JPED Journal

Introduction

Infection is an important cause of morbidity and mortality especially when it occurs in the respiratory system [1]. Children under 5 years of age often experience three to six episodes of acute respiratory infection per year. The World Health Organization (WHO) categorize respiratory infections as the second most important cause of death in children below 5 years old [2]. Viruses are the main cause of lower respiratory tract infections, especially in infants [3]. There has been an improvement in Virus-detection technology in recent years, after the use of the polymerase chain reaction (PCR) which is now available in many clinical settings and able to detect even co-infection with other viruses [4].

HMPV belongs to the paramyxovirus family, which is similar to respiratory syncytial virus (RSV) and often has a wide spectrum of presentations in infants and children [5]. The human metapneumovirus was discovered in the beginning of 2000 by Dr. Van Den Hoogen [5]. It can range from a simple upper respiratory tract infection URTI to a severe lower respiratory tract infection LRTI, which may need intensive care [6]. Most of the HMPV infections are detected in the winter season, between January to April [7].

HMPV infections cause 4% of pediatric hospitalizations, 15– 25% of those need transfer to pediatric intensive care units, with 8–17% requiring mechanical ventilation [8]. The hospitalization due to HMPV may cost around 6000 U.S. dollars per pediatric patient hospitalization [8] Those children with HMPV infections less than 5 years of age were more likely to need oxygen support and a longer average of stay in the pediatric intensive care unit [4.5 days versus 2 days] than those with a negative HMPV result [8] Currently, there is no specific treatment or vaccine for HMPV infection [9]. Due to the clinical severity of the infection by Human metapneumovirus, it is important to study the effect of HMPV on the pediatric age group.

In conclusion, we have a lack of knowledge about the impact of human metapneumovirus in a PICU in Saudi Arabia, as the percentage of children in the Saudi Arabian population is high and they are at risk for viral illnesses, especially during the winter seasons and crowded events such as the annual pilgrimage (hajj) and minor pilgrimages (omrah). Therefore, we are looking for improvement in the clinical course and outcome through our study.

Method

Study design

In our study we assessed the clinical features and outcomes of the pediatric patients with HMPV infections needing admission to the PICU in King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia. The PICU has a capacity of 20 beds. This is a descriptive, retrospective review of medical records for all children confirmed to have HMPV infection, who were admitted to the PICU during 5 years between January 2017 until December 2021. A total of 41 patients were included. The Institutional Review Board at KFMC approved this study with no: IRB00010471.

Inclusion and Exclusion criteria

Inclusion

All pediatric patients younger than 14 years old, male or female, with or without comorbidities, admitted from January 2017 until December 2021 with a positive human metapneumovirus NPA (nasopharyngeal aspirate) detected by PCR (polymerase chain reaction)

Exclusion

Multiple admissions of the patient to PICU in the same hospitalization course, cardiac patients admitted in the cardiac intensive care unit.

Data collection

Electronic medical records of the 41 patients (via the Epic® and Corttex® systems) were reviewed and analyzed for the following data: sex, age, length of stay, type of respiratory support [HFNC, NIV, invasive mechanical ventilators, HFOV, ECMO, nitric oxide] the length of support, incidence of pneumothorax, plural effusion, inotropes, comorbidities including prematurity, asthma, pneumonia, airway anomalies, GERD, sepsis, congenital heart disease, neurological disorders, immunodeficiency states, AKI, and dysmorphism (e.g. Down syndrome). We collected the data regarding the duration and need for PICU care and respiratory support including the type (invasive, non-invasive positive pressure ventilation and oxygen support), inotropic support, renal replacement therapy and extracorporeal membrane oxygenation and survival outcomes.

Results

41 patients of HMPV confirmed by PCR were identified during the study period. The data are summarized in the (Tables 1 and 1A). 21 [51%] patients were females. The age was between 3 months to 14 years old with median of 3 years. The PICU stay ranged from 3 to 105 days with median of 14 days. The majority of cases (31[75%] patients) were admitted between the period between November-March. The most common clinical presentations for the patients were cough, shortness of breath and fever with percentages of 97%, 95% and 80% respectively. 28 [68%] of the patients had a previous admission to PICU due to other co morbidities. One of the most common comorbidities was asthma, which was noted in 26 [63.4%] patients, neuromuscular diseases in 21 [51.2%], followed by gastroenterology disease in 18 [43.9%] patients, which was mostly due to gastroesophageal reflux. Other comorbidities included: prematurity 17.1%, chronic lung disease 29.3%, CHD 39%, genetic disorders 43.9% particularly Down syndrome, and immunodeficiency 4.9%. Viral co-infection was present in nine (21.9 %) subjects, mainly with either rhinovirus in four patients (9.7%) or adenovirus in four patients (9.7%). 28 [68.3%] patients used a bronchodilator as a chronic medication, 19 [46.3%] used a steroid inhaler and 14 [34.1%] used anti-reflux medication.

Table 1: Descriptive Statistics of the metric data.

A total of 35 (85.4%) children required respiratory support: high-flow nasal cannula in 17 [41.5%] patients, noninvasive mechanical ventilation in 20 (48.8 %) patients, invasive mechanical ventilation via endotracheal intubation in 18 (43.9 %) patients, high-frequency oscillatory ventilation in four(9.8%) patients, while ECMO was not used. 23 [56.1%] patients needed a fluid volume bolus, seven [17.1%] patient needed a vasopressor, 14 [34.1%] patients received blood transfusions and two [4.9%] patients needed renal replacement therapy. We found that the patients with previous co-morbidities had an increased need for the respiratory support when compared with healthy patients. The majority of patients 35 [85.4%] were discharged the home and the remaining six [14.6%] patients died in hospital.

Table 1A: Descriptive Statistics of the non-metric data;PICU: pediatric intensive care unit , HFNC: high flow nasal cannula , NIV: noninvasive mechanical ventilation , IMV: invasive mechanical ventilation , HFOV: high frequency oscillatory ventilator , CHD: congenital heart disease , CNS: central nervous system , CP: cerebral palsy , AKI: acute kidney injury , ARDS: acute respiratory distress syndrome , ADINO: adenovirus , RHINO : rhinovirus.