The impact of infection control upon hospital-acquired influenza and respiratory syncytial virus

Associations between hospital structure, infection control and incidence of hospital-acquired viral respiratory infections: a 10-year surveillance study

BACKGROUND

Protecting patients from hospital-acquired viral respiratory infections is a major challenge, but the hierarchy of measures to achieve this is not yet completely clear.

AIM

To describe the epidemiology of hospital-acquired viral respiratory infections and associations with structural hospital factors and adherence to infection control protocols.

METHODS

Retrospective cohort study conducted over 10 consecutive years (2014-2023) within 27 hospital wards in a 900-bed university hospital in Paris, France. All hospitalized adult patients who were tested for at least one virus on a respiratory sample during their stay were included. Structural factors (percentage of double occupancy rooms) and adherence to infection control protocols by healthcare workers (measured by consumption of alcohol-based hand sanitizer and of facemasks) were included as predictors in the model.

MAIN OUTCOME AND MEASURE

Incidence of hospital-acquired viral respiratory infections, defined by a positive PCR test for at least one respiratory virus, performed at least 5 days after hospital admission. Data were analyzed on ward-year aggregated data, with a linear mixed-effects model.

FINDINGS

Overall, 183 994 viral PCR tests were performed over the study period. Incidence of hospital-acquired viral respiratory infections was 0.57/1000 hospital-days. After adjustment on other factors (mean length of stay, use of PCR testing), incidence of hospital-acquired viral respiratory infections in a given ward was significantly associated with: the incidence of community-acquired viral respiratory infections among patients admitted to the ward (+ 0.10/1000 hospital-days per each additional point of incidence; P < 0.001), the number of double-occupancy rooms (+ 0.04/1000 hospital-days per each 10%-increase of double-occupancy rooms; P = 0.03) and masks consumption (+ 0.33/1000 hospital-days per 10 additional masks used per day; P = 0.04). Similar results were found for double-occupancy rooms (+ 0.01/1000 hospital-days per each 10%-increase of double-occupancy rooms; P = 0.012) in the sub-group analysis of influenza cases.

CONCLUSION

In a given hospital ward, the incidence of community-acquired cases and the proportion of double-occupancy rooms are independently associated with the incidence hospital-acquired viral respiratory infections.

Hospital-acquired influenza in the United States, FluSurv-NET, 2011-2012 through 2018-2019

OBJECTIVE

To estimate population-based rates and to describe clinical characteristics of hospital-acquired (HA) influenza.

DESIGN

Cross-sectional study.

SETTING

US Influenza Hospitalization Surveillance Network (FluSurv-NET) during 2011-2012 through 2018-2019 seasons.

METHODS

Patients were identified through provider-initiated or facility-based testing. HA influenza was defined as a positive influenza test date and respiratory symptom onset >3 days after admission. Patients with positive test date >3 days after admission but missing respiratory symptom onset date were classified as possible HA influenza.

RESULTS

Among 94,158 influenza-associated hospitalizations, 353 (0.4%) had HA influenza. The overall adjusted rate of HA influenza was 0.4 per 100,000 persons. Among HA influenza cases, 50.7% were 65 years of age or older, and 52.0% of children and 95.7% of adults had underlying conditions; 44.9% overall had received influenza vaccine prior to hospitalization. Overall, 34.5% of HA cases received ICU care during hospitalization, 19.8% required mechanical ventilation, and 6.7% died. After including possible HA cases, prevalence among all influenza-associated hospitalizations increased to 1.3% and the adjusted rate increased to 1.5 per 100,000 persons.

CONCLUSIONS

Over 8 seasons, rates of HA influenza were low but were likely underestimated because testing was not systematic. A high proportion of patients with HA influenza were unvaccinated and had severe outcomes. Annual influenza vaccination and implementation of robust hospital infection control measures may help to prevent HA influenza and its impacts on patient outcomes and the healthcare system.

Nosocomial Respiratory Viral Infection in the Neonatal Intensive Care Unit

Infections caused by respiratory viruses in neonates during their stay in the neonatal intensive care unit (NICU) are more frequent than generally suspected. Respiratory syncytial virus (RSV), a highly contagious pathogen, is the most common etiologic agent, and it carries a high risk of nosocomial spread. During the RSV season, overcrowding of the NICU, shortage of staff, and unrestricted visitors are factors predisposing outbreaks. Since signs and symptoms of RSV infections are no specific, a high index of suspicion is essential to prevent or limit epidemics. The etiologic agent should be confirmed and polymerase chain reaction (PCR) is the gold-standard test. Shedding of the virus by infected preterm infants is prolonged and RSV lasts for several hours on countertops and other surfaces. The first case should be isolated and strict cohorting must be instituted. Compliance with hand washing must be warranted. Wearing gowns and gloves may help. The severity of nosocomial RSV infections tends to be higher than that of those community acquired. There is no uniform recommendation to start palivizumab during hospital stay of premature and high-risk infants. The use of this monoclonal antibody to stop or limit the spread of outbreaks is controversial. It is recommended by some professional organizations and not by others but its use during large outbreaks in infants at risk who share the room with infected neonates is not uncommon. KEY POINTS: · During peak community epidemic, NICU outbreaks of RSV infections are not uncommon.. · High index of suspicion is essential as initial signs are nonspecific in preterm neonates.. · Isolation and cohorting, strict hand washing, gowns, gloves, and eventually palivizumab are main tools for management..

Focusing on Families and Visitors Reduces Healthcare Associated Respiratory Viral Infections in a Neonatal Intensive Care Unit

Supplemental Digital Content is available in the text.

Healthcare-associated respiratory viral infections (HARVIs) result in significant harm to infants in the neonatal intensive care unit (NICU). Healthcare workers and visitors can serve as transmission vectors to patients. We hypothesized that improved family and visitor hand hygiene (FVHH) and visitor screening would reduce HARVIs by at least 25%.

Use of whole-genome sequencing in the molecular investigation of care-associated HCoV-OC43 infections in a hematopoietic stem cell transplant unit

•

HCoV−OC43 is involved in healthcare–associated infections.

•

HCoV−OC43 genotypes B, E, F and G are identified.

•

Asian and European strains of HCoV−OC43 circulate among patients.

Background

While respiratory viral infections are recognized as a frequent cause of illness in hematopoietic stem cell transplantation (HSCT) recipients, HCoV−OC43 infections have rarely been investigated as healthcare-associated infections in this population.

Objectives

In this report, HCoV−OC43 isolates collected from HSCT patients were retrospectively characterized to identify potential clusters of infection that may stand for a hospital transmission.

Study design

Whole-genome and S gene sequences were obtained from nasal swabs using next-generation sequencing and phylogenetic trees were constructed. Similar identity matrix and determination of the most common ancestor were used to compare clusters of patient’s sequences. Amino acids substitutions were analysed.

Results

Genotypes B, E, F and G were identified. Two clusters of patients were defined from chronological data and phylogenetic trees. Analyses of amino acids substitutions of the S protein sequences identified substitutions specific for genotype F strains circulating among European people.

Conclusions

HCoV−OC43 may be implicated in healthcare-associated infections.

Association Between Children's Hospital Visitor Restrictions and Healthcare-Associated Viral Respiratory Infections: A Quasi-Experimental Study

We investigated the effect of annual winter visitor restrictions on hospital respiratory virus transmission. The healthcare-associated (HA) viral respiratory infection (VRI) transmission index (number of HA VRIs per 100 inpatient community-associated VRIs) was 59% lower during the months in which visitor restrictions were implemented. These data prompt consideration for instituting year-round visitor restrictions.

Hospital-acquired influenza in an Australian tertiary Centre 2017: a surveillance based study

Background

In 2017, Australia experienced its highest levels of influenza virus activity since the 2009 pandemic. This allowed detailed comparison of the characteristics of patients with community and hospital-acquired influenza, and infection control factors that contributed to influenza spread.

Methods

A surveillance based study was conducted on hospitalised patients with laboratory-confirmed influenza at the Canberra Hospital during April–October 2017. Differences between the hospital-acquired and community-acquired patient characteristics and outcomes were assessed by univariate analysis. Epidemiologic curves were developed and cluster distribution within the hospital was determined.

Results

Two hundred and ninety-two patients were included in the study. Twenty-eight (9.6%) acquired influenza in hospital, representing a higher proportion than any of the previous 5 years (range 0.9–5.8%). These patients were more likely to have influenza A (p = 0.021), had higher rates of diabetes (p = 0.015), malignancy (p = 0.046) and chronic liver disease (p = 0.043). Patients acquiring influenza in hospital met clinical criteria for influenza like illness in 25% of cases, compared with 64.4% for community-acquired cases (p < 0.001). Hospital-acquired influenza cases occurred in two distinct clusters. Patients were moved an average of 5 times after diagnosis. Mean length of stay following diagnosis was 13 days compared to 5 days for community-acquired cases (p < 0.001). Of the patients with hospital-acquired influenza, 22 were in shared rooms during their incubation period and 9 were not isolated in single rooms following diagnosis. Treatment was initiated within the recommended 48 h period following symptom onset for 62.5% of hospital-acquired cases compared with 39.8% of community-acquired cases (p = 0.033).

Conclusions

Our results show that clinical presentation differed between patients with hospital-acquired influenza compared with those who acquired influenza in the community. Cases occurred in two clusters suggesting intra-hospital transmission rather than random importation from the community, highlighting the importance of infection control measures to limit influenza spread. Patients with hospital-acquired influenza may present without classical features of an influenza-like illness and this should promote earlier diagnostic testing and isolation to limit spread. Movement of patients after diagnosis is likely to facilitate spread within the hospital.

Essentials of infection prevention in the pediatric population

Application of infection prevention and control (IP&C) measures is synonymous with safety, quality, resource saving, and the rights of all patients, staff and visitors. An extensive literature review was undertaken to identify key IP&C measures that address pediatric-specific requirements, taking into account age-related factors, diseases that occur most frequently among pediatric populations, and the important role of the caregiver in prevention and disease transmission. IP&C initiatives that target and incorporate both human (intrinsic) and environmental (extrinsic) sources of infection are population specific and guide practices and provide safe caring environments when used appropriately. Categories of care specifically geared to the pediatric age-group (0-14 years) are divided into two categories: within-the-healthcare system and outside-of-the-healthcare setting. By taking into account the child's developmental age; physiological, psycho-social and immunological development; differing impacts on the body's natural defense mechanisms, including procedural, device type and length of utilization; and availability of specific technologies and disciplines, the caregiver IP&C strategies can be developed and tailored to address specific needs. Within-the-healthcare setting strategies focus on surveillance, standard and transmission-based precautions, the immune system, age-related factors, institutional regulations, the family and visitation. Outside the healthcare setting preventative and protective measures are vital for providing maximum and comprehensive care. Care provided within and outside the healthcare setting can either be independent of each other or work together to maximize the health and safety of the child. This review article highlights the importance of IP&C knowledge, need for strict adherence to approved standards, and need for auditing compliance to achieve the ultimate goal of providing safe, quality care as well as an infection-free environment.

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.

Exacerbation of asthma and airway infection: is the virus the villain?

Objetivo

Rever a literatura disponível sobre a relação entre infecção viral aguda do trato respiratório e o desencadeamento de exacerbações da asma, identificando os vírus mais prevalentes, os métodos de detecção, bem como os aspectos preventivos e terapêuticos.

Fonte dos dados

Foi realizada uma busca nas bases de dados PubMed, SciELO e Lilacs utilizando os descritores: asma, exacerbação, vírus, criança e infecção respiratória aguda, entre os anos de 2002 e 2013.

Síntese dos dados

Foram selecionados 42 artigos originais que tratavam da identificação de vírus respiratórios durante episódios de exacerbação da asma, em sua maioria estudos transversais. Houve ampla variação na metodologia dos trabalhos avaliados, principalmente em relação à idade das crianças e métodos de coleta e detecção viral. Os resultados apontam que, em até 92,2% das exacerbações, um agente viral foi potencialmente o principal fator desencadeante, sendo o rinovírus humano o mais identificado. O padrão de circulação viral pode ter sido responsável pela sazonalidade das exacerbações. A associação entre infecção viral e inflamação alérgica parece ser determinante para levar ao descontrole clínico‐funcional da asma, porém poucos estudos avaliaram outros fatores desencadeantes em associação com a infecção viral.

Conclusões

Os vírus respiratórios estão presentes na maioria das crianças asmáticas durante os episódios de exacerbação. Os mecanismos fisiopatológicos envolvidos ainda não estão totalmente estabelecidos e o sinergismo entre a inflamação alérgica e infecção viral parece determinar o descontrole da doença. O papel dos outros agentes desencadeantes e protetores não estão claramente determinados.

Exacerbation of asthma and airway infection: is the virus the villain?

OBJECTIVE

To review the available literature on the association between acute viral respiratory tract infection and the onset of asthma exacerbations, identifying the most prevalent viruses, detection methods, as well as preventive and therapeutic aspects.

SOURCES

A search was conducted in PubMed, Lilacs, and SciELO databases, between the years 2002 and 2013, using the following descriptors: asthma exacerbation, virus, child, and acute respiratory infection.

SUMMARY OF THE FINDINGS

A total of 42 original articles addressing the identification of respiratory viruses during episodes of asthma exacerbation were selected, mostly cross-sectional studies. There was a wide variation in the methodology of the assessed studies, particularly in relation to the children's age and methods of collection and viral detection. The results indicate that, in up to 92.2% of exacerbations, a viral agent was potentially the main triggering factor, and human rhinovirus was the most frequently identified factor. The pattern of viral circulation may have been responsible for the seasonality of exacerbations. The association between viral infections and allergic inflammation appears to be crucial for the clinical and functional uncontrolled asthma, but few studies have evaluated other triggering factors in association with viral infection.

CONCLUSIONS

Respiratory viruses are present in the majority of asthmatic children during episodes of exacerbation. The involved physiopathological mechanisms are yet to be fully established, and the synergism between allergic inflammation and viral infection appears to determine uncontrolled disease. The role of other triggering and protective agents is yet to be clearly determined.