What is happening in China?
Five years after the appearance of Covid-19 in Wuhan, social networks are ablaze at the start of 2025 with a new epidemic due to a respiratory infection, the human metapneumovirus (MPVh). While images of crowded hospitals and rumors of a state of emergency have circulated, the situation has become clearer since the World Health Organization’s update on Tuesday January 7.
Thus, according to the WHO, the Chinese Center for Disease Control and Prevention (or Chinese CDC) mentions in its report of January 2, 2025 “an increase in a number of common respiratory infections in the country, as would be expected during winter.”
The figures would also be located “within the usual range for the winter season”. Beijing reports that “the rate of hospitalizations is currently lower than last year at the same time, no emergency declaration has been made and no action has been taken.”
What viruses are currently raging in China?
According to Chinese data, remember that China has a sentinel surveillance system for influenza syndromes and severe acute respiratory infections, the viruses currently prevalent are: seasonal influenza virus, respiratory syncytial virus (RSV), HMPV, and SARS-Cov-2.
The authorities specify that the seasonal flu virus is by far the most common virus currently and is clearly increasing. However, the metapneumovirus is also at work. « MPVh positivity rate among children 14 years and younger showed an increasing trend », said Kan Biao, head of infectious diseases at the China CDC, at a press conference.
What is metapneumovirus?
Little is known about it, but metapneumovirus is not a new virus. According to the WHO, metapneumovirus was first identified in 2001 in the Netherlands. However, according to experts, the virus could have been circulating since the mid-20th century.
The situation is therefore very different than during Covid-19, when health authorities were confronted with an unknown virus, to which humans had never been exposed.
This virus, which occurs most often in winter and early spring, belongs to the pneumoviridae family, a family to which RSV also belongs. According to the US CDC, it is a significant cause of upper and lower respiratory tract infections.
Is this the first alert regarding this virus?
In 2023, the human metapneumovirus panicked the United States. The number of positive MPVh tests was then 36% higher than the average pre-pandemic peak. At its peak, in mid-March 2023, this virus recorded 11% of positive tests compared to only 7% usually.
Dr. John Williams, a pediatrician at the University of Pittsburgh, said at the time: MPVh “is the most important virus you’ve never heard of.” Interviewed by CNN, he has spent his career researching a vaccine and treatment for HMPV.
According to him, it is as present and potentially serious as RSV (responsible for bronchiolitis in particular) and the flu. “These are the big three viruses, in children and adults, most likely to send people to the hospital and cause serious illness, most likely to make older people really sick and even kill them” , he explained to CNN.
https://edition.cnn.com/2023/05/29/health/human-metapneumovirus-explainer-wellness/index.html
-Why are children more affected?
Having contracted the disease once does not confer immunity and it is possible to be infected several times during your life. However, because the disease is more severe during the first infection, children actually have more serious symptoms.
Thus according to a study published in 2021 in The Lancet global healthin 2018, between 10 and 20 million children under 5 years old were contaminated with HMPV worldwide. It would be responsible, for that same year, for 643,000 hospitalizations and 16,100 deaths.
Children are not the only ones to be more exposed. “The youngest and oldest are most exposed, as well as immunocompromised people, that is to say those whose immune system is weakened,” said Margaret Harris, WHO spokesperson.
“People in an at-risk group, such as the elderly or immunocompromised, should seek medical attention if they feel ill”adds the WHO.
https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(20)30393-4/fulltext
How is metapneumovirus transmitted?
The virus is transmitted from one infected person to another through droplets from coughing and sneezing.
But also “during close personal contact, such as touching or shaking hands, touching objects or surfaces that have viruses on them, and then touching your mouth, nose, or eyes” , specifies the United States CDC.
What are the symptoms?
Symptoms commonly associated with MPVh are those of the common cold: cough, wheezing, runny nose, sore throat, nasal congestion and shortness of breath. The complications are similar to those of other viruses responsible for respiratory infections: bronchitis and pneumonia. After 3 to 6 days of incubation, the duration of the illness depends on its severity and remains similar to that of other respiratory viruses.
There is no vaccine or specific antiviral treatment against this virus. Treatments aim to relieve symptoms.
How to prevent the spread of the virus?
Barrier measures are recommended to prevent the transmission of MPVh:
- stay home if you are sick;
- wash your hands often with soap and water;
- wear a mask in busy and/or poorly ventilated places.
Source : OMS, CDC Etats-Unis, The Lancet Global Health, CNN
