Outcome predictors of influenza for hospitalization and mortality in children

Risk factors for hospitalization and pneumonia development of pediatric patients with seasonal influenza during February-April 2023

Objectives

In China influenza remains a low activity for continuous 3 years due to COVID-19 controls. We here sought to study the clinical characteristics and risk factors of the influenza infection among children after the mandatory COVID-19 restrictions were lifted.

Methods

We included 1,006 pediatric patients with influenza A virus (IAV) infection, enrolled in one tertiary hospital in Zhenjiang, Jiangsu Province, China, during February to April 2023. Patients were divided into the outpatient (n = 798) and inpatient (n = 208) groups, and their baseline characteristics were compared between two groups to conclude the risk factors for pediatric hospitalization. Separately, pediatric inpatients (n = 208) were further divided into the pneumonia and non-pneumonia groups with comparison of their clinical characteristics, including their laboratory test results and representative radiological features, to derive the key determinants for pneumonia development after hospitalization.

Results

Compared to outpatients, IAV-infected pediatric inpatients exhibited younger age, higher female: male ratio, more co-infection of influenza B virus (IBV) and hematological abnormality. Multivariate regression analysis determined the independent risk factors of hospitalization to be the clinical symptom of abdominal pain (OR = 2.63, [95% CI, 1.05-6.57], p = 0.039), co-infection of IBV (OR = 44.33, [95% CI, 25.10-78.30], p = 0.001), elevated levels of lymphocytes (OR = 2.24, [95% CI,1.65-3.05], p = 0.001) and c-reactive proteins (CRPs) (OR = 1.06, [95% CI, 1.03-1.08], p = 0.001) upon hospital admission. Furthermore, the cough symptom (OR = 17.39, [95% CI, 3.51-86.13], p = 0.001) and hospitalization length (OR = 1.36, [95% CI, 1.12-1.67], p = 0.002) were determined to be risk factors of pneumonia acquirement for pediatric inpatients.

Conclusion

While the abdominal pain, viral co-infection and some hematological abnormality mainly contribute to hospitalization of pediatric patients with IAV infection, the length of hospital stay and clinical sign of coughing upon hospital admission constitute the key determinants for nosocomial pneumonia development.

Machine-learning-algorithms-based diagnostic model for influenza A in children

BACKGROUND

At present, nucleic acid testing is the gold standard for diagnosing influenza A, however, this method is expensive, time-consuming, and unsuitable for promotion and use in grassroots hospitals. This study aimed to establish a diagnostic model that could accurately, quickly, and simply distinguish between influenza A and influenza like diseases.

METHODS

Patients with influenza-like symptoms were recruited between December 2019 and August 2023 at the Children's Hospital Affiliated to Shandong University and basic information, nasopharyngeal swab and blood routine test data were included. Computer algorithms including random forest, GBDT, XGBoost and logistic regression (LR) were used to create the diagnostic model, and their performance was evaluated using the validation data sets.

RESULTS

A total of 4188 children with influenza-like symptoms were enrolled, of which 1992 were nucleic acid test positive and 2196 were matched negative. The diagnostic models based on the random forest, GBDT, XGBoost and logistic regression algorithms had AUC values of 0.835,0.872,0.867 and 0.784, respectively. The top 5 important features were lymphocyte (LYM) count, age, serum amyloid A (SAA), white blood cells (WBC) count and platelet-to-lymphocyte ratio (PLR). GBDT model had the best performance, the sensitivity and specificity were 77.23% and 80.29%, respectively.

CONCLUSIONS

A computer algorithm diagnosis model of influenza A in children based on blood routine test data was established, which could identify children with influenza A more accurately in the early stage, and was easy to popularize.

Platelet count and risk of severe illness in hospitalised children with Influenza-Like illness

AIM

To examine the clinical significance of thrombocytosis (platelets > 500 × 109 /L) in admitted children with an influenza-like illness.

METHODS

We performed a database analysis consisting of patients evaluated at our medical centers with an influenza-like illness between 2009 and 2013. We included paediatric patients and examined the association between platelet count, respiratory viral infections, and admission outcomes (hospital length of stay and admission to the paediatric intensive care unit) using regression models adjusting for multiple variables.

RESULTS

A total of 5171 children were included in the study cohort (median age 0.8 years; interquartile range, 0.2-1.8; 58% male). Younger age, and not the type of viral infection, was associated with a high platelet count (p < 0.001). Elevated platelet count independently predicted admission outcomes (p ≤ 0.05). The presence of thrombocytosis was associated with an increased risk for a prolonged length of stay (odds ratio = 1.2; 95% Confidence interval = 1.1 to 1.4; p = 0.003) and admission to the paediatric intensive care unit (odds ratio = 1.5; 95% Confidence interval = 1.1 to 2.0; p = 0.002).

CONCLUSION

In children admitted with an influenza-like illness, a high platelet count is an independent predictor of admission outcomes. Platelet count may be used to improve risk assessment and management decisions in these paediatric patients.

The Impact of Thrombocytopenia and Lymphopenia on Mortality in Patients Infected with Influenza Virus: A Retrospective Cohort Study

INTRODUCTION

Influenza virus causes significant global annual morbidity and mortality. Thrombocytopenia is recognized as a poor prognostic factor in sepsis and is associated with mortality, while lymphopenia has been established as a poor prognostic factor in other viral infections. We aimed to assess the incidence of thrombocytopenia and lymphopenia in seasonal influenza and their effect on clinical outcomes.

METHODS

This single-center, retrospective, cohort study included consecutive adult patients, hospitalized in Rabin Medical Center between October 2017 and April 2018, with laboratory-confirmed influenza. Patients were grouped according to blood counts on admission: (1) thrombocytopenia (<150 K/mL), (2) lymphopenia (<0.5 K/mL), and (3) both thrombocytopenia and lymphopenia. Patients without thrombocytopenia and lymphopenia were designated as controls. The primary outcome was 30-day all-cause mortality. Risk factors were identified by univariable and multivariable analyses, using logistic regression and reported as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 625 patients were included, 112 (18%) had thrombocytopenia, 98 (15.6%) had lymphopenia, and 107 (17%) had both. The crude 30-day all-cause mortality was 7.6% (48/625). Mortality rates were 7.1% (8/112) for the thrombocytopenia group, 11.2% (11/98) for the lymphopenia group, and 14.9% (16/107) for patients with both versus 4.2% (13/308) in the control (p = 0.000 for all). In a multivariable regression model, significant thrombocytopenia (<100 K/μL) [OR 5.07 (95% CI 1.5-16.2)], age [OR 1.07 (95% CI 1.02-1.11)], time to oseltamivir [OR 1.006 (95% CI 1.002-1.11)], and significant respiratory support [OR 8.85 (3.4-22.6)] were associated with 30-day all-cause mortality.

CONCLUSION

Patients hospitalized with seasonal influenza and thrombocytopenia <100 K/mL on admission, have an increased 30-day all-cause mortality.

Predictors of unfavorable outcome in children hospitalized with influenza and differences in clinical presentation among serotypes

BACKGROUND

Apart from age and underlying disease, predictors of adverse outcome in children hospitalized with influenza are poorly understood.

OBJECTIVES

Our goal is to determine clinical and laboratory predictors that help identify children at increased risk for an unfavorable course and identify differences in clinical presentation between serotypes.

STUDY DESIGN

A retrospective, observational cohort study conducted at the Rambam Healthcare Campus in Haifa. We analyzed data from electronic records of children < 18 years with influenza A or B infection hospitalized between 2009 and 2020. Multivariate regression analyses were used to identify predictors of unfavorable outcome, defined as mortality, ICU admission, intubation, prolonged length of stay, or bacterial coinfection.

RESULTS

A total of 1077 children were included, of whom 54% were male. The median age was 2.5 years. Influenza A was detected in 797 (74%) and influenza B in 286 (26%) of the cases. Children with influenza A were younger (OR 2.51, 95%CI 1.90-3.33), more likely to have oxygen desaturation <90% (OR 2.44, 95%CI 1.23-4.83) and an elevated CRP>5 mg/dL on admission (OR 2.67, 95% CI 1.63-4.37). In multivariate analyses, oxygen desaturation <90% and CRP > 5 mg/dL at admission had an 11.1 and 4-fold increased risk of unfavorable outcome, respectively, in addition to a 3.1 and 1.6-fold increased risk in the presence of underlying condition or influenza A serotype infection, respectively.

CONCLUSIONS

Data available on admission can help identify children hospitalized with influenza who are at increased risk for complications and unfavorable outcome, encouraging aggressive treatment and care.

Outcome predictors of influenza for hospitalization and mortality in children

Severity of disease caused by influenza virus and the influencing factors that may be different. Moreover, the disease course actually may not be determined specifically in children because of lower seroprotection rates of children. Herein, the results clinic and outcome data of children with influenza from Turkey were reported. We present here the results from 2013 to 2017. Nasopharyngeal swab samples of the children with influenza were investigated via multiplex polymerase chain reaction. A total of 348 children were diagnosed with influenza; 143 (41.1%) were influenza A, 85 (24.4%) were influenza B, and 120 (34.5%) were mixt infection with other respiratory viruses. Fifty-four percent of children admitted to intensive care unit (ICU) were under 2 years of age (p = .001). Having an underlying disease was detected as the main predictor for both hospitalization and ICU stay according to multiple logistic regression analysis (odds ratio [OR], 11.784: 95% confidence interval [CI], 5.212-26.643; p = .001 and OR, 4.972: 95% CI, 2.331-10.605; p = .001, respectively). Neurological symptoms most frequently seen in cases who died (44.4%; p = .02). Lymphopenia was relatively higher (55.6%) and thrombocytopenia was most frequently seen in cases who died (77.8%) with a significant ratio (p = .001). Underlying diseases was found a risk factor for influenza being hospitalized and being admitted to ICU. Children under 2 years of age and with underlying diseases should be vaccinated particularly in countries where the influenza vaccination is still not routinely implemented in the immunization schedule. Highlights Underlying diseases is a risk factor for influenza to be hospitalized and admitted to ICU. Influenza vaccination is of great importance to prevent life-threatening complications of influenza, particularly in children require ICU admission. The possibility to reduce the outpatient visit number by vaccination has a great impact on disease burden in addition to the underestimated crucial social benefits, as well.