Viral etiology of influenza-like illnesses during the influenza season between December 2011 and April 2012

Effectiveness of cocoon strategy vaccination on prevention of influenza-like illness in young infants

During the initial half-year of their existence, infants cannot receive the influenza vaccine, yet they face the greatest susceptibility to severe influenza complications. In this study, we seek to determine whether influenza vaccination of maternal and household contacts is associated with a reduced risk of influenza-like illness (ILI) and severe acute respiratory infection (SARI) in infants. This work was prospectively conducted during the influenza season. A total of 206 infants were included in this study. The percentage of infants with only the mother vaccinated is 12.6% (n:26), and the percent of infants with all household contacts vaccinated is 16% (n:33). Among the infants with only the mother vaccinated, the effectiveness of influenza vaccine is estimated as 35.3% for ILI and 41.3% for SARI. Among infants with all household contacts vaccinated, the effectiveness is estimated as 48.9% for ILI and 76.9% for SARI. Based on the results of multivariate logistic regression analysis, all-household vaccination is a protective factor against SARI (OR: 0.07 95% CI [0.01-0.56]), household size (OR: 1.75, 95% CI [1.24-2.48]) and presence of secondhand smoke (OR: 2.2, 95% CI [1.12-4.45]) significant risk factors for SARI in infants. The mother alone being vaccinated is not a statistically significant protective factor against ILI (OR: 0.46, 95% CI [0.19-1.18]) or SARI (OR: 0.3, 95% CI [0.11-1.21]). Along with the obtained results and analysis, this study provides clear evidence that influenza vaccination of all household contacts of infants aged 0-6 months is significantly associated with protecting infants from both ILI and SARI.

Viral etiology of severe lower respiratory tract infections in SARS-CoV-2 negative hospitalized patients during the COVID-19 pandemic in Kuwait

Background

The prevalence of respiratory infections is largely underexplored in Kuwait. The aim of our study is to determine the etiology of infections from patients who are SARS-CoV-2 negative hospitalized with severe lower respiratory tract infections (LRTIs) in Kuwait during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

We conducted an observational cross-sectional study among severe LRTI patients between September 2021 and March 2022. Respiratory samples from 545 non-COVID-19 severe LRTIs patients were prospectively evaluated with FTD Respiratory 21 Plus® real-time PCR, targeting 20 different viruses and 1 atypical bacterial pathogen.

Results

Among all 545 hospitalized cases, 411 (75.4 %) tested positive for at least one respiratory pathogen. The most common were rhinovirus (HRV) (32.7 %), respiratory syncytial virus (RSV) (20.9 %), metapneumovirus (HMPV) (14.1 %), bocavirus (13.2 %), and influenza A (12.7 %). The proportion of pathogens detected was highest in the under-5 age group, while HKU1 (44.4 %) predominated in the elderly (>50 years).

Conclusion

Our study reveals a high prevalence of respiratory viruses in severe acute lower respiratory tract infections among non-COVID-19 hospitalized patients in Kuwait. HRV remains the main etiology affecting the country, particularly in infants. These results underscore the necessity of employing multiplex PCR for accurate diagnosis and describing the epidemiology of infections among severe lower respiratory tract infections. This will facilitate the use of specific antiviral therapy and help avoid excessive or inappropriate antibiotic therapy.

Platelet Abnormalities in Children with Laboratory-Confirmed Influenza

BACKGROUND

The role of platelets in the immune response against influenza has been raised, and a diagnostic or prognostic value of platelet parameter abnormalities, including platelet count (PLT), or mean platelet volume (MPV), has been suggested. The study aimed to analyze the prognostic value of platelet parameters in children hospitalized due to laboratory-confirmed influenza.

METHODS

We retrospectively verified the platelet parameters (PLT, MPV, MPV/PLT, and PLT/lymphocyte ratio regarding the influenza complications (acute otitis media, pneumonia, and lower respiratory tract infection-LRTI), and the clinical course (antibiotic treatment, tertiary care transfer, and death).

RESULTS

An abnormal PLT was observed in 84 out of 489 laboratory-confirmed cases (17.2%, 44 thrombocytopaenia cases, and 40 thrombocytoses). Patients' age correlated negatively with PLT (rho = -0.46) and positively with MPV/PLT (rho = 0.44), while MPV was not age-dependent. The abnormal PLT correlated with increased odds of complications (OR = 1.67), including LRTI (OR = 1.89). Thrombocytosis was related to increased odds of LRTI (OR = 3.64), and radiologically/ultrasound-confirmed pneumonia (OR = 2.15), mostly in children aged under 1 year (OR = 4.22 and OR = 3.79, respectively). Thrombocytopaenia was related to antibiotic use (OR = 2.41) and longer hospital stays (OR = 3.03). A lowered MPV predicted a tertiary care transfer (AUC = 0.77), while MPV/PLT was the most versatile parameter in predicting LRTI (AUC = 0.7 in <1 yo), pneumonia (AUC = 0.68 in <1 yo), and antibiotic treatment (AUC = 0.66 in 1-2 yo and AUC = 0.6 in 2-5 yo).

CONCLUSIONS

Platelet parameters, including PLT count abnormalities and MPV/PLT ratio, are related to the increased odds of complications and a more severe disease course, and may add important data in assessing pediatric influenza patients, but should be interpreted cautiously due to age-related specificities.

Impact of air pollutants on influenza-like illness outpatient visits under COVID-19 pandemic in the subcenter of Beijing, China

This study aimed to explore the association between air pollutants and outpatient visits for influenza-like illnesses (ILI) under the coronavirus disease 2019 (COVID-19) stage in the subcenter of Beijing. The data on ILI in the subcenter of Beijing from January 1, 2018 to December 31, 2020 were obtained from the Beijing Influenza Surveillance Network. A generalized additive Poisson model was applied to examine the associations between the concentrations of air pollutants and daily outpatient visits for ILI when controlling meteorological factors and temporal trend. A total of 171 943 ILI patients were included. In the pre-coronavirus disease 2019 (COVID-19) stage, an increased risk of ILI outpatient visits was associated to a high air quality index (AQI) and the high concentrations of particulate matter less than 2.5 (PM_2.5 ), particulate matter 10 (PM₁₀ ), sulphur dioxide (SO₂ ), nitrogen dioxide (NO₂ ), and carbon monoxide (CO), and a low concentration of ozone (O₃ ) on lag0 day and lag1 day, while a higher increased risk of ILI outpatient visits was observed by the air pollutants in the COVID-19 stage on lag0 day. Except for PM₁₀ , the concentrations of other air pollutants on lag1 day were not significantly associated with an increased risk of ILI outpatient visits during the COVID-19 stage. The findings that air pollutants had enhanced immediate effects and diminished lag-effects on the risk of ILI outpatient visits during the COVID-19 pandemic, which is important for the development of public health and environmental governance strategies.

A Systematic Review of Influenza Epidemiology and Surveillance in the Eastern Mediterranean and North African Region

Seasonal influenza represents a huge health burden, resulting in significant mortality and morbidity. Following the 2009 H1N1 pandemic, focus has been directed on the burden of influenza globally. Country and regional disease burden estimates play important roles in helping inform decisions on national influenza intervention programmes. Despite improvements in influenza surveillance following the 2009 pandemic, many opportunities remain unexplored in the Eastern Mediterranean and North African (EMNA) region, which has a high prevalence of patients with chronic disease and thus a population at high risk of influenza complications. We conducted a systematic literature review of Embase, Medline, Scopus and the Cochrane Database of Systematic Reviews from 1 January 1998 to 31 January 2020 covering the EMNA region with the aim to describe the epidemiology of influenza in the region and assess the influenza epidemiological surveillance research landscape. Relevant data on study characteristics, population, clinical/virology characteristics and epidemiology were extracted and summarised descriptively. Of the 112 studies identified for inclusion, 90 were conducted in the Eastern Mediterranean region, 19 in North Africa and three across the EMNA region. Data were reported on 314,058 laboratory-confirmed influenza cases, 96 of which were derived from surveillance systems. Amongst the surveillance studies, the percentage of positive cases reported ranged from 1% to 100%. The predominantly identified influenza strain was strain A; H1N1 was the most prominent circulating subtype. Typing was performed in approximately 75% and subtyping in 50% of studies, respectively. Data on those considered most at risk for influenza complications were collected in 21% of studies, highlighting a regional gap for these data. Our review reveals existing gaps in regional estimates of influenza health and economic burden, hospitalisation rates and duration, and highlights the need for robust and high-quality epidemiology data to help inform public health interventions.

Respiratory Tract Pathogens in the COVID-19 Era: Data from a Pediatric Emergency Department

Objective The frequency of coinfections in pediatric Coronavirus disease 2019 (COVID-19) cases and their impact on the clinical course are not fully understood. We aimed to investigate the viral and bacterial respiratory pathogens in children admitted to the pediatric emergency department (PED), their clinical course, and the presence of coinfections during the early months of the COVID-19 pandemic.

Methods Clinical, laboratory and radiological findings, viral and bacterial pathogens detected by multiplex polymerase chain reaction (PCR) tests in nasopharyngeal swabs, clinical course, and treatments of all children who were tested for severe acute respiratory coronavirus 2 (SARS-CoV-2) at the PED between March 16 and May 15, 2020, were recorded. SARS-CoV-2 PCR-positive and negative groups were compared.

Results Out of 570 patients tested for SARS-CoV-2 during the study period, 43 were found positive (7.5%). Non-SARS-CoV-2 viral pathogens were more common in the SARS-CoV-2 PCR-negative group than the SARS-CoV-2 PCR-positive group (13.2%, n = 68 versus 4.7%, n = 2), but this result was not statistically significant. Leukocyte, neutrophil, lymphocyte, and platelet counts were lower in SARS-CoV-2 PCR-positive group. Bacterial panel positivity was significantly higher in the SARS-CoV-2 PCR-positive group compared with the SARS-CoV-2 PCR-negative group (52%, n = 12 versus 28%, n = 91; p < 0.05). The presence of coinfection did not alter the course of therapy in SARS-CoV-2 PCR-positive cases.

Conclusion While viral coinfections were rare, bacterial panel positivity was common in children with COVID-19, but this had not influenced management decisions. The limitations of the tests should be kept in mind while interpreting the results.

Spotlight influenza: Laboratory-confirmed seasonal influenza in people with acute respiratory illness: a literature review and meta-analysis, WHO European Region, 2004 to 2017

BackgroundAcross the World Health Organization European Region, there are few estimates of the proportion of people seeking medical care for influenza-like illness or acute respiratory infections and who have laboratory-confirmed seasonal influenza infection.MethodsWe conducted a meta-analysis of data extracted from studies published between 2004 and 2017 and from sentinel data from the European surveillance system (TESSy) between 2004 and 2018. We pooled within-season estimates by influenza type/subtype, setting (outpatient (OP)/inpatient (IP)) and age group to estimate the proportion of people tested who have laboratory-confirmed and medically-attended seasonal influenza in Europe.ResultsIn the literature review, the pooled proportion for all influenza types was 33% (95% confidence interval (CI): 30-36), higher among OP 36% (95% CI: 33-40) than IP 24% (95% CI: 20-29). Pooled estimates for all influenza types by age group were: 0-17 years, 26% (22-31); 18-64 years, 41% (32-50); ≥ 65 years, 33% (27-40). From TESSy data, 33% (31-34) of OP and 24% (21-27) of IP were positive. The highest proportion of influenza A was in people aged 18-64 years (22%, 16-29). By subtype, A(H1N1)pdm09 was highest in 18-64 year-olds (16%, 11-21%) whereas A(H3N2) was highest in those ≥ 65 years (10%, 2-22). For influenza B, the highest proportion of infections was in those aged 18-64 years (15%, 9-24).ConclusionsLaboratory-confirmed influenza accounted for approximately one third of all acute respiratory infections for which medical care was sought during the influenza season.

Hospital utilization rates for influenza and RSV: a novel approach and critical assessment

BACKGROUND

Influenza and respiratory syncytial virus (RSV) contribute significantly to the burden of acute lower respiratory infection (ALRI) inpatient care, but heterogeneous coding practices and availability of inpatient data make it difficult to estimate global hospital utilization for either disease based on coded diagnoses alone.

METHODS

This study estimates rates of influenza and RSV hospitalization by calculating the proportion of ALRI due to influenza and RSV and applying this proportion to inpatient admissions with ALRI coded as primary diagnosis. Proportions of ALRI attributed to influenza and RSV were extracted from a meta-analysis of 360 total sources describing inpatient hospital admissions which were input to a Bayesian mixed effects model over age with random effects over location. Results of this model were applied to inpatient admission datasets for 44 countries to produce rates of hospital utilization for influenza and RSV respectively, and rates were compared to raw coded admissions for each disease.

RESULTS

For most age groups, these methods estimated a higher national admission rate than the rate of directly coded influenza or RSV admissions in the same inpatient sources. In many inpatient sources, International Classification of Disease (ICD) coding detail was insufficient to estimate RSV burden directly. The influenza inpatient burden estimates in older adults appear to be substantially underestimated using this method on primary diagnoses alone. Application of the mixed effects model reduced heterogeneity between countries in influenza and RSV which was biased by coding practices and between-country variation.

CONCLUSIONS

This new method presents the opportunity of estimating hospital utilization rates for influenza and RSV using a wide range of clinical databases. Estimates generally seem promising for influenza and RSV associated hospitalization, but influenza estimates from primary diagnosis seem highly underestimated among older adults. Considerable heterogeneity remains between countries in ALRI coding (i.e., primary vs non-primary cause), and in the age profile of proportion positive for influenza and RSV across studies. While this analysis is interesting because of its wide data utilization and applicability in locations without laboratory-confirmed admission data, understanding the sources of variability and data quality will be essential in future applications of these methods.

The epidemiologic and clinical features of viral agents among hospitalized children with lower respiratory tract infections

Aim

Acute respiratory tract infections are among the most common infectious diseases worldwide. Respiratory viruses are the leading cause of respiratory infections in children. Herein, we aimed to determine the epidemiologic and clinical feautures of viral agents among hospitalized children with lower respiratory tract infections.

Material and Methods

Nasopharyngeal swab specimens were obtained from the 422 patients hospitalized with a diagnosis of lower respiratory tract infections between December 2012 and December 2016. Multiplex reverse-transcription polymerase chain reaction was performed for the detection of viruses.

Results

Viral respiratory pathogens were detected in 311 patients (73.7%). In regard to respiratory virus subtypes, 103 patients (33.1%) had respiratory syncytial virus, 102 (32.7%) had human rhinovirus, 49 (15.7%) had multiple viruses, 15 (4.8%) had parainfluenzavirus, 13 (4.1%) had adenovirus, nine (2.8%) had human metapneumovirus, eight (2.5%) had human coronaviruses, six (1.9%) had bocavirus, five (1.6%) had influenza virus, and one patient (0.3%) had enterovirus. The median age was lower in patients with multiple viruses (p<0.001). The respiratory syncytial virus was more commonly detected in patients with a history of prematurity (p<0.001). Stridor was more common in other viruses including parainfluenza viruses (p<0.001).

Conclusion

Respiratory viruses are the main causative agents of respiratory tract infections in children. Timely and accurate detection of viruses is necessary in terms of public health. The detection of respiratory viruses also contributes to epidemiologic results and vaccine studies.

Prevalence of upper respiratory tract infections and associated factors among children in Turkey

PURPOSE

Upper respiratory tract infections (URIs) are the most common diseases observed in children aged 0-6 years in Turkey. This study was conducted to investigate URIs in 0-6 year-old children in Turkey.

DESIGN AND METHODS

Data of children aged 0-6 years who were included in the 2014 Turkey Health Survey conducted by the Turkish Statistical Institute were collected from their parents.

RESULTS

In total, 1,293 and 1,732 children with and without URIs, respectively, were identified. The weighted point prevalence of URIs was 42.23%. Compared with the uninsured and female children belonging to high-income families, insured male children belonging to low-income families were more likely to develop URIs (p < .001). Moreover, comorbidities such as communicable diseases, anemia and diarrhea, and factors like health services utilization were associated with URIs. Analysis of health services utilization highlights that URIs were reported more among the children who had not visited a hospital than among those who had visited a hospital, with an odds ratio of 1.23.

CONCLUSIONS

The results of this study provide a deeper understanding of sociodemographic, comorbid, and health services utilization factors associated with URIs. These results provide useful insights for pediatric nursing professionals to improve the quality and efficiency of pediatric respiratory nursing services.

PRACTICE IMPLICATIONS

Collaborative networks with other health professionals, parents, and public health policy-makers are essential to decrease the prevalence of URIs in Turkey. These study results provide several insights for health professionals to improve pediatric action plans for ultimately improving child health status.

Production and characterization of a conserved M2e peptide-based specific IgY antibody: evaluation of the diagnostic potential via conjugation with latex nanoparticles

Antibodies play an important role in combating and controlling viral diseases such as influenza. Immunoglobulin Y (IgY) antibodies have several advantages such as a less invasive manufacturing process, ease of isolation, higher affinity compared with IgG antibodies, and cost-effectiveness. To date, although specific IgY production has been performed for different strains of influenza A, to the best of our knowledge, an IgY against the M2e peptide has not been produced. In the current study, IgY antibodies are produced, purified, and characterized using the M2e peptide sequence for the first time with the intent to apply them for the diagnosis of influenza A virus. Anti-M2e IgY antibodies are obtained from eggs using a two-step purification method. The activity and characterization of the antibodies are determined using an enzyme-linked immunosorbent assay, a nano-spectrophotometer, an SDS-Page assay, and a Western Blot analysis. Finally, anti-M2e IgY antibodies are conjugated to the latex nanoparticles, and the reaction between the influenza A virus and the nanoparticles is demonstrated using light microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. In conclusion, this study shows that anti-M2e IgY antibodies can contribute to the diagnosis, treatment, and prevention of the influenza A virus.

Legionnaire's Disease and its Mimics: A Clinical Perspective

Whenever the cardinal manifestations of a disorder occur in similar disorders, there is potential for a disease mimic. Legionnaire's disease has protean manifestations and has the potential to mimic or be mimicked by other community acquired pneumonias (CAPs). In CAPs caused by other than Legionella species, the more characteristic features in common with legionnaire's disease the more difficult the diagnostic conundrum. In hospitalized adults with CAP, legionnaire's disease may mimic influenza or other viral pneumonias. Of the bacterial causes of CAP, psittacosis and Q fever, but not tularemia, are frequent mimics of legionnaire's disease.

Evaluation of epidemiological and clinical features of influenza and other respiratory viruses

AIM

In our study, we aimed to clinically and epidemiologically evaluate respiratory tract infections the viral agents of which were detected by molecular methods and to compare influenza and other respiratory tract viruses in this context.

MATERIAL AND METHODS

The records of 178 patients aged above 2 years who presented to pediatric emergency outpatient clinic with fever and respiratory tract infection findings between December 2013 and April 2014 were examined retrospectively.

RESULTS

At least one respiratory tract pathogen was detected by polymerase chain reaction in 78.6% (n=140) of the patients: influenza A 33.5%, influenza B 16.4%, respiratory syncytial virus 9.2%, adenovirus 7.8%, rhinovirus 7.1%, coronavirus 7.1%, human metapneumovirus 5.7%, human bocavirus 5.7%, parainfluenza virus 3.5%, coinfection 2.8%. The mean age of the patients was 6.3±3.6 years. Sixty-nine patients (49.2%) were aged between 2 and 5 years. Seventy-one patients (50.7%) were aged 5 years and above. Upper respiratory tract infection was found with a rate of 65.7% and lower respiratory tract infection was found with a rate of 34.2%. It was observed that the distribution of respiratory tract viruses showed variance by age groups. Influenza A infection was observed with the highest rate in both age groups. Influenza B was the second leading agent (p=0.008) above the age of 5 years and respiratory syncytial virus was the second leading agent in the 2-5 year age group (p=0.003). Influenza viruses were detected in 55.9% of 118 patients who were found to be compatible with the definition of "influenza-like illness" specified in the Center for Disease Control and Prevention guidelines and other viral agenst were detected in 44%. No difference could be found between the clinical pictures and radiological findings caused by influenza and other respiratory tract viruses.

CONCLUSIONS

In this study, it was concluded that influenza and other respiratory viruses can not be differentiated definitely by clinical and radiological findings, though there are some differences.

Epidemiology of 11 respiratory RNA viruses in a cohort of hospitalized children in Riyadh, Saudi Arabia

Respiratory tract infections are a principal cause of illness and mortality in children worldwide and mostly caused by viruses. In this study, the epidemiology of 11 respiratory RNA viruses was investigated in a cohort of hospitalized children at a tertiary referral center in Riyadh from February 2008 to March 2009 using conventional and real‐time monoplex RT‐PCR assays. Among 174 nasopharyngeal aspirates, respiratory syncytial virus (RSV) was detected in 39 samples (22.41%), influenza A virus in 34 (19.54%), metapneumovirus (MPV) in 19 (10.92%), coronaviruses in 14 (8.05%), and parainfluenza viruses (PIVs) in 11 (6.32%). RSV, PIVs and coronaviruses were most prevalent in infants less than 6 months old, whereas MPV and influenza A virus were more prominent in children aged 7–24 and 25–60 months, respectively. The majority of the viruses were identified during winter with two peaks observed in March 2008 and January 2009. The presented data warrants further investigation to understand the epidemiology of respiratory viruses in Saudi Arabia on spatial and temporal basis. J. Med. Virol. 88:1086–1091, 2016. © 2015 Wiley Periodicals, Inc.

Mixed viral infections circulating in hospitalized patients with respiratory tract infections in kuwait

The aim of this study was to determine the frequency of viral mixed detection in hospitalized patients with respiratory tract infections and to evaluate the correlation between viral mixed detection and clinical severity. Hospitalized patients with respiratory tract infections (RTI) were investigated for 15 respiratory viruses by using sensitive molecular techniques. In total, 850 hospitalized patients aged between 3 days and 80 years were screened from September 2010 to April 2014. Among the 351 (47.8%) patients diagnosed with viral infections, viral mixed detection was identified in 49 patients (14%), with human rhinovirus (HRV) being the most common virus associated with viral mixed detection (7.1%), followed by adenovirus (AdV) (4%) and human coronavirus-OC43 (HCoV-OC43) (3.7%). The highest combination of viral mixed detection was identified with HRV and AdV (2%), followed by HRV and HCoV-OC43 (1.4%). Pneumonia and bronchiolitis were the most frequent reason for hospitalization with viral mixed detection (9.1%). There were statistical significance differences between mixed and single detection in patients diagnosed with bronchiolitis (P = 0.002) and pneumonia (P = 0.019). Our findings might indicate a significant association between respiratory virus mixed detection and the possibility of developing more severe LRTI such as bronchiolitis and pneumonia when compared with single detection.

Detection of influenza vaccine effectiveness among nursery school children: Lesson from a season with cocirculating respiratory syncytial virus

In the winter influenza epidemic season, patients with respiratory illnesses including respiratory syncytial virus (RSV) infections increase among young children. Therefore, we evaluated the effectiveness of influenza vaccine against influenza-like illness (ILI) using a technique to identify outbreaks of RSV infection and to distinguish those patients from ILI patients. The study subjects were 101 children aged 12 to 84 months attending nursery school. We classified the cases into 6 levels based on the definitions of ILI for outcomes. We established observation periods according to information obtained from regional surveillance and rapid diagnostic tests among children. Multivariate odds ratios (ORs) for each case classification were obtained using a logistic regression model for each observation period. For the entire observation period, ORs for cases with fever plus respiratory symptoms were reduced marginally significantly. For the local influenza epidemic period, only the OR for the most serious cases was significantly decreased (0.20 [95%CI: 0.04-0.94]). During the influenza outbreak among the nursery school children, multivariate ORs for fever plus respiratory symptoms decreased significantly (≥ 38.0°C plus ≥ one symptoms: 0.23 [0.06-0.91), ≥ 38.0°C plus ≥ 2 symptoms: 0.21 [0.05-0.85], ≥ 39.0°C plus ≥ one symptoms: 0.18 [0.04-0.93] and ≥ 39.0°C plus ≥ 2 symptoms: 0.16 [0.03-0.87]). These results suggest that confining observation to the peak influenza epidemic period and adoption of a strict case classification system can minimize outcome misclassification when evaluating the effectiveness of influenza vaccine against ILI, even if influenza and RSV cocirculate in the same season.

Epidemiological characteristics and immune status of children with Respiratory Syncytial Virus

Respiratory Syncytial Virus (RSV) infections are the dominant cause of pneumonia in children. In order to determine the epidemiological characteristics and immune status of children with Respiratory Syncytial Virus, a prospective study was performed among patients with RSV infection. Comparisons between RSV pneumonia group and normal control group, RSV pneumonia group had lower IL-2 (median levels, pg/ml: 3.8 vs. 5.1, P < 0.01), and higher IL-4 (median levels, pg/ml: 3.2 vs. 2.4, P < 0.01), IL-10 (median levels, pg/ml: 12.2 vs. 2.3, P < 0.01), and IFN-γ (median levels, pg/ml: 13.4 vs. 4.6, P < 0.01). The level of IgE among pneumonia patients caused by RSV increased sharply (median levels, mg/L: 48.1 vs. 8.8, P < 0.01). Another amazing finding is that after birth, the degree of IgE of the children infected by RSV increases gradually with age. This effect is at its peak in 0.6 years old. The IgE and eosinophil levels were higher when patients suffered from RSV pneumonia with wheeze (IgE median levels, IU/ml: with wheeze: 72.74 vs. without wheeze: 11.5, P < 0.05; eosinophil median levels, ×10(9) /l: with wheeze: 0.21 vs. without wheeze: 0.05, P < 0.05). The main morbidity crowd is the children under the age of 1 year old. The downregulation of IL2 and the upregulation of IL-4, IL-10, IFN-γ, and IgE happen after RSV infection.