Epidemiology and clinical characteristics of parainfluenza virus 3 outbreak in a Haemato-oncology unit

Phylogenetic lineage dynamics of global parainfluenza virus type 3 post-COVID-19 pandemic

During the coronavirus disease 2019 (COVID-19) pandemic, outbreaks of parainfluenza virus type 3 (PIV-3) decreased due to infection control measures. However, a post-pandemic resurgence of PIV-3 has recently been observed. Nonetheless, the role of viral genetic epidemiology, possibly influenced by a genetic bottleneck effect, remains unexplored. We investigated the phylogenetic structure of the publicly available PIV-3 whole-genome and hemagglutinin-neuraminidase (HN) gene sequences spanning the last 65 years, including the COVID-19 pandemic. Sequences were retrieved from the nucleotide database of the National Center for Biotechnology Information using the search term "Human respirovirus 3." Sequence subsets covering all six genes of PIV-3 or the HN gene were designated as the whole-genome and HN surveillance data sets, respectively. Using these data sets, we constructed maximum-likelihood phylogenetic trees and performed a time-scaled analysis using a Bayesian SkyGrid coalescent prior. A total of 455 whole-genome and 1,139 HN gene sequences were extracted, revealing 10 and 11 distinct lineages, respectively, with >98% concurrence in lineage assignments. During the 2020 COVID-19 pandemic, only three single-lineage clusters were identified in Japan, Korea, and the USA. The inferred year of origin for PIV-3 was 1938 (1903-1963) for the whole-genome data set and 1955 (1930-1963) for the HN gene data set. Our study suggests that PIV-3 epidemics in the post-COVID era are likely influenced by a pandemic-driven bottleneck phenomenon and supports previous hypotheses suggesting s that PIV-3 originated during the early half of the 20th century.IMPORTANCEUsing publicly available parainfluenza virus type 3 (PIV-3) whole-genome sequences, we estimated that PIV-3 originated during the 1930s, consistent with previous hypotheses. Lineage typing and time-scaled phylogenetic analysis revealed that PIV-3 experienced a bottleneck phenomenon in Korea and the USA during the coronavirus disease 2019 pandemic. We identified the conservative hemagglutinin-neuraminidase gene as a viable alternative marker in long-term epidemiological studies of PIV-3 when whole-genome analysis is limited.

The clinical and epidemiological impacts of whole genomic sequencing on bacterial and virological agents

Whole Genome Sequencing (WGS) is a molecular biology tool consisting in the sequencing of the entire genome of a given organism. Due to its ability to provide the finest available resolution of bacterial and virological genetics, it is used at several levels in the field of infectiology. On an individual scale and through application of a single technique, it enables the typological identification and characterization of strains, the characterization of plasmids, and enhanced search for resistance genes and virulence factors. On a collective scale, it enables the characterization of strains and the determination of phylogenetic links between different microorganisms during community outbreaks and healthcare-associated epidemics. The information provided by WGS enables real-time monitoring of strain-level epidemiology on a worldwide scale, and facilitates surveillance of the resistance dissemination and the introduction or emergence of pathogenic variants in humans or their environment. There are several possible approaches to completion of an entire genome. The choice of one method rather than another is essentially dictated by the matrix, either a clinical sample or a culture isolate, and the clinical objective. WGS is an advanced technology that remains costly despite a gradual decrease in its expenses, potentially hindering its implementation in certain laboratories and thus its use in routine microbiology. Even though WGS is making steady inroads as a reference method, efforts remain needed in view of so harmonizing its interpretations and decreasing the time to generation of conclusive results.

Routine, molecular point-of-care testing for SARS-CoV-2 and other respiratory viruses within an acute oncology service improves patient care

OBJECTIVES

COVID-19 has caused significant challenges for infection prevention measures and patient flow in hospital admission pathways. We aimed to assess the impact of replacing laboratory PCR with molecular point-of-care testing (mPOCT) for respiratory viruses including SARS-CoV-2, within an Acute Oncology Service (AOS).

METHODS

This pre- and post-implementation study took place in the AOS of a large teaching hospital, in Southampton, UK. We collected data from two periods: November 25th, 2019 to November 24th, 2020, when respiratory virus testing utilised laboratory PCR, and December 1st, 2020 to May 31st, 2021 following the introduction of mPOCT. The primary outcome was the time to results.

RESULTS

2189 patients were tested in the pre-implementation period and 1540 in the post implementation period. Median (IQR) time to results was 5.8 h (4.2-10.6) pre-implementation and 1.9 h (1.5-3.0) post-implementation (difference -3.6 h [95%CI to -3.8 to -3.5]; p < 0.0001). Median time spent in assessment areas was 6.0 h (4.1-7.9) pre-implementation and 5.5 h (3.8-7.4) post-implementation (p < 0.0001). 20 (0.9%) patients admitted via AOS assessment unit developed hospital-acquired respiratory virus infection pre-implementation versus 0 (0%) post-implementation (p = 0.031).

CONCLUSIONS

Routine mPOCT for respiratory viruses, including SARS-CoV-2, was associated with a reduced time to results, reduced time in assessment areas, and a reduction in the rates of hospital-acquired respiratory virus infection in an acute oncology assessment unit.

A fatal case of neonatal viral sepsis caused by human parainfluenza virus type 3

BACKGROUND

Sepsis is a systemic inflammatory response syndrome caused by severe infection in children, but cases of sepsis associated with human parainfluenza virus (HPIV) have been rarely reported in newborns.

CASE PRESENTATION

We report a case of HPIV-3 positive full-term newborn admitted to the Neonatal Intensive Care Unit of Beijing Children's Hospital due to hematuria, gloomy spirit, inactivity and loss of appetite for 6 h. He had septic shock when he arrived the Accident & Emergency Department requiring immediate intubation and mechanical ventilation. Intravenous antibiotics were started. He had completely negative response to all anti-shock treatments including fluid resuscitation and vasopressor supports, and died 14 h later. Viral nucleic acid detection and metagenomic next-generation sequencing (mNGS) analyses of nasopharyngeal aspirate and blood specimens verified an HPIV-3 infection, with negative bacterial culture results. The HPIV-3 strain detected in this patient was subtyped as HPIV C3a, and two unreported amino acid mutations were found in the HN protein region.

CONCLUSION

The patient had a severe infection associated with HPIV-3, which was the cause of sepsis and septic shock. This study showed the diagnostic value of mNGS in etiological diagnosis, especially in severe neonatal case.

Parainfluenza virus infections in patients with hematological malignancies or stem cell transplantation: Analysis of clinical characteristics, nosocomial transmission and viral shedding

To assess morbidity and mortality of parainfluenza virus (PIV) infections in immunocompromised patients, we analysed PIV infections in a hematology and stem cell transplantation (SCT) unit over the course of three years. Isolated PIV strains were characterized by sequence analysis and nosocomial transmission was assessed including phylogenetic analysis of viral strains. 109 cases of PIV infection were identified, 75 in the setting of SCT. PIV type 3 (n = 68) was the most frequent subtype. PIV lower respiratory tract infection (LRTI) was observed in 47 patients (43%) with a mortality of 19%. Severe leukopenia, prior steroid therapy and presence of co-infections were significant risk factors for development of PIV-LRTI in multivariate analysis. Prolonged viral shedding was frequently observed with a median duration of 14 days and up to 79 days, especially in patients after allogeneic SCT and with LRTI. Nosocomial transmission occurred in 47 patients. Phylogenetic analysis of isolated PIV strains and combination with clinical data enabled the identification of seven separate clusters of nosocomial transmission. In conclusion, we observed significant morbidity and mortality of PIV infection in hematology and transplant patients. The clinical impact of co-infections, the possibility of long-term viral shedding and frequent nosocomial transmission should be taken into account when designing infection control strategies.

Controlling a human parainfluenza virus-3 outbreak in a haematology ward in a tertiary hospital: the importance of screening strategy and molecular diagnostics in relation to clinical symptoms

BACKGROUND

Human parainfluenza 3 (HPIV-3) outbreak at the haemato-oncology ward of the Maastricht University Medical Center in the summer of 2016.

AIM

To describe an effective strategy to control the largest reported HPIV-3 outbreak at an adult haematology-oncology ward in the Netherlands by implementing infection control measures and molecular epidemiology investigation.

METHODS

Clinical, patient and diagnostic data were both pro- and retrospectively collected. HPIV-3 real-time-PCR (HPIV-3 RT-PCR) was validated using oropharyngeal rinse samples. Screening of all new and admitted patients was implemented to identify asymptomatic infection or prolonged shedding of HPIV-3 allowing cohort isolation.

FINDINGS

The HPIV-3 outbreak occurred between 9 July and 28 September 2016 and affected 53 patients. HPIV-3 RT-PCR on oropharyngeal rinse samples demonstrated an up to tenfold higher sensitivity compared to pharyngeal swabs. Monitoring showed that at first positive PCR, 20 patients (38%) were asymptomatic (of which 11 remained asymptomatic) and the average duration of shedding was 14 days (range 1-58). Asymptomatic patients had lower viral load, shorter period of viral shedding (≤14 days) and were mostly immune competent oncology patients. The outbreak was under control 5 weeks after implementation of screening of asymptomatic patients.

CONCLUSION

Implementation of a sensitive screening method identified both symptomatic and asymptomatic patients which had lower viral load and allowed early cohort isolation. This is especially important in a ward that combines patients with varying immune status, since both immunocompromised and immune competent patients are likely to spread the HPIV-3 virus, either through prolonged shedding or through asymptomatic course of disease.

Sources of viral respiratory infections in Canadian acute care hospital healthcare personnel

BACKGROUND

Viral respiratory illnesses are common causes of outbreaks and can be fatal to some patients.

AIM

To investigate the association between laboratory-confirmed viral respiratory infections and potential sources of exposure during the previous 7 days.

METHODS

In this nested case-control analysis, healthcare personnel from nine Canadian hospitals who developed acute respiratory illnesses during the winters of 2010/11-2013/14 submitted swabs that were tested for viral pathogens. Associated illness diaries and the weekly diaries of non-ill participants provided information on contact with people displaying symptoms of acute respiratory illness in the previous week. Conditional logistic regression assessed the association between cases, who were matched by study week and site with controls with no respiratory symptoms.

FINDINGS

There were 814 laboratory-confirmed viral respiratory illnesses. The adjusted odds ratio (aOR) of a viral illness was higher for healthcare personnel reporting exposures to ill household members [7.0, 95% confidence interval (CI) 5.4-9.1], co-workers (3.4, 95% CI 2.4-4.7) or other social contacts (5.1, 95% CI 3.6-7.1). Exposures to patients with respiratory illness were not associated with infection (aOR 0.9, 95% CI 0.7-1.2); however, healthcare personnel with direct patient contact did have higher odds (aOR 1.3, 95% CI 1.1-1.6). The aORs for exposure and for direct patient contact were similar for illnesses caused by influenza.

CONCLUSION

Community and co-worker contacts are important sources of viral respiratory illness in healthcare personnel, while exposure to patients with recognized respiratory infections is not associated. The comparatively low risk associated with direct patient contact may reflect transmission related to asymptomatic patients or unrecognized infections.

Molecular Evolution of the Fusion Protein (F) Gene in Human Respirovirus 3

To elucidate the evolution of human respirovirus 3 (HRV3), we performed detailed genetic analyses of the F gene (full-length) detected from hundreds of HRV3 strains obtained from various geographic regions. First, we performed time-scaled evolutionary analyses using the Bayesian Markov chain Monte Carlo method. Then, we performed analyses of phylodynamics, similarity, phylogenetic distance, selective pressure, and conformational B-cell epitope with the F-protein structural analyses. Time-scaled phylogenetic tree showed that the common ancestor of HRV3 and bovine respirovirus 3 diverged over 300 years ago and subdivided it into three major clusters and four subclusters during the most recent 100 years. The overall evolutionary rate was approximately 10^-3 substitutions/site/year. Indigenous similarity was seen in the present strains, and the mean phylogenetic distance were 0.033. Many negative selection sites were seen in the ectodomain. The conformational epitopes did not correspond to the neutralizing antibody binding sites. These results suggest that the HRV3 F gene is relatively conserved and restricted in this diversity to preserve the protein function, although these strains form many branches on the phylogenetic tree. Furthermore, HRV3 reinfection may be responsible for discordances between the conformational epitopes and the neutralizing antibody binding sites of the F protein. These findings contribute to a better understanding of HRV3 virology.

Molecular evolution of the hemagglutinin-neuraminidase (HN) gene in human respirovirus 3

Human respirovirus 3 (HRV3) is a major causative agent of acute respiratory infections in humans. HRV3 can manifest as a recurrent infection, although exactly how is not known. In the present study, we conducted detailed molecular evolutionary analyses of the major antigen-coding hemagglutinin-neuraminidase (HN) gene of this virus detected/isolated in various countries. We performed analyses of time-scaled evolution, similarity, selective pressure, phylodynamics, and conformational epitope prediction by mapping to HN protein models. In this way, we estimated that a common ancestor of the HN gene of HRV3 and bovine respirovirus 3 diverged around 1815 and formed many lineages in the phylogenetic tree. The evolutionary rates of the HN gene were 1.1 × 10^-3 substitutions/site/year, although the majority of these substitutions were synonymous. Some positive and many negative selection sites were predicted in the HN protein. Phylodynamic fluctuations of the gene were observed, and these were different in each lineage. Furthermore, most of the predicted B cell epitopes did not correspond to the neutralization-related mouse monoclonal antibody binding sites. The lack of a link between the conformational epitopes and neutralization sites may explain the naturally occurring HRV3 reinfection.

An Outbreak of Human Parainfluenza Virus 3 (Phylogenetic Subcluster C5) Infection among Adults at a Residential Care Facility for the Disabled in Croatia, 2018

INTRODUCTION

Although highly pertinent for children, outbreaks of human parainfluenza virus (HPIV) may cause up to 15% of all respiratory illnesses in adults and predispose them to serious adverse outcomes, with HPIV serotype 3 (HPIV3) being the most common. This study represents the first report of an HPIV3 outbreak among adults at a long-term health-care facility in Croatia.

METHODS

A retrospective study was conducted to investigate an outbreak of acute respiratory infection (ARI) at a single residential care facility for the disabled in Croatia. Demographic, epidemiological, and clinical data were collected for all residents, while hospitalized patients were appraised in detail by laboratory/radiological methods. Multiplex PCR for respiratory viruses and sequencing was performed. Partial HPIV3 HN 581 nt sequences were aligned with HPIV3 sequences from the GenBank database to conduct a phylogenetic analysis, where different bioinformatic approaches were employed.

RESULTS

In late June 2018, 5 of the 10 units at the facility were affected by the outbreak. Among the 106 residents, 23 (21.7%) developed ARI, and 6 (26.1%) of them were hospitalized. HPIV3 was identified in 18 (73%) of the residents and 5 (83%) of the hospitalized individuals. Isolated HPIV3 strains were classified within the phylogenetic subcluster C5 but grouped on 2 separate branches of the phylogenetic tree. During the entire outbreak period, none of the institution's employees reported symptoms of ARI.

CONCLUSIONS

Our study has shown that this health care-associated outbreak of HPIV3 infection could have been linked to multiple importation events. Preventive measures in curbing such incidents should be enforced vigorously.

Outbreak of Human Parainfluenza Virus Type 1 in a Kindergarten from China, 2018

Objective  We reported an outbreak of human parainfluenza virus type 1 (HPIV1) in a kindergarten and explored the genetic characteristics of HPIV1 hemagglutinin-neuraminidase (HN) and fusion (F) genes to provide more evidence about HPIV1 outbreaks.

Methods  Suspected cases were the children with an influenza-like illness during June 20 to 26, 2018. Nasopharyngeal swabs were collected and screened to determine the presence of respiratory pathogens by real-time fluorescent quantitative polymerase chain reaction. The HN and F gene sequences of HPIV-positive samples were further amplified and sequenced to confirm the HPIV genotype and identify genetic characteristics. A phylogenetic tree, based on the HN and F genes, was reconstructed by maximum likelihood method.

Results  Fourteen children in the outbreak were diagnosed as upper respiratory tract infection. The most common symptom was cough (10/14), followed by rhinorrhea (5/14), sore throat (4/14), headache (1/14), and abdominal pain (1/14). Eight patients were positive for HPIV1 and negative for other pathogens. Phylogenetic tree demonstrated that the eight strains from the year 2018 in our study located in the clade 2.3. Two specific substitutions (N333S and I509M) in the amino acids of the F protein and two substitutions (V19A and L436I) in the HN protein were different from other strains in the clade 2.

Conclusion  HPIV1 was attributed to the outbreak, which may be related to the genetic variations of HPIV1.

Update on infection control practices in cancer hospitals

Therapies in oncology have evolved rapidly over the last years. At the same pace, supportive care for patients receiving cancer therapy has also evolved, allowing patients to safely receive the newest advances in treatment in both an inpatient and outpatient basis. The recognition of the role of infection control and prevention (ICP) in the outcomes of patients living with cancer has been such that it is now a requirement for hospitals and involves multidisciplinary groups. Some unique aspects of ICP for patients with cancer that have gained momentum over the past few decades include catheter-related infections, multidrug-resistant organisms, community-acquired viral infections, and the impact of the health care environment on the horizontal transmission of organisms. Furthermore, as the potential for infections to cross international borders has increased, alertness for outbreaks or new infections that occur outside the area have become constant. As the future approaches, ICP in immunocompromised hosts will continue to integrate emerging disciplines, such as antibiotic stewardship and the microbiome, and new techniques for environmental cleaning and for controlling the spread of infections, such as whole-genome sequencing. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.

Human respiratory syncytial virus: prevalence, viral co-infections and risk factors for lower respiratory tract infections in children under 5 years of age at a general hospital in the Democratic Republic of Congo

PURPOSE

This study aimed to determine the prevalence of human respiratory syncytial virus (HRSV) acute respiratory infection (ARI) in children under the age of 5 years at the Provincial General Hospital of Bukavu (PGHB), and to analyse factors associated with the risk of ARI being diagnosed as lower respiratory tract infection (LRTI).

METHODOLOGY

A total of 146 children under 5 years visiting the PGHB for ARI between August and December 2016 were recruited, and socio-demographic information, clinical data and nasopharyngeal swabs were collected. The samples were analysed by a multiplex reverse transcriptase polymerase chain reaction targeting 15 different viruses.

RESULTS

Of 146 samples collected, 84 (57.5 %) displayed a positive result of at least one of the 15 viruses. The overall prevalence of HRSV was 21.2 %. HRSV A (30, 20.5 %) was the virus the most detected, followed by HRV (24, 16.4 %), PIV3 (20, 16.6) and ADV (7, 4.79 %). The other viruses were detected in three or fewer cases. There were only 11 (7.5 %) cases of co-infection. HRSV infection, malnutrition, younger age, rural settings, low income and mother illiteracy were associated with the risk of ARI being diagnosed as LRTI in bivariate analyses but, after adjusting for the confounding factors, only HRSV infection and younger age were independently associated with LRTI.

CONCLUSION

The prevalence of HRSV is high among children visiting the PGHB for ARI. HRSV infection and lower age are independently associated with the risk of ARI being diagnosed as LRTI.

Molecular epidemiology and environmental contamination during an outbreak of parainfluenza virus 3 in a haematology ward

Background

Although fomites or contaminated surfaces have been considered as transmission routes, the role of environmental contamination by human parainfluenza virus type 3 (hPIV-3) in healthcare settings is not established.

Aim

To describe an hPIV-3 nosocomial outbreak and the results of environmental sampling to elucidate the source of nosocomial transmission and the role of environmental contamination.

Methods

During an hPIV-3 outbreak between May and June 2016, environmental surfaces in contact with clustered patients were swabbed and respiratory specimens used from infected patients and epidemiologically unlinked controls. The epidemiologic relatedness of hPIV-3 strains was investigated by sequencing of the haemagglutinin–neuraminidase and fusion protein genes.

Findings

Of 19 hPIV-3-infected patients, eight were haematopoietic stem cell recipients and one was a healthcare worker. In addition, four had upper and 12 had lower respiratory tract infections. Of the 19 patients, six (32%) were community-onset infections (symptom onset within <7 days of hospitalization) and 13 (68%) were hospital-onset infections (≥7 days of hospitalization). Phylogenetic analysis identified two major clusters: five patients, and three patients plus one healthcare worker. Therefore, seven (37%) were classified as nosocomial transmissions. hPIV-3 was detected in 21 (43%) of 49 environmental swabs up to 12 days after negative respiratory polymerase chain reaction conversion.

Conclusion

At least one-third of a peak season nosocomial hPIV-3 outbreak originated from nosocomial transmission, with multiple importations of hPIV-3 from the community, providing experimental evidence for extensive environmental hPIV-3 contamination. Direct contact with the contaminated surfaces and fomites or indirect transmission from infected healthcare workers could be responsible for nosocomial transmission.

Viral Pneumonia in Patients with Hematologic Malignancy or Hematopoietic Stem Cell Transplantation

Viral pneumonias in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation cause significant morbidity and mortality. Advances in diagnostic techniques have enabled rapid identification of respiratory viral pathogens from upper and lower respiratory tract samples. Lymphopenia, myeloablative and T-cell depleting chemotherapy, graft-versus-host disease, and other factors increase the risk of developing life-threatening viral pneumonia. Chest imaging is often nonspecific but may aid in diagnoses. Bronchoscopy with bronchoalveolar lavage is recommended in those at high risk for viral pneumonia who have new infiltrates on chest imaging.

Cholesterol reducing agents inhibit assembly of type I parainfluenza viruses

Many enveloped RNA viruses utilize lipid rafts for the assembly of progeny virions, but the role of cholesterol, a major component of rafts, on paramyxovirus budding and virion formation is controversial. In this study, we analyzed the effects of FDA-approved cholesterol-reducing agents, gemfibrozil and lovastatin, on raft formation and assembly of human parainfluenza virus type 1 (hPIV1) and Sendai virus (SeV). Treatment of the human airway epithelial A549 cells with the agents, especially when combined, significantly decreased production of infectious hPIV1 and SeV. Mechanistic analysis indicated that depletion of cellular cholesterol reduced cell surface accumulation of envelope glycoproteins and association of viral matrix and nucleocapsids with raft membrane, which resulted in impaired virus budding and release from the cells. These results indicate that cellular cholesterol is required for assembly and formation of type 1 parainfluenza viruses and suggest that cholesterol could be an attractive target for antiviral agents against hPIV1.

Community acquired respiratory virus infections in cancer patients-Guideline on diagnosis and management by the Infectious Diseases Working Party of the German Society for haematology and Medical Oncology

BACKGROUND

Community acquired viruses (CRVs) may cause severe disease in cancer patients. Thus, efforts should be made to diagnose CRV rapidly and manage CRV infections accordingly.

METHODS

A panel of 18 clinicians from the Infectious Diseases Working Party of the German Society for Haematology and Medical Oncology have convened to assess the available literature and provide recommendations on the management of CRV infections including influenza, respiratory syncytial virus, parainfluenza virus, human metapneumovirus and adenovirus.

RESULTS

CRV infections in cancer patients may lead to pneumonia in approximately 30% of the cases, with an associated mortality of around 25%. For diagnosis of a CRV infection, combined nasal/throat swabs or washes/aspirates give the best results and nucleic acid amplification based-techniques (NAT) should be used to detect the pathogen. Hand hygiene, contact isolation and face masks have been shown to be of benefit as general infection management. Causal treatment can be given for influenza, using a neuraminidase inhibitor, and respiratory syncytial virus, using ribavirin in addition to intravenous immunoglobulins. Ribavirin has also been used to treat parainfluenza virus and human metapneumovirus, but data are inconclusive in this setting. Cidofovir is used to treat adenovirus pneumonitis.

CONCLUSIONS

CRV infections may pose a vital threat to patients with underlying malignancy. This guideline provides information on diagnosis and treatment to improve the outcome.

Parainfluenza Virus Infection

Human parainfluenza viruses (HPIVs) are single-stranded, enveloped RNA viruses of the Paramyoviridaie family. There are four serotypes which cause respiratory illnesses in children and adults. HPIVs bind and replicate in the ciliated epithelial cells of the upper and lower respiratory tract and the extent of the infection correlates with the location involved. Seasonal HPIV epidemics result in a significant burden of disease in children and account for 40% of pediatric hospitalizations for lower respiratory tract illnesses (LRTIs) and 75% of croup cases. Parainfluenza viruses are associated with a wide spectrum of illnesses which include otitis media, pharyngitis, conjunctivitis, croup, tracheobronchitis, and pneumonia. Uncommon respiratory manifestations include apnea, bradycardia, parotitis, and respiratory distress syndrome and rarely disseminated infection. Immunity resulting from disease in childhood is incomplete and reinfection with HPIV accounts for 15% of respiratory illnesses in adults. Severe disease and fatal pneumonia may occur in elderly and immunocompromised adults. HPIV pneumonia in recipients of hematopoietic stem cell transplant (HSCT) is associated with 50% acute mortality and 75% mortality at 6 months. Though sensitive molecular diagnostics are available to rapidly diagnose HPIV infection, effective antiviral therapies are not available. Currently, treatment for HPIV infection is supportive with the exception of croup where the use of corticosteroids has been found to be beneficial. Several novel drugs including DAS181 appear promising in efforts to treat severe disease in immunocompromised patients, and vaccines to decrease the burden of disease in young children are in development.

A molecular epidemiological study of human parainfluenza virus type 3 at a tertiary university hospital during 2013-2015 in Catalonia, Spain

Human parainfluenza virus type 3 (HPIV-3) is one of the most common respiratory viruses particularly among young children and immunocompromised patients. The seasonality, prevalence and genetic diversity of HPIV-3 at a Spanish tertiary-hospital from 2013 to 2015 are reported. HPIV-3 infection was laboratory-confirmed in 102 patients (76%, under 5 years of age). Among <5 years-old patients, 9 (11.5%) were under any degree of immunosuppression, whereas this percentage was significantly higher (19; 79.2%) among patients older than 5 years. HPIV-3 was detected at varying levels, but mainly during spring and summer. All characterized HN/F sequences fell within C1b, C5 and in other two closely C3a-related groups. Furthermore, a new genetic lineage (C1c) was described. Genetic similarity and epidemiological data confirmed some nosocomial infections, highlighting the importance of the HPIV-3 surveillance, particularly in high-risk patients. This study provides valuable information on HPIV-3 diversity due to the scarce information in Europe.

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Children and immunosuppressed adults showed a great susceptibility to infection.

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Valuable information about the current genetic diversity in Europe is provided.

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Different lineages, including a first described, were locally circulating.

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Genetic similarity and epidemiological data confirmed some nosocomial infections.

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The present study highlights the importance of the HPIV-3 surveillance.

Respiratory viruses and their impact in healthcare

PURPOSE OF REVIEW

As viral respiratory infections are responsible for significant morbidity and mortality, and are associated with numerous challenges for infection control, we provide an overview of the most recent publications on healthcare-associated respiratory infections.

RECENT FINDINGS

Populations most susceptible to respiratory viruses include neonates, immunocompromised and elderly populations. Newer polymerase chain reaction-based assays are more sensitive and are able to detect multiple respiratory viruses. The significance of virus detection among asymptomatic individuals, however, remains unclear. There is more evidence of airborne transmission of influenza, but currently N95 masks are recommended only for aerosol generating procedures. Transocular transmission of influenza has been demonstrated in the experimental setting, but further research is needed of transocular transmission of other respiratory viruses. Mandatory vaccination of healthcare workers against influenza has been shown to reduce influenza rates and patient mortality.

SUMMARY

Infection control measures can be supplemented with use of polymerase chain reaction testing to determine causes, but the cornerstone of prevention relies on enforcing appropriate isolation measures for patients: hand hygiene; appropriate use of personal protective equipment by healthcare workers; illness screening of visitors; and influenza vaccination of healthcare workers, patients and families.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Epidemiology and Control: Principles, Practice and Programs

Infectious disease epidemiology is concerned with the occurrence of both infection and disease in populations and the factors that determine their frequency, spread, expression and distribution. Viruses show characteristic infectivity, virulence and pathogenicity. The most well established host factors are age, sex and race, but other host biological and behavioral factors affect acquisition of viral infection and/or its course and manifestations. The physical, chemical and biological environment operates on the virus itself and may also alter the host biological or behavioral response. Viral infections have incubation periods lasting days or weeks, while their pathologic sequelae may not manifest for years or decades. Likewise the degree or intensity of host response and clinical expression may range from largely inapparent to highly lethal. The degree of cell, tissue and organ specificity is high. Common syndromes involve the respiratory, gastrointestinal, and central nervous systems, the liver, and mucocutaneous surfaces. Vertical transmission may produce a variety of congenital and perinatal conditions. Viruses spread by multiple modes, using nearly every bodily surface or fluid as a route of exit or entry, either by direct contact or indirectly through an animal vector or other inanimate vehicle. Different viral Infections occur nearly ubiquitously or sporadically; they may be present continuously throughout a population (endemic) or occur in seasonal rhythm or in unexpectedly explosive form (epidemic). Many viruses are refractory to all known therapeutic agents, while for a few, the increasing number of highly effective agents holds great promise. Vaccines have produced many historical successes including the ultimate goal of eradication, but many viral infections continue to elude effective vaccine development. Major government and private sector programs for treatment and prevention have raised expectations of successful control for certain widespread and serious viral diseases; however, in every case a unique set of scientific, socioeconomic, political and behavioral barriers remains to be overcome.

Multiplex real-time PCR for prompt diagnosis of an outbreak of human parainfluenza 3 virus in children with acute leukemia

Introduction

Human parainfluenza virus type 3 (HPIV-3) causes significant morbimortality in immunocompromised patients. Outbreaks of severe pneumonitis have been previously described in this setting.

Materials and methods

Retrospective observational study in children diagnosed with acute leukemia and a documented HPIV-3 infection in the context of a nosocomial outbreak occurred in a single center.

Result

During summer 2012, an HPIV-3 infection was detected in six hospitalized children with acute leukemia. All the patients had respiratory symptoms and one of them suffered from parotitis.

Conclusion

Early diagnoses using multiplex real-time polymerase chain reaction (PCR) let us control this outbreak. A phylogenetic analysis confirmed person-to-person transmission of a single HPIV-3 variant.