The epidemiological and clinical characteristics of the hospital-acquired influenza infections: A systematic review and meta-analysis

Comparison of 28-Day Mortality Between Hospital- and Community-Acquired Influenza Patients

Objective

This study aimed to compare 28-day mortality between patients have hospital-acquired influenza (HAI) and those have community-acquired influenza (CAI) during the 2017-2019 influenza seasons in a tertiary care center in İstanbul, Türkiye.

Materials and Methods

This retrospective cohort included all hospitalized patients who had confirmed influenza infection and were over 17 years old. HAI was defined as a case of influenza that tested negative in a PCR test or had no signs of influenza on admission but with a positive test result at any point after 72 hours of admission. CAI was defined as a case of influenza diagnosed within 72 hours of admission or before admission. The primary outcome was 28-day mortality after diagnosis. Biological sex, admission to the intensive care unit (ICU), presence of chronic obstructive pulmonary disease, cardiovascular and immunosuppressive comorbidities, influenza subtype, and other variables identified with univariate analyses (p<0.25) were entered into logistic regression analysis.

Results

During the study period, 92 (46%) of 201 hospitalized patients who tested positive for influenza were identified as HAI, and the rest (109) were identified as CAI. Univariate analysis showed no differences between survivors and non-survivors in patient characteristics, except non-survivors were more likely to have an ICU admission. The multivariable logistic regression analysis results showed that HAI was associated with 5.6-fold increased odds of mortality (95% confidence interval [CI]=1.6-19.3; p=0.006), after adjustment for age, gender, comorbidity, and ICU admission.

Conclusion

The results of this study revealed that patients who had HAI were more likely to die within 28 days compared to those who had CAI after controlling for key confounders. The high rate of HAI underscores the critical importance of robust infection control measures for hospital-acquired viral infections. Additional research and targeted interventions are necessary to improve the HAI prognosis.

Patient influenza vaccination reduces the risk of hospital-acquired influenza: An incident test negative-case control study in Lyon university hospital, France (2004-2020)

BACKGROUND

Literature is limited on the impact of patient vaccination on the risk of hospital-acquired influenza (HAI). This test negative case-control study nested in a surveillance program aimed at evaluating the effectiveness of influenza vaccination in reducing the risk of HAI in hospitalized patients during 15 influenza seasons (2004-05 to 2019-20).

METHODS

HAI cases were those who developed influenza like illness (ILI) symptoms at least 72 h after hospitalization and had a positive reverse transcriptase-polymerase chain reaction (RT-PCR). Controls were those with ILI symptoms and a negative RT-PCR test. A nasal swab as well as socio-demographic, clinical data and information on influenza vaccination were collected.

RESULTS

Of the 296 patients included, 67 were confirmed HAI cases. Influenza vaccine coverage was significantly higher among controls compared to HAI cases (p = 0.002). The risk of HAI was reduced by almost 60 % in vaccinated patients.

CONCLUSIONS

A better control of HAI can be achieved by vaccinating hospitalized patients.

Poor hospitalization outcomes in patients undergoing allogeneic hematopoietic stem cell transplant with hospital acquired influenza infection

INTRODUCTION

Although hospital-acquired influenza infection (HAII) is a known complication among immunocompromised patients, the data in the setting of hospitalization for allogeneic hematopoietic stem cell transplant (allo-HSCT) are scarce.

METHODS

A retrospective study using the National Inpatient sample database was done to determine the impact of HAII on hospitalization outcomes among patients admitted for allo-HSCT.

RESULTS

The data for 77 103 allo-HSCT weighted hospitalizations were collected between 2002 and 2019. Among these, only 314 (0.4%) allo-HSCT cases were billed for HAII. Patients with influenza were more likely to have comorbid conditions like chronic obstructive lung disease, diabetes mellitus, hypertension, and myocardial infarction. Multivariate logistic regression revealed that patients with influenza had a higher risk of all-cause mortality: (odds ratio = 4.87, 95% confidence interval: 3.63-6.54; p < .01). Patients with influenza also had statistically higher odds of developing acute kidney injury, septic shock, and respiratory failure requiring mechanical ventilation. They also had a significantly longer length of stay (34 days versus 26 days) and adjusted cost for hospitalization ($195 345 versus $121 967).

CONCLUSION

Our large analysis of real-world data reveals that patients undergoing allo-HSCT that develop HAII are at substantially higher risk of inpatient complications and death.

Influenza Vaccination Coverage and Its Predictors among Self-Reported Diabetic Patients-Findings from the Hungarian Implementation of the European Health Interview Survey

In high-risk populations, such as the elderly or those with serious medical issues, for instance, people with cardiovascular diseases or diabetes, influenza can have devastating effects because it might contribute to severe complications or even death. This makes vaccination against influenza an essential component of public health. The primary objective of our research was to identify the characteristics that influenced whether an individual chose to become vaccinated against influenza, with an emphasis on whether they reported having diabetes. The data were obtained from the Hungarian implementation of the European Health Interview Surveys, which were conducted in 2009, 2014, and 2019. The total sample size was 15,874 people. To determine the variables that were related to vaccination, a multivariate logistic regression analysis that included interactions was performed. The overall vaccination coverage was 13% in 2009 and 12% in 2014 and 2019 among non-diabetic respondents; the coverage was 26% in 2009, 28% in 2014, and 25% in 2019 among diabetic respondents. Despite vaccination coverage in both groups being below the optimal level of 75%, we were able to identify factors influencing vaccination coverage. Among diabetic respondents, younger age, lower education level, sex, and co-morbidities were factors that influenced vaccination status. It is important for authorities managing healthcare and medical practitioners to be aware of the potential effects that influenza can have on diabetic patients; therefore, more efforts need to be made to increase the number of diabetic people receiving a vaccination against influenza.

Effect of influenza vaccination among healthcare workers on hospital-acquired influenza in short-stay hospitalized patients: A multicenter pilot study in France

BACKGROUND

Exposure to infected healthcare workers (HCWs) is a source of hospital-acquired (HA) influenza. We estimated the risk of HA influenza for hospitalized patients by rate of influenza vaccine coverage (IVC) of HCWs.

METHODS

A case-case negative control study nested in a prospective cohort was conducted in 2 French university hospitals during 2 influenza seasons. Each inpatient with influenza-like illness (ILI) provided a nasal swab sample that was systematically analyzed for influenza virus by polymerase chain reaction (PCR) testing. An HA influenza case was a patient with a virological confirmation of influenza with onset of symptoms ≥72 hours after admission to the ward. The IVC rate of HCWs in each participating ward was calculated from the data provided by the occupational health departments. A mixed-effect logistic regression was performed with adjustments on patient sex, age, the presence of a potential source of influenza on the ward in the 5 days prior to the start of the ILI, type of ward and influenza season.

RESULTS

The overall HA influenza attack rate was 1.9 per 1,000 hospitalized patients. In total, 24 confirmed HA influenza cases and 141 controls were included. The crude odds ratio (OR) of HA influenza decreased from 0.52 (95% confidence interval [CI], 0.21-1.29) to 0.14 (95% CI, 0.03-0.63) when the IVC of HCWs increased from 20% to 40%. After adjustment, IVC ≥40% was associated with a risk reduction of HA influenza (aOR, 0.07; 95% CI, 0.01-0.78).

CONCLUSIONS

Considering a limited sample size, influenza vaccination of HCWs is highly suggestive of HA flu prevention among hospitalized patients.Trial Registration: clinicaltrials.gov identifier: NCT02198638.

Hospital acquired COVID-19 infections amongst patients before the rollout of COVID-19 vaccinations, a scoping review

Background

Hospital settings are at increased risk of spreading Coronavirus Disease 2019 (COVID-19) infections, hence non-pharmaceutical prevention interventions (NPPIs) and prioritized vaccination of healthcare workers and resident patients are critical. The status of COVID-19 hospital acquired infections (HAIs) in low-income settings is unclear. We aimed to identify and summarize the existing evidence on COVID-19 HAIs amongst patients, prior to the rollout of vaccines in countries worldwide.

Methods

We conducted a scoping review of English peer-reviewed literature in PubMed, Web of Science and Scopus using a combination of selected search terms. Full texts articles presenting results on COVID-19 HAIs in hospitalised patients before the rollout of vaccines in countries worldwide were eligible. Data extracted from eligible articles included estimates of COVID-19 HAIs, country, and type of hospital setting, and was summarized narratively. Quality assessment of included articles was not possible.

Results

Literature searches generated a total of 5920 articles, and 45 were eligible for analysis. Eligible articles were from Europe, North America, Asia, and Brazil and none were from low-income countries. The proportion of COVID-19 HAIs ranged from 0% when strict NPPIs were applied, to 65% otherwise. The estimates of COVID-19 HAIs did not differ by country but were lower in studies conducted after implementation of NPPIs and in specialized hospital settings for operative surgery. Studies conducted before the implementation of NPPIs or in long-term care and psychiatric wards often reported high estimates of HAI. Although there was no clear trend in general wards, those situated in academic hospitals managed to reduce HAI rates under strict NPPI protocols. Operative surgery settings, unlike psychiatric settings, effectively prevented COVID-19 HAI using tailored NPPIs.

Conclusion

The available evidence shows a high risk of COVID-19 HAIs, the feasibility of preventing HAIs in different healthcare settings and the importance of appropriately tailored NPPIs. There were no data from low-income settings, therefore, it is unclear whether the reported NPPI approaches could be equally effective elsewhere. We recommend routine monitoring of COVID-19 HAIs in countries with low vaccination coverage, to identify and close gaps in NPPIs and understand gains made from vaccinating healthcare workers and hospitalized patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07128-5.

A Meta-Analysis on Evaluation of Nosocomial Infections Amongst Patients in a Tertiary Care Hospital

Background

Hospital-acquired infections, also known as nosocomial infections, are one of the many severe outcomes amongst patients in tertiary care hospitals. Hospital-acquired influenza is amongst the most common infection which has affected huge population.

Objective

We have performed a meta-analysis in order to summarize the effects of epidemiology and clinical characteristics in HAI.

Methods

We performed literature review with help of PubMed, Cochrane Library, Embase, Scopus, Web of Science, China National Knowledge Infrastructure (CNKI), The Global Index Medicus (GIM), and other clinical databases till 2021. Many random models were used in order to obtain pooled proportions, mean difference, odds ratio, and CI.

Results

A total of six studies were analyzed, where a total of 491 nosocomial and 4030 nonnosocomial infection cases were reported. The odds ratio of mortality was 0.02 with 95% CI and the risk ration for males was 1.08 with 95% CI.

Conclusion

The proportion of nosocomial infections in cases of influenza was higher in patients admitted in tertiary care hospitals. Thus, a surveillance system for vaccination for all the high-risk patients must be made mandatory.