Flu season might be coming to an end, but it’s not time to put away the tissues just yet.
A lesser-known respiratory virus, which currently lacks a vaccine or specific treatment, has been gaining traction since winter began, contributing to a rise in various illnesses across the nation.
Wastewater surveillance, a method that monitors pathogens in sewage to gauge community health, indicates that infection levels have reached a “high” category nationwide as of early March.
Interestingly, many Americans may still be unaware of this virus, which presents symptoms similar to other respiratory illnesses like colds, flu, or RSV. “Most people are definitely less familiar with it,” noted Dr. Sharon Nachman, chief of pediatric infectious diseases at Stony Brook Children’s Hospital. When she hears, “I have the flu,” she’s often inclined to suggest it might actually be human metapneumovirus (HMPV).
So, what exactly is this virus that’s causing coughing and sniffles as spring approaches?
What is HMPV?
HMPV was first identified by researchers in the Netherlands back in 2001, although evidence suggests it has been around in humans for at least fifty years. Similar to the flu, HMPV is seasonal, with case counts rising in January, peaking in March and April, before dwindling as the weather warms up. “This is the right time to see it,” Nachman explained. “As flu season wanes, this virus fills that biological gap.”
What are the symptoms of HMPV?
Most HMPV cases are mild and tend to resolve within two to five days. Symptoms include a cough, fever, nasal congestion, sore throat, and sometimes wheezing or shortness of breath. Although most cases are manageable, some can escalate into pneumonia, bronchitis, or middle ear infections. Young children, older adults, and those with weakened immune systems face a greater risk of complications.
How common is HMPV?
Research indicates that almost everyone will encounter at least one strain of HMPV in their lifetime, with the majority of infections happening before the age of five. Surprisingly, despite its frequency, tracking HMPV is quite challenging. “It’s rarely tested for when patients come in with severe colds, making wastewater surveillance one of our few means to observe its spread,” Dr. Alexandria Boehm, a Stanford University professor, stated. Biomarkers from HMPV can be detected in saliva, mucus, urine, and feces, which helps researchers track its prevalence through wastewater.
Recent data shows that nationwide HMPV activity has increased by 70% since February. “Currently, levels in wastewater match what we observed at this time last year, mirroring findings in New York,” Boehm mentioned.
How does HMPV spread?
The virus is transmitted through direct contact with an infected person or by touching surfaces contaminated with the virus, mostly spreading during the initial days of illness. Symptoms generally appear three to seven days after exposure, according to the Cleveland Clinic.
How is HMPV diagnosed and treated?
Diagnosis typically relies on symptoms, though a nasal or throat swab can provide laboratory confirmation. Currently, there is no vaccine or specific treatment available. “This lack of urgency around diagnosis might explain why the public is relatively unfamiliar with it,” Nachman noted jokingly. “There’s really no rush; the advice is usually just to rest and hydrate.”
To mitigate the risk of spreading HMPV, the CDC recommends staying home when sick, washing hands frequently, and sanitizing commonly touched surfaces.
