Human Metapneumovirus Clinical Manifestations

Introduction to Clinical Features

Human metapneumovirus (HMPV) causes respiratory tract infections with clinical presentation varying significantly by age and immune status, including symptoms such as upper respiratory symptoms, which include rhinorrhea, nasal congestion, cough, and fever, in pediatric patients 1
Additional symptoms in pediatric patients include fatigue, expectoration, diarrhea, and headache 2

Symptoms in pediatric patients can progress to include dyspnea, cyanosis, malaise, restlessness, poor feeding, and reduced activity 2
In severe cases, progression to respiratory failure unresponsive to conventional oxygen therapy, septic shock, metabolic acidosis, and coagulation dysfunction may occur in pediatric patients 2

Patients with chronic cardiac or pulmonary diseases are at elevated risk of severe disease 3
The presence of comorbidities, particularly cardiopulmonary disease, substantially increases mortality risk in adult patients 3

No clinical or radiographic criteria reliably distinguish HMPV from bacterial infection, necessitating a low threshold for empirical antibiotics in severe cases 3, 4
Asymptomatic and prolonged viral shedding can occur, complicating infection control 5
Coinfection with other respiratory viruses (especially RSV) is common and obscures attributable morbidity 5
No antiviral agent has established efficacy for HMPV treatment in adults 3, 4
In immunocompromised patients (including HSCT recipients), HMPV can cause severe lower respiratory tract disease with 10-30% mortality 5