The virus inciting pandemic anxieties in China, human metapneumovirus (HMPV), has reportedly infected thousands of Americans over the past year, according to data from the Centers for Disease Control and Prevention (CDC). Since January 2024, around 28,000 Americans have contracted HMPV, an elusive respiratory disease now deemed “the most important virus you’ve never heard of.”
In April 2024, infections peaked, with 1,666 positive cases reported in a single week, accounting for eight percent of all tests conducted during that period. The most recent CDC data indicates a decrease, with a test positivity rate of two percent. Since Thanksgiving, weekly positive cases have oscillated between 200 and 350, a figure health authorities consider normal.
HMPV, primarily causing cold-like symptoms, has been partially linked to a viral outbreak in China, overwhelming hospitals in the northern provinces. Despite the pandemic fears it has sparked, other winter illnesses like Covid-19 and respiratory syncytial virus (RSV) have seen considerably higher rates. For example, over one million Americans have sought emergency care for RSV, while nearly ten million have battled influenza since October 2024.
Emerging in 2001, HMPV can lead to severe conditions like bronchitis and pneumonia, causing breathing difficulties, severe coughs, or wheezing. Its death rate remains uncertain, but experts estimate a mortality rate of 10 to 30 percent among hospitalized patients.
Without vaccines or treatments, the virus spreads through respiratory droplets from coughs or sneezes, close personal contact, and touching contaminated surfaces. The current focus remains on vigilance and hygiene, as American respiratory infections, including Covid-19, influenza, and RSV, continue to hover at high or very high levels nationwide.
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