV, eight EV-RV and 12 RV, increasing the number of positive to 96 NS (2.6%). Among the neonates, 32 NS (11.3%) were positive for EV by PEV. Of the 98 NS tested by the two PCR assays (PEV and PEVRV), 27 were positive and we detected 10 EV, five EV-RV and 12 RV. From January to December 2008, the circulation of EV showed the usual peak in June-July when a small outbreak of aseptic meningitis occurred and an additional autumnal peak corresponding to respiratory tract infections. Five main serotypes were isolated: 19 EV68 (29.7%), 12 CB3 (18.7%), nine E3 (14,1%), six CA9 (9.4%) and six CB1 (9.4%); the 19 EV68 were isolated in October-November and 17/19 (89.5%) of positive patients were hospitalised for severe respiratory diseases.

CONCLUSION

The use of molecular screening techniques (PCR assays and genotyping) on nasal samples collected from patients with respiratory infections allowed a prospective, effective and precise identification of circulating strains.

[Measles and its virus]

After the huge decrease of measles thanks to vaccination, measles reappeared in 2008, with 604 cases reported at the Institut national de veille sanitaire (InVS), then 1,544 cases in 2009 and 2,605 cases up to 2010, June. At the same time, 86 viral strains were detected from saliva samples at the Centre national de référence de la rougeole et des Paramyxoviridae respiratoires (CNR) in 2008, 316 in 2009 and 946 up to August 2010. The reality of the outbreak was confirmed by the increase of the endemic cases: 0.0009% cases in 2008 and 0.004% in 2010, the diffusion to all parts of France, and the more specific attack of infants: 4% in 2008 and 9% in 2010, and of young adults: 17% in 2008 and 38% in 2010. Most of the cases (82%) occurred in non-vaccinated people. The number of hospitalised cases has increased as well, going from 18% in 2008 to 34% in 2010. The strain of this outbreak is a genotype D4. It appeared in 2008 then it spread in 2009 and 2010, representing 19, 75 and 99% of the strains, respectively. All the viruses in this genotype belonged to the Montreal-like cluster described in 1989: Montréal.CAN/89xD4. At the beginning of the outbreak some were closed to a variant which appeared in England in 2007 MVs/Enfield.GBR/14.07(D4), but most of them (95%) are nowidentical to a strain which caused a small focus of measles in the region Vendee at the last trimester 2008: MVs/Montaigu.FRA/43.08(D4). The salivary diagnosis of measles, which was introduced in France in 2005, in parallel to the obligation of reporting measles cases, has been proved very efficient: 75% of saliva are collected in the first four days, and viral RNA was detected in 536 (81%) out the 660 samples received at the CNR up to now in 2010; 136 (21%) saliva had IgM specific antibodies and 18% had neither RNA, nor IgM.

[Mycoplasma pneumoniae and Chlamydophila pneumoniae coinfection in severe pneumoniae among a hospitalized child with respiratory distress: what are the best diagnostic tools for an optimal care?]

The role for Mycoplasma pneumoniae and Chlamydophila pneumoniae in lower and upper respiratory tract infections in childhood increased by use of specialised diagnostic techniques, more and more performant for the early diagnosis of these infections. However, the prevalence of M. pneumoniae and C. pneumoniae as a cause of severe pneumoniae among hospitalized children has been rarely described. We report a case of M. pneumoniae et C. pneumoniae coinfection in a 10-year-old child hospitalized with a respiratory distress.

Childhood myocarditis and parvovirus B19 genotypes

BACKGROUND

Human parvovirus B19 (PVB19) infection is occasionally associated with acute myocarditis. Three cases of children with PVB19 virus-associated myocarditis occurred in a very short period and the same geographical region.

OBJECTIVE

To elucidate if virological factors could be responsible for determining the course of infection, a molecular epidemiologic investigation was performed.

STUDY DESIGN

The diagnosis of myocarditis was established by histology or echocardiography. In the three cases, the PVB19 DNA was detected in different samples. Eight different regions were amplified by PCR using a high fidelity Taq polymerase and sequenced on both strands. Phylogenetic analyses were performed. First, the genotypes of the PVB19 strains were determined, then the intra-patient viral variability was analysed by sequencing PVB19 detected in different specimens sampled from the same patient at the same moment.

RESULTS

Nearly complete sequences of the PVB19 virus (4265nt) were obtained from different samples in the three patients. The phylogenetic analyses showed that PVB19 strains identified clustered with genotype 1a PVB19 strains referenced in GenBank. When compared to the referenced strain NC_000883, the number of substitutions (transitions and transversions) were as follows: 58 for Caen.FRA/19.09, 74 for Caen.FRA/21.09 and 60 for Caen.FRA/24.09. The strains isolated from the same patient showed 100% of similarity.

CONCLUSIONS

Viral myocarditis is a frequently unrecognized cause of post-inflammatory cardiomyopathy. The detailed molecular analyses do not give rise to virological markers associated with myocarditis in these children.

[Bronchiolitis viruses]

In Normandy (France), human respiratory syncytial virus (hRSV) was detected in 64.1% of acute bronchiolitis in hospitalized children, rhinovirus in 26.8%, human metapneumovirus (hMPV) in 7.6%, and parainfluenza virus (PIV) in 3.4%. The viruses causing acute bronchiolitis in the community were hRSV (42%), rhinovirus (19.5%), coronavirus (8%), PIV (3.5%), and hMPV (2.5%). In 53.7% of the cases, hRSV infected infants (86.9%), 53.7% being less than 6 months of age. Of the hRSV cases, 48.2% were detected in November and December and 44.5% in January and February. The hRSV epidemic started the 1st or 2nd week of October but it varied from one year to another and from one region to another. hRSV acute bronchiolitis increased from 261 cases in epidemics from 1999-2003 to 341 cases from 2004-2009. Rhinoviruses gave acute bronchiolitis in 38.4% of cases. A rate of 54.6% of viruses was detected in September and October and 38.5% in March and April. A total of 34.2% of infected infants were under 6 months of age, 37.8% between 6 months and 2 years, and 19.5% were between 2 and 5 years old. hMPV epidemics coincided with hRSV epidemics, but they accounted for one-sixth the number of cases. HMPV infected infants (74%) who were older than those infected with hRSV, and the diagnosis was bronchiolitis (59%) and pneumonia (17%). PIV infections (about 100 cases per year) included PIV3 (62.7%), PIV1 (25.3%), and PIV2 (7.3%). PIV1 infections occurred every 2 years in the fall. PIV3 infections were observed every year during the fall and winter, with peaks of infections in the spring in the years without PIV1. There were acute cases of bronchiolitis in 29.8% of PIV3 infections and 18.3% in PIV1 infections.

[Seasonal flu]

La grippe saisonnière est due aux virus influenza A et B. Il s’agit de virus enveloppés dont le génome est constitué de sept à huit fragments d’ARN. Les différents sous-types sont déterminés par la nature des deux glycoprotéines de surface HA et NA. La grippe saisonnière est une maladie épidémique et hivernale dans les zones à climat tempéré. Son épidémiologie est liée à la grande variabilité du virus au cours du temps, nécessitant la mise en place d’un système d’alerte détectant chaque année les variants circulants dominant et déterminant la composition vaccinale. Les symptômes cliniques de la grippe ne sont pas suffisamment spécifiques pour permettre le diagnostic sans examen virologique. Cela est particulièrement vrai en période non épidémique, chez les sujets de plus de 65 ans et chez les enfants de moins de cinq ans. L’enfant représente une cible privilégiée des infections à virus influenza. Le recours à l’hospitalisation est d’autant plus élevé que l’enfant est jeune. Chez le nourrisson, l’infection peut être paucisymptomatique et s’accompagner de manifestations non respiratoires (léthargie, convulsions, malaises). Le diagnostic virologique de la grippe est justifié chez tous les sujets hospitalisés pour un syndrome respiratoire compatible avec une infection à virus influenza. Il existe plusieurs outils permettant une recherche directe du virus dans les sécrétions respiratoires : isolement du virus en culture, détection d’antigènes, détection moléculaire de l’ARN. Le choix de la méthode se fait selon les caractéristiques du test : sensibilité, spécificité, rapidité et simplicité de réalisation, coût.

Development of duplex real-time PCR for detection of two DNA respiratory viruses

A method was developed for the detection and quantitation of HAdV (human adenovirus) and HBoV (human bocavirus) based on a duplex real-time PCR, the AB PCR, using a Smartcycler instrument. A control real-time PCR was carried out on albumin DNA to standardise the non-homogenous respiratory samples. No cross-reactivity was observed with viruses or bacteria that could be found in the respiratory tract. The diagnosis rate using the AB PCR on clinical samples was 10.7%: 3.4% for HBoV detection, 6.9% for HAdV detection and 0.3% double detection HBoV-HAdV. The clinical and epidemiological characteristics of the HAdV- and HBoV-infected patients were evaluated. In the HAdV-positive group and the HBoV-positive group the samples were classified according to the severity of the disease. The HAdV viral load did not appear to be linked to the severity of the disease. Conversely, the difference between the two HBoV groups, severe and non-severe, was significant statistically when the comparison was based on the viral load (P=0.006) or after adjustment of the viral load to the number of cells in the samples (P=0.02).

Detection of human bocavirus in hospitalised children

AIM

The objectives of this study are to assess the frequency of human bocavirus (HBoV) infection in hospitalised children and to study the clinical symptoms associated with the detection of HBoV.

METHODS

Two groups of hospitalised children were included in this study: group 1 consisted of 1946 children hospitalised from 1st September 2004 to 30th May 2005, and group 2 consisted of 448 children hospitalised from 1st November 2003 to 30th March 2004. The respiratory specimens were tested by polymerase chain reaction.

RESULTS

In the first group, HBoV was detected by polymerise chain reaction in 11/828 (1.3%) of nasal specimens that tested negative for other respiratory viruses. One child tested positive for HBoV in both a nasal aspirate and stool sample. In the second group, nasal specimens were tested for all respiratory viruses, including HBoV. The presence of HBoV infection was detected in seven children (1.6%). Detection of a mixed viral population was observed in four of these children. The main symptoms in children infected with HBoV were rhinitis (50%), cough (45%), dyspnoea (28%), wheezing (28%), fever (23%) and diarrhoea (22%). The final clinical diagnoses were bronchiolitis (seven children), rhinopharyngitis (five children), the exacerbation of asthma (two children) and pneumonia (one child). Moreover, four children have associated gastroenteritis.

CONCLUSION

These results contribute to the interest in the HBoV detection in children. HBoV detection in hospitalised children with or without any other respiratory virus detection was essentially associated with lower respiratory tract infection and in a lower score with upper respiratory tract infection and gastroenteritis.