Two Cases of Primary Human Parainfluenza Virus 1 Pneumonia in Which Bronchoalveolar Lavage Fluid Yielded Human Parainfluenza Virus 1

Respiratory virus infections of the lower respiratory tract elevate bronchoalveolar lavage eosinophil fraction: a clinical retrospective study and case review

BACKGROUND

Eosinophilic airway inflammation caused by respiratory virus infection has been demonstrated in basic research; however, clinical investigations are lacking. To clarify the extent to which respiratory virus infection induces airway eosinophilic inflammation, we reviewed the results of bronchoalveolar lavage (BAL) and respiratory virus testing performed at our hospital.

METHODS

Among the BAL procedures performed at the University of the Ryukyu Hospital from August 2012 to September 2016, we collected cases of acute respiratory disease in which multiplex polymerase chain reaction (PCR) was used to search for respiratory viruses. The effect of respiratory virus detection on BAL eosinophil fraction was analyzed using statistical analysis. A case study was conducted on respiratory virus detection, which showed an elevated BAL eosinophil fraction.

RESULTS

A total of 95 cases were included in this study, of which 17 were PCR-positive. The most common respiratory virus detected was parainfluenza virus (eight cases). The PCR-positive group showed a higher BAL eosinophil fraction than the PCR-negative group (p = 0.030), and more cases had a BAL eosinophil fraction > 3% (p = 0.017). Multivariate analysis revealed that being PCR-positive was significantly associated with BAL eosinophil fraction > 1% and > 3%. There were nine PCR-positive cases with a BAL eosinophil fraction > 1%, of which two cases with parainfluenza virus infection had a marked elevation of BAL eosinophil fraction and were diagnosed with eosinophilic pneumonia.

CONCLUSIONS

Cases of viral infection of the lower respiratory tract showed an elevated BAL eosinophil fraction. The increase in eosinophil fraction due to respiratory virus infection was generally mild, whereas some cases showed marked elevation and were diagnosed with eosinophilic pneumonia. Respiratory virus infection is not a rare cause of elevated BAL eosinophil fraction and should be listed as a differential disease in the practice of eosinophilic pneumonia.

Peripheral blood parameters for predicting PICU admission and mechanical ventilation in pediatric inpatients with human parainfluenza virus-induced pneumonia

Human parainfluenza viruses (hPIVs)-induced pneumonia is an important cause of pediatric hospitalization, and some develop severe pneumonias requiring pediatric intensive care unit (PICU) admission and mechanical ventilation (MV). The aim of this study is to investigate the value of peripheral blood (PB) parameters available on admission in predicting the need for PICU admission and MV due to pneumonia caused by hPIVs. A total of 331 cases including 277 (83.69%) on the general ward (GW) and 54 (16.31%) on the PICU were enrolled between January 2016 and June 2021. Of 54 patients admitted to the PICU, 24 patients (7.25%) received MV, whereas 30 (9.06%) did not. For both the PICU and GW groups, infants accounted for the highest proportion while school children had the lowest. Compared with the GW group, the PICU group had significantly higher rates of premature birth, fatigue, sore throat, headache, chest pain, tachypnea, dyspnea, and underlying diseases including congenital tracheal stenosis, congenital heart disease (CHD), metabolic disorder, and neurological disorder (ND), but significant lower proportion of exclusive breastfeeding and Z-scores for weight-for-height, weight-for-age, height-for-age, and body-mass-index (BMI)-for-age (BMIZ). Higher levels of some leukocyte differential counts (LDC)-related parameters including counts of neutrophil (N), ratios of neutrophil-to-lymphocyte ratio (NLR), derived neutrophils/(leukocytes minus neutrophils) ratio (dNLR), and platelet-to-lymphocyte ratio (PLR), lower levels of some other LDC-related parameters including lymphocyte (L) and monocyte (M) counts, ratios of lymphocyte-to-monocyte ratio (LMR), lymphocyte-to-C-reactive protein ratio, and prognostic nutritional index (PNI), and lower levels of PB protein (PBP)-related parameters including red blood cell (RBC), hemoglobin, total protein (TP), and serum albumin were observed in the PB of patients in the PICU compared with those in the GW. Notably, higher PLR level and two comorbidities including CHD and ND were identified as independent risk factors for PICU admission, while lower PNI level as well as smaller numbers of RBC and L as good predictors. Low levels of TP might be a useful predictor of the need for MV. Overall, the relative contributions of LDC- and PBP-related factors for accurate identification of patients required PICU admission accounted for 53.69% and 46.31%, respectively. Thus, determination of whether a patient with hPIVs-induced pneumonia is admitted to PICU involves consideration of both the LDC- and PBP-related parameters.

Coding-Complete Genome Sequence of a Human Respirovirus 1 Strain from a Clinical Sample in Arizona

Human respirovirus 1 is a single-stranded, negative-sense RNA virus in the family Paramyxoviridae. Using a high-throughput metagenomic approach, we identified and sequenced the coding-complete genome of a human respirovirus 1 strain from a nasal pharyngeal swab sample from a local health clinic in Tempe, Arizona.

Human respirovirus 1 is a single-stranded, negative-sense RNA virus in the family Paramyxoviridae. Using a high-throughput metagenomic approach, we identified and sequenced the coding-complete genome of a human respirovirus 1 strain from a nasal pharyngeal swab sample from a local health clinic in Tempe, Arizona.