Understanding Human Metapneumovirus, as cases emerge from China: Explained Premium

China pilots monitoring system for pneumonia of unknown origin amid rising respiratory infections, including human metapneumovirus, in winter and spring.

Last week, China’s diseases control authority said that it was piloting a monitoring system for pneumonia of unknown origin, with cases of some respiratory diseases expected to rise through the winter. According to a Reuters report, this move to establish a dedicated system was aimed at helping authorities set up protocols to handle unknown pathogens. The country was already witnessing an upward trend in overall infections as of mid-December, and was expecting to see more respiratory infections in the winter and spring. One of the pathogens that was detected, and which showed an upward trend in the northern provinces especially among people under the age of 14, was human metapneumovirus, as per the report.

Subsequently, viral posts showcasing crowds of people in what looked like Chinese hospitals began doing the rounds on social media along with statements about China allegedly declaring an emergency over this virus. However, so far, there has been no such official declaration.

Human metapneumovirus (HMPV) is a respiratory virus that causes mild infections similar to that caused by a common cold. First identified by scientists in 2001, the virus belongs to the Pneumoviridae family, of which respiratory syncytial virus (RSV), measles and mumps are also members.

HMPV can cause both upper and lower respiratory tract infections and is generally seen in winter and early spring. Children, the elderly and those with weakened immune systems are more susceptible to the infection and to developing complications from it.

Symptoms can resemble those caused by a common cold. They include a cough, runny or blocked nose, sore, throat, fever and wheezing. The estimated incubation period is three to six days. In most people, the illness goes away on its own within a few days, with rest and supportive care at home. In a few people however, complications such as bronchitis or pneumonia may arise, requiring medical care.

HMPV spreads through contact with an infected person or touching objects that have the virus on them. This can be through: secretions from coughs, sneezes; close contact with someone who has the infection such as shaking hands, hugging; toughing a doorknob or a phone or a keyboard that may be contaminated with the virus and then touching the mouth, nose or eyes.

There is no vaccine and there is no specific antiviral to treat HMPV. Most people require over-the-counter medications to relieve fever and pain, possibly with a decongestant. Antibiotics will not work for HMPV.