Sudden Infant Death Associated with Rhinovirus Infection

A less than one-month-old infant with symptoms of rhinitis died unexpectedly in his sleep. He was not born prematurely and had no known underlying disease. Cerebrospinal fluid, nasopharyngeal and lung samples, and rectal swab were found to be positive for subgroup A rhinovirus, while the blood was negative. This case highlights the important finding that the rhinovirus, a common pathogen associated with upper respiratory tract infections, can sometimes, as the only pathogen, lead to complications such as a cerebrospinal infection and be involved in the sudden infant death syndrome (SIDS). Vigilance is necessary in case of viral infections in the infant's environment, and measures of hygiene and protection must be encouraged in order to reduce the risk of the SIDS.

Relative distribution of HPV genotypes in histological cervical samples and associated grade lesion in a women population over the last 16 years in Burgundy, France

Human papillomavirus is a predominant sexually transmitted viral pathogen. Our objective was to analyze the relative distribution of genotypes over time and to determine the genotypes associated with adverse clinical lesions. The study was based on data from adult women with cytological abnormalities from whom histological samples were obtained from 2005 to 2021. HPV genotyping was performed using PCR and INNO-LiPA assay (Fujirebio). Among the 1,017 HPV-positive biopsies, 732 (72%) were infected with a single HPV genotype and 285 (28%) were infected with several HPV genotypes. Most of the infections involved the high-risk genotypes 16, 31, and 52. Throughout the study period, HPV 16 was the most encountered genotype (541, 53.2%), while HPV 18 was rather under-represented (46, 4.5%), especially in invasive cervical carcinoma. HVP52 (165, 16.2%) was detected mainly from 2008 to 2014, and its distribution reached 19.7% in 2011. Such epidemiological data underlines the possibility of an emergence of a high-risk genotype. The most detected low-risk HPV in combination with high-risk HPV was HPV 54 in 6.5% of samples. Monoinfection by HPV 16 led statistically more often to severe lesions than multi-infection involving HPV 16 (p < 0.001), while for HPV 52, 31 or 33, multi-infections were significantly associated with severe lesions (p < 0.001 for each of these three genotypes). HPV 16 was involved in 55.2% of high-grade lesions and in situ carcinoma and 76.3% of invasive carcinomas. In severe lesions, HPV 16 participation was predominant, whereas diverse genotypes were seen in low-grade lesions. Importantly, we observed that high-risk genotypes, for example HPV 52, can emerge for a few years then decrease even without vaccine pressure.

Humoral and cellular immune response after severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccination in heart transplant recipients: An observational study in France

INTRODUCTION

Heart transplant (HT) recipients have a high risk of developing severe COVID-19. Immunoglobulin G antibodies are considered to provide protective immunity and T-cell activity is thought to confer protection from severe disease. However, data on T-cell response to mRNA vaccination in a context of HT remains limited.

METHODS

In 96 HT patients, a IFN-γ release assay and an anti-Spike antibody test were used to evaluate the ability of SARS-CoV-2 mRNA vaccines to generate cellular and humoral immune response. Blood samples were collected few weeks to 7 months after vaccination. Multiple fractional polynomial and LASSO regression models were used to define predictors of T-cell response.

RESULTS

Three to five months after vaccination, three doses of vaccine induced a positive SARS-CoV-2 T-cell response in 47% of recipients and a positive humoral response in 83% of recipients, 11.1% of patients remained negative for both T and B cell responses. Three doses were necessary to reach high IgG response levels (>590 BAU/mL), which were obtained in a third of patients. Immunity was greatly amplified in the group who had three vaccine doses plus COVID-19 infection.

CONCLUSION

Our study revealed that T and B immunity decreases over time, leading us to suggest the interest of a booster vaccination at 5 months after the third dose. Moreover, a close follow-up of immune response following vaccination is needed to ensure ongoing immune protection. We also found that significant predictors of higher cellular response were infection and active smoking, regardless of immunosuppressive treatment with mycophenolate mofetil (MMF).

Beyond QuantiFERON-TB Results, the Added Value of a Weak Mitogen Response

Introduction

While QuantiFERON-TB gold (QFT) is frequently used, little attention is paid to the mitogen response. How it could be impacted and associated with outcomes is poorly known.

Methods

Retrospective, case-control study in hospitalized patients who underwent QFT testing in two hospitals between 2016 and 2019. We defined two groups of cases with either negative [interferon (IFN)-γ ≤ 0.5 IU/ml, official threshold] or weak (0.5–2 IU/ml) mitogen response, and one group of controls with normal (>2 IU/ml) mitogen response.

Results

A total of 872 patients were included. An ongoing infection was independently associated with both a negative (RR = 4.34; 95% CI = 2.94–6.41) and a weak mitogen response (RR = 2.44; 95% CI = 1.66–3.58). Among tuberculosis patients, a weak mitogen response was associated with a false-negative QFT result (75%) compared to a normal response (20%). Decreasing mitogen response (normal, weak and negative, respectively) was associated with increasing length of hospital stay [median (interquartile range) 5 (3–13), 11 (5–21) and 15 (10–30) days; p < 0.001] and increasing hospital mortality (3, 7, and 15%; p < 0.001).

Conclusion

Clinicians should take notice of the mitogen response since IFN-γ concentrations lower than <2 IU/ml were associated with false-negative QFT results in tuberculosis patients, independently associated with ongoing infections, and could be associated with worse prognosis.

Local Emergence of A del HV69-70 SARS-CoV-2 Variant in Burgundy, France

In the autumn of 2020, a short-lived epidemic of a spike del69-70 deletion variant of SARS-CoV-2 was identified, with most cases (n = 95) found in Montceau-les-Mines, France. This spike gene target failure (SGTF) variant spread quickly in nursing homes. The Alpha variant, which also harbors this deletion, appeared in Burgundy in January 2021 after the disappearance of the Montceau-les-Mines del69-70 variant. Our findings illustrate the risk of the fast spread of geographically isolated variants and reinforce the need for the continuous tracking of outbreaks. In some cases, these studies may reveal emerging variants that affect public health or vaccine development.

Epidemiological characteristics and clinical outcomes of human rhinovirus infections in a hospitalized population. Severity is independently linked to RSV coinfection and comorbidities

Human rhinovirus (hRV) is a predominant respiratory viral pathogen. The determinants that lead to adverse clinical outcomes in hospitalized patients are unclear. Our objective was to analyze the epidemiological and clinical characteristics of hRV infections in a hospitalized population and to compare non-severe and severe infections. The study was based on data from all patients with a respiratory episode admitted to Hospital from October 2015 to September 2016. During the study period, out of 2465 respiratory episodes, 434 were detected positive for hRV. Most of the coinfections involved the respiratory syncytial virus (RSV) and very few influenza viruses. A possible interference between rhinovirus and influenza virus is suggested. Airway involvement was present in a large part of hRV infections with 28.4 % (n = 48/169) of bronchiolitis and 3.6 % (n = 6/169) of bronchitis. One third of patients had at least one of the following severity criteria: need for oxygen therapy, hospitalization ≥ 5 days, and admission to the ICU. On multivariate analysis, a respiratory co-infection with RSV and the presence of a chronic respiratory disease (including a history of asthma) were shown to be independent risk factors for the onset of a severe infection in patients ≤ 2 years old. In a case control study based on 70 patients, hRV-A was the predominant lineage, followed closely by hRV-C. High viral load or viral genotypes were not associated with severe infection.

Epidemiological and clinical characteristics of patients infected with enterovirus D68, France, July to December 2014

In 2014, the United States (US) experienced a nationwide outbreak of enterovirus D68 (EV-D68) infection with 1,152 cases reported mainly in hospitalised children with severe asthma or bronchiolitis. Following the US alert, 11 laboratories of the French enterovirus (EV) surveillance network participated in an EV-D68 survey. A total of 6,229 respiratory samples, collected from 1 July to 31 December 2014, were screened for EV-D68 resulting in 212 EV-D68-positive samples. These 212 samples corresponded to 200 EV-D68 cases. The overall EV-D68 positivity rates among respiratory samples were of 5% (184/3,645) and 1.1% (28/2,584) in hospitalised children and adults respectively. The maximum weekly EV-D68 positivity rates were of 16.1% for children (n = 24/149; week 43) and 2.6% for adults (n = 3/115; week 42). Of 173 children with EV-D68 infection alone, the main symptoms were asthma (n = 83; 48.0%) and bronchiolitis (n = 37; 21.4%). One child developed acute flaccid paralysis (AFP) following EV-D68-associated pneumonia. Although there was no significant increase in severe respiratory tract infections reported to the French public health authorities, 10.7% (19/177) of the EV-D68 infected children and 14.3% (3/21) of the EV-D68 infected adults were hospitalised in intensive care units. Phylogenetic analysis of the viral protein 1 (VP1) sequences of 179 EV-D68 cases, revealed that 117 sequences (65.4%), including that of the case of AFP, belonged to the B2 variant of clade B viruses. Continuous surveillance of EV-D68 infections is warranted and could benefit from existing influenza-like illness and EV surveillance networks.

Human metapneumovirus in patients hospitalized with acute respiratory infections: A meta-analysis

This meta-analysis aimed to estimate the prevalence of human metapneumovirus (hMPV) infections in patients hospitalized for acute respiratory infection (ARI) and to study factors associated with this prevalence. Medline and ScienceDirect databases were searched for prospective observational studies that screened hospitalized patients with ARI for hMPV by RT-PCR, with data available at December 27, 2014. The risk of bias was assessed regarding participation rate, definition of ARI, description of diagnostic technique, method of inclusion identical for all subjects, standardized and identical sampling method for all subjects, analysis performed according to the relevant subgroups, and presentation of data sources. Random-effect meta-analysis with arcsine transformation and meta-regressions was used. In the 75 articles included, the prevalence of hMPV among hospitalized ARI was 6.24% (95% CI 5.25-7.30). An effect of the duration of the inclusion period was observed (p=0.0114), with a higher prevalence of hMPV in studies conducted during periods of 7-11 months (10.56%, 95% CI 5.97-16.27) or complete years (7.55%, 95% CI 5.90-9.38) than in periods of 6 months or less (5.36%, 95% CI 4.29-6.54). A significant increase in the incidence with increasing distance from the equator was observed (p=0.0384). hMPV should be taken into account as a possible etiology in hospitalized ARI.

RNA interference in vitro and in vivo using DsiRNA targeting the nucleocapsid N mRNA of human metapneumovirus

Human metapneumovirus causes respiratory diseases with outcomes that can be severe in children, the immunocompromised, and the elderly. Synthetic small interfering RNAs (siRNAs) that silence targeted genes can be used as therapeutic agents. Currently, there is no specific therapy for hMPV. In this study, we designed Dicer-substrate siRNAs (DsiRNAs) that target metapneumovirus sequences on the mRNAs of the N, P, and L genes. In vitro, six DsiRNAs were shown to inhibit virus replication using cell proliferation tests. Of those, the DsiRNA that targets the most conserved mRNA sequence was then resynthesized in Evader™ format with heavy 2'-O-methyl modification of the guide strand. In a murine model, the prophylactic administration of this Evader™ DsiRNA was effective at partially inhibiting viral replication of hMPV (13×10(3) vs. 29×10(3)PFU/g of lung; p<0.01), which was not the case for the control, a mismatched DsiRNA. Inhibition was achieved without inducing cytokines or off-target effects. Moreover, the specificity of the siRNA mechanism of action was demonstrated in vitro and in vivo using 5'-RACE methodology. This in vivo approach of using a DsiRNA against hMPV is an important step in the development of synthetic siRNA as a therapeutic agent for this virus.

Epidemiological and clinical features of hMPV, RSV and RVs infections in young children

BACKGROUND

Human metapneumovirus (hMPV) has recently been isolated from children with acute respiratory tract infections (RTIs). The epidemiological and clinical characteristics of hMPV infection need further investigation.

OBJECTIVES

The purpose of this study was to compare the clinical features of hMPV, respiratory syncytial virus (RSV) and rhinoviruses (RV) infections in children less than 3 years of age presenting to an emergency department with acute respiratory illness.

STUDY DESIGN

From December 2002 to April 2004, all children under age three (n=931) admitted for acute respiratory illness to Dijon Hospital, France, were investigated for respiratory viruses in nasal washes.

RESULTS

hMPV was detected in 6% of children (in 10.1% (n=38) the first winter and in 3.3% (n=17) the second winter); RSV was detected in 28.5% of the children, while rhinoviruses were found in 18.3%. Five hMPV-infected children had evidence of dual infection, two with RSV and three others with RV. The median age of the patients with hMPV infection was 6 months, and the main clinical symptoms were rhinorrhea (74.5%) and cough (67%). A lower tract disease occurred in 66% of hMPV-positive patients. Gene sequencing of hMPV isolates revealed co-circulation of the two major groups of hMPV during the study period; no difference in pathogenicity was found. There was no difference in the prevalence of bronchiolitis where hMPV, RSV or rhinoviruses were present. Asthma was found more often in hospitalized children with hMPV and rhinoviruses than among those with RSV (p<0.001).

CONCLUSIONS

These results provide further evidence of the importance of hMPV as a pathogen associated with respiratory tract infection in children.

Immune response and alteration of pulmonary function after primary human metapneumovirus (hMPV) infection of BALB/c mice

Human metapneumovirus (hMPV), a recently identified virus, causes upper and lower respiratory tract diseases. In this study, we show that BALB/c mice inoculated with hMPV exhibited significant morbidity on 1--2 days post-infection, when airway obstruction was found. Increased airway hyper-responsiveness to metacholine was found on day 4 concurrent with lung viral replication. Both IgG1 and IgG2a hMPV-specific antibodies were found in sera, while interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were found in bronchoalveolar lavage. Lung histology showed parenchymal pneumonia and increased lymphocytic infiltration. We present here an animal model that may be helpful in studying hMPV pathogenesis and evaluating the effects of vaccines.