The human metapneumovirus (hMPV) is one of the most common viral pathogens responsible for respiratory illness. It belongs to a group of similar viruses that include respiratory syncytial virus (RSV) and parainfluenza virus. Human metapneumovirus can range in severity from asymptomatic to acute. Though the virus can occur at any age, the populations most at risk are the very young, patients with compromised immune systems and the elderly. It often presents as severe wheezing in pediatric patients, but can also cause croup or pneumonia.
Human metapneumovirus was first identified in 2001 by researchers at Erasmus Medical Center in the Netherlands. Led by the chief of the Virology Department and professor of virology, Dr. Albert Osterhaus, the team of researchers found the pathogen in cultures from 28 children, hospitalized in Erasmus Medical Center at that time, with respiratory conditions of unknown causes. Other laboratories throughout the world have since confirmed the presence of human metapneumovirus. The widespread nature of the antibodies specific to hMPV, found in human blood samples from various laboratories, suggests that the viral pathogen has been a cause of respiratory infections in humans for over 50 years.
Human metapneumovirus most often causes upper respiratory symptoms, including nasal congestion, runny nose, cough, and sore throat. Flu-like symptoms, such as fever, body aches, and vomiting may also result from hMPV. Less common conditions associated with the virus include bronchiolitis, conjunctivitis, otitis media, diarrhea, and rash. Infection with the human metapneumovirus can exacerbate symptoms in patients with asthma, and may cause difficulty breathing and more severe respiratory illness in the very young, elderly or immuno-compromised patients. The virus may also be present with no clinical manifestations.
The human metapneumovirus is most often spread through direct or close contact with respiratory secretions from those who have been infected. The virus can also be spread through contact with objects contaminated with respiratory secretions from an infected person. Once exposed, the person may develop symptoms within three to five days. Reinfection with hMPV may occur, though symptoms tend to be milder after the initial infection. In the United States, hMPV occurs most often in the late winter and early spring.
Treatment of human metapneumovirus may include medications to minimize symptoms. Fever reducers, antihistamines, and treatments to improve breathing can be particularly helpful. The spread of hMPV may be prevented through proper and frequent hand-washing, covering the mouth and nose with a tissue when coughing or sneezing, and prompt disposal of the contaminated tissue.