hMPV: A Harmful Virus with Risk of Pneumonia

     During a time when many people are focusing on RSV and influenza, another virus that is increasingly being detected in young children and the elderly is hMPV, or Human Metapneumovirus. Although this virus is not widely known, it typically causes symptoms similar to the common cold. However, in some cases, it can lead to severe respiratory illnesses, particularly in young children with weakened immune systems, who may be at risk of developing pneumonia.

What is hMPV?

     hMPV (Human Metapneumovirus) belongs to the same family as RSV (Respiratory Syncytial Virus), but it is structurally distinct. Nevertheless, its pattern of outbreak in Thailand is quite similar to RSV, with increased incidence commonly observed during the late rainy season and into the winter.

Transmission Period of hMPV

     hMPV was first discovered in the Netherlands in 2001. It can produce signs and symptoms similar to other respiratory viral infections. The incubation period after exposure is approximately 3–6 days, and patients can remain contagious for 1–2 weeks.

It Can Affect Both Children and Adults

     The virus may cause upper respiratory tract infections, such as cold-like symptoms, or lower respiratory tract infections, such as bronchitis or pneumonia. It is now increasingly recognized as a cause of respiratory tract infections in both children and adults.

Particular Concern for Young Children and the Elderly

     The virus is especially concerning in children under the age of five, many of whom may be experiencing their first infection and could exhibit more severe symptoms. Elderly individuals and those with underlying medical conditions—such as heart disease, lung disease, or compromised immune systems—are also at higher risk. Furthermore, reinfection is possible.

How is hMPV Transmitted?

• Through respiratory droplets from coughing or sneezing
• By direct contact with contaminated nasal secretions, saliva, or objects
• By touching contaminated surfaces and then touching the eyes, mouth, or nose

Symptoms of hMPV Infection

     Symptoms are similar to those of the common cold or other general respiratory infections and may include: fever, cough, runny nose, sore throat, Difficulty breathing or shortness of breath

Some patients may experience:

• Noisy breathing or wheezing, particularly those with a history of asthma, chronic bronchitis, or emphysema
• Symptoms resembling bronchiolitis, bronchitis, or pneumonia
• Gastrointestinal symptoms such as diarrhea, nausea, or vomiting

Diagnosis

     Currently, hMPV can be diagnosed via nasal swab, followed by antigen testing or PCR (Polymerase Chain Reaction) testing.

Treatment

• There is no specific antiviral treatment for hMPV at this time. Treatment focuses on relieving symptoms:
• Administration of antipyretic medication to reduce fever
• Ensuring adequate fluid intake
• Encouraging rest
• In cases of difficulty breathing, oxygen therapy or bronchodilator inhalation may be necessary
• Some patients, especially young children, may require hospitalization

Although no vaccine currently exists for hMPV, the risk of infection can be reduced by:

• Frequently washing hands with soap or alcohol-based hand sanitizer for at least 20 seconds
• Avoiding touching the eyes, nose, or mouth with unwashed hands
• Avoiding close contact with individuals who have respiratory symptoms
• Refraining from taking young children to crowded places
• Regularly cleaning toys and items frequently used by children, as the virus can survive on surfaces for 2–3 hours and is easily destroyed by soap and disinfectants
• Keeping sick children at home to allow for recovery and prevent transmission

Final Note from an Infectious Disease Specialist

     Although hMPV may seem like a minor virus, it should not be underestimated, particularly in young children and individuals with underlying health conditions. If symptoms such as fever, cough, rapid breathing, or fatigue arise, it is advisable to consult a physician promptly for appropriate diagnosis and management. Early intervention can significantly reduce the risk of serious complications.