A new virus seems to threaten the planet, coming again, like the first deadly coronavirus, from China. This time it's metapneumovirus (HMPV) and experts are again calling on China to be transparent, as HMPV cases sweeping the Asian country appear to be doubling now in the US.
HDN Newsroom
U.S. health authorities are on alert because of the metapneumovirus. Western experts are publicly calling on China to be more transparent about the virus outbreak flooding its hospitals as data shows the virus is on the rise in the US.
Beijing downplayed footage of overcrowded waiting rooms and hospital wards posted on social media, saying respiratory infections were "less severe" and "smaller in scale" compared to last year.
This has led some to fear there are similarities to the current situation and the outbreak of Covid-19 in 2019, an outbreak initially downplayed by China. China is believed to be experiencing a surge in cases of the relatively unknown human metapneumovirus virus (HMPV), which usually causes cold-like symptoms such as a stuffy nose, headache, shivering and fatigue.
Dr Sanjaya Senanayake, associate professor of infectious disease medicine at the Australian National University, said it was "vital for China to communicate its data on this outbreak in a timely manner", including "data on who is infected". He added: "We will also need genomic data to confirm that HMPV is the culprit and that there are no major mutations of concern. Such genomic data will also guide vaccine development."
At the same time, the US is experiencing its own surge in HMPV cases, with positive test rates doubling from early to late December. According to the latest CDC data, just 300 positive test results were reported during the last week of December, based on the latest available data. The U.S. CDC said it was "monitoring" cases in China but believes they are "not a cause for concern in the U.S."
Dr Andrew Catchpole, chief scientific officer at hVIVO infectious disease biotechnology, said that while HMPV is commonly reported in the colder months, "it appears that severe infection rates may be higher in China than we would expect in a normal year"
He added: "HMPV is a common part of the winter cold that causes viruses in most countries with seasonality. " It's not common for it to be of great concern about high numbers of hospitalizations, but it's not clear how high the numbers are or whether problems arise purely due to compression with high levels of flu and COVID."
HMPV first appeared in 2001 and usually causes symptoms of the common cold. However, more serious symptoms such as bronchitis, bronchiolitis and pneumonia may occur, with sufferers experiencing shortness of breath, severe coughing or wheezing. Children, the elderly and immunocompromised patients are at the highest risk of serious complications.
Because the virus is usually mild, its exact mortality rate is unknown. However, experts estimate that 10-30% of patients hospitalized with HMPV die in the US.
Dr Senanayake warned that the rise in HMPV cases in China looks like a "bad flu season" in the US and is not likely to escalate into a global problem. "At this stage, the likelihood is that China is experiencing a bad HMPV season, in the same way that in a few years we have an overwhelming flu season.
"This could be due to a combination of viral and behavioral factors, but it should calm down."
Vasso Apostolopoulou, professor of immunology at RMIT University in Australia, said rising cases and increasing pressure on healthcare systems in densely populated areas such as China showed the need for more surveillance. "Ensuring effective monitoring and timely responses will be key to mitigating the public health risks from this outbreak."
China's CDC urged people to take precautions such as washing hands, but rebuffed claims that hospitals would be overwhelmed.
Chinese Foreign Ministry spokesman Mao Ning said: "Respiratory infections tend to peak in the winter season. The diseases appear to be less severe and spreading on a smaller scale compared to last year."
Similar to Covid, HMPV spreads through respiratory droplets circulating in the air when a person coughs or sneezes. Close personal contact such as shaking hands and touching contaminated surfaces can also transmit the disease.
Researchers estimate that one in 10 respiratory illnesses in U.S. children is caused by HMPV. The CDC estimates that 20,000 children under five in the U.S. are hospitalized with HMPV each year. There are no vaccines or specific treatments for the disease.
Prof Jill Carr, a virologist in the College of Medicine and Public Health at Flinders University in Australia, stressed that the current outbreak in China is not likely to cause a global crisis. He said: "This is very different from the COVID-19 pandemic, where the virus was completely new to humans and resulted from animal transmission and spread to pandemic levels because there was no prior exposure or protective immunity in the community.
The scientific community also has some understanding of the genetic diversity and epidemiology of HPMV, the kind of effects the virus has on the lungs, and established laboratory testing methods – again, very different from the COVID-19 pandemic, where a new lung disease emerged. As we saw, there was little information about how the virus can vary and spread, and we had no initial diagnostic tests.
According to the National Respiratory and Intestinal Virus Surveillance System (NREVSS), a CDC database, HMPV cases in the U.S. are increasing compared to this time last year. Data from the week of December 28, the most recent available, shows a test positivity rate of 1.9%. Out of about 13,800 total tests for that week, that adds up to just under 300 confirmed cases.
What We Know About the Reaping Virus in China - Symptoms, Diagnosis and Treatments
The HMPV virus that is ravaging China, causing global concern, was discovered in 2001 and belongs to the family of Pneumoviridae, the same family as respiratory syncytial virus (RSV), according to the US Centers for Disease Control and Prevention (CDC).
It usually causes upper and lower respiratory tract infections, causing symptoms similar to those of the common cold or flu.
Symptoms commonly associated with HMPV, as noted by the CDC, include: cough and runny or stuffy nose, fever, sore throat, wheezing, or shortness of breath in severe cases.
In some cases, the infection can escalate into bronchitis, pneumonia or asthma exacerbations.
HMPV affects people in all age groups, but according to the CDC most vulnerable are children under five, particularly infants, older adults, particularly those over 65, and people with weakened immune systems or chronic respiratory conditions such as asthma or COPD
HMPV spreads through droplets from coughing or sneezing, close contact, such as touching or shaking hands, when we touch contaminated surfaces and then bring our hands to our mouth, nose or eyes.
According to the CDC, this virus has a seasonal pattern circulating in late winter and spring in temperate regions.
Experts recommend the following steps to reduce the risk of infection with HMPV and other respiratory diseases:
Wash hands frequently with soap and water for at least 20 seconds
Avoid touching your face with unwashed hands
Use a mask in crowded areas where there is an outbreak
Stay at home when sick to prevent the spread of the virus
Regularly clean frequently touched surfaces
According to the CDC, HMPV infection can usually be confirmed by:
Direct detection of the viral genome by nucleic acid amplification test (NAAT).
Direct detection of viral antigens in respiratory secretions by immunofluorescence or enzyme immunoassay.
Routine testing is rare unless symptoms are severe or there is an epidemic.
There is no specific antiviral treatment or vaccine for HMPV.
According to the Cleveland Clinic, management focuses on relieving symptoms:
-Hydration and proper rest
-Use over-the-counter medicines for pain, congestion and fever.
-In severe cases, hospitalisation for oxygen therapy or intravenous fluids may be required
Is HMPV like Covid-19? How worried should we be?
Fears of a Covid-19 style pandemic are overblown, the experts said, noting that pandemics are typically caused by novel pathogens, which is not the case for HMPV.
HMPV is globally present and has been around for decades. This means people across the world have "some degree of existing immunity due to previous exposure", Dr Hsu said.
"Almost every child will have at least one infection with HMPV by their fifth birthday and we can expect to go onto to have multiple reinfections throughout life," says Paul Hunter, a medical professor at University of East Anglia in England.
"So overall, I don't think there is currently any signs of a more serious global issue."
Still, Dr Hsu advises standard general precautions such as wearing a mask in crowded places, avoiding crowds where possible if one is at higher risk of more severe illness from respiratory virus infections, practising good hand hygiene, and getting the flu vaccine.
