HMPV outbreak: Seasonal respiratory infections increasing in Northern Hemisphere, including HMPV, says WHO

The recent uptick in cases of seasonal flu, rhinovirus, RSV, and hMPV in China aligns with typical seasonal patterns, as confirmed by the World Health Organisation (WHO) on Wednesday. WHO spokesperson Dr. Margaret Harris noted that respiratory infections are on the rise in China during the winter months, with seasonal flu being the most prevalent, according to the Chinese Center for Disease Control and Prevention.

Dr. Harris mentioned that China's levels of respiratory infections are within the expected range for this time of year. Authorities have reported that hospital admissions are currently lower compared to the same period last year, and there have been no emergency declarations or responses activated. 

She said at this time of year, many countries in the Northern Hemisphere experience an increase in acute respiratory infections, commonly attributed to seasonal outbreaks of respiratory pathogens such as influenza, RSV, hMPV, and mycoplasma pneumonia.

Regular surveillance is conducted in many countries to monitor these infections and pathogens. Currently, some countries in the temperate Northern hemisphere have seen a rise in influenza-like illness and acute respiratory infection rates in recent weeks, surpassing normal seasonal levels.

Regarding HMPV, which was first identified in 2001, Dr. Harris explained that this virus has been circulating in the human population for an extended period. This update was provided by WHO during a press briefing in Geneva.

“China’s reported levels of respiratory infections are within the usual range for the winter season. Authorities report that hospital utilization is currently lower than this time last year, and there have been no emergency declarations or responses triggered," the WHO spokesperson said in Geneva.

Dr. Harris noted that hMPV is a common virus that typically spreads during the winter and spring months, causing respiratory symptoms similar to those of a common cold. 

She clarified that, similar to other viruses that cause the common cold, hMPV can lead to more severe illness in individuals with weakened immune systems, including newborns and the elderly. However, individuals across all age groups can be affected, not just these vulnerable populations. 

HMPV explained

Discovered in 2001, HMPV is a member of the Pneumoviridae family, which also includes Respiratory Syncytial Virus (RSV). Serological studies indicate that the virus has been circulating in human populations for over 60 years and is widespread globally.

HMPV can cause upper and lower respiratory illnesses in individuals of all age groups, with young children, elderly individuals, and those with compromised immune systems being at higher risk.

The US Centers for Disease Control and Prevention (CDC) states that common symptoms of HMPV infection include cough, fever, nasal congestion, and shortness of breath.

Dr. Li Tongzeng, a leading physician at Beijing You’an Hospital, explains that HMPV spreads through respiratory droplets, direct contact like handshakes, or contact with contaminated surfaces. The virus has an incubation period of three to five days.

Some ways to prevent the spread of HMPV include wearing masks, practicing regular hand washing, and boosting immunity through healthy habits.

Doctors advise against the use of antiviral medications to treat HMPV. A respiratory expert in Shanghai emphasized the importance of not relying solely on antiviral drugs since there is no vaccine available for HMPV and its symptoms can be similar to those of a common cold.

In 2023, cases of HMPV were reported in several countries including the Netherlands, Britain, Finland, Australia, Canada, the US, and China.

HMPV cases in India

In Mumbai, a six-month-old girl was diagnosed as the eighth case of human metapneumovirus (HMPV) in India, and the third case in Maharashtra. The infant was admitted to the hospital on January 1 with symptoms including severe cough, chest tightness, and a drop in oxygen levels to 84%. After receiving treatment for five days, she was discharged. Previous cases in Maharashtra involved a seven-year-old and 13-year-old in Nagpur. Additional confirmed cases were reported in Karnataka (2), Gujarat (1), and Tamil Nadu (2).