White blood cell count, C-reactive protein and erythrocyte sedimentation rate in respiratory syncytial virus infection of the lower respiratory tract

Community-Acquired Pneumonia in Children

ABSTRACT

Community-acquired pneumonia (CAP) is the most common cause of childhood mortality globally. In the United States, CAP is a leading cause of pediatric hospitalization and antibiotic use and is associated with substantial morbidity. There has been a dramatic shift in microbiological etiologies for CAP in children over time as pneumococcal pneumonia has become less common and viral etiologies have become predominant. There is no commonly agreed on approach to the diagnosis of CAP in children. When indicated, antimicrobial treatment should consist of narrow-spectrum antibiotics. In this article, we will describe the current understanding of the microbiological etiologies, clinical presentation, diagnostic approach, risk factors, treatment, and future directions in the diagnosis and management of pediatric CAP.

New Generation of Systemic Inflammatory Markers for Respiratory Syncytial Virus Infection in Children

AIM

This study evaluated the relationship between the systemic immune-inflammatory index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) with clinical findings of respiratory syncytial virus (RSV) infection among children with a diagnosis of lower respiratory tract infection (LRTI).

METHODS

The study was conducted between 1 January 2020 and 1 January 2022 in a pediatric clinic. This retrospective study included 286 consecutive patients between 0 and 12 years of age, 138 of whom were RSV (+) (48.25%) and 148 of whom were RSV (-) (51.75%). The detection of the RSV antigen was carried out using the chromatographic immunoassay method on nasopharyngeal swabbing samples.

RESULTS

CRP content was significantly higher in patients with RSV (+) than in children with RSV (-), while NLR, PLR, and SII, as inflammatory parameters, were significantly lower. Fever, coughs, and wheezing were the most common symptoms in the RSV (+) groups (100%). RSV infections were the highest in November, October, and December, in that order. The AUC was statistically significant for parameters in all groups. AUC values were 0.841 (95%: 0.765-0.917) for leukocytes, 0.703 (95%: 0.618-0.788) for lymphocytes, 0.869 (95%: 0.800-0.937) for CRP, 0.706 (95%: 0.636-0.776) for NLR, 0.779 (95%: 0.722-0.836) for PLR, and 0.705 (95%: 0.633-0.776) for SII. CRP was found to have both high sensitivity (80.4%) and high specificity (82.4%) among all parameters. While the ROC analysis results showed similar results for children under two years old, only CRP and NLR were statistically significant in this group.

CONCLUSION

CRP performed better than other blood parameters as a marker. The NLR, PLR, and SII index were significantly lower in LRTI patients with RSV (+) than in those with RSV (-), which implies a higher grade of inflammation. If the cause of the disease can be determined by this method, disease management will be easier, and unnecessary antibiotics could be avoided.

Molecular epidemiology of respiratory syncytial virus among children and adults in India 2016 to 2018

Respiratory syncytial virus (RSV) is a common cause of respiratory tract infections among children less than 5 years of age and the elderly. This study intended to determine the circulating genotypes of RSV among severe acute respiratory illness (SARI) cases during the period 2016–2018 in India, among hospitalized acute febrile illness cases of age ranging from 1 to 65 years. Throat/nasopharyngeal swab samples were subjected for testing RSV and subgroups by real-time reverse transcriptase polymerase chain reaction (RT-PCR), further sequencing and phylogenetic analysis were performed for the second hypervariable region of the G gene. RSV-A and B subtypes co-circulated during the years 2016, 2017, and 2018, with RSV-A as the dominant subtype in 2016, and RSV-B as the dominant subgroup in 2017 and 2018. Phylogenetic analysis revealed that the circulating genotypes of RSV were GA2 (16/16), of RSV-A, and GB5 (23/23) of RSV-B in the South, North, and Northeast region of India during the period between 2016 and 2018. Here we report the first study comprising the distribution of RSV-A and B genotypes in the different geographic regions of India among children and adults during the year 2016 to 2018. We also report GA2.3.7 lineage of GA2 genotype for the first time in India to the best of our knowledge.

Expression patterns and association analysis of the porcine DHX58 gene

RIG-1 signalling is responsible for the detection of cytoplasmic viral RNA molecules. DEXH(Asp-Glu-X-His) box polypeptide 58 (encoded by DHX58) is a negative regulator of the RIG-1 signalling pathway. In human, the DHX58 gene can be upregulated and can inhibit the RIG-1 signalling pathway during viral infection. In this study, porcine DHX58 gene expression patterns were studied. According to our results, the porcine DHX58 gene was upregulated not only by the stimulation of Poly I:C but also by the stimulation of lipopolysaccharides (LPS). One polymorphism (g.4919G>C), detected in the ninth intron,was significantly associated with some blood parameters including the red cell distribution width of 1-day-old pigs and white blood cell counts, lymphocyte absolute counts, and platelet distribution width of 17-day-old pigs (P < 0.05). Moreover, the individuals with the genotype GG have a significantly higher mean white blood cell count than individuals with genotype CC or GC (P < 0.05). Our study indicates that DHX58 is an important gene that is associated with the immune response in swine.

Empiric antibiotics are justified for infants with respiratory syncytial virus lower respiratory tract infection presenting with respiratory failure: a prospective study and evidence review

OBJECTIVE

Although some studies indicate a low risk of serious bacterial infection in infants with respiratory syncytial virus (RSV), these studies focused on patients who did not progress to respiratory failure. We hypothesized the composite diagnosis of concomitant bacterial pneumonia (CBP) is common in lower risk infants with RSV who present in respiratory failure. The aim of the study was to investigate the incidence of CBP in low-risk infants mechanically ventilated for RSV respiratory failure and to compare the results with other studies searched for in MEDLINE.

DESIGN

Prospective, descriptive study, and literature review. Two MEDLINE searches were done using the terms 1) respiratory syncytial virus (RSV) and pneumonia, and 2) RSV, pneumonia, and antibiotics.

SETTING

Tertiary pediatric intensive care unit (PICU) in the Northeast United States.

PATIENTS

We prospectively enrolled 23 infants admitted to our PICU with RSV infection and respiratory failure over a 27-month period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All infants were intubated on arrival or soon thereafter; 22 had diagnostic tracheal aspiration performed, and 20 had blood cultures obtained shortly after admission. All had white blood cell count, temperature measured, and chest radiograph. Only one had antibiotics before culture. The length of mechanical ventilation, PICU course, and hospital stay were recorded.The primary outcome variable was the composite diagnosis of CBP as determined by the following criteria: 1) isolation of pathogenic bacteria from a tracheal aspirate, 2) blood culture, 3) chest radiograph, 4) temperature abnormality, and 5) peripheral white blood cell count. In our study, 7 infants met four criteria (probable pneumonia); 6 met three criteria (possible pneumonia); and 10 infants met less than three criteria. By tracheal aspirate criteria alone, 9 of 23 (39%) had probable pneumonia and 9 of 23 had possible pneumonia by previously published criteria. The mean length of mechanical ventilation for 7 infants who met four criteria was 10 +/- 2.7 (sem) days; for 6 infants who met three criteria, 10.5 +/- 2.1 days; and for infants who met less than three criteria 7.4 +/- 0.9 days. The mean PICU stay was 14.3 +/- 3.6 days for infants who met four criteria; 14.3 +/- 3.0 days for infants who met three criteria; and 9.9 +/- 1.4 days for infants who met less than three criteria. The mean hospital stay was 16.3 +/- 3.4 for infants who met four criteria; 18.7 +/- 2.8 days for infants who met three criteria; and 24.8 +/- 9.6 days for infants who met less than three criteria. These differences were not statistically significant. A MEDLINE search was performed using the terms 1) RSV and pneumonia, and 2) RSV, pneumonia, and antibiotics.

CONCLUSIONS

While the small size of this study does not permit definitive conclusions, these data, in combination with other data from the literature, suggest that composite evidence of bacterial pneumonia in otherwise low-risk infants with RSV presenting with respiratory failure is 20% or higher and the use of empirical antibiotics for 24 to 48 hrs pending culture results may be justified and could be used until CBP is excluded.

Azithromycin does not improve disease course in hospitalized infants with respiratory syncytial virus (RSV) lower respiratory tract disease: a randomized equivalence trial

BACKGROUND

Nearly half of all hospitalized infants with respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD) are treated with (parenteral) antibiotics. The present study was designed to test our hypothesis that the use of antibiotics would not lead to a reduced duration of hospitalization in mild to moderate RSV LRTD.

METHODS

Seventy-one patients < or =24 months of age with a virologically confirmed clinical diagnosis of RSV LRTD were randomized to azithromycin 10 mg/kg/day (n = 32) or placebo (n = 39) in a multicenter, randomized, double-blind, placebo-controlled equivalence trial during three RSV seasons (2002-2004 through 2005-2006). Primary endpoint was duration of hospitalization, secondary endpoints included duration of oxygen supplementation and nasogastric tube feeding, course of RSV symptom score, number of PICU referrals and number of patients who received additional antibiotic treatment. Data were analyzed according to the intention-to-treat principle using the Mann-Whitney U-test or chi2 test considering P < 0.05 as statistically significant.

RESULTS

Included patients were comparable with respect to baseline demographics, clinical characteristics, laboratory and roentgenologic investigations. The mean duration of hospitalization was not significantly different between patients treated with azithromycin or placebo (132.0 +/- 10.8 vs. 139.6 +/- 7.7 hr, P = 0.328). Azithromycin was not associated with a stronger resolution of clinical symptoms represented by the RSV symptom score. Four patients were treated with antibiotics after 72 hr, three of them were assigned to placebo (P = 0.406).

CONCLUSIONS

Infants and young children with RSV LRTD do not benefit from routine treatment with antibiotics (ISRCTN number 86554663).

Concurrent bacterial infection and prolonged mechanical ventilation in infants with respiratory syncytial virus lower respiratory tract disease

OBJECTIVE

To identify demographic, clinical, and laboratory variables predictive for a concurrent bacterial pulmonary infection in ventilated infants with respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD) and investigate antimicrobial drug use.

DESIGN AND SETTING

Retrospective, observational study in a 14-bed pediatric intensive care unit.

PATIENTS

82 infants younger than 1 year of age with a virologically confirmed RSV LRTD during 1996-2001, of whom 65 were mechanically ventilated.

RESULTS

Microbiological data were available from 38 ventilated infants, 10 of whom had a positive blood culture (n=1) or endotracheal aspirate (n=9) obtained upon admission to the pediatric intensive care unit (PICU). Infants with a positive culture had a lower mean gestational age but were otherwise demographically comparable to those with negative culture results. Infants with a positive culture were ventilated 4 days longer. Indicators for a concurrent bacterial infection were comparable between ventilated and nonventilated infants. Antimicrobial drugs were used in 95.1% of infants (100% of ventilated infants) with a mean duration of 7.8+/-0.3 days. The moment of initiation and duration of antimicrobial drug treatment varied considerably.

CONCLUSIONS

We observed in ventilated infants a low occurrence of concurrent bacterial pulmonary infection, but infants with positive cultures needed prolonged ventilatory support. Improvement in the diagnosis of a pulmonary bacterial infection is warranted to reduce the overuse of antimicrobial drugs among ventilated infants with RSV LRTD and to restrict these drugs to the proper patients.

Incidence of respiratory viruses in preterm infants submitted to mechanical ventilation

The objectives of this study were to determine the incidence of infection by respiratory viruses in preterm infants submitted to mechanical ventilation, and to evaluate the clinical, laboratory and radiological patterns of viral infections among hospitalized infants in the neonatal intensive care unit (NICU) with any kind of acute respiratory failure. Seventy-eight preterm infants were studied from November 2000 to September 2002. The newborns were classified into two groups: with viral infection (Group I) and without viral infection (Group II). Respiratory viruses were diagnosed in 23 preterm infants (29.5%); the most frequent was respiratory syncytial virus (RSV) (14.1%), followed by influenza A virus (10.2%). Rhinorrhea, wheezing, vomiting and diarrhea, pneumonia, atelectasis, and interstitial infiltrate were significantly more frequent in newborns with nosocomial viral infection. There was a correlation between nosocomial viral infection and low values of C-reactive protein. Two patients with mixed infection from Group I died during the hospital stay. In conclusion, RSV was the most frequent virus in these patients. It was observed that, although the majority of viral lower respiratory tract infections had a favorable course, some patients presented a serious and prolonged clinical manifestation, especially when there was concomitant bacterial or fungal infection.

Bronchiolitis caused by respiratory syncytial virus in an area of portugal: epidemiology, clinical features, and risk factors

The aim of the present study was to analyse the clinical and epidemiological characteristics of bronchiolitis caused by respiratory syncytial virus (RSV) in 225 children observed in a paediatric hospital in Lisbon, Portugal, and to determine the clinical, epidemiological, or laboratory parameters that correlate with greater severity of the disease. This prospective study included hospitalised and ambulatory children younger than 36 months of age with a diagnosis of bronchiolitis and was conducted during two consecutive RSV epidemiological seasons (November-March 2000/01 and 2001/02). The median age of the patients was 5 months, and the male-to-female ratio was 1.6:1. RSV was isolated in 60.9% of patients, predominantly in the hospitalised group. The subtype A:B ratio was 7.4:1 and was similar in both seasons. RSV-positive patients were younger, had more severe clinical forms of bronchiolitis, and fewer changes in leucocyte total and differential counts. Among infected patients, higher clinical severity scores occurred in association with first wheezing episodes, overcrowded households, attendance at day-care centres, or prematurity (<36 weeks). This first prospective study of RSV epidemiology in Portugal provides a foundation for appropriate surveillance programmes of RSV infection in this country. A multicentre study is desirable in order to delineate optimal prophylactic and therapeutic guidelines for RSV infection in Portugal.

Clinical and laboratory study of newborns with lower respiratory tract infection due to respiratory viruses

OBJECTIVES

To determine the prevalence of lower respiratory tract infection due to respiratory viruses in the neonatal period at admission to the neonatal intensive care unit and to compare the clinical, laboratory and radiological aspects of the clinical course, according to the etiological agent, in the neonatal period.

METHODS

Ninety newborns were studied, from January 1999 to January 2001, with bronchiolitis and/or pneumonia. The newborns were classified into three groups, according to the etiological agent identified initially: viral infection (group A), mixed viral-bacterial infection (group B), and bacterial infection (group C).

RESULTS

The virus was identified in 72 newborns (80.0%); the most prevalent was respiratory syncytial virus (RSV) (44.4%), followed by influenza A virus (22.2%). Coughing, wheezing and an interstitial infiltrate were significantly more frequent in newborns with viral infection. Mixed infection was more associated with sepsis. There was a correlation between viral infection and low values of initial and subsequent white blood cell count and C-reactive protein. RSV was the most important virus in these patients.

CONCLUSIONS

It was observed that, although the majority of viral respiratory infections had a favorable course, some patients presented a serious and prolonged clinical manifestation, especially when there was concomitant bacterial infection.

Clinical and epidemiological aspects of respiratory syncytial virus lower respiratory tract infections

This paper has analyzed respiratory syncytial virus lower respiratory tract infections in 201 hospitalized children. In children with wheezing, erythrocyte sedimentation rate (ESR) was significantly higher in those with pneumonia than with syndroma pertussis, while the white blood cell (WBC) count was significantly lower in patients with bronchitis than in those with bronchiolitis and syndroma pertussis. Bronchodilatators were applied in 75.6% and corticosteroids in 20% of patients. Ten patients were ventilated. Fatal disease outcome was observed in one infant. Twelve consecutive-year study of respiratory syncytial virus (RSV) infections showed that 27.3% of these diseases were bronchiolitis and pneumonia.