HMPV in Children and Adults: Causes, Symptoms and Effective Treatments

HMPV, belonging to the paramyxovirus family, was identified back in 2001. This virus has emerged as a significant yet previously unrecognised cause of respiratory infections across different age groups, such as infants, children and adults. HMPV is responsible for an estimated 5–25% of respiratory infections in infants and children, and 1.5–10.5% of such infections in adults.

HMPV and RSV

HMPV and RSV are often considered ‘viral cousins’ as they belong to the same virus family and present similar symptoms and clinical outcomes. Both viruses exhibit overlapping seasonal patterns, with RSV cases typically peaking in the early winter months, while HMPV cases tend to surge from mid-winter through early spring.

Symptoms and risk factors

Several symptoms are associated with HMPV that can vary in severity, often resembling those of other respiratory viruses. Common symptoms in adults include:

• Runny nose  
• Sore throat  
• Mild fever  
• Nasal congestion  
• Fatigue
• Headache
• Chronic cough
• Children, on the other hand, may exhibit more pronounced symptoms, such as:
• Coughing
• Wheezing  
• Difficulty breathing  
• High fever
• Nasal congestion
• Decreased appetite
• Irritability

Generally, adults experience mild flu-like symptoms. Complications can occur in immunocompromised individuals, premature babies or people with chronic lung disease, where symptoms may progress to:

Asthma exacerbations: Frequent episodes of asthma symptoms such as wheezing, shortness of breath and chest tightness

Acute bronchitis: Inflammation and congestion in the small airways of the lungs, primarily affecting young children and infants

Pneumonia: An infection of the lungs

Transmission

HMPV infections are transmitted from an infected person to others through:

• Respiratory droplets from coughing and sneezing
• Personal contact, such as shaking hands or touching
• Touching items or surfaces infected with the virus then touching the mouth, nose or eyes.

How long can someone become contagious with the HMPV Virus?

Typically, HMPV is contagious for 3 to 7 days. HMPV has an incubation period of three to six days, with most people experiencing symptoms three to five days after exposure. During this incubation phase, an infected person may be contagious even without symptoms, making containment difficult. This trait emphasizes the significance of taking preventive steps to limit the spread of viral infection.

Preventive measures

• Employ good hygiene: Wash hands with soap and water for a minimum of 20 seconds.  
• Avoid close contact: Avoid close contact with individuals with flu-like symptoms such as sore throat, cold, fever and cough.
• Disinfect surfaces: Wash frequently touched items and surfaces.
• Use masks: Wear masks in crowded areas to prevent droplet transmission.
• Stay home when sick: If you are unwell, avoid spreading the infection to others by self-isolating.
• Stimulate immune system: Supporting the body’s natural defence against infections can be achieved through a healthy lifestyle, which includes balanced nutrition, physical activity and adequate sleep.

These measures can be taken to prevent the contraction of HMPV and minimise virus transmission. Health experts particularly recommend high-risk individuals to take adequate precautions, especially during peak winter and spring months.

When should you seek healthcare consultation?

Medical attention is warranted if an individual experiences the following symptoms:

• High fever with temperature exceeding 104 degrees Fahrenheit
• Experiencing significant trouble in breathing
• Signs of cyanosis, such as bluish lips and skin, indicating a lack of oxygen
• Worsening of existing health conditions

Diagnosis

• Assessment of symptom and medical history: Healthcare providers typically begin the assessment by examining your signs, symptoms and medical history.
• Collection of swab sample: A soft-tipped stick (swab) may be used to collect a sample of your throat or nose. The collected samples are tested for pathogens using various techniques, such as reverse transcription-polymerase chain reaction (RT-PCR), nucleic acid amplification test (NAAT) or enzyme immunoassay.
• Additional diagnostic procedures: In certain cases, your healthcare provider may advise bronchoscopy or chest X-ray to examine the changes in the air passages of the lungs.

Treatment and management  

No vaccine or antiviral treatment is available to prevent or treat HMPV infection. Therefore, the primary HMPV management primarily focuses on managing the symptoms. Here are some of the common approaches:

• Hydration: Ensure that the person stays well-hydrated.
• Rest: It is important to take proper rest as it allows the body’s immune system to recover.
• Medications: The type of medications prescribed depends on your symptoms and severity of illness as determined by your healthcare provider.  

Most HMPV infections resolve on their own within a few days to a few weeks with supportive care. However, it’s important to seek your healthcare provider when you or someone you know experiences HMPV symptoms.  

Hospital care

Although this is a common virus, severe sickness caused by HMPV could lead to hospitalisation. In the hospital, healthcare providers can closely monitor your condition and take steps to prevent it from worsening. Treatment options may include:

• Oxygen therapy: If patient is hypoxic or low oxygen saturation, patient may receive supplementary oxygen through a nasal tube or face mask.
• IV fluids: Intravenous fluids can be administered to maintain hydration.
• Corticosteroids (if indicated in patient): They might be used to alleviate symptoms and reduce inflammation.
• Antibiotics (if any super added bacterial infection): These are prescribed only to treat bacterial infections; however, if an individual gets a secondary infection from bacteria like pneumonia, your doctor may prescribe them.

Conclusion

Human metapneumovirus is a common respiratory pathogen that typically causes mild self-limited illness in those who do not have other chronic underlying diseases. However, it can become severe in vulnerable groups, such as young children, elderly people or people with a weak immune system. The best thing we can do about this infection is to maintain a healthy lifestyle and be aware of the symptoms. If you experience severe symptoms or have any difficulties associated to HMPV infection, you should check with your healthcare physician.