Washington, Jun 1 (IANS): While cases of Covid-19 and respiratory syncytial virus (RSV) were decreasing across the US, infections of another respiratory virus, called human metapneumovirus (HMPV), were on the rise, according to the Centers for Disease Control and Prevention (CDC).

The percentage of tests positive for HMPV surged to 17.5 per cent for antigen tests and 9.6 per cent for PCR tests at the end of March, Xinhua news agency reported citing the latest CDC data.

During the four years before the pandemic, the weekly percentage of HMPV positive tests never reached higher than 7.7 per cent, the data revealed.

Discovered in 2001, HMPV is in the Pneumoviridae family along with RSV.

Broader use of molecular diagnostic testing has increased identification and awareness of HMPV as an important cause of upper and lower respiratory infection, according to the CDC.

HMPV can cause upper and lower respiratory disease in people of all ages, especially among young children, older adults, and people with weakened immune systems.

Surveillance data from CDC's National Respiratory and Enteric Virus Surveillance System shows HMPV to be most active during late winter and spring in temperate climates.

Symptoms commonly associated with HMPV include cough, fever, nasal congestion, and shortness of breath, according to information on the CDC website.