Human metapneumovirus (HMPV) is a respiratory virus in the Paramyxoviridae family, first identified in 2001. It is closely related to respiratory syncytial virus (RSV), and both belong to the Pneumoviridae family. HMPV can cause upper and lower respiratory tract infections, with cases occurring throughout the year without a defined seasonal pattern.
Epidemiology
HMPV affects individuals of all ages and is primarily transmitted through respiratory droplets from coughs and sneezes or by direct and indirect contact with contaminated surfaces. The incubation period ranges from 3 to 6 days. The virus spreads easily in crowded settings such as schools and healthcare facilities, where close physical contact is common.
Certain groups are at higher risk of severe illness, including young children—particularly infants under six months and those born prematurely—immunosuppressed individuals, older adults, and people with chronic conditions such as asthma or chronic obstructive pulmonary disease (COPD). HMPV is widely present in South Africa and has been detected in various regions worldwide.
Clinical Presentation
Most cases of HMPV result in mild upper respiratory tract symptoms similar to the common cold. These may include a cough, runny nose, nasal congestion, fever, or sore throat, with symptoms typically improving within three to five days.
However, in some cases, HMPV can lead to more severe lower respiratory tract infections such as bronchitis, bronchiolitis, or pneumonia. In severe cases, it may cause acute respiratory distress syndrome, particularly in high-risk individuals.
Diagnosis
HMPV cannot be clinically distinguished from other respiratory viral infections based on symptoms alone. Laboratory testing is necessary for confirmation, particularly in severe cases requiring specific management. Diagnosis is confirmed through a polymerase chain reaction (PCR) test performed on a nasal or throat swab sample.
Prevention
There are currently no vaccines available for HMPV, though vaccine development is in the late stages. Preventive measures focus on reducing transmission through good hygiene practices. These include frequent handwashing with soap and water, avoiding touching the face, and maintaining distance from individuals who are sick. Covering coughs and sneezes, avoiding the sharing of utensils, and staying home when experiencing symptoms can also help prevent spread.
Management
For mild cases, HMPV is typically self-limiting and can be managed at home with rest, hydration, and medications to relieve fever and discomfort.
Severe cases may require supportive care in a healthcare setting, including oxygen supplementation, intravenous fluids, and bronchodilators for respiratory distress. There are no specific antiviral treatments for HMPV, so management focuses on symptom relief and supportive care.
In healthcare settings, infection prevention and control (IPC) measures are essential to limit transmission. Standard precautions, along with droplet and contact precautions, should be followed when treating patients with HMPV, particularly in environments where respiratory droplets and contaminated surfaces contribute to the spread.
For more detailed information, refer to the HMPV Clinician Fact Sheet.