Prevalence of B. pertussis infection in children with clinically suspected pertussis

Whooping Cough Cases Increase in Central Italy after COVID-19 Pandemic

Pertussis continues to be a highly contagious respiratory infection, especially in children, with cyclical peaks of disease spread every three to five years. Here, we report relevant cases of B. pertussis infection between August 2023 and January 2024, and compare them with B. pertussis prevalence in pediatric patients admitted to the Reference Italian Pediatric Hospital, located in Rome, from January 2015 to July 2023. A total of 5464 tests for B. pertussis were performed during the study period, and 6.9% were positive. At the time of the COVID-19 pandemic, there was a sharp decrease in the presence of B. pertussis, which reappeared only in August 2023, recording five new cases. All five children presented with paroxysmal cough 5 to 10 days before admission. Four patients had other mild respiratory symptoms and moderate B. pertussis DNA levels (Ct mean: 26). Only one child, with very high B. pertussis DNA levels (Ct: 9), presented with severe respiratory failure. The patients with mild/moderate infection achieved clinical recovery while the patient with the severe manifestation died of cardiac arrest. These observations highlight the reemergence of pertussis even in vaccinated countries and its association with morbidity and mortality especially in young children. This emphasizes the importance of rapid diagnosis to immediately implement appropriate treatment and monitoring of immune status.

Clinical evaluation of metagenomic next-generation sequencing for detecting pathogens in bronchoalveolar lavage fluid collected from children with community-acquired pneumonia

This study is to evaluate the usefulness of pathogen detection using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) specimens from children with community-acquired pneumonia (CAP). We retrospectively collected BALF specimens from 121 children with CAP at Tianjin Children's Hospital from February 2021 to December 2021. The diagnostic performances of mNGS and conventional tests (CT) (culture and targeted polymerase chain reaction tests) were compared, using composite diagnosis as the reference standard. The results of mNGS and CT were compared based on pathogenic and non-pathogenic organisms. Pathogen profiles and co-infections between the mild CAP and severe CAP groups were also analyzed. The overall positive coincidence rate was 86.78% (105/121) for mNGS and 66.94% (81/121) for CT. The proportion of patients diagnosed using mNGS plus CT increased to 99.18%. Among the patients, 17.36% were confirmed only by mNGS; Streptococcus pneumoniae accounted for 52.38% and 23.8% of the patients were co-infected. Moreover, Bordetella pertussis and Human bocavirus (HBoV) were detected only using mNGS. Mycoplasma pneumoniae, which was identified in 89 (73.55%) of 121 children with CAP, was the most frequent pathogen detected using mNGS. The infection rate of M. pneumoniae in the severe CAP group was significantly higher than that in the mild CAP group (P = 0.007). The symptoms of single bacterial infections (except for mycoplasma) were milder than those of mycoplasma infections. mNGS identified more bacterial infections when compared to the CT methods and was able to identify co-infections which were initially missed on CT. Additionally, it was able to identify pathogens that were beyond the scope of the CT methods. The mNGS method is a powerful supplement to clinical diagnostic tools in respiratory infections, as it can increase the precision of diagnosis and guide the use of antibiotics.

Clinical characteristics of children with airway malacia complicated by pneumonia

Background

Airway malacia is an important cause of noisy breathing, recurrent wheezing and respiratory infections, chronic coughing, and episodes of respiratory distress in young children. As the clinical manifestations of airway malacia are not common, many clinicians have insufficient understanding of this disease. So the purpose of this study is to summarize the pathogenic bacteria and clinical manifestations of airway softening complicated with pneumonia in children.

Methods

Children hospitalized with airway malacia complicated by pneumonia were eligible for enrollment from January 1, 2013 to December 31, 2019. Medical records of patients were reviewed for etiology, clinical characteristics, and laboratory examination results.

Results

A total of 164 pneumonia patients with airway malacia were admitted. The male-to-female ratio was 3:1. The age of patients ranged from 1 month to 4 years old. The median age was 6 (3–10) months. The most commonly detected pathogen were Mycoplasma pneumoniae (25/164, 15.24%), Streptococcus pneumoniae (18/164, 10.98%), and respiratory syncytial virus (16/164, 9.76%). Common signs among the 164 patients with confirmed airway malacia included cough (98.78%), wheezing (67.07%), fever (35.37%), intercostal retractions (23.17%), dyspnea (10.98%), cyanosis (11.11%), and crackles (50%). Compared with those without airway malacia, the incidence of premature delivery and mechanical ventilation was higher, and the duration of symptoms before admission (median, 13.5 d) and hospital stay (median 10.0 d) were longer. Of the children with pneumonia, 11.59% of those with airway malacia required supplemental oxygen compared with 4.88% of those without airway malacia (p < 0.05).

Conclusion

The median age of children with airway malacia was 6 months. The most common pathogen in patients with airway malacia complicated by pneumonia was Mycoplasma pneumoniae. Patients with airway malacia complicated by pneumonia often presented with a longer disease course, more severe symptoms, and had delayed recovery.

Virus Coinfection is a Predictor of Radiologically Confirmed Pneumonia in Children with Bordetella pertussis Infection

Introduction

This study aimed to prospectively investigate the burden of pertussis in southeast Chinese children hospitalized with lower respiratory tract infection (LRTI) during a pertussis outbreak and to compare the outcomes of Bordetella pertussis infection with or without virus coinfections.

Methods

Children < 24 months of age hospitalized with LRTI were prospectively enrolled from January 2017 to December 2019. Demographic and clinical information were recorded, and respiratory tract samples were tested for the presence of B. pertussis and ten common viruses by polymerase chain reaction (PCR).

Results

Bordetella pertussis PCR was positive in 6.1% (202/4287) of the patients. Only 146 (72.3%) B. pertussis infections met the Centers for Disease Control and Prevention case definition for pertussis. Among the 202 subjects with B. pertussis infections, 81 (40.1%) were coinfected with at least 1 respiratory virus, with human rhinovirus being the most commonly detected virus (25.7%). No differences in clinical severity were observed between children with single B. pertussis infection and those with virus coinfection [odds ratio (OR) 0.75; 95% confidence interval (CI) 0.39–1.44]. However, children with virus coinfection were significantly more likely to present with radiologically confirmed pneumonia than those with a single B. pertussis infection (OR 2.62; CI 1.39–4.91).

Conclusions

Bordetella pertussis infection contributed to a high proportion of LRTI hospitalizations among southeast Chinese children. There were no significant differences in clinical severity between children with virus coinfection and single B. pertussis infection, although children coinfected with virus coinfection presented with pneumonia more frequently than those with single B. pertussis infection.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00376-5) contains supplementary material, which is available to authorized users.