In March, around 11 per cent of PCR tests and 20 per cent of antigen tests for human metapneumovirus (HMPV) were positive in the US.
The PCR tests’ positivity rate has increased by 36 per cent in comparison to the pre-pandemic levels. Although the percentages were high in April, they decreased in May.
A report published by the Centres for Disease Control and Prevention report stated that there has been a decrease in positivity rates during the warmer months, which is similar to what has been observed in flu and colds.
The data states that the Antigen Detection rate and PCR Detection rate as observed on April 3, 2023, were 19.395 and 10.368, respectively, which decreased to the rate of 0.000 and 2.558, respectively, when observed on May 20, 2023.
The Centers for Disease Control and Prevention’s report states that human metapneumovirus (HMPV) can affect a person’s upper and lower respiratory tracts irrespective of their age and have higher vulnerability in older adults, young children, and individuals with weakened immune systems.
HMPV’s severe cases can lead to bronchitis or pneumonia. The incubation period for HMPV is around 3 to 6 days, and the recovery period from the illness depends on its severity. However, it is similar to other respiratory infections such as colds
What is human metapneumovirus?
First discovered in 2001 in the Netherlands, human metapneumovirus is a type of paramyxovirus, which is a family of viruses that cause multiple common infections.
Other paramyxoviruses include respiratory syncytial virus (RSV), parainfluenza, measles and mumps.
“This one usually causes a cold — not a big deal in most individuals,” stated Monica Gandhi, an infectious-disease expert at the University of California at San Francisco.
In 2001, the experts had collected 28 samples from children who were suffering from unexplained respiratory infections. A few children were very ill and needed mechanical ventilation, but their test results didn’t show positive for any known pathogens.
Why is metapneumovirus being discussed?
There has been a surge in cases of human metapneumovirus, just like other respiratory illnesses.
This month, the Centres for Disease Control and Prevention reported unusual spikes in cases across the United States.
According to virus experts, there has been an increase in the number of viruses, which include RSV. The experts have speculated that this may have occurred as an aftereffect of lockdowns and masking due to the coronavirus pandemic.
As per experts, if our systems have small interactions with viruses, it prepares our body to better handle exposure to viruses in future.
However, after years of social distancing and masking in school, children are left with fewer biological defences to fight the exposure to multiple viruses at once.
What are the symptoms of HPMV?
The virus, which has been observed to usually make its appearance in spring and winter, most commonly affects the body’s upper respiratory tract and leads to nasal congestion, cough and shortness of breath, along with fever. The illness generally lasts three to seven days.
Can HPMV turn into a serious illness?
Usually, human metapneumovirus is mild, however, the infection can lead to more serious consequences for older adults, young children, older adults and those people with weakened immune systems.
Human metapneumovirus has been spreading similarly to other viruses through airborne particles which are produced by sneezing or coughing, by getting in physical contact with a person who is carrying the virus, or handling objects which are contaminated by the virus and then touching the nose, eyes or mouth, according to the CDC.
Gandhi emphasised that the virus can spread even from someone who is asymptomatic. As per a study, at least 38 per cent of infections are recorded as asymptomatic human metapneumovirus infections.
“But the time you’re most infectious in all infectious diseases is when you’re having active symptoms because you’re spreading it — you’re coughing it out through your mouth, you’re sneezing it out through your nose,” Gandhi stated.
Is there a vaccine for the virus? How is HMPV treated?
No vaccines have till now being created for human metapneumovirus, and medical treatment for the illness remains limited to supportive care.
“We try to make you feel better and make sure that your breathing is okay while your body fights off the virus,” stated William Schaffner, who is a professor of infectious diseases and preventive medicine at Vanderbilt University.
Schaffner said that severe cases are rare in which people have been reported to be facing difficulty in breathing. However, he added, “We can put them in an intensive care unit and treat them there,” but generally people fully recover on their own.