Without a vaccine or antiviral drug, HMPV, unknown to the general public, is infecting more and more people in the United States. In 2018, it was responsible for the deaths of more than 16,000 children under the age of 5 worldwide. Details.
It seems to come out of nowhere. Yet discovered in 2001, HMPV, human metapneumovirus, is increasingly talked about in the press across the Atlantic. And for good reason ! As it attacks the most fragile, very young children, seniors and immunocompromised people, the number of positive HMPV tests was 36% higher this year compared to the pre-pandemic average peak. At its peak, in mid-March, this virus recorded 11% of positive tests against only 7% usually. The figures could be largely underestimated since the tests are carried out during hospitalization and many patients are unaware of the existence of HMPV.
No immunity
Unlike the flu or Covid-19, no vaccine or antiviral drug exists to treat the virus.
The most common symptoms are cough, fever, nasal congestion and shortness of breath. According to the US Centers for Disease Control and Prevention (CDC), these symptoms can progress to bronchitis, pneumonia, lower and upper respiratory tract infection.
HMPV is transmitted through secretions, coughing and sneezing, close contact with an infected person or contact with objects carrying the virus. Cured people are not immune and can be reinfected throughout their lives.
As common as RSV and the flu?
According to Dr. John Williams, a pediatrician at the University of Pittsburgh, HMPV “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 (respiratory syncytial virus, responsible for bronchiolitis in particular) and the flu. “These are the three big viruses, in children and adults, most likely to send people to hospital and cause serious illness, most likely to make old people really sick and even kill them” , he explains to CNN.
Thus, according to a study published in 2020 in The Lancet global health, in 2018, between 10 and 20 million children under the age of 5 were infected with HMPV worldwide. It would be responsible, for this same year, for 643,000 hospitalizations and 16,100 deaths. The CDC regrets that health professionals do not systematically test their patients and recommends tests in winter and spring, when the virus is circulating.
To note : discovered in 2001 by Dutch scientists, HMPV was so named because of its proximity to the avian metapneumovirus which infects birds. It would be a zoonosis, passed from birds to humans.